茶多酚抗高尿酸血症的实验研究

THE EXPERIMENTAL STUDY ON EFFECTS OF TEA POLYPHENOLS AGAINST HYPERURICEMIA IN RATS

目的观察茶多酚(TP)对高尿酸血症大鼠体内尿酸水平的影响,探讨其降低血尿酸作用的可能机制。方法取雄性SD大鼠30只,分为空白对照、高尿酸血症模型、TP低、中、高剂量5组,每组6只。对模型组及TP干预组大鼠灌胃给以15 g/kg·d酵母膏、200 mg/kg·d腺嘌呤及30 mg/kg·d氧嗪酸钾联合造模30d;TP干预组在造模10d后灌胃给予TP,连续20d,剂量分别为100、200、300 mg/kg·d,模型组继续灌胃造模剂,空白组灌胃等量生理盐水。实验结束时,测定血液和尿液中的尿酸(UA)、肌酐(Cr)及尿素氮(UN)含量,检测肝脏和血清中的黄嘌呤氧化酶(XOD)活性以及尿酸排泄分数(FEUA)。结果模型组血尿酸水平较空白对照组明显升高(P<0.01),TP干预组血尿酸水平较模型组明显降低(均P<0.01);各组尿酸浓度及24h尿酸排泄量均无显著性差异(均P>0.05);模型组肝脏XOD活性明显高于空白对照组(P<0.01),TP低剂量组显著低于模型组(P<0.05);TP中剂量组FEUA较空白对照组和模型组相比,显著升高(P<0.005)。结论 TP能降低酵母膏、腺嘌呤和氧嗪酸钾联合诱导的高尿酸血症大鼠血尿酸水平,其作用机制可能与抑制肝脏XOD活性有关。

Objective To observe the effect of tea polyphenols on uric acid level in hyperuricemic rats, and to explore the possible mechanism. Methods Male SD rats were divided into normal control group, hyperuricemic model group and low dose, medium dose, high dose of tea polyphenols groups. The rats of model group and tea polyphenols groups were administered intragastrically with yeast 15g/（kg·d）, adenine 200 mg/（kg·d） and Oxonic 30mg/（kg·d） for 30 days to establish the model of hyperuricemia. From the 10th day after modeling, the tea polyphenols groups were treated with 100, 200, 300 mg/（kg·d） of tea polyphenols by oral gavage for 20 days. The model and control groups were continually treated with modeling agent and saline, respectively. At the end of the experiment, biochemical parameters including uric acid （UA）, urine nitrogen （UN） and creatinine （Cr） were tested. Meanwhile, the activity of xanthine oxidase （XOD） in liver and serum as well as FEUA were evaluated. Results The blood uric acid level of rats in model group was significantly higher than those of the controls （P〈0.01）. The blood uric acid level in all TP groups was significantly lower than those of the model group （all P〈0.01）. There was no significant difference in urine uric acid level among different groups （all P〉0.05）. The activity of XOD in liver in model group was significantly higher than those of the controls （P〈0.01）, and lower in low dose group than those of the model group （P〈0.05）. The FEUA level of rats in medium group was higher than those of the controls and models （P〈0.005）. Conclusion Tea polyphenols reduce blood uric acid level in rats with hyperuricemia and the related mechanism may be associated with its inhibition on the activity of XOD in liver.