Glycaemic evaluation of Psidium guajava']java in rats

Background & objectives: Many plant polysaccharides exhibit hypoglycaemic effect. Though the fruit of Psidium guajava is known to contain free sugars, the fruit extract showed hypoglycaemic effect in alloxan treated mice and human subjects. The present study was aimed to determine the glycaemic potential of R guajava fruit peel extract on blood glucose level (BGL) of normal and streptozotocin-induced sub-diabetic rats during fasting blood glucose (FBG) and glucose tolerance test (GTT). Methods: Female albino Wistar rats (n=42) were divided into seven equal groups, and were given different doses of fruit peel extract. Diabetes was induced by streptozotocin injection (ip) at a dose of 45 mg/kg body weight. Blood glucose levels were measured after collecting the blood from tail veins. Results: The diabetic and sub-diabetic models showed hyperglycaemic effect from a single oral administration of variable doses of P guajava fruit peel extract. The maximum rise of 26.51 per cent was observed in BGL from a dose of 400 mg/kg bw exactly after 8 h of administration in normal rats whereas the maximum rise of 90.7 per cent was observed with the same dose of 400 mg/kg bw after 2 h of glucose administration in sub-diabetic rats. Interpretation & conclusion: The hyperglycaemic effect of E guajava fruit peel suggests that the diabetic patients should peel off the guava fruits before consuming. However, it can also be useful in controlling hypoglycaemia occasionally caused due to excess of insulin and other hypoglycaemic drugs.