ABSTRACT

There is an increasing demand for natural antioxidant to replace synthetic addictives in the food and pharmacologicals. Annona muricata (Soursop) possess remarkable phyto-medicinal values attributable to its enormous phytochemical content, especially its annonaceous acetogenins. This study was carried out to investigate the influence of aqueous and methanolic extracts stem-bark of Annona muricata on antioxidant enzyme activities (Catalase, CAT) and lipid peroxidation status (malondialdehyde, MDA) of Wistar rats (WR). Wistar Rats weighing between 150-190 g were housed according to standard ethical rules of handling experimental animals, divided into six groups, group one served as control while the others were experimental groups that were administered 200, 500, 1000, 3000 and 5000 mg/kg body weights of aqueous and methanolic extract respectively per rats. The extracts were administered to the rats for a period of 28 days, after which the rats were fasted over-night before they were sacrificed using for onward laboratory assays using standard assay protocols. The activities of the key antioxidant enzymes catalase, were studied in the heart, pancreas, liver and kidneys. Results obtained for Catalase level showed significant increase for the groups administered 1000 mg/kg b.wt aqueous extract in comparison to control in liver (p<0.05) and significant increase for 500 mg/kg b.wt in comparison to 3000 and 5000 mg/kg b.wt in heart for methanolic extract. MDA had no significant difference for methanolic extract (p>0.05) in all organs but had significant increase for 1000 mg/kg b.wt for aqueous extract in liver and also there was noteable decrease in MDA level within groups in comparison to control for different organ. The antioxidant enzymes showed remarkable beneficial changes, an indication of good potentials to avert lipid peroxidation and ameliorate oxidative stress that could arise due to increased production of prooxidants.