Alteration in Antioxidant Enzyme Activities by Nickel-Induced Hepatotoxicity in Wistar Rats: Ameliorating Effect of the Aqueous Extract of Myristica fragrans (nutmeg)

Abstract

The ameliorating effect of Myristica fragrans (nutmeg) on lipid peroxidation (LOP), reduced glutathione (GSH), glutathione-s-transferaes (GST), glutathione peroxidase (GPx), Catalase (CAT), Superoxide dismutase (SOD) as well as some liver marker enzymes were examined using a model of NiCl₂–induced oxidative stress in rats. Thirty male Wistar rats were used in this study. They were randomized into 5 groups of six rats per group. Animals in group I received distilled water and normal rat feed only. Rats in groups II and III received only 0.75 mg/kg/day and 1.5 mg/kg/day of NiCl₂ respectively. All rats in groups IV and V were pretreated with 200 mg/kg body weight and 300mg/kg body weight of the aqueous extract of Myristica fragrans (AEMF) respectively. In addition to the doses of the extracts administered to the above groups, group IV rats received 0.75 mg/kg/day of NiCl₂ while group V animals were treated with 1.5 mg/kg/day of NiCl₂. All administration was carried out by gastric intubation for 30days. NiCl₂ caused significant increase (p<0.05) in the level of MDA formation in the liver, suggesting pro-oxidant induced membrane damage. These were followed by a significant decrease (p<0.05) in the levels of GSH, GPx, GST, SOD and CAT. The aqueous extract of Myristica fragrans (AEMF) in a dose related manner, significantly (p<0.05) reduce the level of MDA as well as the antioxidant markers to a near constant value when compared with the control. Pretreatment with AEMF also led to a significant decrease (p<0.05) in liver marker enzymes (ALT, ALP, AST, LDH, GGT and CK) when compared with the NiCl₂ treated rats in a dose-dependent manner. Upon the administration of AEMF, histological examination did not reveal much pathophysiological changes when compared with the control.