Abstract
Antidiabetic activity of Vernonia amygdalina and its possible synergism with glibenclamide was checked. Forty-eight rats were used for the research, for hypoglycermic study of V. amygdalina alone, they were grouped into five of six rats each. Group 1 was the negative control and was administered distilled water orally. Groups 2, 3, and 4 were the treatment groups which received 100, 200 and 300 mg/kg body weight of the V. amygdalina extract respectively orally by intubation. Group 5 was the positive control group which received a known antidiabetic drug, glibenclamide. Diabetes was induced with alloxan. For the synergism study, another 18 rats grouped into 3 of six rats each was used. Both groups of glibenclamide only and glibenclamide plus V. amygdalina extract were dosed for 14 days orally by intubation, thereafter were sacrificed and blood collected from the heart for analysis. There were 5 replicates grouped by weight throughout the study and both single and synergistic studies had the same controls. The effect of V. amygdalina extract was checked on blood glucose and its possible synergism with glibenclamide. All results in treatment groups were compared with the normal control at statistical confidence of p<0.05. The result shows that V. amygdalina extract reduced blood glucose levels in the test groups as the dose of extract increased. Combination of V. amygdalina with glibenclamide demonstrated a further reduction in blood glucose levels in the treatment rats groups. Therefore addition of V. amygdalina into glibenclamide increased efficacy in the diabetic rats. The interaction between V. amygdalina and glibenclamide in this work was additive and therefore synergistic.

Key words: Blood glucose, Diabetes, Glibenclamide, Synergism, Vernonia amygdalina,