Ameliorative Effects of Moringa oleifera Leaf Extract on the Cobalt Chloride-Induced Liver Damage in Adult Wistar Rats

Abstract

Ajibade AJ*, Ogunmola IA, Okeleye AE

Cobalt is a natural element found throughout the environment. Cobalt is an essential trace element being an integral part of vitamin B12. Cobalt is toxic to virtually all organs of the body and has been shown to have significant debilitating effects on the nervous, renal, hepatic and hemopoietic systems. The liver is considered as one of the target organs affected by cobalt toxicity owing to the site of storage after exposure. Conversely, the leaf extract of Moringa oleifera is hepatoprotective amongst other medicinal and nutritional benefits. The present study therefore evaluated the effects of Moringa extract on cobalt chloride-induced liver damage in adult male wistar rats. 40 healthy male wistar rats weighing 90-120 g were used for the study and were divided into 5 groups of 8 animals per group. Group A served as control and was given normal feed and distilled water, Group B was the cobalt-treated group(45 mg/kg), Group C received cobalt (45 mg/kg) and low dose of Moringa extract (250 mg/kg) body weights, Group D received cobalt (45 mg/ kg) and high dose of Moringa extract (500 mg/kg) body weights. The rats were orally administered in their respective dosages for 52 days before sacrifice. The weights of the wistar rats were recorded on weekly basis. On the 53rd day, the wistar rats were sacrificed by cervical dislocation. The liver of each rat was removed and weighed and fixed in 10% normal saline. Blood samples were obtained and used for the analyses of some hepatic marker enzyme. Statistical analysis was done and tested for significance using student’s t-test and histological assessment using H and E techniques. The result showed that the final body weights of rats in group C and E increased significantly (p<0.05) and a significant (p<0.05) decrease in the final body weights of rat in group D when compared with the control. There was no significant difference between the control and the treated in the liver weights. The biochemical analysis of hepatic enzymes showed a significant (p<0.05) increase in the activity of Alanine Transaminase (ALT) in group B and D, and significant (p<0.05) decrease in group E when compared with the control. The level of Aspartate Transaminase (AST) showed a significant (p<0.05) increase in group B, C, and D when compared with the control. The level of Alkaline Phosphatase (ALP) showed a significant (p<0.05) increase in group B and D, and decrease in group E when compared with the control. Histological study of the liver revealed that liver parenchyma appeared grossly infiltrated and distorted in group B and C, while group D and E revealed preserved hepatic histoarchitecture similar to that of control group A. The study concluded that cobalt chloride caused alterations in hepatic tissue consistent with observed changes in enzyme activities. Administration of leaf extract of Moringa oleifera ameliorated the deleterious effects of cobalt chloride induced hepatic damage in wistar rats. It is recommended that further studies aimed at corroborating these findings should be carried out.