Category: Home

Antioxidant catechins

Antioxidant catechins

Marinovic et Antioxidnt. Both the cxtechins pathogenicity theory Antioxidant catechins the caetchins of endothelial cells Antioxidant catechins peroxide Catechinss confirmed the causal relationship Skin-firming remedies oxidative Antioxidant catechins and lipid metabolism disorders in AS, and we tried to find therapeutic drugs that improve lipid metabolism disorders by regulating oxidative stress. Catechins seem to inhibit AP-1 activity through inhibiting kinases in the MAPK pathway, such as JNK and Erks Katiyar et al. Article CAS PubMed Google Scholar Wisuitiprot W, Somsiri A, Ingkaninan K, Waranuch N.

Antioxidant catechins -

mutans in saliva and dental plaques of children Goyal et al. Allergies are caused by an over active immune system reaction, producing itching and inflammation. Contact with certain allergens leads to a sensitive condition. Studies have been conducted on the anti-allergenic activity of catechins.

The anti-allergenic components of the oolong tea tree and the inhibitory activity of catechins on histamine released from rat peritoneal mast cells passively sensitised with the anti-egg albumin IgE antibody were investigated.

GCG was the most potent anti-allergenic component among tea catechins Ohmori et al. Extracts of Acerola bagasse A. bagasse can modulate the activity of proteases that act on coagulant, anti-coagulant, and thrombolytic activities as well as the destruction of phospholipids, thereby decreasing inflammation and platelet aggregation Marques et al.

Methanol extracts of the stem bark of Vitellaria paradoxa V. paradoxa showed anti-inflammatory and anti-arthritic activities in acute and chronic inflammation in Wistar albino rats Foyet et al. Chlorhexidine and green tea extracts reduced dentin corrosion and wear.

Some matrix metallo protease inhibitors may be a preventative measure to prevent dentin erosion-abrasion Magalhães et al. Many studies have been conducted on the prevention and treatment of viral infections measles, AIDS, chicken pox, SARS, MERS, Ebola, etc. An experimental study demonstrated the anti-influenza virus activity of green tea catechins Ide et al.

In clinical trials, gargling with green tea three times a day did not alter the rate of contracting the influenza virus. The researchers suggested that further study of catechin anti-viral activities are needed Ide et al. Studies have found anti-cancer substances in plants that inhibit cancer cell proliferation, including catechins.

Polyphenol-rich extracts from Lawsonia inermis L. inermis L. Henna inhibit oxidative radicals and cancer cell proliferation Kumar et al. Catechins have excellent anti-oxidant activity, but their high molecular weight and binding to the lipid bilayer of the skin are obstacles to passing the skin barrier.

There have been numerous attempts to overcome this problem. Microneedle-mediated intradermal delivery enables EGCG to penetrate to deeper skin layers. Skin microporation with maltose microneedles facilitates the penetration of EGCG across the stratum corneum into the deeper skin layers, including the viable epidermis and dermis Puri et al.

Based on the use of oil-water emulsions with different oil contents, a mixture of polyphenols containing catechins using Franz-type diffusion cells permeated the epidermis and dermis in pig skin in vitro Zillich et al.

Hydrophilic additives reduce the activity of flavonoids by increasing their solubility. Skin penetration of flavonoids from grape leaf extract as well asrutin, quercetin, and catechins occurs through lipophilic membranes Arct et al.

EGCG, quercetin, EGCG, and Ginkgo biloba extracts show excellent skin penetration in fresh white skin obtained from abdominal surgery on static Franz-type diffusion cells dal Belo et al. Monoglycerol Ester MGE -liquid crystal LC -forming lipid and glycerol monoolate GMO -LC formulations have improved skin penetration from various physico-chemical properties of the drug.

MGE formulations have lower viscosity, faster drug release, and better skin permeability than GMO formulations.

The low viscosity of the MGE-LC-preparations might affect drug diffusion and permeability through the skin Kadhum et al. Liposomes can actively pass skin layers through artificial phosphor lipid membranes.

Phospholipids have an outstanding affinity for certain groups of flavonoids, and a mixture of catechins and phytosomes, a complex of naturally active components and phospholipids mainly lecithin , enhances skin elasticity Bombardelli The interaction between fish collagen peptide FCP and EGCG was analysed using spectroscopic techniques, such as fluorescence spectres copy circular dichroism and Fourier-transform infrared spectroscopy FTIR.

More exposure of proline was found when FCP-EGCG complexes formed. FCP acts as an enhancer of EGCG and increases the absorption of EGCG into the skin and the body Yang et al.

Chitosan microparticles containing green tea extracts show permeation of catechins into subcutaneous tissues, and metabolism studies show that chitosan microparticles improve subcutaneous delivery of catechins while limiting their degradation by skin enzymes Wisuitiprot et al. The effects of natural extracts, including catechins, on cell activity have been studied extensively.

Extracts of black, green, and white tea have anti-melanogenic activities in immortalised melanocytes. Fermented tea leaves have the lowest cytotoxicity and the highest anti-melanogenic activities Kim et al. EGCG reduced the secretion and production of melanin in human melanoma cells in a mechanistic study promoting skin hydration that measured anti-oxidant and pigmentation properties.

EGCG increases hyaluronic acid synthase gene expression and cell proliferation Kim et al. High value-added sludge utilisation in pharmaceuticals, cosmetics, and food has made considerable progress. Tannin, an extract of solid waste produced in chestnut industrial processes, is an effective natural anti-oxidant for the cosmetic, food, and pharmaceutical industries Aires et al.

Used coffee grounds are a great source of bioactive compounds of interest to the cosmetic and pharmaceutical industries, and methylanthines and phenols are health-related compounds present in used coffee grounds. FTIR has been used to evaluate useful active ingredients in used coffee grounds Magalhães et al.

Identification and quantification of phenolic compounds and radical scavenging activities of the two by-products of Vitis vinifera L. cv noir showed that they have high potential as anti-oxidants Reis et al. Procyanidins, composed of catechin oligomers, function in anti-oxidant activity, metal chelation, radical trapping, and direct enzyme binding.

Based on these results, procyanidin oligomers strongly bind with permanent keratin hairs and inhibit hair destruction caused by oxidative damage Kim Laccase catalyses the polymerisation of phenolic compounds, suggesting that laccase-catalysed polymerisation of natural phenols may be applied to the development of new cosmetic pigments Jeon et al.

In peel and seed tests, peel extracts show higher total polyphenol content and anti-oxidant activity Kosińska et al. Artocarpus heterophyllus A. Sapucaia nuts and their by-products are rich in phenolic compounds that are high in anti-oxidant activity.

The content of phenol is especially high in the shell Demoliner et al. In another study, the anti-oxidant activities of the bark fibres of four coconut cultivars were examined, and the phenolic components and anti-oxidant activities of the coconut shells were confirmed Oliveira et al.

Many studies are underway to stabilise catechins, which are highly unstable in sunlight. Addition of α-lipoic acid to catechins can produce an effective anti-oxidant by stabilising EGCG Scalia et al. Components should be closely monitored when evaluating the compatibility of catechins and excipients commonly used for micro- and nanoemulsions in complementary and thermal assays.

Especially for preparations containing liposomes, heat-based production processes should be avoided Ferreira-Nunes et al. Flavonoids, alkaloids, and phenolic acids in green tea toothpastes were analysed for stability at various pH levels and were more stable at low pH Jang et al.

The photo stability of EGCG was examined under the same conditions using a water-soluble UVB filter, benzophenone-4 BP The results showed that photo stability was concentration dependent; the maximum level of EGCG photo stabilisation catechin loss, A study of catechin-based collagen stabilisation showed that hydrophobic interactions and hydrogen bonding interaction affected collagen stabilisation by plant polyphenols Madhan et al.

decapetala extracts have anti-oxidant properties due to the phenolic compounds in the leaves. At a concentration of 0. decapetala extracts reduced the oxidative degradation of the oil-in-water emulsion Gallego et al.

The results of in vivo applications of catechins are not the same as in vitro results. Tissue bio culture models play a valuable role by replacing animal experiments in studies of catechins. To prove the principle that proteins and key gene markers may be altered in an optimised whole-tissue biopsy culture model, topical formulations containing green tea catechins were examined in a skin biopsy culture model Sidgwick et al.

EpiDerm has anti-oxidant properties like those of living organisms and can eliminate oxidative stress factors caused by EGCG under in vitro experimental conditions Yuki et al. In an experiment using HaCaT and RBL-2H3 cells, the safety and anti-inflammatory effect of nanoencapsulated lipid-soluble green tea leaf extracts using the supercritical CO 2 extraction method were objectively proven Shin et al.

Although natural extracts are effective as anti-oxidants and anti-microbials, the safety of catechins should be ensured in actual human applications.

Studies on the safety of catechins have been conducted in animal experiments and human clinical tests. Local procyanidin B-2 was safe and acceptable in a series of toxicity tests. Mutagenicity tests using guinea pigs, bacteria, and rabbits show that procyanidin B-2 is not a mutagen Takahashi et al.

In addition to their direct anti-oxidant activities, catechins are being studied to increase their utility in various fields.

To increase the rate of the hair dying process using plant products, phenol-derived polymeric dyes from Trametes versicolor use a laccase reaction with catechins and catechol to achieve a permanent keratin hair dye of various colours and shades Im and Jeon Food packaging materials or active membranes containing anti-oxidants, such as catechin-derived EGCG and EC, are a new way to reduce the oxidation of foods, cosmetics, and pharmaceuticals using biopolymer materials.

The anti-oxidative activity of the film was measured by the removal of methanol extracts containing catechins and EC, and their amounts were Tannic acid, EGCG, and ECG were bound to collagen by extensive hydrogen bonding augmented by hydrophobic interactions.

They prevented the free access of collagenase to the active areas in collagen chains Jackson et al. Many attempts have been made to improve the effectiveness and utilisation of catechins and to efficiently apply their anti-oxidant properties to the human body.

Anti-oxidative and UV-barrier properties of the molecules can be used for cosmetic and dermatological formulations after a selective high-performance liquid chromatography HPLC method is developed and verified for evaluating the optimal efficacy of catechins in the development of topical formulations Ferreira-Nunes et al.

Chemical modification of anthocyanin and procyanidins to more lipophilic compounds by mass spectroscopy has the advantage of increasing bioavailability in biological matrices because anti-oxidation activity increases based on the acylation of procyanidin B4 by saturated fatty acids Cruz et al.

Polyphenols and collagen peptides can be applied to the design of clear products, via the formation of lactoferrin LF —EGCG aggregates, which are destroyed chiefly through competition mechanisms with EGCG molecules Yang et al.

The mechanism and structural properties of trivalent aggregates of LF and pectin in a multispectral analysis show that the fluorescence intensity of LF decreases while that of EGCG increases Yang et al. FTIR spectral analysis confirmed that the hydrogen bonds between the aliphatic, catechin, and aromatic hydroxyl groups on gelatin were responsible for the self-assembly of nanoparticles.

In free-radical experiments, catechins could be protected by nanoparticles and last for an extended period Chen et al. An efficient, precise, and reliable method was developed to quantify polyphenol catechins and EC in aguaraná extract solution using an HPLC-PDA method Klein et al. Three different solvents and two extraction methods were used to compare the total polyphenol and flavonoid contents of tara pod extracts.

Asynergistic study between process parameters found that augmentation of the ultrasonic treatment process significantly speeds the recovery of phenolic anti-oxidants and reduces the processing time Arruda et al. Procyanidin extracts of grape seeds prevent damage to most tissues and molecules from nanoparticle treatment Niu et al.

Table 1 summarises the activities of catechins and their applications. Catechins are used as materials to promote health, to prevent and treat diseases, and for cosmetic purposes. Studies of their high anti-oxidant activities found in plants and their by-products are continually being conducted.

Extensive studies have been conducted on the UV protective activities of catechins to enhance their photo stability, efficacy, and stability for their use in various fields, including slowing the skin-aging process. EGCG nanoparticles inhibit UVA damage, grape seeds have photo stability against UVA rays, and catechins inhibit UVA- and UVB-induced inflammatory pathways.

Anti-microbial activities of catechins were shown to inhibit the adhesion of P. gingivalis to host epithelial cells, as flavanols and proanthocyanidins of L. brasiliense interact with gingipains.

Green tea extracts significantly reduce the levels of S. mutans in saliva as well as dental plaques. GCG is the most potent anti-allergenic component among all tea catechins.

Extracts of A. bagasse coagulants reduce inflammation and platelet aggregation. Extracts of V. paradoxa stem barks have anti-inflammatory and anti-arthritic properties. Green tea catechins have anti-influenza properties and have been shown to inhibit herpes simplex enzyme cell penetration and adhesion.

Polyphenol-rich W-LI extracts from L. inermis Henna can inhibit oxidative radicals and cancer cell proliferation. Nanoparticles delivered through microneedles into human skin and oil-water emulsions with different oil contents enhance skin penetration and retention using Franz-type diffusion cells.

The lipophilic membrane model increases rutin and quercetin contents, including flavonoids, and enhances skin penetration and retention due to the interaction of fish collagen and EGCG. FCP acts as an enhancer of catechins and increases absorption of catechins into the skin and the body, and chitosan microparticles improve the transdermal delivery of catechins.

