Antibacterial and Antifungal Activity of the Essential Oil Extracted by Hydro-Distillation from Artemisia annua Grown in West-Cameroon

Abstract

This study was carried out to assess the in vitro antimicrobial potential of the Essential Oil (EO) extracted by hydro-distillation from the variety of A. annua grown in West Cameroon. This evaluation was conducted by testing the microbial growth inhibition through agar diffusion, minimal inhibitory and minimal lethal concentrations. Tested microorganisms included bacteria isolates belonging to the following categories: Staphylococcus aureus, Escherichia coli, Salmonella Enteritidis, Shigella flexneri, Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Vibrio cholerae. This activity was also tested on a dimorphic fungal species, Candida albicans. Data analysis revealed that the EO possessed an intrinsic antimicrobial activity that was potentiated by the solvent (DMSO). Inhibition zone diameters varied from 6 (Pseudomonas aeruginosa and Shigella flexneri) to 45 mm (Vibrio cholerae). It was also observed that Vibrio cholerae was susceptible to the lowest concentration of the essential oil used (0.3 mg/mL), while Pseudomonas aeruginosa was shown to tolerate the highest (80 mg/mL). Also, the minimal inhibitory and lethal concentrations were equal (MLC/MIC=1), implying the absolute lethal property of the oil. This lethal potential on fungi, Gram-negative and Gram-positive bacteria makes of this plant an appropriate candidate for new conventional antimicrobial drug production and infectious disease prevention. Well exploited, it might be used to control the current epidemics of Vibrio cholerae-associated cholera in Cameroon. Additional studies should also be conducted to lay down reliable basis for comprehensive test interpretations that take into account correlations between these in vitro test results and the ones that would be obtained with conventional antimicrobials.