The antioxidant effects of vitamin C on liver enzymes: aspartate aminotransferase, alanine aminotranferease, alkaline phosphatase and gamma-glutamyltransferase activities in rats under Paraquat insult

Abstract

Paraquat (PQ) is a bipyridylium herbicide; applied around trees in orchards and between crop rows to control broad-leaved and grassy weeds. Its oxidation results in the formation of superoxides which causes damage to cellular components. In this study, we determined the antioxidant effect vitamin C has on the liver enzymes [aspartate aminotransferase (SGOT), alanine aminotranferease (SGPT), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT)] of rats under this toxic insult. Male rats in groups (A, B, C and D) were intraperitoneally injected with different sublethal increasing doses (0, 0.02, 0.04 and 0.06 g/kg body weigh) of PQ respectively on monthly basis. Subsequently, the subgroups (A2, B2, C2 and D2) were given orally, 200 mg/L vitamin C, while the subgroups A1, B1, C1, and D1, received only water. Four animals per subgroup were decapitated on monthly basis and blood samples taken for enzyme assay. The parameters studied were - SGOT, SGPT, ALP and GGT - liver enzymes. The dose and time dependent PQ toxicity effect resulted in highly elevated Liver enzymes activities. The subgroups on vitamin C had significantly lower enzyme activities when compared to the same subgroups on only PQ insult. But the values were high when compared to the control subgroups (A1 and A2). These results were indication that vitamin C when given at moderate doses and maintained for a longer period could be a life saving adjunct to toxic insult.

Keywords

• Paraquat, antioxidant, vitamin C, reactive oxygen species.