Yang T T, Koo M W
Department of Pharmacology, Faculty of Medicine, University of Hong Kong, Hong Kong.
Pharmacol Res. 1997 Jun;35(6):505-12. doi: 10.1006/phrs.1997.0176.
Chinese teas with different degrees of fermentation were examined for their effect on diet-induced hypercholesterolemia in rats. The teas tested were Chinese Green tea, Jasmine, Iron Buddha, Oolong and Pu erh. Hypercholesterolemia was induced by feeding rats with a cholesterol-enriched diet for 1 week. They were then treated with different tea extracts together with a cholesterol-enriched diet for another 8 weeks. Chinese Green tea and Jasmine tea, both with a minimum degree of fermentation, were found to have significant serum and liver cholesterol lowering effects. They also reduced the increase in liver weight due to lipid deposition. All tea treatments lowered the atherogenic index and increased the HDL-total cholesterol ratio, while HDL-cholesterol and triglyceride levels were not significantly affected. Analysis of catechin levels in tea extracts showed that the individual catechin component in Chinese Green tea and Jasmine tea were significantly higher than the others. (-)-Epicatechin gallate and (-)-epigallocatechin gallate in the tea extracts may account for their hypocholesterolemic effect.
研究了不同发酵程度的中国茶对大鼠饮食诱导的高胆固醇血症的影响。所测试的茶有中国绿茶、茉莉花茶、铁观音、乌龙茶和普洱茶。通过给大鼠喂食富含胆固醇的饮食1周来诱导高胆固醇血症。然后，它们再用不同的茶提取物与富含胆固醇的饮食一起处理8周。发现发酵程度最低的中国绿茶和茉莉花茶具有显著降低血清和肝脏胆固醇的作用。它们还减少了由于脂质沉积导致的肝脏重量增加。所有茶处理均降低了动脉粥样硬化指数并提高了高密度脂蛋白与总胆固醇的比率，而高密度脂蛋白胆固醇和甘油三酯水平未受到显著影响。对茶提取物中儿茶素水平的分析表明，中国绿茶和茉莉花茶中的单个儿茶素成分明显高于其他茶。茶提取物中的（-）-表儿茶素没食子酸酯和（-）-表没食子儿茶素没食子酸酯可能是它们降胆固醇作用的原因。
