Antidiabetic and Hepatoprotective Effects of Psidium guajava L Fruit Puree on Alloxan-induced Diabetes in Wistar Rats

Abstract

Psidium guajava L. (fam. Myrtaceae) is a semi-deciduous tree endemic to tropical and subtropical areas. The leaves, roots and bark have long been used for folkloric and medicinal purposes such as in the treatment of hypertension, fever, toothache and diarrhoea. The purpose of this study was to evaluate the antidiabetic and hepatoprotective effects of Psidium guajava fruits in alloxan-induced diabetic rats. Fresh guava fruits were chopped and blended into a smooth paste (purée). The purée was weighed, dissolved in freshly prepared normal saline in appropriate stock concentrations and used in a 21-day treatment. Acute toxicity studies of the fruit purée conducted in mice showed no toxicity up to 5000 mg/kg. Experimental animals were acclimatized for 7 days while diabetes was induced using alloxan monohydrate (150 mg/kg) intra-peritoneally. After a 21-day treatment of diabetic rats with 200 and 400 mg/kg of Psidium guajava fruit purée, the fasting and random blood glucose levels decreased significantly (p < 0.05) relative to that of the diabetic control. Also, there was a significant reduction in serum aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase levels of rats treated with 200 and 400 mg/kg of Psidium guajava fruit purée compared to the diabetic control. Thus, it could be inferred that Psidium guajava fruit purée is safe at high doses, suppresses hyperglycemia and protects the liver by decreasing lipid peroxidation and improve antioxidant status in alloxan-induced diabetic rats. These results provide the scientific evidence for its use as a nutraceutical agent in the management of diabetes and hepatotoxicity.