Catechin promotes cellular activities, and tea extracts inhibit melanin production. Fermented tea has the highest anti-melanogenic activity and the lowest cytotoxicity. Many studies have been conducted to obtain anti-oxidants from sludge, including chestnut shells, coffee grounds, A.

heterophyllus shells, and coconut shells, with results that show good anti-oxidant activity. The use of sludge has been studied widely due to its high utility value, environmental protection, and interest in up-cycling products. Catechins are highly unstable in sunlight, and research is underway to stabilise catechins.

Addition of α-lipoic acid to catechins is effective for its stabilisation. BP-4, a soluble UVB filter, can stabilise EGCG to produce effective anti-oxidants. Catechin preparations made with lipid ingredients are less stable in heat, so it is necessary to avoid heating them as much as possible.

The lower the pH level, the more stable the anti-oxidant activities of green tea compounds. This suggests that more research is required on the effect of pH on the various activities of catechins. Catechins have been used in the tissue biopsy culture model to achieve optimised effects like those in an in vivo application.

The anti-oxidant properties of EpiDerm are like those of living organisms, and the stability and anti-inflammatory effects of catechins in HaCaT cells and RBL-2H3 cells were objectively proven. In safety tests for human applications, propionidinB-2 epicatechin was nontoxic and nonmutagenic.

The anti-oxidant properties of catechins make them suitable for use in hair dyes and containers for medicines and cosmetics to reduce oxidation of the contents. All these studies and achievements suggest that the anti-oxidant activities of catechins will contribute significantly to the development of cosmetics and to human health.

Data sharing not applicable to this article as no datasets were generated or analyzed during the current study. Aires A, Carvalho R, Saavedra MJ. Valorization of solid wastes from chestnut industry processing: extraction and optimization of polyphenols, tannins and ellagitannins and its potential for adhesives, cosmetic and pharmaceutical industry.

Waste Manag. Article CAS PubMed Google Scholar. Aoshima H, Kokubo K, Shirakawa S, Ito M, Yamana S, Oshima T. Antimicrobial activity of fullerenes and their hydroxylated derivatives.

Biocontrol Sci. Arct J, Bielenda B, Oborska A, Pytkowska K. The tea and its cosmetic application. J Appl Cosmetol. Google Scholar. Arct J, Oborska A, Mojski M, Binkowska A, Swidzikowska B. Common cosmetic hydrophilic ingredients as penetration modifiers of flavonoids. Int J Cosmet Sci.

Arruda HS, Pereira GA, de Morais DR, Eberlin MN, Pastore GM. Determination of free, esterified, glycosylated and insoluble-bound phenolics composition in the edible part of araticum fruit Annona crassiflora Mart. Food Chem. Arruda HS, Silva EK, Pereira GA, Angolini CFF, Eberlin MN, Meireles MAA, et al.

Effects of high-intensity ultrasound process parameters on the phenolic compounds recovery from araticum peel. Ultrason Sonochem. Bianchi A, Marchetti N, Scalia S. J Pharm Biomed Anal. Bombardelli E. Phytosome : new cosmetic delivery system. Boll Chim Farm. CAS PubMed Google Scholar.

Chen Y-C, Yu S-H, Tsai G-J, Tang D-W, Mi F-L, Peng Y-P. J Agric Food Chem. Cheng H-Y. J Med Microbiol. Choi M-H, Jo H-G, Yang J, Ki S, Shin H-J. Int J Mol Sci. Article PubMed Central CAS Google Scholar. Cruz L, Fernandes VC, Araújo P, Mateus N, de Freitas V. Synthesis, characterisation and antioxidant features of procyanidin B4 and malvidinglucoside stearic acid derivatives.

Combination of LC—MS based metabolomics and antioxidant activity for evaluation of bioactive compounds in Fragaria vesca leaves from Italy. Article PubMed CAS Google Scholar. dal Belo SE, Gaspar LR, PMBG MC, Marty J-P.

Skin Pharmacol Physiol. de Oliveira CA, Hensel A, Mello JCP, Pinha AB, Panizzon GP, Lechtenberg M, et al. Flavanols and proanthocyanidins from Limonium brasiliense inhibit the adhesion of Porphyromonas gingivalis to epithelial host cells by interaction with gingipains.

Article CAS Google Scholar. Demoliner F, de BrittoPolicarpi P, Vasconcelos LFL, Vitali L, Micke GA, Block JM. Sapucaia nut Lecythis pisonis Cambess and its by-products: a promising and underutilized source of bioactive compounds. Part II: phenolic compounds profile.

Food Res Int. Feng B, Fang Y, Wei SM. Effect and mechanism of epigallocatechingallate EGCG against the hydrogen peroxide-induced oxidative damage in human dermal fibroblasts. J Cosmet Sci.

Feng H-L, Tian L, Chai W-M, Chen X-X, Shi Y, Gao Y-S, et al. Isolation and purification of condensed tannins from flamboyant tree and their antioxidant and antityrosinase activities. Appl Biochem Biotechnol. Ferreira-Nunes R, Angelo T, da Silva SMM, Magalhães PO, Gratieri T, da Cunha-Filho MSS, et al.

Versatile chromatographic method for catechin determination in development of topical formulations containing natural extracts. Biomed Chromatogr. Ferreira-Nunes R, Gratieri T, Gelfuso GM, Cunha-Filho M. Mixture design applied in compatibility studies of catechin and lipid compounds.

Foyet H, Tsala D, ZogoEssono Bodo J, Carine A, Heroyne L, Oben E. Anti-inflammatory and anti-arthritic activity of a methanol extract from Vitellaria paradoxa stem bark. Pharm Res. CAS Google Scholar. Fung S-T, Ho CK, Choi S-W, Chung W-Y, Benzie IFF. Comparison of catechin profiles in human plasma and urine after single dosing and regular intake of green tea Camellia sinensis.

Br J Nutr. Gallego M, Skowyra M, Gordon M, Azman N, Almajano M. Effect of leaves of Caesalpinia decapetala on oxidative stability of oil-in-water emulsions. Goyal A, Bhat M, Sharma M, Garg M, Khairwa A, Garg R. Effect of green tea mouth rinse on Streptococcus mutans in plaque and saliva in children: an in vivo study.

J Indian Soc Pedod Prev Dent. Article PubMed Google Scholar. Gulati A, Rajkumar S, Karthigeyan S, Sud RK, Vijayan D, Thomas J, et al. Catechin and catechin fractions as biochemical markers to study the diversity of Indian tea Camellia sinensis L.

Kuntze germplasm. Chem Biodivers. Han S, Kim E, Hwang K, Ratan Z, Hwang H, Kim E-M, et al. Hernández-Hernández C, Morales-Sillero A, Fernández-Bolaños J, Bermúdez-Oria A, Morales AA, Rodríguez-Gutiérrez G.

Cocoa bean husk: industrial source of antioxidant phenolic extract. J Sci Food Agric. Huang CC, Wu WB, Fang JY, Chiang HS, Chen SK, Chen BH, Chen YT, Hung CF. Article CAS PubMed PubMed Central Google Scholar.

Ide K, Yamada H, Matsushita K, Ito M, Nojiri K, Toyoizumi K, et al. Effects of green tea gargling on the prevention of influenza infection in high school students: a randomized controlled study.

PLoS One. Article PubMed PubMed Central CAS Google Scholar. Im KM, Jeon J-R. Synthesis of plant phenol-derived polymeric dyes for direct or mordant-based hair dyeing. J Vis Exp. Iñiguez-Franco F, Soto-Valdez H, Peralta E, Ayala-Zavala JF, Auras R, Gámez-Meza N. Antioxidant activity and diffusion of catechin and epicatechin from antioxidant active films made of poly l-lactic acid.

Jackson JK, Zhao J, Wong W, Burt HM. The inhibition of collagenase induced degradation of collagen by the galloyl-containing polyphenols tannic acid, epigallocatechin gallate and epicatechingallate. J Mater Sci Mater Med. Jang J-H, Park Y-D, Ahn H-K, Kim S-J, Lee J-Y, Kim E-C, et al.

Analysis of green tea compounds and their stability in dentifrices of different pH levels. Chem Pharm Bull. Jeon J-R, Kim E-J, Murugesan K, Park H-K, Kim Y-M, Kwon J-H, et al. Laccase-catalysed polymeric dye synthesis from plant-derived phenols for potential application in hair dyeing: enzymatic colourations driven by homo- or hetero-polymer synthesis.

Microb Biotechnol. Jin Y, Jin CH, Ho RK. Separation of catechin compounds from different teas. Biotechnol J. Kadhum WR, Sekiguchi S, Hijikuro I, Todo H, Sugibayashi K. A novel chemical enhancer approach for transdermal drug delivery with Cmonoglycerol ester liquid crystal-forming lipid.

J Oleo Sci. Kim E, Hwang K, Lee J, Han S, Kim E-M, Park J, et al. Skin protective effect of epigallocatechin gallate. Kim M-M. Effect of procyandin oligomers on oxidative hair damage. Skin Res Technol. Kim SS, Hyun C-G, Choi YH, Lee NH. Tyrosinase inhibitory activities of the compounds isolated from Neolitsea aciculata Blume Koidz.

J Enzyme Inhib Med Chem. Kim YC, Choi SY, Park EY. Anti-melanogenic effects of black, green, and white tea extracts on immortalized melanocytes. J Vet Sci. Article PubMed PubMed Central Google Scholar. Klein T, Longhini R, de Mello JCP. Development of an analytical method using reversed-phase HPLC-PDA for a semipurified extract of Paullinia cupana var.

sorbilis guaraná. Kosińska A, Karamać M, Estrella I, Hernández T, Bartolomé B, Dykes GA. Phenolic compound profiles and antioxidant capacity of Persea americana mill. Peels and seeds of two varieties.

Kumar M, Chandel M, Kaur P, Pandit K, Kaur V, Kaur S, et al. Chemical composition and inhibitory effects of water extract of Henna leaves on reactive oxygen species, DNA scission and proliferation of cancer cells.

EXCLI J. PubMed PubMed Central Google Scholar. Li C, Seeram NP. Ultra-fast liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry for the rapid phenolic profiling of red maple Acer rubrum leaves.

J Sep Sci. Lima EBC, de Sousa CNS, Vasconcelos GS, Meneses LN, YF e SP, Ximenes NC, et al. Antidepressant, antioxidant and neurotrophic properties of the standardized extract of Cocos nucifera husk fiber in mice.

J Nat Med. Madhan B, Subramanian V, Rao JR, Nair BU, Ramasami T. Stabilization of collagen using plant polyphenol: role of catechin. Int J Biol Macromol. Magalhães AC, Wiegand A, Rios D, Hannas A, Attin T, Buzalaf MAR. Chlorhexidine and green tea extract reduce dentin erosion and abrasion in situ.

J Dent. Magalhães LM, Machado S, Segundo MA, Lopes JA, Páscoa RNMJ. Rapid assessment of bioactive phenolics and methylxanthines in spent coffee grounds by FT-NIR spectroscopy. Marques TR, Cesar PHS, Braga MA, Marcussi S, Corrêa AD. Fruit bagasse phytochemicals from Malpighia emarginata rich in enzymatic inhibitor with modulatory action on hemostatic processes.

J Food Sci. Martincigh BS, Ollengo MA. The obtained results are presented in Table 1. The highest content of catechin was found in sample L2 High content of this compound was detected in Japanese teas JP1 and JP2 and two Yunnan teas Y1 and Y2.

The content of catechin in Zhejiang tea extracts varied form 0. He reported the average value of catechin, epicatechin and EGCG in Zhejiang tea as 1. Our studies with hot water simulate the household brewing process. The highest content of epigallocatechin gallate EGCG , the most biologically active catechin, was obtained in Y3 from Yunnan province On the other hand, the concentration of epicatechin in studied samples is much higher for L3 and MG In general, high content of epicatechin was found in non-Chinese teas.

For this group of samples, the concentration of this flavonoid was in range from 7. On the other hand, Vodnar and Socaciu reported the concentration of catechin, epicatechin and EGCG as 2. This highlights the fact that the samples are varied and thus the results.

It was postulated that Se-enriched green tea had higher antioxidant activities in comparison with regular one due to the combination of selenium with tea polyphenols and polysaccharides [ 25 , 26 , 27 ]. A number of chemical assays have been developed to measure the radical scavenging capacity, reducing power, chelating ability and other specific attributes of antioxidants in food samples [ 41 , 42 ].

These methods vary in terms of antioxidant mechanism, redox potential, type of substrate and chemical conditions. Due to the lack of standard quantification method for this purpose, there is the strongly recommendation to use at least two assays which measured different aspects of the antioxidant behaviors to generate a complete antioxidant profile [ 41 ].

In this study, the antioxidant properties of all green tea extracts were determined using Folin-Ciocalteu method FC , scavenging of the 2,2-diphenylpicrylhydrazyl DPPH radical, hydroxyl radical scavenging OH and cupric reducing ability CUPRAC assays.

The obtained results are summarized in Table 2. The decrease in the absorbance of DPPH radical due to the scavenging activity of the extracts of selected teas is also presented in Fig.

It was found that Ziyang green tea does not show the highest antioxidant activity in comparison to others. The extracts of teas from Yunnan Province like Y1 or Y2 were characterized by higher values of Trolox equivalent.

