Abstract:
Introduction: Traditional herbal medicines are attracting significant attention in global health debates with
various traditional herbal remedies being used as the basis for modern medicines. The aim of this research
was to explore the potential antimicrobial activity of six medicinal plants.
Methods: In vitro antimicrobial activity of essential oils extracted from Lavandula angustifolia,
Cymbopogon citratus, Mentha piperita as well as extracts from Chenopodium ambrosioides, Aloe
ankoberensis and Aloe pulcherima were determined using an agar diffusion technique. The minimum
inhibition zone concentration (MIZC) was determined by a twofold serial dilution using a modified agar
dilution method. Results: Results demonstrated that 50 μL of the essential oils from three plants had
antimicrobial activity. The MIZC of essential oil from L. angustifolia for the growth of Staphylococcus
aureus, Escherichia coli and Candida albicans ranges from 12.5 % (v/v) to 25 % (v/v). Whereas, the
MIZC of essential oils from C. citratus and M. piperita for the growth of these pathogens ranged from
6.25 % (v/v) to 12.5 % (v/v). The MIZC of ethanol extract of C. ambrosioides, A. ankoberensis and A.
pulcherima for both S. aureus and E. coli were 250 mg/mL and 125 mg/mL, respectively. However,
petroleum ether and chloroform extracts (1000 mg/mL) of C. ambrosioides, A. ankoberensis and A.
pulcherima failed to inhibit these organisms.
Conclusion:These findings suggest that the herbal essential oils and extracts had activity against S.
aureus, E. coli, and C. albicans. Ethanol extracts appear to have a better antimicrobial activity than
petroleum ether and chloroform extracts
