Tea Catechins Protect Goat Skeletal Muscle against H2O2-Induced Oxidative Stress by Modulating Expression of Phase 2 Antioxidant Enzymes

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• 作者：Rong-Zhen Zhong ; Yi Fang ; Gui-Xin Qin ; Hao-Yang Li ; Dao-Wei Zhou
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2015
• 出版时间：September 16, 2015
• 年：2015
• 卷：63
• 期：36
• 页码：7921-7928
• 全文大小：251K
• ISSN：1520-5118

文摘

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 卤 0.12 to 0.71 卤 0.21 and 1.03 卤 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鈥?activities decreased (P < 0.001) to 2.97 卤 0.37 U/mg protein or 42.1 卤 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 卤 0.37 to 1.34 卤 0.13 and 1.43 卤 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 鈮?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.