Antioxidant effect of ocimum gratissiumum linn. leaf against carbon tetrachloride (ccl4)-induced oxidative stress in wistar albino rats

The leaves of Ocimum gratissimum (OG) were assayed for its phytochemical, vitamin and essential mineral content. Also, ethanol leaf extract of OG was investigated for antioxidant activity against carbon tetrachloride (CCl4)-induced oxidative stress in Wistar albino rats. Plasma lipid peroxidation inhibition and activities of the antioxidant enzymes, superoxide dismutase (SOD) and glutathaine peroxidase (GPx) were used as antioxidant indices, while Vitamin E (1000 IU, d-alpha-tocopheryl acetate soft-gel capsule) served as reference. Phytochemical analysis revealed the presence of Flavonoids, terpenoids, alkaloids and glycosides. The mean levels of zinc (Zn), manganese (Mn), copper (Cu) and iron (Fe) were 1.54, 6.16, 4.76 and 21.16 ppm, respectively, while those of beta-carotene, vitamins C and E were 0.222  0.02, 1.59  0.15 and 19.96  0.69 mg/100g. Result of the bioassay demonstrated that the CCl4-intoxicated rats were subjected to oxidative stress as indicated by low activities of their antioxidant enzymes; SOD (54.0  8 U/l), GPx (67254  1790 U/l) and high plasma lipid peroxidation index (61.86  4.09 µg/ml) when compared with normal control rats value of 202.5  23 U/l, 81497  1012 U/l and 48.78  8.04 µg/ml, respectively. The ethanol extract of O. gratissimum leaf reversed this situation as shown by the increased activity of the antioxidant enzymes and lipid peroxidation inhibition. The results indicated that ethanol extract of O. gratissium leaf significantly protected the rats from CCl4-induced oxidative stress. Furthermore, its antioxidant effect is dose-related.