茶多酚对二恶英所致肝损的作用及机理研究

EFFECTS OF TEA POLYPHENOLS ON LIVER DAMAGE CAUSED BY TCDD AND ITS POSSIBLE MECHANISM

[目的]研究茶多酚(TP)对二恶英(TCDD)所致肝损毒作用的保护作用及可能机理。[方法]实验分为5组:对照组;TCDD组(终浓度20nmol/L);TP低、中、高剂量组。TP组(20nmol/LTCDD+终浓度分别为5、10、25mg/L的茶多酚)。分别给药处理后,测定超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)的活性。[结果]与TCDD组相比,5mg/L和10mg/LTP使细胞的生存率由59.74%上升到65.5%和80.0%,给予TCDD后SOD、GSH-Px活性降低与对照组比较差异有统计学意义;TCDD+低、中剂量TP组SOD及GSH-Px值高于TCDD组(P﹤0.05),而MDA的含量降低;但TP剂量(25mg/L)再增加时其拮抗作用不明显。[结论]TP在一定程度上缓解TCDD所致的肝损伤,其可能机制可能与抗氧化功能有关。

[ Objective ] To study the protective effects of tea polyphenols （TP） on liver damage caused by TCDD and its possible mechanism. [Methods] Mice were divided into five groups randomly, control group, TCDD group, TCDD plus highdose TP group, TCDD plus middle-dose TP group and TCDD plus low-dose TP group. Livers in low. middle and high dose TP group were respectively stimulated by three different concentrations of TP （5. 10 and 25mg/L）. After treatment, activities of superoxide dismutase （SOD） and catalase （CAT）, MDA and glutathione peroxidase （GSH-Px） were determined. [Results] Comparing with TCDD group, the L-02 cell survival rates in 5 and 10 mg/L TP groups increased from 59.74% to 65.5% and 80.0% respectively. The levels of SOD, GSH, CAT increased, the level of MDA decreased. Activities of SOD and GSH-Px in TCDD group were significantly lower than those in controls ; activities of SOD and GSH-Px in TCDD plus low. middle-dose TP groups were significantly higher than those in TCDD group （P 〈 0.05 ） ; but when TP dose reincreasmg, the antagonistic action was not obvious in 25 mg/L TP group. [Conclusion] TP could alleviate liver damage caused by TCDD in certain extent, with a possible mechanism of antioxidation.