Comparative and Interactive Studies of Aqueous Leaf Extracts of <i>Ocimum gratissimum</i> Linn. (Lamiaeceae),Vitamins C and E on the Basal Serum Phosphatase Levels of Male Guinea Pigs

Abstract

The present study was designed to investigate the comparative effects of aqueous leaf extract of Ocimum gratissimum Linn. (Lamiaceae), vitamin C and vitamin E on the basal serum phosphatases- alkaline phosphatase (ALP), total acid phosphatase (ACPT) and prostatic acid phosphatase (ACPP) of the male guinea-pig. Also investigated were the
interactive effects of these agents on the biochemical parameters. Adult male guinea-pigs were divided into nineteen groups of five animals each and orally administered with different doses of O. gratissimum (11-352 mg/kg), vitamin C (1.25-80 mg/kg), vitamin E (75-2400mg/kg) and the last group (control) was given distilled water. Animals were sacrificed after 4h and blood samples collected and analyzed for ALP, ACPT, and ACPP. In another set of animals, O. gratissimum was administered 1h before obtaining the dose-responses of vitamins C and E and vice versa. O. gratissimum (11-352mg/kg), vitamin C (1.25-80mg/kg) and vitamin E (75-2400mg/kg) caused significant (p<0.05) dose-dependent decreases in basal serum levels of ACPT and ACPP without an effect on ALP in the male guinea-pig. Basal ACPT level was decreased from 24.5±1.04 IU/L to 2.75±0.25 IU/L, 8.75±1.48 IU/L and 9.75±1.25 IU/L, while ACPP was decreased from 6.5±0.29 IU/L to 1.5±0.29 IU/L, 3.5±1.24 IU/L and 2.5±0.29 IU/L by O. gratissimum, vitamins C and E respectively. Pretreatment with O. gratissimum (11mg/kg) before administration of increasing doses of vitamins C and E enhanced the dose-responses of vitamin C on ACPT and ACPP, and antagonized the effects of vitamin E on ACPT and ACPP. However, pretreatments with vitamins C and E significantly increased O. gratissimum-induced dose-responses on ALP, ACPT and ACPP at p<0.05. These effects on ALP were dose-dependent and more significant (p<0.05). Pretreatments with vitamins C (at 88mg/kg of O. gratissimum) and E (at 176mg/kg of O. gratissimum) decreased basal ALP level from 30.25±0.86 IU/L to 18.25±0.63 IU/L and 19.25±0.48 IU/L (equivalent to 39.4% and 36.36% decreases) respectively. In this study, O. gratissimum, vitamins C and E, individually decreased various basal serum phosphatase levels and interact positively to create a synergy. These results may be due to the antioxidative actions of these agents acting through the inhibition of various transduction pathways- protein kinase C and calcium.

Keywords:

Ocimum gratissimum, basal phosphatase, vitamin C and vitamin E.