Antimicrobial and Antioxidant Activities of the Stem Bark of <i>Cussonia bancoensis</i>

Abstract

Cussonia bancoensis is used in Ghana mainly for the management of pain and treating infectious diseases. This study investigated the antibacterial and antifungal effect of the methanol, ethyl acetate and petroleum ether extracts of the stem bark of C. bancoensis by the agar dilution method. The antioxidant activity of the methanol extract was also investigated by DPPH free radical scavenging assay, total antioxidant capacity and total phenol content determined. The methanol and ethyl acetate extracts inhibited growth of all tested microorganisms with the exception of Streptococcus pyogenes in the antimicrobial assay. The minimum inhibitory concentrations ranged from 625 µg mL-1 to 2500 µg mL-1 for susceptible organisms. The petroleum ether extract had no antimicrobial activity at the concentrations used. The methanol extract scavenged DPPH with an IC50 value of 2.890 µg mL-1 and a total antioxidant capacity of 110.6 ± 41.15 mg g-1 (ascorbic acid equivalent). The total phenolic content expressed as tannic acid equivalent was 43.40 ± 14.70 mg g-1. The results of this study justifies to some extent the use of C. bancoensis in the treatment of microbial infections and supports the ethnomedical evidence that the plant could be a potential source of natural antimicrobial and antioxidant agents.

Antimicrobial activity, toxicity and phytochemical screening of selected medicinal plants of Losho, Narok County, Kenya

“…Among the C. holstii extracts tested for antifungal activity, only the organic extracts were active against C. albicans in both agar well and disc diffusion methods with a MIC of 62.5 mg/mL. This is in agreement with another member of the same genus C. bancoensis which reports antifungal activity of methanol, ethyl acetate and petroleum ether extracts of the stem bark against the same microorganism and minimum inhibitory concentrations ranged from 0.625 mg/mL to 2.5 mg/mL (Mireku et al 2014). More so, Njoroge and Bussman (2007) that C. holstii is used for traditional management of ear, nose and throat (ENT) diseases in central Kenya.…”

“…S. alata recorded a MIC value of 15.625 mg/mL against P. aeruginosa and MRSA which was in line with another member of the same genus S. swietenioides against S. aureus (Mahida and Mohan 2007). Activity of C. holstii against the MRSA recorded a MIC value of 15.625 was in line with De Villiers et al (2010) and Mireku et al (2014) that some other species of the same genus against E. coli and P. aeruginosa. MIC value (31.25 mg/mL) was revealed by organic extracts of O. kirkii against MRSA in was in line with Maragesi et al (2008).…”