Comparative Effects of Three Herbs and Standard Hypoglycaemic Agents on Blood Glucose in Normoglycaemic, Hyperglycaemic and Alloxan-Induced Diabetic Male Rats

Background: The prevalence of diabetes mellitus has risen exponentially in the last decade and an increasing number of people are using herbal supplements. Objective: We aimed to assess the relative efficacy of three promising herbs as potentially emerging alternative/adjunct treatment for diabetes. Materials and Methods: One hundred and ninety-two male Sprague-Dawley rats were used. A third of the animals were randomly rendered diabetic with alloxan (150 mg/kg), another third injected 50% dextrose (5 g/kg); and the last third constituted the controls. The rats were variously administered aqueous leaf extract of Momordica foetida (500 mg/kg), Vernonia amygdalina (500 mg/kg) and Tapinanthus butungii (500 mg/kg), glibenclamide (5 mg/kg) chlorpropamide (250 mg/kg), and human insulin lente (0.1 I.U./kg). Results: Extract of Momordica foetida caused maximal anti-diabetic effect in six hours, Vernonia amygdalina ten hours, while Tapinanthus butungii continued to cause reduction after ten hours. The three extracts caused greater blood glucose reductions than glibenclamide in the diabetic rats, while exhibiting comparable effects with chlorpropamide and insulin. Conclusions: Tapinanthus butungii is more effective in lowering blood glucose than Momordica foetida and Vernonia amygdalina in alloxan-induced diabetic rats. Leaf extract of Momordica foetida should be useful in rapidly lowering blood glucose, while that of Tapinanthus butungii in situations that require more subtle reductions and in conditions in which prolonged hypoglycaemic actions are desirable.