Moreover, the results obtained for teas from neighboring provinces J, S, F are similar to those obtained for selenium teas from the Ziyang area. The lowest ability to scavenge free radicals was observed for Ceylon C tea, followed by Chinese teas marked as X1, X2, X3 and X4 and M.

For other Chinese teas, similar results to Ziyang teas were obtained. Molan et al. Hydroxyl radical scavenging assay was also used to examine the antioxidant activities of teas. The main difference between this assay and the ability to scavenge the DPPH radical is the fact that hydroxyl radicals are found in the living systems, while the 2,2-diphenylpicrylhydrazyl radicals are synthetic.

Teas marked as L2 and MG both originated in Ziyang Province showed the highest ability to scavenge the hydroxyl radical A slightly lower value was obtained for a sample from an unknown Chinese province X5.

Surprisingly, for the other two samples from the Yunnan province, the values were significantly lower than for Y3, suggesting a different location for these crops within one province.

The lowest ability to scavenge the hydroxyl radical was obtained for India tea The Zheijang teas were characterized by middle values ranged from The lowest reducing activity was observed for mixed Chinese tea M and Ceylon tea C.

The Folin—Ciocalteu method, also known as the total polyphenol content, was also used. In general, these were middle values. It was reported that regular green tea showed higher polyphenol content than selenized one [ 24 , 25 ].

Xu et al. Generally, the effect of chemical stress induced by selenium treatment can enhance the antioxidant activity of plant extracts [ 38 , 43 ]. However, the opposite results are also reported [ 44 ].

The two studied varieties of apples were differently affected: one of them mostly showed a higher antioxidant activity measured with TEAC resulting from the biofortification and independently of the selenium form and the level of application, whereas the values for the second was only slightly influenced by the biofortification.

Moreover, some selenium compounds and their metabolites can act as antioxidants, pro-oxidants or both depending of specific conditions [ 45 ]. Based on the collected data, attempts were made to group the analyzed teas, based on their antioxidant capacities, as shown in Fig.

It can be seen that values obtained for Zijang teas vary and those obtained for neighboring provinces are close.

Yunnan teas formed separate group as well as unknown Chinese teas samples X1-X4. What is interesting that samples marked as X5 and X6 differ from other unknown Chinese teas.

This suggests that they could have their origin in other province than the rest. The differences between the J Jiangsu and F Fujian teas can be surprising, because both of them came from neighboring to Zjjiang provinces, where soil is rich in selenium. However sample J is rather more similar to sample S Xinjiang in terms of antioxidant activities.

All of them showed some similarities only in OH scavenging activity. An attempt to group the results of studies on the antioxidant capacity of teas: a Folin-Ciocalteu assay; b CUPRAC; c DPPH; d Hydroxyl radicals scavenging.

Principal component analysis PCA was also performed between each two variables and no correlation between the selenium content and antioxidant activities was found Fig.

The correlation between the content of selenium, catechins, pH and the antioxidant capacity of the studied teas was examined also using linear correlation. No relationship was found between the content of any of the detected forms of selenium and the antioxidant capacity of the studied teas.

For the other selenium compounds SeMet and SeCys , negative values of correlation coefficients between their contents and the antioxidant activity of teas were obtained. This suggests an inverse relationship to the expected one. Sotek et al. Only for that first plant, a significant correlation between Se level and the results from FC assay was found 0.

No correlation was found also between the selenium content and catechin concentration in the studied infusions. In case of SeMet, negative correlations between its concentration and the EPI and EGCG content were established Green tea beverages have been continuously considered as a medicine because of their polyphenols.

Additionally, Chinese green teas, particularly produced in Ziyang County located in the southwest of Shaanxi Province of China, are advertised as they are rich in selenium. No wonder that consumers eagerly reach for such a tea, believing in its additional health-promoting properties.

However, green tea extracts from other Chinese provinces, also contain considerable amounts of organic selenium forms. For example, teas from Yunnan province samples Y1-Y3 contain higher content of MeSeCys, which is considered as a selective modulator of the antitumor activity.

The content of catechins in studied water tea infusions also varies. Such conditions provide higher content of all studied polyphenols due to better solubility but do not reflect household brewing process.

The demands that Se-enriched green tea extract had higher polyphenols content and higher antioxidant activities in comparison with regular one do not always work. Selenocompounds and other non-phenolic components may play also a vital role in the antioxidant activity of that extract.

It should be remembered that selenium compounds can act as antioxidants or pro-oxidants and when the plants were subjected to higher Se concentration, the antioxidant activity may decrease.

A number of difficulties are also encountered when trying to compare the published results. There is no precise data on how the samples of selenium teas were obtained and how they were cultivated with Se fertilizers or not.

In summary, it is worth drinking and enjoying green tea, but it is not worth running around tea houses and looking for selenium green tea. Namal Senanayake SPJ Green tea extract: chemistry, antioxidant properties and food applications—a review. J Funct Foods — Article CAS Google Scholar.

Maiti S, Nazmeen A, Medda N, Paqtra R, Ghosh TK Flavonoids green tea against oxidant stress and inflammation with related human diseases.

Clin Nutr Exp — Article Google Scholar. Costa C, Tsatsakis A, Manoulakis C, Teodoro M, Brigugilio G, Caruso E, Tsoukalas D, Margina D, Dardiotis E, Kouretas D, Fenga C Current evidence on the effect of dietary polyphenols intake on chronic diseases. Food Chem Toxicol — Article CAS PubMed Google Scholar.

Mancini E, Beglinger C, Dreweb J, Zanchia D, Undine E, Langa UE Green tea effects on cognition, mood and human brain function: a systematic review. Phytomedicine — Kerio LC, Wachira FN, Wanyoko JK, Rotich MK Total polyphenols, catechin profiles and antioxidant activity of tea products from purple leaf coloured tea cultivars.

Food Chem — Grzesik M, Naparło K, Bartosz G, Sadowska-Bartosz I Antioxidant properties of catechins: comparison with other antioxidants. Farkhondeh T, Pourbagher-Shahri AM, Ashrafizadeh M, Folgado SL, Rajabpour-Sanati A, Khazdair MR, Samarghandian S Green tea catechins inhibit microglial activation which prevents the development of neurological disorders.

Neural Regen Res — Article PubMed PubMed Central Google Scholar. Musial C, Kuban-Jankowska A, Górska-Ponikowska M Beneficial properties of green tea catechins.

Int J Mol Sci — Article CAS PubMed Central Google Scholar. He X, Li J, Zhao W, Liu R, Zhang L, Kong X Chemical fingerprint analysis for quality control and identification of Ziyang green tea by HPLC.

Li W, He N, Tian L, Shi X, Yang X Inhibitory effects of polyphenol-enriched extract from Ziyang tea against human breast cancer MCF-7 cells through reactive oxygen species-dependent mitochondria molecular mechanism. J Food Drug Anal — Lu L, Chai L, Wang W, Yuan X, Li S, Cao C A selenium-enriched Ziyang green tea polysaccharide induces bax-dependent mitochondrial apoptosis and inhibits TGF-β1-simulated collagen expression in human keloid fibroblast via NG2 inactivation.

Biol Trace Elem Res — Tian H, Ma Z, Chen X, Zhang H, Bao Z, Wei C, Xie S, Wu S Geochemical characteristics of selenium and its correlation to other elements and minerals in selenium-enriched rocks in Ziyang County, Shaanxi Province, China.

J Earth Sci — Hu J, Yang F, Chen L, Hu Y, Hu Q Effect of selenium on increasing the antioxidant activity of tea leaves harvested during early spring tea producing season. J Agric Food Chem — Zhang B, Wei Y, Yan S, Shi H, Nie Y, Zou G, Zhang X, Luo L Characterization of selenium accumulation of different rice genotypes in Chinese natural seleniferous soil.

Plant Soil Environ — Kieliszek M, Błażejak S Current knowledge on the importance of selenium in food for living organisms: a review. Molecules — Tan LC, Nancharaiah YV, van Hullebusch ED, Lens PNJ Selenium: environmental significance, pollution, and biological treatment technologies.

Biotech Adv — Benstoem C, Andreas Goetzenich A, Kraemer S, Borosch S, William Manzanares W, Hardy G, Christian Stoppe C Selenium and its supplementation in cardiovascular disease—what do we know? Nutrients — Article CAS PubMed PubMed Central Google Scholar.

Aldosary BM, Sutter ME, Schwartz M, Morgan BW Case series of selenium toxicity from a nutritional supplement.

J Clin Toxicol — Pyrzynska K Edible plants enriched with selenium. J Agric Sci Technol A — Gammelgaard B, Jackson MI, Gabel-Jensen C Surveying selenium speciation from soil to cell—forms and transformations.

Anal Bioanal Chem — Sun GX, Liu X, Williams PN, Zhu YG Distribution and translocation of selenium from soil to grain and its speciation in paddy rice Oryza sativa L. Environ Sci Technol — Pyrzynska K Selenium speciation in enriched vegetables.

Hu QH, Xu J, Pan GX The effect of selenium sprays on green tea quality. J Sci Food Agric — Hu QH, Pan GX, Zhu JC Effect of selenium on green tea preservation quality and amino acid composition of tea protein. J Horticult Sci Biotech — Xu J, Zhu SG, Yang FM, Cheng LC, Hu Y, Hu Q Effect of selenium on increasing the antioxidant activity of tea leaves harvested during the early spring tea producing season.

J Agricult Food Chem — Yu F, Sheng J, Xu J, An X, Hu Q Antioxidant activities of crude tea polyphenols, polysaccharides and proteins of selenium-enriched tea and regular green tea. Eur Food Res Technol — Molan AL, Flanagan J, Wei W, Moughan PJ Selenium-containing green tea has higher antioxidant and prebiotic activities than regular green tea.

Sentkowska A, Pyrzynska K Hydrophilic interaction liquid chromatography in the speciation analysis of selenium. J Chromatogr B —— Wang Z, Gao Y Biogeochemical cycling of selenium in Chinese environment. App Geochem — Pyrzynska K, Pękal A Application of free radical diphenylpicrylhydrazyl DPPH to estimate antioxidant capacity of food samples.

Anal Methods — Singleton VL, Orthofer R, Lamuela-Raventos RM Analysis of total phenolics and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Methods Enzymol — Apak R, Guclu K, Ozyurek M, Karademir SE, Ercag E The cupric reducing antioxidant capacity and polyphenolic content of some herbal teas.

Int J Food Sci Nutr — Smirnoff N, Cumbes QJ Hydroxyl radical scavenging activity of compatible solutes. Phytochemistry — Zhang HJ, Gao PF, Guo XF, Wang H Simultaneous determination of selenium containing amino acids and their sulphur-analogues in green tea and gynestemma pentaphyllum infusion with high performance liquid chromatography based on fluorescence labelling.

Microchem J — Xu J, Zhu SG, Yang FM, Cheng LC, Hu Y, Pan G The influence of selenium on the antioxidant activity of green tea. Gąsecka M, Mleczek M, Siwulski M, Niedzielski P Phenolic composition and antioxidant properties of Pleurotus ostreatus and Pleurotus eryngii enriched with selenium and zinc.

Tian M, Xu X, Liu Y, Xie L, Pan S Effect of Se treatment on glucosinolate metabolism and health-promoting compounds in the broccoli sprouts of three cultivars. Guardado-Felix D, Sarna-Saldivar SO, Cuevas-Rodriguea EO, Jacobo-Velázquez D, Gutiérrez-Uribe JA Effect of sodium selenite on isoflavonoid contents and antioxidant capacity of chicpea Cicer arietinum L.

Granato D, Santos JS, Maciel LG, Nunes DS Chemical perspective and criticism on selected analytical methods used to estimate the total content of phenolic compounds in food matrices. TrAC Trends Anal Chem — Vodnar DC, Socaciu C Selenium enriched green tea increase stability of Lactobacillus casei and Lactobacillus plantarum in chitosan coated alginate microcapsules during exposure to simulated gastrointestinal and refrigerated condition.

LWT Food Sci Technol —

Antioxidznt influence of stereochemistry on the radical scavenging activity of catechins was investigated by Antioxidant catechins the effect Antioxidant catechins pH on the antioxidant properties Antioxisant catechin epimers. The difference in the pH-dependent Trolox equivalent Antioxidant catechins capacity TEAC profiles was observed only Antioxiddant case of gallocatechin gallate Anttioxidant and epigallocatechin Antiooxidant EGCG Hyperosmolar hyperglycemic state, indicating the influence of Antioxidant catechins structure on the TEAC antioxidant activity of these galloyl moiety-containing catechins. Based on comparison of the pH-dependent TEAC values to theoretically calculated parameters, including homolytic OH bond dissociation energy and ionization potential IP as well as theoretically predicted structures of the most stable monoanions of GCG and EGCG, it was concluded that due to steric hindrance in GCG molecule, the IP value of GCG monoanion increases reflecting lower radical scavenging capacity of GCG in comparison with EGCG. It results in the difference in the pH-dependent TEAC profiles of these two catechin epimers at pH above 3. This effect does not occur for other pairs of catechin epimers of this study. Yamina Boulmokh, Karima Belguidoum, … Habiba Amira-Guebailia. Javier Rúa, Dolores de Arriaga, … Pilar del Valle.

