Effect of catechin on carbohydrate metabolism.

Effect of varying concentrations of catechin on blood glucose levels was examined in male rats. Catechin exerted maximum hypoglycemic action at a dose of 10 mg/kg BW/day. Above this dose, the activity decreased gradually and blood sugar returned to almost normal levels at a concentration of 100 mg/kg BW/day. At optimum dose of catechin there was increase in the hepatic glycogen levels. Incorporation of [14C] glucose into glycogen in vitro was also increased. Glycogen synthase activity was found increased significantly whereas glycogen phosphorylase showed a decrease showing that hypoglycemic effect of catechin is due to increased glycogenesis and decreased glycogenolysis.