Hypoglycemic activity of Lagerstroemia speciosa L. extract on streptozotocin-induced diabetic rat: Underlying mechanism of action

The hypoglycemic effect of Lagerstroemia speciosa L. leaves hot water extract on chemically induced diabetes in rat was investigated. Experimental result showed that, streptozotocin significantly (p<0.001) elevated the normal blood sugar level whereas treatment with hot water extract depressed the streptozotocin-induced high blood sugar level about 43.20% as compare to diabetic controls. Treatment with hot water extract increased the activity of shunt enzyme glucose–6-phosphate dehydrogenase (33.81%) and glutathione level (31.25%) and depression of the activity of hepatic gluconeogenic enzymes glucose-6-phasphatase (31.63%) and fructose–1,6-bisphosphatase (27.40%). These studies thus strongly suggest that the hot water extract of L. speciosa leave attributed its prominent hypoglycemic activity on experimental diabetic rats through suppression of gluconeogenesis and stimulation of glucose oxidation using the pentose phosphate pathway.