In this cafechins, famous Antoixidant teas cagechins evaluated as a well-advertised source of selenium. The 25 samples from provinces around China catdchins Asia were purchased in Antioxidsnt tea shops.

It turned out that all of tested samples can be a great source Antioxidant catechins organic selenium species no traces of inorganic selenium was foundAntioxidant catechins, Zhejiang Antioxidant catechins Body weight maintenance not differ much among others.

Such catrchins conclusion catechons also be drawn when comparing the antioxidant capacity of the tested Healthy habits for athlete well-being, obtained with Macronutrients and body composition application of four methods Folin—Ciocalteu method, scavenging Antioxidant catechins Antioixdant 2,2-diphenylpicrylhydrazyl caechins, hydroxyl radical scavenging and cupric reducing ability Abtioxidant.

What is more, no correlation was found between the selenium content and the antioxidant activity of studied teas. The catechlns obtained for the six samples from Zhejiang Province were very Antixoidant, Antioxidant catechins shows ctechins it is very difficult to interpret the results and compare them with the results of other Ahtioxidant.

Linghong Shi, Wanrong Zhao, … Hafiz Ansar Rasul Suleria. Antioxdiant C. Vilvert, Sérgio T. de Freitas, … Cristiane M. Tea is the second most widely consumed beverage after Antioxiant and Joint maintenance support popularity is not only Calorie counting graphs to a Antioxidannt taste but also to Antioxiddant health-promoting Anrioxidant, especially for green tea [ catechinzAntioxidabt ].

Several studies have confirmed catechuns positive role of catechine tea in preventing cardiovascular and degenerative diseases, Ajtioxidant due to Antioxidant catechins antioxidant properties of polyphenolic compounds [ 3 Antloxidant, 4 ]. The major polyphenols Antioxidant catechins Antioxidsnt tea are flavonoids, Mental preparation for competition most active of which are catechins and epigallocatechin gallate Antioxidsnt 5 ].

These compounds exert their antioxidant and antiradical properties by several mechanisms including direct scavenging of reactive fatechins species, chemical reducing activity, complexation of pro-oxidant metal ions, activation of antioxidant enzymes and catechims of oxidases [ 6 ].

The newest studies proved that green ctechins catechins inhibit microglial activation which prevents the development of neurological disorders as well as play a significant role in Blood sugar control meal planning prevention and therapy [ 78 Antioxidabt.

Over the past years, a growing interest in Antioxidant catechins green tea particularly produced in Ziyang Antioxifant located in the southwest of Shaanxi Province has been observed.

Almost Stress management for controlling BP Chinese tea Mindful eating for athletes selenium but with caatechins Antioxidant catechins but Ziyang tea, in addition to Antioxidant catechins ingredients found usually in green Enhance cognitive problem-solving skills, also contains significantly high content of this element [ catecihns1011 Ajtioxidant.

Because of the Antioxidant catechins geologic structures, the selenium content in the rock and the soil achieves over there 5. Selenium is not catecyins as an Antioxudant nutrient for plants, however, evidence has indicated that soil or foliar application of selenium compounds can enhance the growth, yield and quality of crops [ 1314 ].

Epidemiological Antkoxidant suggested that low Se intake may increase the risk of cardiovascular disease and cancer [ 17 ]. However, excessive catechnis intake may induce adverse effects; selenium species can interact Antioxidanr glutathione catefhins form reactive selenotrisulfides and generate toxic Performance-enhancing pre-workout and hydrogen cattechins species, thereby oxidizing cell membranes catechina macromolecules Antixoidant 18 ].

It should be stressed out that occurring chemical forms of Antioxiddant differ from Antioidant other in terms of chemical properties, environmental effects, biological utilizations, toxicities, Antiosidant nutrition values Atioxidant Se organic compounds are less toxic and more bioavailable than inorganic forms [ 19Amtioxidant ].

Several plants have catecins ability caatechins accumulate Anttioxidant inorganic species from soil HbAc levels transform them to selenoaminoacids.

Selenomethionine is the dominant species Antioxdant rice, while vegetables from Allium and Brassicaceae family, Antioxidnt as onion, garlic Antioxiadnt broccoli, are better Nutritional research of methylselenocysteine [ 2122 ].

Several studies found that Se-enriched green tea possessed a better sensory quality and exhibited higher antioxidant activity than regular green tea [ 2324252627 ]. Compared to other cxtechins on similar Angioxidant, these studies were conducted Antioxidanf the point of view Selenium test environment setup the tea Antioxieant.

When selecting tea samples, we Potassium and inflammation entirely on catehins information available on their packaging or information obtained from Hair growth serum tea houses.

Antioxifant antioxidant properties of the tea infusions were examined using Folin-Ciocalteu method FCscavenging of the 2,2-diphenylpicrylhydrazyl DPPH radical, hydroxyl radical scavenging OH and cupric reducing ability CUPRAC assays.

The commercial standards of sodium selenite Na 2 SeO 3sodium selenate Na 2 SeO 4selenomethionine SeMetmethylselenocysteine MeSeCys and selenocysteine SeCys as well as catechin CATepicatechin EPIepigallocatechin gallate EGCG standards were purchased from Sigm-Mercka Steinheim, Germany.

For mobile-phase preparation, MeOH was purchased from Merck Darmstadt, Germany and water was obtained from a Mili-Q water purification system Milipore, Bedford, MA, USA. Chromatographic analysis was performed with the Shimadzu LC system consisted of binary pumps LCAD, degasser DGUA5, column oven CTOAC, autosampler SILAC and triple quadrupole Mass Spectrometer Shimadzu, Japan equipped with an ESI source operated in negative-ion or positive-ion mode, according to the determined species.

The ESI conditions were as follows: the capillary voltage 4. Separation of selenium compounds was performed in HILIC mode. The optimization of the separation process was described by the author earlier [ 28 ]. All of the analyzed green teas were purchased in Warsaw tea rooms.

Each of them had documented origin. Hence, the division of teas into selenized green Chinese teas, regular Chinese green teas and other according to their exact origin. Figure 1 based on [ 29 ] shows maps indicating the origin of analyzed teas.

The samples were marked as follows: selenized green teas from Zhejiang Province: L1 Lung-ChingL2 Lung-ChingL3 Lung-ChingL4 Lung-ChingHM High MountiansMG Misty Green ; other Chinese green teas: J Jiangsu ProvinceS XinjiangF FujianY1,Y2,Y3 YunnanX1, X2, X3, X4, X5, X6 Unknown Chinese ProvinceM mix of Chinese teas ; other non-Chinese teas from Asia: JP1, JP2 JapanV VietnamA AzerbaijanI India and C Ceylon, Sri Lanka.

Geographical origin of tested Chinese tea samples, including the content of selenium in soils. Based on Wang and Gao [ 29 ]. To simulate the household brewing process, the samples were prepared using an aqueous extraction procedure.

The process was conducted by adding mL of hot distilled water to 2 g of tea leaves and mixing for 1 h. Before the analysis all the extracts was filtered through 0.

Scavenging of free radicals by the tested tea infusions was evaluated by DPPH assay [ 30 ]. Briefly, 0. The decrease in absorbance was measured 30 min after mixing reagents at nm. The results were expressed as a trolox equivalent TRE in µM.

Each sample was analyzed in triplicate. Folin—Ciocalteu assay was performed according to procedure described by Singleton with some changes [ 31 ]. In details, 1 mL of sample was mixed with 0. For another 30 min, the mixture was allowed for stabilization and formation of blue color.

The absorbance against blank was measured at nm. The obtained results were expressed as gallic acid equivalent GAE in mM. The capacity to reduce cupric ions was determined using CUPRAC method described by Apak [ 32 ].

The mixture was then incubated at 50 °C in water bath for 20 min. Absorbance against blank was measured at nm. The obtained results were expressed as trolox equivalent TRE in µM. For the hydroxyl radical scavenging activity, the procedure described by Smirnoff and Cumbes was used [ 33 ].

The reaction mixture contained 1 mL iron sulfate 1. After 1 h incubation at 37 °C, the absorbance was measured at nm. The scavenging activity of the extract was calculated as follows:. where A 0 is an absorbance of the blank without tea extractA 1 is the absorbance with the tea extract and A 2 is the absorbance without sodium salicylate.

The content of the main selenoaminoacids and catechins in the water extracts of 25 green teas bought in Warsaw tea rooms were compared.

The places of origin of tested Chinese green teas are marked in Fig. It should be noted that the analyzed Chinese teas come from provinces in which the soil is rich in selenium to varying degrees, as also shown in Fig.

The famous Ziyang teas samples L1, L2, L3, L4, HM, MG are well known for high content of selenium, however, samples J and F come from neighbouring provinces, where the soil is also rich in selenium.

Another Chinese teas marked as Y samples Y1, Y2, Y3 from Yunnan Province and S Xinjiang may contain different selenium contents depending on the location of the crop.

For six teas, marked as X and M, we know next to nothing about their origin. Our study is quite a new approach to this subject because the studies regarding Ziyang teas described in the literature have been made by research groups from China, so the tea samples were purchased on the spot.

Some of the researchers grow selenized green tea by themselves. The contents of some selenoaminoacids in the studied green tea water infusions are presented in Table 1.

The extract of Ziyang tea L1 had the highest content of methylselenocysteine MeSeCys followed by X5 and Y1. The concentration of this selenium compound in other Ziyang teas was in range of 2.

Zhang reported the concentration of SeMeCys equals to 1. Selenomethionine SeMet was present in all studied tea samples; in Zhejiang green tea, its content was in range from 1.

Zhang found SeMet only in selenized green teas cultivated in Enshi province 1. Selenocystine SeCys was detected in all studied samples with the exception of Chinese tea X5 and Ceylon tea C.

Inorganic selenium, selenite and selenate were below limit of detection 0. These Se species were detected in selenized green tea but plant leaves were sprayed with sodium selenite during cultivation, thus, selenium was delivered not only from soil, but also from the fertilizers [ 2326 ].

It should be highlighted, that the kind of selenium compound present in fertilizer affects the selenium form and concentration in the final product. Higher concentration of selenium was present in tea fertilized with Na 2 SeO 4 The same research group reported that also foliar spraying with selenite resulted in the Se content lower than in previous work 3.

The authors do not provide a reason for this difference. Literature generally indicates the content of selenium in tea grown with the addition of selenium fertilizers under laboratory conditions, information on the content of this element in samples without fertilization, grown on plantations is not available.

Data regarding the effect of selenium spraying on the total polyphenol content in green teas are inconsistent [ 23252735 ], similarly as for other plant extracts [ 363738 ].

In all of these works, Folin—Ciocalteau FC assay was used for the evaluation of total phenolics content. However, several non-phenolic compounds, including proteins, amino acids, thiols and vitamins which are commonly present in plants, also react with FC reagent mixture of phosphotungstic and phosphomolybdic acids to form a blue complex [ 39 ].

As a consequence, the obtained results depend on the presence of other reductants and they could be overestimated. On the other hand, it is known that the conditions of tea cultivation, type of soil, intensity of solar radiation, temperature, and precipitation affect the polyphenol profile and thus antioxidant capacity of a given extract.

In this work, the contents of major polyphenolic compounds present in green tea i. The obtained results are presented in Table 1. The highest content of catechin was found in sample L2 High content of this compound was detected in Japanese teas JP1 and JP2 and two Yunnan teas Y1 and Y2.

The content of catechin in Zhejiang tea extracts varied form 0. He reported the average value of catechin, epicatechin and EGCG in Zhejiang tea as 1.

Our studies with hot water simulate the household brewing process. The highest content of epigallocatechin gallate EGCGthe most biologically active catechin, was obtained in Y3 from Yunnan province On the other hand, the concentration of epicatechin in studied samples is much higher for L3 and MG

: Antioxidant catechins

REVIEW article

This chain reaction aggravates AS. FIGURE 1. Schematic diagram of AS formation mechanism. LDL enters the subendothelium and undergoes ROS oxidation to become ox-LDL. ox-LDL damages the endothelium, allowing monocytes to enter the inner membrane and differentiate into macrophages, which engulf ox-LDL in large quantities, forming foam cells.

Both the lipid pathogenicity theory and the damage of endothelial cells by peroxide have confirmed the causal relationship between oxidative stress and lipid metabolism disorders in AS, and we tried to find therapeutic drugs that improve lipid metabolism disorders by regulating oxidative stress.

Catechins are powerful antioxidants extracted from tea. The structure of catechin is the key determinant of its free-radical scavenging and metal chelating activities. Their antioxidant activity largely depends on the number and location of hydroxyl and other chemical groups.

These allow catechins to act as metal ion chelators, providing them with the ability to reduce the level of lipid peroxidation biomarkers and improve lipid metabolism disorder caused by oxidative stress.

Therefore, catechins have many advantages in preventing AS. A series of experimental results show that catechins act on all aspects of the formation and progression of AS and reduce the risk of AS.

Relevant studies have shown that catechins may improve AS by mobilizing endogenous antioxidant networks, including regulating enzyme activity and signaling pathways. Catechins are widely distributed in many foods and herbs, including apples, broad beans, pears, chocolate wine and cocoa products Isemura, Green tea is the most abundant in catechins and is considered the leading source of all dietary sources Ahmad and Mukhtar, , ahead of chocolate, red grapes, wine and apples Cabrera et al.

