SOME KINDS OF TEAS SUPPRESS A SIDERATION OF DIABETES IN STREPTOZOTOCIN-ADMINISTERED RATS

We studied the effects of Maccha and alcohol extracts of Maccha and Ma te tea in streptozotocin (STZ)-induced diabetic rats. By the continuou s feeding of these substances prior to STZ administration, the elevati ons of urinary glucose excretion and fasting blood sugar were suppress ed, suggesting alleviation of diabetic manifestations. At the same tim e, the increase in serum lipids, which is a sign of complications in d iabetes, was also suppressed; and the concentrations of serum and live r thiobarbituric acid-reactive substance (TEARS) were significantly de creased. The decrease in liver NAD was also suppressed, indicating all eviation of disorders caused by oxidation in the body. The serum uric acid level, which is assumed to elevate in diabetes to compensate for the disorders attributable to oxidation, was significantly lowered. Th ese results suggest that antioxidant components such as the catechins contained in the tested tea leaves act to scavenge STZ-induced radical s and thereby alleviate the disorders caused by oxidation in the body attributable to the formation of radicals.