Studies on the effects of Vernonia amygdalina leaf extract and fractions on biochemical and hematological parameters in diabetic rats

Vernonia amygdalina L, Asteraceae (Bitter leaf) is a common traditional anti-diabetic remedy in many parts of Nigeria. Some scientific studies have confirmed its efficacy in both experimental animals and humans. In this study, we investigated the subacute toxicity of the leaf extract and fractions of Vernonia amygdalina, as well as their effects on biochemical and hematological parameters in alloxan-induced diabetic rats. Diabetes was induced in rats with a single intravenous injection of alloxan monohydrate (70mg/kg). The alcohol extract and its chromatographic fractions were orally administered to the diabetic rats once daily for 28 days. The blood sugar lowering effects and the biochemical and heamatological effects of the treatments were determined. The vital organs were also examined for possible abnormality. The results confirmed the anti-diabetic potency of V. amygdalina leaf extract. Chromotographic fraction F6 exhibited the most potent anti-diabetic effect at a dose of 160mg/kg. In addition, it significantly (P<0.05) decreased elevated serum levels of TG, LDL-C, VLDL-C, and increased HDL-C level in diabetic rats. At the doses of 160 and 320mg/kg, there was a significant (P<0.05) increase in the lymphocyte counts. Urea and creatinine levels were significantly reduced while electrolyte levels were on the average increased. Diabetes associated elevation of hepatic enzymes (AST, ALT and ALP) were significantly reduced. Histological examination revealed no remarkable abnormality in the vital organs of the treated rats. These results suggest that in addition to its hypoglycemic and hypolipidermic effects, V. amygdalina is capable of normalizing the biochemical and heamatological abnormalities associated with diabetes mellitus.