RESUMO
Numerous bioactive compounds and phytochemicals have been reported to be present Annona muricata (Soursop). Some of these chemical compounds have been linked to the ethnomedicinal properties of the plant and its antioxidant properties. The aim of this study was to assess the proximate composition, phytochemical constituents and in vitro antioxidant properties of A. muricata using standard biochemical procedures. The defatted Annona muricata crude methanolic extracts of the different parts of the plant were used for the estimation of proximate composition and phytochemical screening. The crude methanolic extracts of the different parts of the plant were also fractionated using solvent-solvent partitioning. Petroleum ether, chloroform, ethyl acetate, methanol, and methanol-water (90:10) were the solvents used for the fractionation. The different fractions obtained were then used to perform in vitro antioxidant analyses including, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, ferric reducing properties, and hydroxyl radical scavenging ability. The leaf methanolic extract had a higher lipid content, whereas its chloroform fraction demonstrated a better ability to quench DPPH free radical. The root-bark methanol-water, leaf methanol, fruit pulp chloroform, and leaf petroleum ether fractions demonstrated potent ferric reducing properties. The leaf and stem-bark petroleum ether fractions demonstrated better hydroxyl-free radical scavenging abilities. The leaf and fruit pulp of Annona muricata have a very potent antioxidant ability compared to the other parts of the plant. This can be associated with the rich phytochemicals and other phytoconstituents like phenols, flavonoids, alkaloids, and essential lipids, etc. Significant correlations were observed between the antioxidant status and phytochemicals present. These results thus suggest that some of the reported ethnomedicinal properties of this plant could be due to its antioxidant potentials.
