title: Tea Catechins Protect Goat Skeletal Muscle against H₂O₂-Induced Oxidative Stress by Modulating Expression of Phase 2 Antioxidant Enzymes.
abstract: To study the mechanisms of tea catechins (TCs) in goat muscles against oxidative stress, skeletal muscle cells (SMCs) induced by H2O2 or not were incubated with TCs or 3H-1,2-dithiole-3-thione (D3T) and were defined as H2O2, H2O2D3T, H2O2TC, D3T, and TC treatments, respectively. Results showed that, similar to effects of D3T, TCs regulated mRNA and protein expression of antioxidant enzymes by suppressing Keap1 protein expression in SMCs from 1.58 ± 0.12 to 0.71 ± 0.21 and 1.03 ± 0.11 in H2O2TC and TC groups, respectively; however, effects differed in oxidative condition of cells and among enzymes. In stressed cells, TCs increased catalase and glutathione S-transferases (GST) activities (P < 0.001), whereas both enzymes' activities decreased (P < 0.001) to 2.97 ± 0.37 U/mg protein or 42.1 ± 1.85 mU/mg protein, respectively, in unstressed SMCs. Subsequently, an in vivo experiment in goats fed grain supplemented with TCs or D3T following infusion with H2O2 was conducted to further verify mechanisms of TC action. As seen in vitro, TCs reduced Keap1 protein expression (P < 0.001) from 2.11 ± 0.37 to 1.34 ± 0.13 and 1.43 ± 0.23 in H2O2TC and TC groups, respectively, in muscle. However, dietary TCs increased plasma CuZn superoxide dismutase and GST activities (P < 0.001) regardless of oxidative stress. Moreover, feeding TCs to goats under both conditions increased meat color and tenderness (P ≤ 0.001). In conclusion, TCs protected goat muscles against oxidative stress and subsequently improved meat quality by modulating phase 2 antioxidant enzymes and Keap1 expression.
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University , Changchun, Jilin 130118, People's Republic of China.|Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences , Changchun, Jilin 130102, People's Republic of China.
authors.forename: Rong-Zhen
authors.initials: RZ
authors.lastname: Zhong
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences , Changchun, Jilin 130102, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Fang
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University , Changchun, Jilin 130118, People's Republic of China.
authors.forename: Gui-Xin
authors.initials: GX
authors.lastname: Qin
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences , Changchun, Jilin 130102, People's Republic of China.
authors.forename: Hao-Yang
authors.initials: HY
authors.lastname: Li
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences , Changchun, Jilin 130102, People's Republic of China.
authors.forename: Dao-Wei
authors.initials: DW
authors.lastname: Zhou
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D028241:Camellia sinensis / Q000737:chemistry*; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D002392:Catechin / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D006041:Goats; D006861:Hydrogen Peroxide / Q000633:toxicity; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D002392:Catechin; D006861:Hydrogen Peroxide; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione
keywords: D3T; Keap1−Nrf2 pathway; goat; oxidative stress; tea catechins