Antidiabetic activity of alcoholic stem extract of Nervilia plicata in streptozotocin-nicotinamide induced type 2 diabetic rats

Ethnopharmacological relevance: Nervilia plicata (Orchidaceae) has long been used in the antidiabetic medicinal preparations of traditional healers of Wayanad (Kerala), but recuperative potential of the plant was remained undefined. We demonstrated the regenerative potential of the plant extract on kidney affected by type 2 diabetes besides lowering blood glucose. Aim of the study: The aim of the current study was to investigate the recuperative and regenerative potential of alcoholic stem extract of Nervilia plicata on streptozotocin-nicotinamide induced type 2 diabetic models. Materials and methods: Non insulin dependent diabetes mellitus (NIDDM) was induced in overnight fasted rats by intramuscular injection (IMI) of 60 mg/kg STZ and 120 mg/kg of nicotinamide after 5 min interval. Blood glucose was assessed by a glucometer, serum urea and creatinine levels were determined by diacetylmonooxime method and Jaffe reaction respectively. Kidney sections were taken and stained with Masson's tri-dye and Periodic Acid Schiff (PAS) and examined for structural changes. Also lipid peroxidation product (LPP) levels were determined as thio barbituric acid reactive substance levels (TBARS) method. Results: On administration of 5 mg/kg of plant extract, blood glucose levels of the NIDDM rats showed 62.00 and 76.29% decrease in the blood glucose levels on day 0 and day 30 respectively. Damages caused to the kidney tissue were negligible or not seen. Serum urea and creatinine levels showed 6149 and 70.96% decrease on day 30. LPP levels of kidney and pancreas showed 70.58 and 77.41% decrease respectively. Conclusion: These results demonstrate significant antidiabetic and regenerative potential of the Nervilia plicata, justifying the use of plant in the indigenous system of medicine. Isolation and characterisation of the compound(s) playing pivotal role in the cure would open new vistas in the therapy of type 2 diabetes. (C) 2010 Elsevier Ireland Ltd. All rights reserved.