抄録
We studied the effects of Maccha and alcohol extracts of Maccha and Mate tea in streptozotocin (STZ)-induced diabetic rats. By the continuous feeding of these substances prior to STZ administration, the elevations of urinary glucose excretion and fasting blood sugar were suppressed, suggesting alleviation of diabetic manifestations. At the same time, the increase in serum lipids, which is a sign of complications in diabetes, was also suppressed; and the concentrations of serum and liver thiobarbituric acid-reactive substance (TBARS) were significantly decreased. The decrease in liver NAD was also suppressed, indicating alleviation 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. These results suggest that antioxidant components such as the catechins contained in the tested tea leaves act to scavenge STZ-induced radicals and thereby alleviate the disorders caused by oxidation in the body attributable to the formation of radicals.
