In-Vitro Assessment of Antioxidant and Antimicrobial Activities of Methanol Extracts of Six Wound Healing Medicinal Plants

Abstract

In this study, quantitative values of antioxidant activity of crude methanolic extracts of five Wound healing medicinal plants (Amaranthus spinosus, Anogeissus leiocarpus, Spondia monbin, Corchorus olitorius, and Mallotus oppositifolia) were investigated. The investigation used DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical as a substrate and Ferric reducing antioxidant power (FRAP) assay to determine both scavenging ability and the reducing properties. Antioxidant was further analysed quantitatively for flavonoid content, total phenolic content in the crude methanolic extracts using spectrophotometric assay.

The result showed that all plants exhibited scavenging ability and strong reducing activity although the ability differed markedly among the various plant samples. The highest scavenging ability (% inhibition) was exhibited by A. leiocarpus (95.86 ± 0.1) followed by C. olitorius (94.19 ± 0.06) while the lowest was from A. spinosus (40.87±2.5). The reducing power was also highest in A. leiocarpus followed by S. monbin; while A. spinosus showed the least reducing power. In quantitative analysis, again A. leiocarpus was found to have the highest phenolic content (1294.81± 3.0 mg/g) with A. spinosus recording the least phenol and flavonoid content.

The crude methanol extracts were also screened for their antimicrobial activity against four common pathogenic microorganisms (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Citrobacter sp.) associated with wound infection by well diffusion method. All the extracts were found to inhibit the growth of both gram (+) and gram (-) bacteria organisms tested.

Keywords: Radical scavenging effect, phenolic compounds, antioxidant activity