4种茶叶水提物的利尿作用

Diuretic effect of four tea water extracts

目的比较研究绿茶、乌龙茶、红茶和普洱茶水提物的利尿作用。方法分别灌胃给予生理盐水负荷大鼠0.5 g.kg-1和1.0 g.kg-1剂量的4种茶叶水提物,测定大鼠4 h尿量及尿液中Na+、K+排泄量。结果与模型对照组比较,4种茶叶水提物均能使大鼠4 h尿量及尿液中Na+排泄量显著增加,但对尿液中K+排泄量的影响则有所不同,其中乌龙茶和红茶水提物均能使大鼠尿液中K+排泄量显著增加,而绿茶和普洱茶水提物对尿液中K+排泄量无显著性影响。结论 4种茶叶水提物均有明显的利尿作用,其中普洱茶的利尿作用与氢氯噻嗪相当,但对尿液中K+排泄量无显著性影响,可避免噻嗪类利尿药常见副作用—低钾血症的发生,是一种具有较好利尿功能的健康茶饮。

Objective To comparatively study the diuretic effect of the water extracts of green tea, oolong tea,black tea and Pu＇er tea. Methods Four teas water extracts at the doses of 0. 5 g .kg-1 and 1.0 g.kg-1 were orally administered to saline-loaded rats, the urinary volume during four hours and the excretion of sodium and potassium in the urine were measured. Results Four tea water extracts resulted in a significant increase in urine volume of four hours and urinary sodium excretion. And they were different in urinary potas- sium excretion, the water extracts of oolong and black tea resulted in a significant increase in urinary potassium excretion,but the water extracts of green tea and pu＇er tea had no significant influence on urinary potassium excretion compared with model group. Conclusions Four tea water extracts show significant diuretic effects. Among them, the diuretic effect of pu＇er tea is equivalent to that of hydrochlorothiazide, but without significant influence on the urinary potassium excretion. Thus, drinking of pu＇er tea could avoid the occurrence of low postassemia that is a common side effect of thiazide diuretic agents. As a result,pu＇er tea is a healthy tea drink with a prefect diuretic effect.