Evaluation of antidiabetic and antioxidant activity of Moringa oleifera in experimental diabetes

Moringa oleifera, a widely cultivated species in India, is an exceptionally nutritious vegetable with a variety of potential uses in treating rheumatism, venomous bites, and microbial infections. In the present study, we investigated the antidiabetic and antioxidant effects of methanol extracts of M. oleifera pods (MOMtE) in streptozotocin (STZ)-induced diabetic albino rats.

Diabetic rats were treated with 150 or 300 mg/kg MOMtE for 21 days and the antidiabetic effects of the extract were evaluated by measuring changes in biochemical parameters in the serum and pancreatic tissue. Two phytoconstituents, namely quercetin and kaempferol, were isolated from the MOMtE extract and their structures were determined using nuclear magnetic resonance and infrared spectroscopy.

The progression of diabetes was significantly reduced after MOMtE treatment. In treated rats, both doses of MOMtE induced a significant reduction in serum glucose and nitric oxide, with concomitant increases in serum insulin and protein levels. Furthermore, MOMtE treatment increased antioxidant levels in pancreatic tissue, with concomitant decreases in levels of thiobarbituric acid-reactive substances. Histologic examination of the pancreas from diabetic rats showed degenerative changes in β-cells; MOMtE treatment significantly reversed the histoarchitectural damage to the islets cells.

In conclusion, M. oleifera exerts protective effects against STZ-induced diabetes. The MOMtE exhibited significant antidiabetic and antioxidant activity and active constituents may be isolated from the extract for evaluation in future clinical studies.