<i>In vitro</i> antibacterial activity of the ethanolic extract of <i>Chrysophyllum albidum</i> cotyledon and its formulation into a topical cream for the treatment of dermatological infections

Abstract

Minimum inhibitory concentrations (MIC) and antibacterial activities of the ethanolic extract of Chrysophyllum albidum cotyledon and its cream on dermatological infection causing agents was investigated using agar diffusion method with gentamicin as the positive control. Zones of inhibition diameters were: 11.8 ± 0.2 mm (Pseudomonas aeruginosa), 11.3 ± 0.5 mm (Staphylococcus aureus) and 11.3±0.5mm (Escherichia coli). The cream formulation of the extract displayed related MIC ≥ 11.7 ± 0.3 mm at higher concentrations. Gentamicin (80μg/ml) displayed 11.5 ± 0.5 mm for P. aeruginosa and at 40 μg/ml a higher value 16.3 ± 0.5 mm for S. aureus and E. coli 26.3 ± 3.3 mm. Formulated cream of extract had antibacterial activity in the at 150 - 250 mg/ml range with zone of inhibition diameter values for E. coli (11.7 ± 0.9 mm), S. aureus (11.8 ± 0.3 mm) and P. aeruginosa (17.5 ± 0.5 mm). Gentamicin cream manifested antibacterial activity at concentrations ≥ 100μg/ml. The extract possessed bactericidal effects comparable with gentamicin. Formulation of extract into cream decreased antibacterial activity, suggestive of the need to increase its concentration in the cream for treatment and management of dermatological conditions.

Keywords: Chrysophyllum abidum, anti-bacterial activities, gentamicin, topical cream, minimum inhibitory concentration, zone of inhibition