Assessment of the antidiabetic activity of Myrcia uniflora extracts in streptozotocin diabetic rats.

Several metabolic parameters were used to determine the evolution of the diabetic state of streptozotocin diabetic rats treated with aqueous leaf extracts from Myricia uniflora, a plant widely used in northern Brazil for treatment of diabetes. The effect of the extracts on the intestinal absorption of glucose and on the evolution of diabetes of diabetic rats adapted to a high protein, carbohydrate-free diet were also investigated. Treated rats received twice a day, by gavage, during three weeks, 7.5 mg of lyophilized powder, corresponding to about 60 mg of dried leaves, prepared from percolations with boiled water, Treatment of diabetic rats fed a stock, balanced diet did not affect body weight gain but reduced the hyperglycemia, polyphagia, polydipsia, urine volume and the urinary excretion of glucose and urea. Myrcia administration for 3 weeks had no effect on the weight of epididymal and retroperitoneal adipose tissue, or on the concentrations of pancreatic and serum insulin. The intestinal absorption of glucose, measured with a perfusion technique in situ, was markedly inhibited by Myrcia (7.5 mg of lyophilized powder per ml of perfusion solution). The effects of Myrcia treatment on diabetic rats adapted to a carbohydrate-free diet were similar to those obtained in rats fed the stock diet. The data show that aqueous extracts of Myrcia has a beneficial effect on the diabetic state, mainly by improving metabolic parameters of glucose homeostasis.(ABSTRACT TRUNCATED AT 250 WORDS)