Evaluation of the ameliorative roles of vitamins A, C and E on reduced glutathione in Clarias gariepinus (Burchell, 1822) fingerlings exposed to lead nitrate

Abstract

The ever-increasing anthropogenic activities all over the world that usually led to release of plethora of pollutants such as lead calls for concern. In the present study the effects of lead nitrate on the production of antioxidants such as reduced glutathione (GSH) in C. gariepinus and how such effects can be ameliorated through administration of vitamins were investigated. C. gariepinus fingerlings (whose initial weight ranged from 3-11g) were exposed to sub-lethal concentrations of Pb (00, 26mg/L, 44mg/L, 61mg/L and 79mg/L) with replicate in each case. 26mg/L each of the vitamins were administered across all bud. Fresh concentrations of both toxicant and vitamins were administered every 72 hours for a period of 12 weeks every time the water medium was changed. The various treatments group include Pb (Pb only), PbVA (Pb+vitamin A), PbVC ((Pb+vitamin C) and PbVE (Pb+vitamin E) with T1-T4 and replicates in each case. 3 samples of the fish were randomly selected and sacrificed from each aquarium tank every 2 weeks of the exposure period. The gills, kidneys and liver were excised from these specimens and homogenized in sodium phosphate buffer. These were then assayed for GSH productions levels in each case. The data generated were subjected to one way analysis of variance and considered significant at P≤0.05. From the results: In the Pb only group, the mean values of the GSH produced in the liver of the control samples were significantly higher than other treatments. The highest mean values of 82.04±0.13µg/ml, 30.84±0.10µg/ml and 31.30±0.10µg/ml were obtained in the liver, kidney and gills of the fish, respectively. In fish samples exposed to PbVA group, the highest mean values of 23.57±0.10µg/ml, 58.74±0.07µg/ml and 52.72±0.07µg/mlwere obtained in the liver, kidney and gills, respectively. In C. gariepinus exposed to PbVC group, the highest mean values obtained in the liver, kidneys and gills were 25.79±0.07µg/ml, 28.40±0.13µg/ml and 37.55±0.03µg/ml, respectively. In PbVE group, the highest mean value of 57.21±0.03µg/ml, 83.51±0.07µg/ml and 63.29±0.07µg/ml were btained in the liver, kidneys and gills, respectively. The liver of the samples exposed to Pb only group displayed higher level of response to the toxicant with the highest GSH produced in the lowest concentration in comparison to other fish organs. In the PbVA group the response was more in the kidney in the highest concentration. There were general low levels of production in all organs of the fish in the PbVC group. The kidneys of the PbVE group exhibited the highest level of GSH production in comparison to other organs. The kidneys and liver of C. gariepinus in this research were fully engaged in mitigating the effects of the toxicant in the presence of the vitamins. Administration of higher concentrations of the vitamins could enhance better understanding of the ameliorative roles of the vitamins against the deleterious effects of the toxicant.