Effect of maerua subcordata (Gilg) DeWolf extracts on blood glucose level in rodents

Background: Maerua subcordata is used as a herbal medicine for the management of diabetes, among others. This study aimed to evaluate the safety and effects on blood glucose level (BGL) of M. subcordata extracts using a rodent model. Methods: The leaf and root extracts were first evaluated using STZ-induced diabetic Swiss albino mice at doses of 250 and 500 mg/kg body weight. Then the fruit, leaf, root and seed extracts were studied using normoglycemic, glucose-challenged, and STZ-nicotinamide induced diabetic SD rats at a dose of 300 mg/kg body weight. Results: acute toxicity studies at 2g/kg revealed no obvious toxicity signs. Leaf extract exhibited a considerable fasting BGL-lowering effect in normoglycemic, glucose-challenged, and STZ-nicotinamide induced diabetic SD rats and STZ-induced diabetic mice that were comparable to glibenclamide and metformin. The root extract enhanced BGL in normoglycemic and glucose-challenged rats but displayed milder anti-diabetic activity in STZ-nicotinamide induced diabetic rats and appreciable anti-diabetic activity in STZ-induced diabetic mice, with the lower dose showing higher activity. The fruit and seed extracts enhanced glycaemia in normoglycemic but controlled glycaemia in glucose-challenged rats, implying these extracts may control postprandial hyperglycemia. Conclusion: M. subcordata leaf extract revealed significant and dose-dependent glycaemia-lowering effect in different rodent models, while the root extract showed inconsistent antidiabetic activity, both in terms of dose and rodent type. The fruit and seed extracts showed postprandial hyperglycemia-controlling potential. Accordingly, verified, optimised, and standardized botanical preparation may be suggested, expecting potential health benefits, including the management of diabetes.