BIOSYNTHESIS OF SILVER NANOPARTICLE USING PSIDIUM GUJAVA LEAF EXTRACT AND SCREENING OF ITS ANTIDIBETICS ACTIVITY

Objective: Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia and associated complications affecting multiple organs. Psidium guajava L. (family Myrtaceae) has been traditionally used in the management of diabetes in various parts of India. The present study aimed to evaluate the antidiabetic potential of aqueous leaf extract and biosynthesized silver nanoparticles of Psidium guajava in streptozotocin-induced diabetic rats. Methods: Experimental diabetes was induced in overnight-fasted Wistar rats by a single intraperitoneal injection of streptozotocin (55 mg/kg) prepared in 0.1 M citrate buffer (pH 4.5). After 72 hours, rats with fasting blood glucose levels ≥200 mg/dL were selected for the study. Diabetic rats were treated orally for 21 days with Psidium guajava aqueous extract (200 and 300 mg/kg), Psidium guajava silver nanoparticles (200 and 300 mg/kg), and metformin (100 mg/kg) as the standard drug. Blood glucose levels, lipid profile parameters, and body weight changes were evaluated. Results: Treatment with Psidium guajava extract and its silver nanoparticles significantly reduced blood glucose levels in diabetic rats in a dose-dependent manner. Both treatments also improved lipid profile by reducing serum triglycerides, total cholesterol, LDL, and VLDL while increasing HDL levels. Additionally, treatment prevented diabetes-induced body weight loss. The nanoparticle formulation exhibited greater antidiabetic efficacy compared to the aqueous extract and showed effects comparable to metformin. Conclusion: The findings indicate that Psidium guajava possesses significant dose-dependent antihyperglycemic and hypolipidemic activity. Biosynthesized silver nanoparticles demonstrated enhanced therapeutic efficacy compared to crude extract. These results support the traditional use of Psidium guajava in diabetes management and suggest its potential as a promising natural antidiabetic agent. KEYWORDS: Psidium guajava, silver nanoparticles, diabetes mellitus, streptozotocin, antihyperglycemic activity, lipid profile.