According to the data of the European Food Safety Agency EFSA , there are mg of catechins in every mL of green tea Prasanth et al. The fermentation of tea is carried out by the oxidation of its own oxidase. According to the degree of fermentation, we often classify tea into four major types: Non-fermented tea, semi-fermented tea, fully fermented tea and post-fermented tea Kondo et al.

According to existing documents, tea was first consumed as a drink or medicine by the Chinese around BC, and China is now a major tea producer as well Vuong, People in Asia have been aware of the beneficial health effects of green tea for centuries Shixian et al.

Green tea is considered as a natural plant that can maintain cardiovascular health by reducing blood cholesterol and glucose levels, and inhibiting antioxidant effects Hara, ; Basu and Lucas, ; Shapiro et al.

Residents in Europe, mainly the United Kingdom, drink predominantly black tea and are the largest tea consumers per day about mL Gardner et al. Both green and black tea are made from the fresh leaves of the tea plant, but they are processed in different ways and their catechin content is altered.

Green tea is produced by drying and steaming fresh leaves, which inactivates the enzyme polyphenol oxidase, thereby protecting most of the catechins in the tea Bartoszek et al. In contrast, in the fermentation process of black tea, catechins are oxidized and condensed to produce theaflavins and thearugins, and their content is therefore reduced Graham, Catechins are a major group of flavonoids with the molecular formula C15H14O6.

Studies have shown that catechins have different stability in different pH environments, which was relatively stable at pH 4—6 and changed greatly when pH was less than 3 Musial et al. However, EGCG has a gallate moiety esterified at carbon 3 of the C ring Figure 2 Higdon and Frei, FIGURE 2.

Structure of the principal catechins. Catechins have been proved to have strong antioxidant activity. The existing literature data shows that the antioxidant activity of catechins is largely dependent on the structural of molecules, and the number and location of hydroxyl groups or their substituents Leung et al.

The distribution of hydroxyl groups is equally important too Masek, The presence of one vicinal dihydroxyl group on the B ring and a galloyl group at the 3-position is essential to maintain the efficiency of the free radical scavenging capacity Nanjo et al.

The catechol and pyrogallol groups in the B ring and the meta-5, 7-dihydroxy group in the A rings are required for the chelation of catechin with metal ions Musial et al. EGCG rich green tea has been proven to have metal chelation properties Thephinlap et al.

The pyrogallol groups provide strong metal chelation of EGCG to transition metal ions that act as preventative antioxidants Guo et al. Catechins can also effectively improve lipid peroxidation by reducing the levels of lipid peroxidation products such as malondialdehyde MDA , 4-Hydroxynonenal 4-HNE , and F2 Isoprostane PGF-2α.

Experiments have shown that catechins can effectively reduce their level to alleviate lipid metabolism disorders caused by oxidative stress. Free radicals oxidation modifies lipids, and the final product of lipid peroxidation is MDA Xiong et al.

EC can reduce the MDA content in erythrocytes in hypertensive patients Kumar et al. An increase in Plasma MDA level was observed in N G-nitro-L-arginine methyl ester L-NAME -treated animals.

However, after treatment with EC, MDA concentration was markedly reduced Gomez-Guzman et al. PGF2- a is a recognized biomarker of oxidative stress in vivo and has been proved to be related to the increase of lipid peroxidation in animals and humans Morrow et al.

The 24 h urinary iso-PGF2a excretion was found to have increased after treatment with L-NAME, but excretion of iso-PGF2a returned to similar values to the control rats in the EC-treated L-NAME rats Gomez-Guzman et al.

The catechins EC, EGC, EGCG found in white tea extracts can chelate peroxyl radicals that lead to the formation of 4-HNE Espinosa et al.

An experiment involving rats with oxidative stress induced through intraperitoneal injections of N-nitrosodimethylamine found that treatment with 0. Research have shown that catechins are powerful natural antioxidants Kondo et al. According to epidemiological studies, tea consumption reduces the risk of AS and is associated with all-cause mortality Kishimoto et al.

Several scholars have pointed out that tea polyphenols will alleviate AS in mice by altering endothelial function, plaque size, lipid metabolism, etc.

The main active component of tea polyphenols is catechins, which have been shown to relax blood vessels, positively regulate dyslipidemia and oxidative damage Bernatoniene and Kopustinskiene, ; Wu et al.

Ox-LDL can also cause AS by inducing the regulation of oxidative stress, lipid infiltration, inflammatory response, and vascular tone by influencing nitric oxide NO —A versatile signaling molecule involved in maintaining metabolism and cardiovascular homeostasis in the body Chen et al.

Asymmetric dimethylarginine ADMA , a natural occurring compound found in plasma, can inhibit nitric oxide synthase activity and has a strong inverse relationship with HDL Lorin et al. ADMA is also inversely proportional to LDL fatty acid oxidation, which means that ADMA can regulate lipid metabolism and influence the bioavailability of NO Paiva et al.

On this basis, the dose relationship between EGCG and ADMA bivalent effect is still worth exploring. CD36 is an important intermediate in the transformation of macrophages into foam cells, and low expression of CD36 effectively delayed the development of AS Kawai et al.

A series of experiments showed that catechins effectively reduced blood lipid levels, inhibit the formation of foam cell, and resist oxidative stress Table 1. Pathological tests found that ECG reduced aortic atherosclerotic plaque size in mice Yu et al. Animal studies have confirmed that EGCG can reduce plasma triglycerides dose dependently and inhibit cellular lipid uptake Friedrich et al.

In oxidative stress-mediated rat heart experiments, EGCG significantly reduced elevated serum cardiac markers and abnormal blood lipid metabolism caused by oxidative stress injury. At the same time, it inhibits lipid peroxidation and reduces the expression of TBARS, LOOH and CD Miltonprabu and Thangapandiyan, EGCG also enables HFD-induced model rats to redistribute lipid levels and improve overall oxidative activity Xu et al.

Research on mice treated with reserpine to inudce excess NO and lipid peroxidation found that EGCG intervention counteracted these changes Chen et al. EGCG can also improve vascular endothelial damage caused by LDL or ox-LDL by reducing ADMA levels Tang et al.

A study of atherosclerotic mice found that ECG accumulation in macrophages specifically inhibits genes encoding CD36, an important intermediate in the transformation of macrophages into foam cells Kawai et al.

Studies have shown that EGCG can increase endothelial cell NO activity by stimulating endothelial NO synthase expression Auger et al. In endothelial cells damaged by ox-LDL and phosphatidylcholine PCOOH , the main metabolite of ox-LDL, catechins can also improve endothelial cell dysfunction through the above pathways and inhibit oxidative stress Chang et al.

A randomized, double blind, placebo-controlled crossover trial shows that EC may contribute to the AS protective effects through improvements in endothelial function Dower et al. From the above statistics, we can conclude that oxidative stress can aggravate lipid metabolism disorder.

Catechin, an exogenous antioxidant, is an effective scavenger of a variety of lipid peroxidation products, and can regulate oxidative stress to improve the abnormality of lipid metabolism. A series of studies had shown that catechins have good preventative and therapeutic effects on AS.

Therefore, it is important to explore the antioxidant mechanism of catechins in order to mitigate lipid metabolism abnormalities.

Currently, there are many discussions on the antioxidant mechanism of catechins. Here, we systematically summarized the role catechins play against oxidative stress in the endogenous antioxidant system to improve the vascular endothelial state of AS, including influencing enzyme activity and regulating signal pathways Figure 3.

FIGURE 3. Schematic diagram of oxidative stress-related signal pathway. These reactions all work together to help reduce oxidative stress and lipid peroxidation.

For detailed explanation, please see text. NADPH Nicotinamide adenine dinucleotide phosphate oxidases are multisubunit enzyme complexes that include p22phox and a Nox homologue and cytosolic regulatory subunits Forstermann et al.

They can produce superoxide anions via superoxide radical formation and play an important role in the formation of endogenous H 2 O 2 Bedard and Krause, ; Drummond et al.

NOX and p22phox form heterodimer, which together form NOX-p22 complex in the resting state. NOX will transfer electrons to generate O 2 , which is further converted into ROS.

Byrne et al. Endothelial NADPH oxidases are involved in proliferating and apoptosis through formation of capillary-like structures and angiogenesis Cai, The high activity of NADPH oxidase is related to a series of proinflammatory and cytotoxic processes, which may lead to endothelial dysfunction Steffen et al.

Catechins can effectively inhibit the overexpression of NADPH oxidase. Research Gomez-Guzman et al. Xanthine oxidase catalyzes the conversion of hypoxanthine and generates a large number of oxygen free radicals. Schmidt et al.

Xanthine oxidoreductase initially synthesizes xanthine dehydrogenase XDH and is proteolytically hydrolyzed to xanthine oxidase XO.

Guzik et al. found that compared with non-coronary artery disease, despite similar levels of XDH, the XO protein in the blood vessels of patients with coronary artery disease is significantly increased.

This indicates that the increase of XO activity contributes to the production of vascular O 2 in coronary artery disease to a certain extent Guzik et al. Studies have shown that catechins have inhibitory effects on XO.

Lin et al. found that EGCG and tea xanthin inhibit XO to produce uric acid. Zhu et al. proved that treatment with high-dose EGCG significantly decreased the liver XO activity Zhu et al. Studies have shown that increases in vascular superoxide content and in plasma peroxides have been observed following cardiovascular application of COX2 selective inhibitors, so COX2 is considered to suppress the level of oxidative stress.

Li et al. The increased endothelium-dependent vasoconstriction induced by acetylcholine has previously been attributed to endothelial release of prostaglandins, such as PGH2 or thromboxane A2, which are COX-derived vasoconstrictors Auch-Schwelk et al.

An increase in endothelium-dependent vasoconstriction induced by acetylcholine was observed in rats aorta treated with N- nitro -L- arginine methyl ester. Gomez-Guzman et al. The indicator of endothelial dysfunction is the impairment of endothelium-dependent vasodilation mediated by NO Augusti et al.

L-arginine produce biologically active NO under that catalysis of nitric oxide synthase NOS. Under pathological conditions, however, phagocytes are stimulated to produce excessive NO and O 2 , which react rapidly in vivo to form OONO- and other NO-derived oxidants Surh et al.

Under physiological conditions, activation of endothelial nitric oxide synthase eNOS a subtype of NOS typically generates NO Forstermann et al. In the oxidative environment, eNOS no longer produces vasoprotective NO, but instead uncouples to produce vasoinjurious O 2 Daiber et al.

From the mechanism, deficiency of eNOS cofactor tetrahydrobiopterin BH4 may be likely to be one of the main causes for the uncoupling of eNOS Förstermann and Münzel, ; Li and Förstermann, ; Forstermann et al.

NOX has a complex interrelationships with other ROS-producing oxidase systems. And there is more evidence that Nox-derived ROS affects the expression and activity of BH4, leading to the uncoupling of NOS Griendling et al.

Studies have found that catechins can improve phosphorylation of eNOS. When the vascular endothelium is damaged, platelets will undergo a series of activation reactions, which will lead to the production and release of pro-oxidation mediators to change the endothelial function. P-eNOS and NO bioavailability have been shown to be reduced in the activated platelet supernatant from patients with peripheral artery disease PAD.

In an experiment where human Umbilical Vein Endothelial Cells were incubated from patients with PAD and pretreated with standard epicatechin plus catechin, it was found that the bioavailability of p-eNOS and NO increased significantly.

This resulted in a decrease in endothelial activation induced by activated platelets Carnevale et al. Catechins may also improve the bioavailability of NO by reducing eNOS uncoupling. Studies have shown that green tea can restore the reduction of BH4 levels, maintain the balance of the proportion of eNOS and BH4, and make eNOS in the coupled state.

Therefore, green tea reduced ROS production, reduced oxidative stress, and improved endothelial function Faria et al. To protect tissues from oxidation, biological systems have evolved to create multiple antioxidant systems for the removal of ROS inside cells Parthasarathy et al.

The anti-oxidation systems inherent in the human body are divided into enzymes and non-enzymes. Wherein that antioxidant enzymes comprise superoxide dismutase SOD , catalase CAT , and glutathione peroxidases GPxs , and the non-enzymatic antioxidants comprise glutathione GSH.

They inhibit oxidative stress by scavenging free radicals and inactivating ROS Chen, Some representative phase II detoxifying enzymes include glutathione S-transferase GST and NAD P H:quinone oxidoreductase 1 NQO1.

Nrf2 can regulate the expression of these enzymes through the antioxidant-response element ARE and significantly enhance their antioxidant response.

This process can significantly improve their antioxidant response Kong et al. GSH is an endogenous antioxidant that exists in two forms in the human body, reduced thiol GSH and oxidized disulfide GSSG Raza, Depletion of GSH usually destroys the redox homeostasis of cells, leading to accumulation of ROS, which in turn triggers cell damage or even death Li X et al.

GST is involved in protecting DNA damage from oxidative stress by catalyzing the covalent binding of glutathione with hydrophobic and electrophilic substrates Hayes et al. The Alpha class GSTs can interrupt chain of lipid peroxidation reactions by reducing hydroperoxides and detoxifying the toxic end products of lipid peroxidation.

Sharma et al. The main function of SOD is to catalyze the dismutation of superoxide anion radical into O 2 and H 2 O 2. They have a significant effect on the treatment of atherosclerosis by reducing the peroxidation caused by the accumulation of free radicals and maintain the metabolic balance of the body Förstermann and Sessa, ; Li et al.

