Phytochemical screening, Antimicrobial and Antioxidant activities of crude extracts of Scenecio abyssinicus flower

Abstract

With the emergence of more resistant pathogenic micro-organisms against synthetic antibiotic, it is pertinent to search for plant extracts with broad spectrum antimicrobial compounds from folklore medicine. The n-hexane, ethyl acetate and methanolic extract of Senecio abyssinicus flower were investigated for their phytochemical composition, antimicrobial and antioxidant activities. Standard methods, disk diffusion method and 2, 2-diphenyl-2-picryl-hydrazyl free radical (DPPH.) were used to determine the phytochemical composition, the antimicrobial activity and the in-vitro antioxidant activity respectively. The flower was found to contain alkaloids, flavonoid, saponins, tannins, anthraquinones and steroids. The antibacteria linvestigation of the n-hexane, ethyl acetate and methanolic extracts of Senecio abyssinicus flower inhibited the growth of Staphyloccocus aureus, Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa at concentrations between 50 and 200mg/ml. The ethyl acetate extract exhibited higher intrinsic antifungal properties on Candida albicans, Aspergillus niger, Rhizopus stolon, and Pneumonae notatum. Only the methanol extract acted as hydrogen/electrons donor or scavenger of radicals with IC50 of 46.24 μg/mL while that of Ascobic acid (standard) was found to be 12.24 μg/mL.