Synergistic Blood Sugar Lowering Effect of the Combined Leaf Extract of Vernonia amygdalina (Del), Telfairia occidentalis and Ocimum gratissimum in Alloxan Induced Diabetic Rats

Abstract

Background: The incidence of diabetes mellitus is reportedly on the rise, especially in developing countries, and it is estimated that these countries will witness a 69% increase between 2010 and 2030. A high cost of medical care of diabetes is forcing an increasing number of people into the use of herbal alternatives for cure. In particular, polyherbal strategies of diabetic management are being canvassed as offering better prospects for maximal therapeutic effect and minimum adverse effects. We therefore assessed the effect of a cocktail of Vernonia amygdalina, Telfairia occidentalis and Ocimum gratissimum on blood sugar in diabetic rats. Materials and Methods: Eighty (80) male adult wistar rats weighing 80-150g were divided into four equal groups (A, B, C and D) and rendered diabetic by intraperitoneal administration of alloxan 150 mg/kg (Sigma St. Louis, MO, USA). Each group of diabetic rats was further divided into four sub-groups of five rats each and treated with Vernonia amygdalina, Telfairia occidentalis, Ocimum gratissimum and a combination of all three extracts respectively. Sub-groups 1, 2 and 3 were administered 10 mg/kg, 50 mg/kg and 500 mg/kg of the corresponding extract, while sub-group 4 rats of every group received distilled water and served as control. All administrations were given intraperitoneally and 12 hour post-treatment blood glucose levels determination undertaken. Results: The leave extracts of Vernonia amygdalina, Telfairia occidentalis and Ocimum gratisimum each possessed significant blood sugar lowering activity in diabetic rats, for all dosage levels. In combination, they produced a synergistic blood sugar lowering effect relative to each constituting part.Conclusion: Vernonia amygdalina, Telfairia occidentalis and Ocimum gratissimum are each effective in causing hypoglyceamia singly and in combination. Their synergistic interplay may hold the potential for a more cost-effective approach to human diabetic management in resource constrained settings as Nigeria.

Keywords: Vernonia amygdalina, Telfairia occidentalis, Ocimum gratissum, diabetes mellitus, polyherbalism, synergistic effect.