HYPOGLYCAEMIC ACTIVITY OF VERNONIA AMYGDALINA (DEL.) EXTRACTS IN NORMAL AND ALLOXAN-INDUCED RATS
Vernonia amygdalina (Del.) is widely cultivated in tropical Africa and known for its bitter principles. The extracts of this plant are used in folklore medicine to treat fevers, measles, tuberculosis, toothaches, parasitic infections, asthma, diarrhoea and in managing diabetes mellitus. The growing concerns arising from the treatment and management of the diabetes prompted this study. Hence, the hypoglycaemic potentials of leaf, stem and root (squeezed and methanolic) extracts of the plant were investigated in normo-glycaemic and alloxan-induced rats. The blood glucose levels in normal and diabetic rats were determined after the administration of 300mg/kg of extract and 150mg/kg of alloxan monohydrate at time (t) = 0, 1, 2 and 4 h. The hypoglycaemic activities of the squeezed extracts of leaves, stem and roots were not significant in both normal and diabetic rats. However, the methanolic extracts of the leaves and roots demonstrated significantly remarkable hypoglycaemic activities compared with the activity given by the stem extract. The methanolic extracts of leaves and root have shown to be effective in lowering blood glucose level (80% reduction after 4h) while the stem afforded a poorly 20% reduction after 4 h. The results from this study have lent scientific credence to the ethnobotanical use of the plant in the treatment and management of diabetes mellitus. However, the claims that the stem is as effective in the herbal therapy of this metabolic disease can not be supported by the results obtained from this study.