Thesis Abstract

Oxidative stress is one of the mechanisms involved in lead poisoning. The present study investigated the role of ascorbic acid, thiamine, pyridoxine, tocopherol, individually and in cocktail in mitigating the biochemical alterations induced by subchronic administration of 500mg/kg of lead acetate for 6 weeks. Thirty-five wistar albino rats divided into seven groups of five animals in each group were used for this study. All the animals were fed ad libitum. The first group which served as the negative control received no treatment. The second group which served as the positive control had 500mg of lead acetate added per kg of feed. All other groups received same regimen as the second group but in addition, four other groups received 300mg/kg diet of pyridoxine, thiamine, ascorbic acid and tocopherol respectively, while the last group received 300mg of vitamin mixture containing 75mg each of thiamine, pyridoxine, ascorbic acid and tocopherol per kg of diet. The rats were sacrificed after 6 weeks and sera obtained from the blood samples were analysed for alanine transaminase(ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) activities. Urea and creatinine concentrations were also evaluated. The results indicated that exposure of the animals to lead resulted in a significant increase (p<0.05) in ALT, AST and ALP activities as well as in urea and creatinine concentrations in the positive control group (121.10 ± 4.27 U/L, 180.80 ± 4.26U/L , 227.93 ± 11.14U/L; 62.20 ± 3.29mg/dl and 1.64 ± 0.16mg/dl respectively) when compared with the negative control group ( 75.17 ± 1.39U/L, 126.16 ± 9.13U/L, 146.47 ± 10.04U/L, 35.43 ± 3.18mg/dl and 1.08 ± 0.05mg/dl respectively), indicating damage in the liver and kidney cell membranes. The activities of ALT, AST and ALP as well as the levels of urea and creatinine were significantly lower (p<0.05) in the cocktail treated group (90.67 ± 2.67U/L, 128.68 ± 2.20U/L, 154.43 ± 2.16U/L, 35.72 ± 1.67mg/dl and 1.10 ± 0.04mg/dl respectively), pyridoxine treated group (91.81 ± 2.97U/L, 146.29 ± 3.26U/L, 174.19 ± 12.18U/L, 45.56 ± 4.6mg/dl and 1.25 ± 0.03mg/dl respectively) and all other groups that received vitamin supplementation when compared with the positive control. This indicates that thiamine, pyridoxine, ascorbic acid-tocopherolandhave αameliorative effect on lead induced toxicity on liver and kidney of wistar albino rats. The results also showed that the cocktail group had all the biochemical parameters most significantly lowered suggesting a greater potency in lead toxicity amelioration.

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