Antimicrobial activities of Lippia javanica from Eastern Cape Province of South Africa

Abstract

Background and Aims Lippia javanica is an aromatic plants with several biological active compounds including the essential oils. The antimicrobial activity of the essential oil extract from the fresh and dried leaves of Lippia javanica was validated. Methods The essential oil was extracted from fresh and dried leaves and the composition were identified using GC-MS. The brine shrimp lethality test was used to assess the toxicity of the oils. Antibacterial and antifungal activity of the plant extracts were determined on bacteria and fungi strains. One-way analysis of variance (ANOVA) was used to compare the data among the plant fractions at 0.05% alpha level. Results The essential oils obtained from the fresh and dried leaves of Lippia javanica have similar chemical composition with most documented reports on other Lippia species. Nineteen active compounds were found to be present in all test oils of Lippia javanica. No significant variations between the aromatic profiles of the fresh and dried leaves, but the extracted oil yielded more in the dried leaves than the fresh leaves (2.7%: 0.7%). The brine shrimp assay of the essential oils extracted from both fresh and dried leaves of Lippia javanica showed LC₅₀ values of 35.7 and 48.7 µg/mL. The oils exhibited a concentration dependent toxicity against brine shrimp. Lippia javanica shows more antibacterial and antifungal potency than the control drug. Conclusion Based on this study, it can be inferred that the essential oil obtained from the leaves of Lippia javanica are less toxic and have high antimicrobial potency.