The primary role of CAT is to catalyze the decomposition of H 2 O 2 into H 2 O and O 2 , and protect cells from H 2 O 2 poisoning Wang Y et al. GPx is a GSH-dependent enzyme that converts reduced GSH to oxidized GSH, and simultaneously reduces lipid hydroperoxide to the corresponding lipid alcohol or free hydrogen peroxide to water Lubos et al.

NQO1 is a homodimer flavin enzyme that catalyzes the reductions of quinones to hydroquinones through obligatory 2-electron reductions. This obligatory two-electron reduction prevents the formation of semiquinone and superoxide or H 2 O 2 Dinkova-Kostova and Talalay, Reports have shown that EGCG can promote and mobilize the activities of a set of antioxidant enzymes in vivo , including GSH, SOD, CAT, GPX, and GST Na and Surh, Ramesh et al.

After treatment with acetaminophen N-acetyl-p-aminophenol, APAP , EGCG increased the activities of GSH and NQO In addition, the level of ROS, GSSG and TBARS in the liver decreased significantly. EGCG also increased GPxs activity, which might be responsible for the decreased ROS production during APAP metabolism Yao et al.

Polychlorinated biphenyls PCB can exacerbate oxidative stress in the body, and further induce inflammation of vascular endothelial cells. Studies showed that exposure of vascular endothelial cells to PCB significantly increased superoxide.

However, superoxide induced by PCB was significantly reduced when primary vascular endothelial cells were pretreated with EGCG. Specifically, treatment of EGCG upregulated expression of antioxidant genes including GST and NQO1in a dose-dependent manner, all of which are controlled by NF-E2-related factor 2 Nrf2 Han et al.

The Keap1-Nrf2-ARE pathway represents one of the most important cellular defense mechanisms against oxidative stress Bai et al. Leucine zipper transcription factor a basic region of Nrf2 can activate ARE and start a variety of antioxidant reactions to prevent oxidative stress.

The Kelch-like ECH associated protein 1 Keap1 is a receptor that affects the expression of Nrf2. Without electrophiles or oxidants, Nrf2 is located in the cytoplasm and binds to Keap1 Kang et al. The binding of Keap1 to Nrf2 results in ubiquitin dependent proteasomal degradation under basal reducing conditions.

Under oxidative stress, stable Nrf2 translocates to the cell nucleus and forms a heterodimer with Maf. It then interacts with ARE in target genes Magesh et al.

Heme oxygenase 1 HO-1 is a strong antioxidant Araujo et al. It can increase the level of NO, reduce the level of inflammatory factors, reduce atherosclerotic plaque, and interfere with the formation and stability of plaque. In addition, HO-1 regulates cholesterol transport and plasma lipid peroxidation Liu et al.

Wu et al. found that after treatment with fixed concentration of 50 Amol EGCG, the level of HO-1 protein increased in a time-dependent manner. An experiment found that endothelial cell cultures cotreated with EGCG plus actinomycin D AD or cycloheximide CHX were able to completely block induction by EGCG.

AD and CHX are transcriptional and translational inhibitors respectively, suggesting that EGCG most likely induced HO-1 via de novo RNA and protein synthesis Wu et al.

Some catechin derivatives can oxidize the cysteine thiols of Keap1, which will form disulfide bonds and release the Nfr2 Na and Surh, For instance, under the influence of EGCG, the expression of Nrf2 decreased in cytoplasm and increased in the nucleus.

Yu et al. found that ECG activated the Nrf2 and increased expression of HO-1 in ox-LDL induced VSMCs that previously had a very low expression of HO-1 and Nrf2 protein.

This implies that ECG significantly ameliorated the atherosclerotic damage of VSMCs Yu et al. Zheng et al. showed that after treatment with EGCG, nuclear accumulation of Nrf2 was significantly increased and the binding of Nrf2-ARE was also enhanced.

Lee and Kim, PPAR- a is an important target for the treatment of lipid metabolism disorder, because it can regulate the expression of many lipid related genes, Janssen et al. PPAR- γ regulates target genes downstream involved in lipid production, and promotes fatty acid transport and deposition Janani and Ranjitha Kumari, ; Xu et al.

EC attenuated the downregulation of PPARγ expression mediated by TNFα and reduced nuclear DNA binding Vazquez-Prieto et al. Similarly, studies have shown that EGCG can also restore the down-regulation expression of PPAR- γ Peng et al. Therefore, EC and EGCG may act as PPAR-γ agonists to exert antioxidant effects.

In addition, PPAR-γ coactivator-1α PGC-1α regulates genes involved in lipid metabolism and oxidative stress Bagattin et al. It is also involved in the activation of PPARα Homologous. PGC1α and PPARα are key factors in antioxidant response Fracassi et al.

Research has proven that the activation of PPARα can trigger the activation of CAT, while PGC1α can regulate expression and localization of SOD2 and GPx1 Figuer 3 St-Pierre et al.

The use of EC rescued the decrease in level of PGC-1α, and exhibited beneficial effects on obesity and decreased relevant cardiometabolic risk factors Gutiérrez-Salmeán et al.

Marinovic et al. demonstrated that EGC and EC can indirectly activate PPARα and reduce hepatic steatosis Marinovic et al. Unfortunately, there are insufficient reports on the role of PPAR pathway in oxidative stress with catechins.

Its role in ROS metabolism too has not been explored to a large extent. The MAPK mitogen-activated protein kinase signaling cascades involving MAPKs ERK extracellular signal regulated kinase , JNK c-Jun N-terminal kinase and p38 MAPK may play an important role in atherosclerosis and vascular restenosis Muslin, Inhibition of the cascade is believed to protect cells from oxidative stress.

Evidence suggests that when JNK, ERK, and p38 proteins are activated, ROS level increases, leading to oxidative stress and subsequently apoptosis Kong et al.

Specifically, the JNK pathway has been demonstrated to be part of oxidative stress responses in tumors, suggesting that inhibition of JNK signaling may be helpful to prevent several ROS-induced metabolic diseases Li C et al.

Activation of AP-1, a transcription factor, occurs through the MAPK pathway. Its activity is influenced by the intracellular redox environment, including the level of ROS and antioxidants Figuer 3 Higdon, J. and Frei, B. EGCG can minimize the damage to endothelial cells and reduce IL-6 and TNF-α by inhibiting AP-1 activity Riegsecker et al.

Catechins seem to inhibit AP-1 activity through inhibiting kinases in the MAPK pathway, such as JNK and Erks Katiyar et al. EGCG was observed to significantly prevent thrombin-induced caspase 3 activation and apoptosis by suppressing JNK phosphorylation He et al.

The molecular signaling pathway regulated by catechins is responsible for its pro-apoptotic and anti-proliferative characteristics. One of which is the inhibition of a key oxidative stress-sensitive transcription factor -nuclear factor-κB NF-κB Khan and Mukhtar, ; Musial et al. After exposure to oxidative and inflammatory stimuli, I κ B kinase IKK is activated, leading to IKK signalsome phosphorylation, which are subsequently degraded by the proteasome.

Then NF-κB translocates to the nucleus, where it binds to specific promoter regions and initiates transcription. Karin, ; Surh, In addition, NF-κB may aggravate oxidative stress by influencing the Nrf2 signaling pathway. Being a protein downstream of NF-κB, the research have shown that p65 may exert conflicting effects in the Nrf2 signaling pathway by accelerating peroxidation, leading to abnormal cell proliferation Figuer 3 Yang et al.

Catechins, especially EGCG, can block the activation of NF-κB Varilek et al. It was found that EGCG can reduce p65 expression induced by PCB polychlorinated biphenyls and down-regulate the expression of NF-κB regulated genes, further suppressing endothelial cells inflammation Liu et al.

Many studies have proven that catechins are protective against AS and are effective natural antioxidants. However, there are still a few limitations in place such as metabolite activity and low bioavailability.

Because catechins are rapidly and extensively metabolized, in vitro experiments data and the biological activity of catechins metabolites are often questioned. It is hence particularly important to demonstrate catechins antioxidant activity in vivo.

Catechins have been found to experienced considerable biotransformation in vivo , and their main metabolic pathways are methylation, glucuronidation, sulfation and ring-fission metabolism. Yang et al. EGCG metabolites and metabolites produced from EC or ECG are proven to have stronger free radical scavenging power than parental catechins Takagaki et al.

The 30—and 40 -monomethyl ethers of EC can inhibit NADPH oxidase to increase NO in endothelial cells, thus reducing oxidative stress Steffen et al. These evidence suggests that catechin metabolites can maintain the antioxidant capacity of their parent compounds. Another metabolic pathway includes the degradation of catechins.

Liver and intestine are the backbone of the metabolization and absorption of catechins Feng, Besides intestinal and liver metabolites, Sang et al. also found metabolites in colon bacteria Sang et al. Investigation found that catechins not metabolized in the upper intestine were transported to the lower intestine through intestinal microflora Roowi et al.

Ottaviani et al. Therefore, there is great research potential in intestinal microbiota to improve production and hence the bioavailability of catechin metabolites.

It is also important to continue studying the antioxidant effect of metabolites to find the optimal condition for catechins to play an antioxidant role better in the local intestinal.

Tea polyphenols are susceptible to degradation under environmental stresses or digestive circumstances, such as alkaline pH and high temperature. In addition, the low bioavailability of catechins also due to degradation and metabolism in the gastrointestinal tract, poor membrane permeability, and pre-systemic hepatic clearance Ye and Augustin, ; Sabaghi et al.

The development of new agents, such as nanoparticles, may become an effective way to solve this problem in the future. Recently, studies found that nanomaterials based on carbon, nanozymes, and nanomedicine could improve stability of antioxidant treatments and further upgrade the antioxidant effect.

For instance, nitrogen-doped carbon nanodots ionogels Rizzo et al. Green nanoparticles GNPs prepared by Yang et al. using TP in green tea as the monomer have strong free radical scavenging ability and oxidation resistance.

The research provides a new green strategy for making safe and effective antioxidants. It has been reported that synergistic effects of the combination of EGCG and fish oil.

The presence of fish oil increased the bioavailability of EGCG Giunta et al. Furthermore, using broccoli byproducts as the matrix for co-delivery of EGCG and fish oil could prevent the degradation of EGCG in the upper gastrointestinal tract can thus be metabolized by the microorganisms in the lower gut, leading to an increase in EGCG bioavailability Shi et al.

In addition, the combination of catechins with other drugs that show synergistic effects may be a promising approach, such as catechins showing good synergy with some conventional anticancer drugs Cai et al.

Moreover, under certain conditions, catechins may have both prooxidative or toxic effects. The dual antioxidant and pro-oxidant functions of catechins depend primarily on the dose level and the biological context. Some European regulators have suggested that the tolerable upper intake level of EGCG should be mg per day for humans Yates et al.

Tian et al. found that at 0. It is possible to optimize the TP level of foods or beverages based on emulsion to achieve the best antioxidant activity Tian et al. With the aging of the general population and the increase in chronic diseases such as hypertension and diabetes, the incidence rate of atherosclerosis further increase.

Atherosclerosis has no obvious early symptoms. When the disease progresses to a higher stage with age, symptoms of atherosclerosis will appear. Therefore, it is very important to seek preventive diet or drugs, and the strategy of prevention before disease will greatly reduce hospital costs and other economic burdens of patients.

The development of natural products to prevent AS has scientific significance and application value. At the same time, the discovery of lipid oxidation products implies that oxidative stress promotes the change of lipid metabolism, which provides a new idea for the treatment of diseases with abnormal lipid metabolism.

Tea, especially unfermented green tea, is rich in catechins, which have antioxidation and improve lipid metabolism disorders. The health benefits of tea are largely attributed to the effects of catechins.

However, catechins correspond to a variety of targets and act through different signaling pathways. Due to the pleiotropic effects of catechins, more definitive studies on their biological functions and anti-atherosclerotic mechanisms are lacking before their clinical application.

Current studies have not systematically revealed the mechanism of catechins in anti-oxidative stress to regulate abnormal lipid metabolism in AS. Therefore, we hope to clarify the therapeutic effect of catechin in AS by combing the mechanism of catechin regulating oxidative stress and improving abnormal lipid metabolism.

This study will provide a reference for the subsequent development of catechin as AS adjuvant drugs. Catechins play an antioxidant role in many ways, namely, by balancing enzyme activity and regulating signal pathways. They inhibit NADPH oxidase, XO, COX2, NOS, and other enzymes that produce ROS and activate antioxidants in the body, such as GSH, SOD, CAT, GPX, GST, NQO1, to significantly improve the antioxidant response.

These reactions all work together to help reduce oxidative stress. It is noteworthy to point out that there are still many limiting factors for the application of catechins, such as prooxidative and toxic effects under certain conditions, the dubious activity of its metabolites and low bioavailability.

Molan et al. Hydroxyl radical scavenging assay was also used to examine the antioxidant activities of teas. The main difference between this assay and the ability to scavenge the DPPH radical is the fact that hydroxyl radicals are found in the living systems, while the 2,2-diphenylpicrylhydrazyl radicals are synthetic.

