ABSTRACT
Herbal medicine is the oldest form of health care known to mankind. A concoction of Vitex simplicifolia leaf is widely used in sub Saharan Africa for treatment of diabetes mellitus and a lot other diseases. The study investigated the hypoglycemic, hypolipidemic, antioxidant and hepato-renal toxicity of fractionated extract of Vitex simplicifolia leaf on alloxan-induced diabetic rats. The plant extract was fractionated in solvents of varying polarities (aqueous, methanolic, hexane and ethyl acetate). 250, 500 and 1000mg/kg of body weight of the fractionated extracts were administered to the diabetic rats, aqueous (groups 4, 5 and 6), methanolic (groups 7, 8 and 9), ethyl acetate (groups 10, 11 and 12), hexane (groups 13, 14 and 15). Groups 1 and 2 were normal and diabetic control, while group 3 was administered glibenclimade (reference drug). Fasting blood glucose, lipid profile, liver glycogen content, superoxide dismutase (SOD), vitamins A, C and E, AST, ALP, ALT, unconjugated bilirubin and serum electrolytes; sodium, chloride, carbonate, urea and creatinine were determined. The result of the study showed that there was significant decrease (P< 0.05) in fasting blood glucose level, with the aqueous fraction showing percentage reduction of 72,75 and 81%, n-hexane 58,71 and 77%, ethyl acetate 54,70 and 71%, glibenclimade (reference drug) 65% and methanol 8, 16 and 17% at 250,500 and 1000 mg/kg of body weight respectively. Oral administrations of fractionated extracts aqueous, ethyl acetate and N-hexane of Vitex Simplicifolia for 21 days significantly increase liver glycogen content, however, the methanolic fraction showed no significant change. All the fractionated extracts showed no significant changes in lipid profile , SOD, vitamins A, E and C. Aqueous, methanolic and ethyl acetate fractions significantly increase ALP (P<0.05) and significantly decrease (P<0.05) AST. However, the n- hexane fraction showed significant increase in ALP AST and unconjugated bilirubin. Aqueous fraction of Vitex simplicifolia showed no significant change in Na, K and chloride but significantly increase urea and significantly decrease (P<0.05) creatinine and HCO3. But the methanol and ethyl acetate fraction significantly increased urea, sodium and chloride but showed no significant change in HCO3, potassium, chloride and creatinine .The histopathological studies of the liver showed mild to moderate sinusoidal lymphocytosis with prominent kupfer cells and focal portal inflammation in the test groups. The kidneys of the test groups showed mild to moderate distal tubular epithelial cell oedema and mild interstitial inflammation. In conclusion, the four fractionated extracts of Vitex simplicifolia leaf extract were observed to posses? potent hypoglycaemic activity but have no hypolipidemic and antioxidant potential. However, it was also observed to possess a moderate hepato-renal toxicity.