Abstract
Japanese green tea leaves were successively extracted by refluxing with the following solvents; n-hexane, benzene, benzene, ether, chloroform, acetone, ethanol, 60% ethanol in water and hot water. We examined the effect of an intravenous administration of these green tea extracts on the arterial blood pressure of rabbits. The hypotensive activity was found both in alcoholic extract and in hot water extract. When the hot water extract was administered in a dose of 20 mg/kg body weight, the arterial blood pressure was depressed by 35 to 45 mmHg. Gel filtration chromatography of the extract on the column of Sephadex G-50 demonstrated that the active substance existed in a fraction of high molecular weight.
