Effect of methanolic extract of Vernonia amygdalina (common bitter leaf) on lipid peroxidation and antioxidant enzymes in rats exposed to cycasin.

This study investigated the effect of a methanolic extract of Vernonia amygdalina (VA) on lipid peroxidation and antioxidant status of the colon of rats maintained on a normal diet containing 5% Cycas revoluta (cycads). Fifty male Wistar albino rats were randomly assigned into five groups of ten experimental animals in a study that lasted for six weeks. One control group was maintained on a normal diet only while another group was fed a normal diet containing 5% cycads. The other three groups were maintained on the normal diet and 5% cycads and orally fed 200 mg VA/kg body weight for 1, 5 or 6 weeks. The results obtained revealed that the level of malondialdehyde (an index of lipid peroxidation) was significantly elevated (p < 0.05) in rats exposed to cycads only compared with the control. However, oral administration of VA in conjunction with exposure to cycads appeared to reduce the extent of lipid peroxidation to values that are not significantly (p > 0.05) different from those of the control. The activity of Superoxide Dismutase (SOD) was significantly reduced (p < 0.05) in the experimental animals fed cycads compared with the controls. Oral administration of VA seemed to counteract the effect of cycads on SOD in the colon as no significant difference (p > 0.05) was observed in rats fed VA compared with the controls. The results of this study suggest that methanolic extract of VA may mitigate the biochemical consequences of cycasin-induced lipid peroxidation in the colon of rats.