Teas marked as L2 and MG both originated in Ziyang Province showed the highest ability to scavenge the hydroxyl radical A slightly lower value was obtained for a sample from an unknown Chinese province X5. Surprisingly, for the other two samples from the Yunnan province, the values were significantly lower than for Y3, suggesting a different location for these crops within one province.

The lowest ability to scavenge the hydroxyl radical was obtained for India tea The Zheijang teas were characterized by middle values ranged from The lowest reducing activity was observed for mixed Chinese tea M and Ceylon tea C.

The Folin—Ciocalteu method, also known as the total polyphenol content, was also used. In general, these were middle values. It was reported that regular green tea showed higher polyphenol content than selenized one [ 24 , 25 ].

Xu et al. Generally, the effect of chemical stress induced by selenium treatment can enhance the antioxidant activity of plant extracts [ 38 , 43 ]. However, the opposite results are also reported [ 44 ].

The two studied varieties of apples were differently affected: one of them mostly showed a higher antioxidant activity measured with TEAC resulting from the biofortification and independently of the selenium form and the level of application, whereas the values for the second was only slightly influenced by the biofortification.

Moreover, some selenium compounds and their metabolites can act as antioxidants, pro-oxidants or both depending of specific conditions [ 45 ]. Based on the collected data, attempts were made to group the analyzed teas, based on their antioxidant capacities, as shown in Fig.

It can be seen that values obtained for Zijang teas vary and those obtained for neighboring provinces are close. Yunnan teas formed separate group as well as unknown Chinese teas samples X1-X4.

What is interesting that samples marked as X5 and X6 differ from other unknown Chinese teas. This suggests that they could have their origin in other province than the rest.

The differences between the J Jiangsu and F Fujian teas can be surprising, because both of them came from neighboring to Zjjiang provinces, where soil is rich in selenium. However sample J is rather more similar to sample S Xinjiang in terms of antioxidant activities.

All of them showed some similarities only in OH scavenging activity. An attempt to group the results of studies on the antioxidant capacity of teas: a Folin-Ciocalteu assay; b CUPRAC; c DPPH; d Hydroxyl radicals scavenging. Principal component analysis PCA was also performed between each two variables and no correlation between the selenium content and antioxidant activities was found Fig.

The correlation between the content of selenium, catechins, pH and the antioxidant capacity of the studied teas was examined also using linear correlation.

No relationship was found between the content of any of the detected forms of selenium and the antioxidant capacity of the studied teas.

For the other selenium compounds SeMet and SeCys , negative values of correlation coefficients between their contents and the antioxidant activity of teas were obtained.

This suggests an inverse relationship to the expected one. Sotek et al. Only for that first plant, a significant correlation between Se level and the results from FC assay was found 0. No correlation was found also between the selenium content and catechin concentration in the studied infusions.

In case of SeMet, negative correlations between its concentration and the EPI and EGCG content were established Green tea beverages have been continuously considered as a medicine because of their polyphenols.

Additionally, Chinese green teas, particularly produced in Ziyang County located in the southwest of Shaanxi Province of China, are advertised as they are rich in selenium. No wonder that consumers eagerly reach for such a tea, believing in its additional health-promoting properties.

However, green tea extracts from other Chinese provinces, also contain considerable amounts of organic selenium forms.

For example, teas from Yunnan province samples Y1-Y3 contain higher content of MeSeCys, which is considered as a selective modulator of the antitumor activity. The content of catechins in studied water tea infusions also varies.

Such conditions provide higher content of all studied polyphenols due to better solubility but do not reflect household brewing process. The demands that Se-enriched green tea extract had higher polyphenols content and higher antioxidant activities in comparison with regular one do not always work.

Selenocompounds and other non-phenolic components may play also a vital role in the antioxidant activity of that extract.

It should be remembered that selenium compounds can act as antioxidants or pro-oxidants and when the plants were subjected to higher Se concentration, the antioxidant activity may decrease.

A number of difficulties are also encountered when trying to compare the published results. There is no precise data on how the samples of selenium teas were obtained and how they were cultivated with Se fertilizers or not.

In summary, it is worth drinking and enjoying green tea, but it is not worth running around tea houses and looking for selenium green tea. Namal Senanayake SPJ Green tea extract: chemistry, antioxidant properties and food applications—a review. J Funct Foods — Article CAS Google Scholar. Maiti S, Nazmeen A, Medda N, Paqtra R, Ghosh TK Flavonoids green tea against oxidant stress and inflammation with related human diseases.

Clin Nutr Exp — Article Google Scholar. Costa C, Tsatsakis A, Manoulakis C, Teodoro M, Brigugilio G, Caruso E, Tsoukalas D, Margina D, Dardiotis E, Kouretas D, Fenga C Current evidence on the effect of dietary polyphenols intake on chronic diseases. Food Chem Toxicol — Article CAS PubMed Google Scholar.

Mancini E, Beglinger C, Dreweb J, Zanchia D, Undine E, Langa UE Green tea effects on cognition, mood and human brain function: a systematic review. Phytomedicine — Kerio LC, Wachira FN, Wanyoko JK, Rotich MK Total polyphenols, catechin profiles and antioxidant activity of tea products from purple leaf coloured tea cultivars.

Food Chem — Grzesik M, Naparło K, Bartosz G, Sadowska-Bartosz I Antioxidant properties of catechins: comparison with other antioxidants. Farkhondeh T, Pourbagher-Shahri AM, Ashrafizadeh M, Folgado SL, Rajabpour-Sanati A, Khazdair MR, Samarghandian S Green tea catechins inhibit microglial activation which prevents the development of neurological disorders.

Neural Regen Res — Article PubMed PubMed Central Google Scholar. Musial C, Kuban-Jankowska A, Górska-Ponikowska M Beneficial properties of green tea catechins. Int J Mol Sci — Article CAS PubMed Central Google Scholar.

He X, Li J, Zhao W, Liu R, Zhang L, Kong X Chemical fingerprint analysis for quality control and identification of Ziyang green tea by HPLC. Li W, He N, Tian L, Shi X, Yang X Inhibitory effects of polyphenol-enriched extract from Ziyang tea against human breast cancer MCF-7 cells through reactive oxygen species-dependent mitochondria molecular mechanism.

J Food Drug Anal — Lu L, Chai L, Wang W, Yuan X, Li S, Cao C A selenium-enriched Ziyang green tea polysaccharide induces bax-dependent mitochondrial apoptosis and inhibits TGF-β1-simulated collagen expression in human keloid fibroblast via NG2 inactivation. Biol Trace Elem Res — Tian H, Ma Z, Chen X, Zhang H, Bao Z, Wei C, Xie S, Wu S Geochemical characteristics of selenium and its correlation to other elements and minerals in selenium-enriched rocks in Ziyang County, Shaanxi Province, China.

J Earth Sci — Hu J, Yang F, Chen L, Hu Y, Hu Q Effect of selenium on increasing the antioxidant activity of tea leaves harvested during early spring tea producing season. J Agric Food Chem — Zhang B, Wei Y, Yan S, Shi H, Nie Y, Zou G, Zhang X, Luo L Characterization of selenium accumulation of different rice genotypes in Chinese natural seleniferous soil.

Plant Soil Environ — Kieliszek M, Błażejak S Current knowledge on the importance of selenium in food for living organisms: a review. Molecules — Tan LC, Nancharaiah YV, van Hullebusch ED, Lens PNJ Selenium: environmental significance, pollution, and biological treatment technologies.

Biotech Adv — Benstoem C, Andreas Goetzenich A, Kraemer S, Borosch S, William Manzanares W, Hardy G, Christian Stoppe C Selenium and its supplementation in cardiovascular disease—what do we know?

Nutrients — Article CAS PubMed PubMed Central Google Scholar. Aldosary BM, Sutter ME, Schwartz M, Morgan BW Case series of selenium toxicity from a nutritional supplement. J Clin Toxicol — Pyrzynska K Edible plants enriched with selenium. J Agric Sci Technol A — Gammelgaard B, Jackson MI, Gabel-Jensen C Surveying selenium speciation from soil to cell—forms and transformations.

Anal Bioanal Chem — Sun GX, Liu X, Williams PN, Zhu YG Distribution and translocation of selenium from soil to grain and its speciation in paddy rice Oryza sativa L. Environ Sci Technol — Pyrzynska K Selenium speciation in enriched vegetables.

Hu QH, Xu J, Pan GX The effect of selenium sprays on green tea quality. J Sci Food Agric — Hu QH, Pan GX, Zhu JC Effect of selenium on green tea preservation quality and amino acid composition of tea protein. J Horticult Sci Biotech — Xu J, Zhu SG, Yang FM, Cheng LC, Hu Y, Hu Q Effect of selenium on increasing the antioxidant activity of tea leaves harvested during the early spring tea producing season.

Cocos nucifera Linn. Palmae husk fiber ethanolic extract: antioxidant capacity and electrochemical investigation. Comb Chem High Throughput Screen. Ow Y-Y, Stupans I. Gallic acid and gallic acid derivatives: effects on drug metabolizing enzymes. Curr Drug Metab. Parisi OI, Puoci F, Iemma F, Curcio M, Cirillo G, Spizzirri UG, et al.

Flavonoids preservation and release by methacrylic acid-grafted N-vinyl-pyrrolidone. Pharm Dev Technol. Puri A, Nguyen HX, Banga AK. Microneedle-mediated intradermal delivery of epigallocatechingallate.

Reis GM, Faccin H, Viana C, da Rosa MB, de Carvalho LM. Vitis vinifera L. cv Pinot noir pomace and lees as potential sources of bioactive compounds. Int J Food Sci Nutr. Rojas LB, Quideau S, Pardon P, Charrouf Z. Colorimetric evaluation of phenolic content and GC-MS characterization of phenolic composition of alimentary and cosmetic argan oil and press cake.

Scalia S, Marchetti N, Bianchi A. Comparative evaluation of different co-antioxidants on the photochemical- and functional-stability of epigallocatechingallate in topical creams exposed to simulated sunlight. Sharma A, Gupta P, Verma AK. Preliminary nutritional and biological potential of Artocarpus heterophyllus L.

shell powder. J Food Sci Technol. Shi M, Nie Y, Zheng X-Q, Lu J-L, Liang Y-R, Ye J-H. Ultraviolet B UVB Photosensitivities of tea catechins and the relevant chemical conversions. Shin MC, Park SK, Jung SH. The inhibitory effect on cytotoxicity and nitric oxide NO of the nano-encapsulated extraction of lipid-soluble green tea leaves.

J Nanosci Nanotechnol. Shoko T, Maharaj VJ, Naidoo D, Tselanyane M, Nthambeleni R, Khorombi E, et al. Anti-aging potential of extracts from Sclerocarya birrea A. Hochst and its chemical profiling by UPLC-Q-TOF-MS.

BMC Complement Altern Med. Sidgwick GP, McGeorge D, Bayat A. Functional testing of topical skin formulations using an optimised ex vivo skin organ culture model.

Arch Dermatol Res. Singh BN, Shankar S, Srivastava RK. Green tea catechin, epigallocatechingallate EGCG : mechanisms, perspectives and clinical applications. Biochem Pharmacol. Skowyra M, Falguera V, Gallego G, Peiró S, Almajano MP. Antioxidant properties of aqueous and ethanolic extracts of tara Caesalpinia spinosa pods in vitro and in model food emulsions.

Spizzirri UG, Iemma F, Puoci F, Cirillo G, Curcio M, Parisi OI, et al. Synthesis of antioxidant polymers by grafting of gallic acid and catechin on gelatin. Takahashi T, Yokoo Y, Inoue T, Ishii A.

Toxicological studies on procyanidin B-2 for external application as a hair growing agent. Food Chem Toxicol. Tsuchiya H, Sato M, Kato H, Okubo T, Juneja LR, Kim M.

Simultaneous determination of catechins in human saliva by high-performance liquid chromatography. J Chromatogr B Biomed Sci Appl. Wisuitiprot W, Somsiri A, Ingkaninan K, Waranuch N. In vitro human skin permeation and cutaneous metabolism of catechins from green tea extract and green tea extract-loaded chitosan microparticles.

Xia J, Song X, Bi Z, Chu W, Wan Y. UV-induced NF-κB activation and expression of IL-6 is attenuated by - -epigallocatechingallate in cultured human keratinocytes in vitro. Int J Mol Med. Yang W, Liu F, Xu C, Sun C, Yuan F, Gao Y.

Yang W, Xu C, Liu F, Sun C, Yuan F, Gao Y. Yang W, Yuan F, Gao YX. Interaction of fish collagen peptide with epigallocatechin gallate.

Guang Pu Xue Yu Guang Pu Fen Xi. Yoshino S, Mitoma T, Tsuruta K, Todo H, Sugibayashi K. Effect of emulsification on the skin permeation and UV protection of catechin.

Yuki K, Ikeda N, Nishiyama N, Kasamatsu T. Mutat Res Genet Toxicol Environ Mutagen. Zhang W, Yang Y, Lv T, Fan Z, Xu Y, Yin J, et al. J Biomed Mater Res B Appl Biomater. Zhong Y, Shahidi F. Lipophilized epigallocatechin gallate EGCG derivatives as novel antioxidants.

Zillich OV, Schweiggert-Weisz U, Eisner P, Kerscher M. Polyphenols as active ingredients for cosmetic products. Zillich OV, Schweiggert-Weisz U, Hasenkopf K, Eisner P, Kerscher M.

