茶多酚对染铅大鼠肝脏的保护作用

摘要

目的 探讨茶多酚对染铅大鼠肝脏的保护作用.方法 SD大鼠40只,随机分成正常对照组,模型组,茶多酚高、中、低剂量组,每组8只.正常对照组给予去离子水1.0 mL腹腔注射,其余4组腹腔注射醋酸铅15 mg·kg-1,每日1次,连续10d;给予腹腔注射醋酸铅当天,空白对照组及模型组灌胃0.9％氯化钠溶液,茶多酚组高、中、低剂量组分别灌胃给予茶多酚2.0,1.0,0.5 g·kg-1,连续30 d.测定血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)及肝匀浆超氧化物歧化酶(SOD)、丙二醛(MDA)评价茶多酚对染铅大鼠肝脏的保护作用.结果 正常对照组,模型组,茶多酚高、中、低剂量组ALT分别为(52±7),(245±32),(139±47),(158±67),(240±28)U·L-1；AST分别为(45±8),(256±35),(147±53),(174±23),(236±32)U· L-1;SOD分别为(120±13),(33±9),(89±28),(79±24),(67±15)U·mg-1,MDA分别为(2.6±0.7),(10.5±1.6),(3.6±1.2),(5.3±1.5),(9.5±1.2)mmol·mg-1.与正常对照组比较,模型组ALT、AST显著升高(P＜0.01)；与模型组比较,茶多酚高、中剂量组ALT、AST显著降低(P＜0.01),低剂量组无明显降低作用.与空白对照组比较,模型组肝匀浆SOD显著降低、MDA显著升高(P＜0.01)；与模型组比较,茶多酚高、中剂量组肝匀浆SOD显著升高,MDA显著降低(P＜0.01),低剂量组SOD活性显著升高(P＜0.01),但MDA清除不明显.结论 茶多酚具有一定的肝脏保护作用,其作用机制可能与提高过氧化物酶活性、清除过氧化产物从而保护细胞膜有关.%Objective To investigate the protective effect of tea polyphenols on liver of rats exposed to lead. Methods Forty SD rats were randomly divided into the normal control ( NG), model control (CG) , high-dose ( HG) , middle-dose (MG) and low-dose of tea polyphenols groups ( LN) , 8 rats in each group. The rats in the NG were given with intraperitoneal injection of 1. 0 mL deionized water, those in the others were intraperitoneally injected with lead acetate 15 mg·kg-1 , once a day for consecutively 10 days; meanwhile, rats in the NG and CG were treated with 0. 9% NaCl, and those in the HG, MG, LG were orally administered with 2.0, 1.0, 0.5 g·kg-1 tea polyphenols for 30 consecutive days, respectively. The serum ALT, AST and liver SOD, MDA were determined to assess the liver protection of tea polyphenols for rats exposed to lead. Results ALT of NG, CG, HG, MG, LG were (52±7) ,(245±32), (139+47), (158+67), (240±28) U·L-1, respectively; AST were (45±8), (256±35), (147±53) ,(174±23), (236±32) U ·L-1.respectively; SOD were (120±13), (33±9), (89±28), (79±24), (67+15) U·mg-1 .respectively; MDA were (2.6±0.7), (10.5±1.6), (3.6±1.2), (5.3± 1.5) ,(9.5±1.2) nmol·mg-1, respectively. Compared with those in NG, ALT, AST and liver MDA of CG were significantly increased, while liver SOD significantly reduced (P<0. 01 ) ; the ALT, AST and liver MDA in HG and MG were significantly lower ( P<0.01), but the liver SOD was significantly higher than those in CG ( P<0. 01). While the LG significantly increased SOD activity (P<0. 01) , but didn't obviously clear liver MDA. Conclusion Tea polyphenols showed liver protective effect, the mechanism of which might be related to enhancing peroxidase activity and scavenging free radicals.