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 (ACP
T)
and prostatic acid phosphatase (ACP
P) 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 ACP
T and ACP
P 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 ACP
T and ACP
P at p<0.05. Basal serum
concentrations of ACP
T and ACP
P changed from 23.50±1.04 and 7.50±0.29 to 8.25±0.75 and 2.25±0.29 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.
