茶多酚对铅脂质过氧化损伤拮抗作用的研究

目的 探究茶多酚（TP）对铅（Pb）致细胞脂质过氧化损伤的拮抗作用。方法 Wistar雄性大鼠60只随机分为6组，分别给予0、50、100、300mg/kg不同浓度TP灌胃、第6、8、10天分别给予乙酸铅40mg/kg腹腔注射，对照组给予蒸馏水灌胃，腹腔注射生理水。第11日眶静脉采血，继续TP灌胃1周后处死动物，取股动－静脉混合血、肝、脑组织实验。结果 （1）单纯染铅组大鼠体重较非染铅组明显降低，差异有显著性（P＜0．05），而同时予TP100、300mg/kg灌胃可明显拮抗铅对大鼠生长抑制，末次染铅24h、1周的大鼠体重与TP相关系数为r＝0．973（P＜0．01）和r＝0．9979（P＜0．01），呈正相关。（2）末次染铅24h、1周的染铅大鼠较非染铅大鼠血、肝、脑丙二醛（MDA）含量明显升高，差异有显著性（P＜0．05）；超氧化物歧化酶（SOD）活力抑制，差异有显著性（P＜0．05），TP100、300mg/kg灌胃可拮抗铅的上述作用；同时染铅大鼠血、肝、脑谷胱甘肽（GSH)水平、谷胱甘肽－S－转移酶（GST）活力亦发生明显改变，而TP100、300mg/kg灌胃可拮抗铅的作用。结论 TP可明显拮抗铅致大鼠血、肝、脑脂质过氧化损伤而具有防治、拮抗铅中毒的重要功能。

Antagonism of tea polyphenols on lead-induced lipid peroxidation

Objective To investigate the antagonism of green tea polyphenols(TP) on lead induced lipid peroxidation. Methods 60 male Wistar rats were given TP(0,50,100,300 mg/kg) orally for 18 days.Meanwhile,lead acetate(40 mg/kg,for 3 times) were injected( i.p. ) on the 6th,8th,10th day,and saline for the control group.On the 11th day,the blood from orbit vein was used to determine malonaldehyde(MDA),the activities of superoxide(SOD),glutathione s tranferase(GST) and the contents of glutathione(GSH).All rats were raised as above,and were killed a week later.The samples of blood,liver and brain were taken for test. Results (1)There was a significant difference between the body weight of the lead treated rats and that of the control group( P <0.05) after 24 hours or 1 week after lead treatment,and there was significant positive correlation between the body weight of lead treated control and TP groups, r =0.973( P <0.01) and r =0.998( P <0.01) respectively.(2)After 24 hours or 1 week of the lead treatment,MDA in the blood,liver,brain of lead treated rats were significantly higher( P <0.05) and SOD activities were significantly lower( P <0.05) than those in the control group respectively,but TP 100,300 mg/kg taken had protective roles against lead poisonous effects.Meanwhile,lead influenced the level of GSH and the activities of GST in the blood,liver,brain of the rats,and TP 100,300 mg/kg taken had protective roles against lead effects on GSH and GST. Conclusion TP may play an important role in chemoprotective effect on lead induced lipid peroxidation.