| 摘要 |
PURPOSE:To obtain a therapeutic agent for diabetic complications such as diabetic cataract or diabetic neuropathy by using an extract having inhibiting activities against aldose reductases. CONSTITUTION:This inhibitor of aldose reductases contains an extracted fraction of black tea prepared as follows as an active ingredient: The extract fraction of the black tea is obtained by extracting the black tea with water, separating the resultant extract according to reversed phase liquid chromatography and freeze-drying three fractions [A, B and C, respectively at (0.62-0.67), (1.40-1.46) and (1.51-1.57) ratio of holding times to caffeine] other than epicatechin. Thereby, the extract having the inhibiting activities against the aldose reductases equal to or higher than those of a thioxothiazolidineacetic acid derivative which is a control compound is obtained. |