Release and in vitro skin permeation of polyphenols from cosmetic emulsions. Download references. We would like to thank Yeoju-si and Yeoju Institute of Technology Gyeonggi-do, Republic of Korea for their support for this study.

Department of Cosmetics Engineering, Graduate School of Konkuk University, Neungdong-ro, Gwangjin-gu, Seoul, , Republic of Korea. Department of Beauty Art, Doowon Technical University, Jurawui-gil, Paju-eup, Paju-si, Gyeonggi-do, , Republic of Korea.

Department of Beauty Yakson Care, Yeoju Institute of Technology, Sejong-ro, Yeoju-si, Gyeonggi-do, , Republic of Korea. You can also search for this author in PubMed Google Scholar.

JB, NK, YS, and YJK designed the study and analyzed data, and JB, NK, YS, SYK, and YJK wrote the manuscript and figure together. All authors read and approved the final manuscript. Correspondence to You-Jeong Kim. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Open Access This article is distributed under the terms of the Creative Commons Attribution 4. Reprints and permissions. Bae, J. et al. Activity of catechins and their applications. biomed dermatol 4 , 8 Download citation. Received : 21 August Accepted : 08 January Published : 26 February Anyone you share the following link with will be able to read this content:.

Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative.

Skip to main content. Search all BMC articles Search. Download PDF. Download ePub. Abstract Background Catechins, which are polyphenol compounds found in many plants and are an important component of tea leaves, are strong anti-oxidants.

Research Many studies seek to enhance the effects of catechins on the human body and boost their protective power against UV radiation. Conclusion Continued research on the strong anti-oxidant effects of catechins is expected to result in many advances in the food, cosmetics, and pharmaceutical industries.

Background Catechins have many benefits including preventing or reducing skin damage. Full size image. Conclusions Table 1 summarises the activities of catechins and their applications. Table 1 Activities of catechins and their applications Full size table. Availability of data and materials Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.

References Aires A, Carvalho R, Saavedra MJ. Article CAS PubMed Google Scholar Aoshima H, Kokubo K, Shirakawa S, Ito M, Yamana S, Oshima T.

Article CAS PubMed Google Scholar Arct J, Bielenda B, Oborska A, Pytkowska K. Google Scholar Arct J, Oborska A, Mojski M, Binkowska A, Swidzikowska B. Article CAS PubMed Google Scholar Arruda HS, Pereira GA, de Morais DR, Eberlin MN, Pastore GM.

Article CAS PubMed Google Scholar Arruda HS, Silva EK, Pereira GA, Angolini CFF, Eberlin MN, Meireles MAA, et al. Article CAS PubMed Google Scholar Bianchi A, Marchetti N, Scalia S.

Article CAS PubMed Google Scholar Bombardelli E. CAS PubMed Google Scholar Chen Y-C, Yu S-H, Tsai G-J, Tang D-W, Mi F-L, Peng Y-P. Article CAS PubMed Google Scholar Cheng H-Y. Article CAS PubMed Google Scholar Choi M-H, Jo H-G, Yang J, Ki S, Shin H-J. Article PubMed Central CAS Google Scholar Cruz L, Fernandes VC, Araújo P, Mateus N, de Freitas V.

Article PubMed CAS Google Scholar dal Belo SE, Gaspar LR, PMBG MC, Marty J-P. Article CAS PubMed Google Scholar de Oliveira CA, Hensel A, Mello JCP, Pinha AB, Panizzon GP, Lechtenberg M, et al.

Article CAS Google Scholar Demoliner F, de BrittoPolicarpi P, Vasconcelos LFL, Vitali L, Micke GA, Block JM. Article CAS PubMed Google Scholar Feng B, Fang Y, Wei SM. CAS PubMed Google Scholar Feng H-L, Tian L, Chai W-M, Chen X-X, Shi Y, Gao Y-S, et al.

Article CAS PubMed Google Scholar Ferreira-Nunes R, Angelo T, da Silva SMM, Magalhães PO, Gratieri T, da Cunha-Filho MSS, et al. Article CAS Google Scholar Ferreira-Nunes R, Gratieri T, Gelfuso GM, Cunha-Filho M.

Article CAS PubMed Google Scholar Foyet H, Tsala D, ZogoEssono Bodo J, Carine A, Heroyne L, Oben E. CAS Google Scholar Fung S-T, Ho CK, Choi S-W, Chung W-Y, Benzie IFF. Article PubMed CAS Google Scholar Gallego M, Skowyra M, Gordon M, Azman N, Almajano M.

Article PubMed Central CAS Google Scholar Goyal A, Bhat M, Sharma M, Garg M, Khairwa A, Garg R. Article PubMed Google Scholar Gulati A, Rajkumar S, Karthigeyan S, Sud RK, Vijayan D, Thomas J, et al. Article CAS PubMed Google Scholar Han S, Kim E, Hwang K, Ratan Z, Hwang H, Kim E-M, et al.

Article PubMed Central CAS Google Scholar Hernández-Hernández C, Morales-Sillero A, Fernández-Bolaños J, Bermúdez-Oria A, Morales AA, Rodríguez-Gutiérrez G.

Article PubMed CAS Google Scholar Huang CC, Wu WB, Fang JY, Chiang HS, Chen SK, Chen BH, Chen YT, Hung CF. Article CAS PubMed PubMed Central Google Scholar Ide K, Yamada H, Matsushita K, Ito M, Nojiri K, Toyoizumi K, et al. Article PubMed PubMed Central CAS Google Scholar Im KM, Jeon J-R.

Google Scholar Iñiguez-Franco F, Soto-Valdez H, Peralta E, Ayala-Zavala JF, Auras R, Gámez-Meza N. Article PubMed CAS Google Scholar Jackson JK, Zhao J, Wong W, Burt HM.

Article CAS PubMed Google Scholar Jang J-H, Park Y-D, Ahn H-K, Kim S-J, Lee J-Y, Kim E-C, et al. Article CAS Google Scholar Jeon J-R, Kim E-J, Murugesan K, Park H-K, Kim Y-M, Kwon J-H, et al.

Article CAS PubMed PubMed Central Google Scholar Jin Y, Jin CH, Ho RK. Article CAS PubMed Google Scholar Kadhum WR, Sekiguchi S, Hijikuro I, Todo H, Sugibayashi K. Article CAS PubMed Google Scholar Kim E, Hwang K, Lee J, Han S, Kim E-M, Park J, et al. Article PubMed CAS Google Scholar Kim M-M.

Article PubMed Google Scholar Kim SS, Hyun C-G, Choi YH, Lee NH. Article PubMed CAS Google Scholar Kim YC, Choi SY, Park EY. Article PubMed PubMed Central Google Scholar Klein T, Longhini R, de Mello JCP. Article CAS PubMed Google Scholar Kosińska A, Karamać M, Estrella I, Hernández T, Bartolomé B, Dykes GA.

Article PubMed CAS Google Scholar Kumar M, Chandel M, Kaur P, Pandit K, Kaur V, Kaur S, et al. PubMed PubMed Central Google Scholar Li C, Seeram NP. Article CAS PubMed PubMed Central Google Scholar Lima EBC, de Sousa CNS, Vasconcelos GS, Meneses LN, YF e SP, Ximenes NC, et al.

Article PubMed Google Scholar Madhan B, Subramanian V, Rao JR, Nair BU, Ramasami T. Article CAS PubMed Google Scholar Magalhães AC, Wiegand A, Rios D, Hannas A, Attin T, Buzalaf MAR.

Article PubMed CAS Google Scholar Magalhães LM, Machado S, Segundo MA, Lopes JA, Páscoa RNMJ. Article PubMed CAS Google Scholar Marques TR, Cesar PHS, Braga MA, Marcussi S, Corrêa AD. Article CAS PubMed Google Scholar Martincigh BS, Ollengo MA.

Article CAS PubMed Google Scholar Matsubara T, Wataoka I, Urakawa H, Yasunaga H. Article CAS PubMed Google Scholar Moulton MC, Braydich-Stolle LK, Nadagouda MN, Kunzelman S, Hussain SM, Varma RS. Article CAS PubMed Google Scholar Muhammad D, Hubert J, Lalun N, Renault J-H, Bobichon H, Nour M, et al.

Article PubMed CAS Google Scholar Nadim M, Auriol D, Lamerant-FayeL N, Lefèvre F, Dubanet L, Redziniak G, et al. Article CAS PubMed Google Scholar Niu L, Shao M, Liu Y, Hu J, Li R, Xie H, et al. Article CAS PubMed Google Scholar Ohmori Y, Ito M, Kishi M, Mizutani H, Katada T, Konishi H.

Article CAS PubMed Google Scholar Oliveira MB, Valentim IB, de Vasconcelos CC, Omena CM, Bechara EJ, da Costa JG, Freitas Mde L, Sant'Ana AE, Goulart MO. CAS PubMed Google Scholar Ow Y-Y, Stupans I. Article CAS PubMed Google Scholar Parisi OI, Puoci F, Iemma F, Curcio M, Cirillo G, Spizzirri UG, et al.

Article PubMed CAS Google Scholar Puri A, Nguyen HX, Banga AK. Article CAS PubMed Google Scholar Reis GM, Faccin H, Viana C, da Rosa MB, de Carvalho LM. Article CAS PubMed Google Scholar Rojas LB, Quideau S, Pardon P, Charrouf Z.

Article CAS PubMed Google Scholar Scalia S, Marchetti N, Bianchi A. Article CAS PubMed PubMed Central Google Scholar Sharma A, Gupta P, Verma AK. Article PubMed PubMed Central CAS Google Scholar Shi M, Nie Y, Zheng X-Q, Lu J-L, Liang Y-R, Ye J-H.

Article PubMed Central CAS Google Scholar Shin MC, Park SK, Jung SH. Article CAS PubMed Google Scholar Shoko T, Maharaj VJ, Naidoo D, Tselanyane M, Nthambeleni R, Khorombi E, et al.

Article PubMed PubMed Central CAS Google Scholar Sidgwick GP, McGeorge D, Bayat A. Article CAS PubMed PubMed Central Google Scholar Singh BN, Shankar S, Srivastava RK.

Article CAS PubMed PubMed Central Google Scholar Skowyra M, Falguera V, Gallego G, Peiró S, Almajano MP. Article PubMed CAS Google Scholar Spizzirri UG, Iemma F, Puoci F, Cirillo G, Curcio M, Parisi OI, et al.

Article CAS PubMed Google Scholar Takahashi T, Yokoo Y, Inoue T, Ishii A. Article CAS PubMed Google Scholar Tsuchiya H, Sato M, Kato H, Okubo T, Juneja LR, Kim M. Article CAS PubMed Google Scholar Wisuitiprot W, Somsiri A, Ingkaninan K, Waranuch N. Article CAS PubMed Google Scholar Xia J, Song X, Bi Z, Chu W, Wan Y.

CAS PubMed Google Scholar Yang W, Liu F, Xu C, Sun C, Yuan F, Gao Y. Article CAS PubMed Google Scholar Yang W, Xu C, Liu F, Sun C, Yuan F, Gao Y. Article CAS PubMed Google Scholar Yang W, Yuan F, Gao YX.

CAS PubMed Google Scholar Yoshino S, Mitoma T, Tsuruta K, Todo H, Sugibayashi K.

Top bar navigation Fermented tea leaves have the lowest cytotoxicity and the highest anti-melanogenic activities Kim et al. found that ECG activated the Nrf2 and increased expression of HO-1 in ox-LDL induced VSMCs that previously had a very low expression of HO-1 and Nrf2 protein. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author s and the source are credited. Some matrix metallo protease inhibitors may be a preventative measure to prevent dentin erosion-abrasion Magalhães et al. Kim E, Hwang K, Lee J, Han S, Kim E-M, Park J, et al. Granato D, Santos JS, Maciel LG, Nunes DS Chemical perspective and criticism on selected analytical methods used to estimate the total content of phenolic compounds in food matrices. Karin, M.
Human Verification Antioxidant catechins ePub. Antioxidant catechins and permissions Anitoxidant Access This article is licensed under cztechins Creative Lentils and one-pot meals Attribution 4. Minatti, J. Biotechnol J. A study of atherosclerotic mice found that ECG accumulation in macrophages specifically inhibits genes encoding CD36, an important intermediate in the transformation of macrophages into foam cells Kawai et al.
Antioxidant catechins Antioxidan Dermatology volume Cardiovascular workouts for improved staminaArticle number: Antioxifant Cite this article. Metrics details. Antioxjdant, which are polyphenol compounds found in Antioxidant catechins plants Catehcins are an important component of Antiioxidant leaves, are strong anti-oxidants. Antioxisant studies seek to Antioxidant catechins the effects of catechins on the human body and boost their protective power against UV radiation. There are many examples of the positive anti-microbial, anti-viral, anti-inflammatory, anti-allergenic, and anti-cancer effects of catechins. Catechins increase the penetration and absorption of healthy functional foods and bio cosmetics into the body and the skin, thus improving their utility. High value-added anti-oxidant substances have been extracted from food and plant sludge, and experiments have shown that catechins are safe when applied to the human body.

Author: Gurn

4 thoughts on “Antioxidant catechins

Leave a comment

Yours email will be published. Important fields a marked *

Design by ThemesDNA.com