Antioxidant Activity of the Aqueous Crude Extract of Ocimum gratissimum LINN. Leaf on Basal and Cadmium-induced Serum Levels of Phosphatases in Male Guinea-pigs.

The antioxidant activity of the aqueous crude extract of Ocimum gratissimum Linn. leaf on the basal and traumatized (cadmium-induced) serum levels of alkaline phosphatase (ALP), total acid phosphatase (ACPT) and prostatic acid phosphatase (ACPP) of the male guinea-pig (GP) were evaluated. Preliminary experimentation showed that the effects of the aqueous crude extract of O. gratissimum on basal serum phosphatases were slightly more in the oral than the intraperitoneal (i.p) route. Oral administration of 20mg of O. gratissimum caused a timedependent decrease in the basal serum levels of ACPT and ACPP without an effect on ALP values. The inhibitory effects compared to the control were maximum at 4 hours. Furthermore, O. gratissimum given orally, caused significant dose-dependent decreases (p<0.05) of the basal serum levels of ACPT and ACPP at p<0.05. Basal serum concentrations of ACPT and ACPP changed from 23.50\ub11.04 and 7.50\ub10.29 to 8.25\ub10.75 and 2.25\ub10.29 IU at 20mg, representing 65 and 70 % decreases respectively. In contrast, 0.25-8mg/kg of cadmium (Cd) given intraperitoneally, caused significant dose-dependent increases (p<0.05) in the phosphatase enzymes. However pretreatment with 5mg of the crude extract, which on its own had little effect on basal serum phosphatase levels, followed by i.p administration of Cd, caused a reversal of the Cd-induced dose-response curves on the various phosphatase levels to negative values. These results may be due to the oxidative and the antioxidative biochemical antagonistic properties of the agents used in these experiments. They may also be due to enzyme conformational changes and effects of eugenols and flavonoids in the crude extract of O. gratissimum