Evaluation of Anti-Diabetic Activity of the Combined Extract of Gurmar Leaves and Lemon Peel in Streptozocin Induced Diabetic Rats

Abstract

Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia resulting from defects in insulin secretion, insulin action, or both. The increasing prevalence of diabetes and the adverse effects associated with long-term use of synthetic anti-diabetic drugs have encouraged the search for safer and more effective herbal alternatives. The present study was undertaken to evaluate the anti-diabetic activity of the combined extract of Gurmar leaves (Gymnema sylvestre) and Lemon peel (Citrus limon) in streptozotocin-induced diabetic rats. The plant materials werecollected, authenticated, shade dried, and subjected to extraction using suitable solvents. Preliminary phytochemical screening of the combined extract revealed the presence of alkaloids, flavonoids, tannins, glycosides, saponins, phenolic compounds, and terpenoids, which are known to possess significant pharmacological activities. Acute oral toxicity studies were performed according to OECD guidelines and the extract was found to be safe at the selected dose levels.Experimental diabetes was induced in Wistar rats using streptozotocin (STZ). The animals were divided into different groups including normal control, diabetic control, standard drug-treated group, and extract-treated groups receiving low and high doses of the combined extract. Treatment was continued for the specified experimental period and various biochemical parameters were evaluated, including blood glucose level, body weight, lipid profile, liver function markers, and antioxidant parameters. The results demonstrated that administration of the combined extract significantly reduced blood glucose levels in diabetic rats when compared with the diabetic control group. The extract also improved body weight, restored altered lipid parameters, and showed beneficial effects on antioxidant enzyme levels. Histopathological examination of pancreatic tissue revealed partial regeneration and protection of β-cells in extract-treated groups. The anti-diabetic effect of the combined extract may be attributed to the synergistic action of bioactive phytoconstituents present in Gymnema sylvestre and Citrus limon, which possess antioxidant and pancreatic protective properties. The study concludes that the combined extract of Gurmar leaves and Lemon peel exhibits significant anti-diabetic activity in streptozotocin-induced diabetic rats and may serve as a promising natural therapeutic agent for the management of diabetes mellitus. Further studies are required to isolate the active constituents and establish the exact mechanism of action.