Antidiabetic effect of Neopicrorrhiza scrophulariiflora on type 2 diabetic model rats

Abstract

Introduction: Neopicrorrhiza srophulariiflora (NS), which is locally known as “kutki / katuki” in Nepali is available at 3500-4800 m, east to west Himalayan region of Nepal. It is being used as indigenous antidiabetic plant in Nepal by the local people in the treatment of diabetes. The present study was carried out to evaluate the antidiabetic property of NS in streptozotocin (STZ) induced type 2 diabetic model rats.

Methods: NS dried rhizomes, collected from mountainous region of Nepal, was extracted with 80% ethanol and water by cold percolation method. The extracts were administered at a dose of 1.25gkg1 body weight for 21 consecutive days to type 2 diabetic male Long-Evans rats, bred at BIRDEM animal house. Type 2 diabetes was induced by a single intraperitoneal injection of STZ to 48 hour old pups (Long Evans) from BIRDEM Animal house. Serum glucose was estimated by GOD POP method, on 0 day and by decapitation on 21st day by tail tip method.

Results: Ethanol extract of N. srophulariiflora significantly (p<0.05) improved oral glucose tolerance in type 2 rats in comparison to control group at the end of the study period. It was also found that the water extract and ethanol extracts significantly lowered serum glucose level of type 2 diabetic rats in both prandial states (simultaneously with oral glucose load p><0.05; at 75min and 30 minutes prior to oral glucose load p><0.05; at 105min) compared to water fed control group. Administration of Glibenclamide (5 mgkg-1) also produced significant reduction (p><0.01) in serum glucose concentration in type 2 diabetic rats.

Conclusions: N. srophulariiflora is beneficial for treating Type 2 diabetes and therefore merits further exploration and researches both chemically and biologically to identify the active principle(s) and mechanism of action.