DEFENSE ANTIOXIDANTS AND LIPID PERIOXIDATION IN AMIETOPHRYNUS MACULATUS AND PTYCHADENA PUMILIO AS A POLLUTION BIO-MONITORING TOOL IN SELECTED AREAS OF LAGOS STATE

Abstract

The sensitivity of African amphibians; Amietophrynus maculatus and Ptychadena pumilio were exploited in determining oxidative stress induced by heavy metals pollution; lead (Pb), cadmium (Cd), manganese (Mn), chromium (Cr), zinc (Zn) and nickel (Ni), which is one of the factors that may have contributed to amphibian population decline.  The study investigated the overall mean concentration of the selected heavy metals in the heart, liver, kidney and activities of Superoxide dismutase (SOD), Catalase (CAT) and Glutathione (GSH) as well as the level of lipid peroxidation product; malondialdehyde (MDA), in the liver of the sampled animals in five selected locations in Lagos State (Ibafo, Iwaya, Makoko 1, Makoko 2 and Unilag). Three healthy and  matured P. pumilio (62.00 ± 5.00g) and A.maculatus (79.00 ± 5.00g) were randomly collected from three points of each selected locations. The results showed that the overall mean concentration (mg/kg) of the selected heavy metals in descending order in A. maculates and P. pumilio were as follows: Heart (Zn >Mn>Pb/Ni > Cr > Cd; Zn >Mn>Pb> Ni > Cd > Cr), Liver (Zn >Mn>Pb> Cd > Ni > Cr; Zn >Mn>Pb> Cd > Cr > Ni) and Kidney (Zn >Mn>Pb> Cd > Cr > Ni; Zn >Mn>Pb> Cd > Cr > Ni) respectively. In addition, the overall range of antioxidant activities (U/mg) in A. maculates and P. pumilio sampled in the various locations varied significantly (P < 0.05) as follows; SOD (4.42-42.70; 5.14-30.62); CAT 10.84-17.82; 7.94-19.72); GSH (3.74-33.11; 4.42-12.17) and MDA (0.01-0.05;0.01-0.05) respectively. GSH was most depleted in both animals sampled from Ibafo. Therefore the sensitivity of the amphibians and the role of these biomarkers could be a good battery of monitoring tools in assessing the environmental health in environmental toxicology studies