Antimicrobial Effects of Aloe vera, Psidium guajava and Hibiscus sabdariffa Extracts on Selected Pathogens

Abstract

Plant materials are repositories of bioactive compound of medicinal values. Traditional medicines relies on the therapeutic potential of herbal plants. This study aimed to assess the antimicrobial effects of Aloe vera, Psidium guajava and Hibiscus sabdariffa extracts on Salmonella typhi, Staphylococcus aureus and Escherichia coli and Candida albicans. Plant extracts were obtained by soxhlet extraction, using ethanol as solvent. Extracts were qualitatively screened for the presence of alkaloid, saponins, flavonoid and tannins. Saponins and flavonoids were detected in all plant extracts; alkaloid in P. guajava and H. sabdariffa extracts, and tannins in A. vera and P. guajava extracts. The concentrations of the residual plant extracts was 2.0 mg/ml for A. vera, 2.1 mg/ml for P. Guajava and 1.83 mg/ml for H. sabdariffa. Staphylococcus aureus was only susceptible to A. vera. Salmonella typhi was not sensitive to all extract. Escherichia coli was sensitive to all extracts in the order H. sabdariffa>P. guajava>A. vera. Candida albicans was sensitive to A. vera and P. guajava extracts. The MIC of A. vera was 2.0 mg/ml for S. aureus, E. coli and C. albicans respectively. The MIC of P. guajava was 0.021 mg/ml and 2.1 mg/ml for E. coli and C. albicans respectively. The MIC of H. sabdariffa was 1.83 mg/ml for E. coli. The results show that A. vera, H. sabdariffa and P. guajava extracts contain phytochemicals with inhibitory potencies against S. aureus, E. coli and C. albicans. These plant material may prove useful as natural remedies for managing infections caused by susceptible microorganisms.