绿茶对微囊藻毒素诱导肝肾氧化损伤的拮抗效应

Antagonism effects of green tea against microcystin induced oxidant damage on liver and kidney

目的探究绿茶对微囊藻毒素 LR(MC-LR)诱导肝肾氧化损伤的拮抗效应。方法 40只雄性小鼠分为空白对照组、MC-LR 染毒组(MC-LR)、绿茶低剂量拮抗组(MC-LR+绿茶2)、绿茶高剂量拮抗组(MC-LR+绿茶12)共4组,实验第1天起 MC-LR+绿茶2、MC-LR+绿茶12组即每日给予2 g/L 和12 g/L 的绿茶自由饮用,连续18 d。自第6天开始,MC-LR、MC-LR+绿茶2、MC-LR+绿茶12组均每日给予 MC-LR 10 μg/kg 腹腔注射1次,空白对照组给予二甲砜腹腔注射,连续13 d。第19天眶静脉取血后处死动物,对脏器系数、血清生化指标、抗氧化酶及脂质过氧化物水平、肝肾组织病理改变等指标进行检测和分析。结果绿茶明显拮抗 MC-LR 所致小鼠体重的下降。绿茶明显拮抗 MC-LR 造成的血清丙氨酸转氨酶、天冬氨酸转氨酶和肌酐的升高。绿茶可抑制 MC-LR 致小鼠脂质过氧化物丙二醛水平的升高,较 MC-LR 染毒组 MDA 均值 13.98 nmol/ml 相比差异有统计学意义。绿茶高剂量拮抗明显升高血清谷胱甘肽及超氧化物歧化酶水平,其均值分别为467.29 mg/L 和139.22 U/ml,与空白、MC-LR 染毒组相比差异有统计学意义。给予绿茶可使 MC-LR 所致的肝肾病理损伤减轻。结论绿茶可提高抗氧化酶活性,清除体内自由基,减轻氧化损伤,从而明显拮抗 MC-LR诱导的肝肾毒性损伤。

Objective To evaluate the antagonism effects of green tea （GT） against micrecystin LR （MC-LR） induced hepatotoxicity and nephrotoxicity in mice. Methods All 40 male mice were randomly divided into four groups. Mice in group Ⅲ and IV were pretreated with green tea for free drink at doses of 2 g/L and 12 g/L prior to MC-LR intoxication, for consecutively 18 days. The toxin treatment mice were administered continually intraperitoneal injections of MC-LR at a dose of 10 μg · kg^-1 · d^-1 bw from day 6^th till sacrifice, continually 13 days. Mice were sacrificed and immediately subjected to necropsy, and the body weight, relative organ weight, serum biochemical parameters, antioxidant enzyme levels （SOD and GSH）, lipid peroxidation products （MDA） and histopathology were systematically evaluated. Results MC-LR exposure led to increase the oxidative stress and organ injury was significantly observed through biochemical parameters and microscopic evaluation. However, high dose of GT pretreatment caused a significant elevation in serum GSH and SOD levels, and a decrease of serum MDA level as compared with MC-LR control. The mean values of GSH and SOD activities were separately 467.29 mg/L and 139. 22 U/ml in group IV. Subsequently, GT pretreatment obviously diminished the serum ALT, AST and Cr activities. Those pathological damages in liver and kidney, were to a certain extent, lessened in GT pretreatment mice in correlation with the biochemical parameters. Conclusion GT might elevate antioxidant defense system, dean up free radicals, lessen oxidative damages and protect liver and kidney against MC-LR induced toxicity.