Comparative Assessment of the Phytochemical Composition and Antimicrobial Activity of Ogirisi (Newbouldia Leavis) Rootbark and Rootwood Extracts

Abstract

The study was aimed at a comparative evaluation of the phytochemical constituents and antimicrobial activity of the rootwood and rootbark of Newbouldia leavis extracts. The powdered samples were explored using two solvents (ethanol and ethylacetate) as extractants. Phytochemical assay of the crude extracts were done following standard procedures. The results of preliminary phytochemical screening of samples revealed that carbohydrates, alkaloids, flavonoids, phenolics and terpeniods were present in all extracts; saponins and glycosides in ethanol extracts and tannins in all extracts except ethylacetate. The results also show the absence of steroids and phlobatannins in all extracts. The comparative phytochemical evaluation of the ethanol extracts of both the rootwood and rootbark samples showed the presence of these bioactive compounds in varying concentrations. Ethanol proved to be a better extractant for saponins and tannins than ethylaceate and this could be attributed to the difference in their polarities. The antimicrobial activity was carried out using the agar well diffusion method against: Escherichia coli, Staphylococus aureus, Candida albicans and Salmonella typhi. The results of the anti-microbial tests revealed that the rootbark extracts showed a broader spectrum of activity than the rootwood. The antibacterial and antifungal activities of the extracts were notably inhibitory against the test pathogens at MIC values of 2.5 – 10 mg/ml as against the MIC values of 1.25 mg/ml obtained for the standard antibiotics. In conclusion, the wide range of inhibitory zone diameter recorded could be as a result of singular or synergistic action (s) of the bioactive compounds present. Keywords: Phytochemicals, Antimicrobials, Newbouldia leavis DOI: 10.7176/JNSR/13-10-01 Publication date: May 31 st 2022