In vitro Antibacterial Activity of Essential Oil from the Fruits of Toddalia asiatica (L) Lam. (Rutaceae)

Abstract

This study was aimed at evaluating the antibacterial prospective of essential oil (EO) extracted from Toddalia asiatica L. against four pathogenic bacteria. The essential oil was steam-distilled using a modified Clevenger-type apparatus and its chemical composition established by gas chromatography - mass spectrometry. Disc diffusion method was used to assess the antimicrobial activity of the essential oil against the test pathogens while tube dilution method was used for the determination of minimum inhibitory concentration and minimum bactericidal concentration of the EO on the test bacteria. The highest activity of the EO was observed against E. coli where a mean inhibition zone of 34.00 mm was recorded at a concentration of 100 % followed by B. cereus where a mean inhibition zone of 32.33 mm was recorded at an oil concentration of 50 %. The minimum inhibitory concentrations and minimum bactericidal concentrations of the EO on the test pathogens were in the range of 3.13 - 12.25 % and 12.25 - >50 %, respectively. When compared to tetracycline which was used as the standard, crude essential oil of T. asiatica had significantly higher activity in three out of four studied bacterial strains. These findings justify the continued use of T. asiatica extracts in traditional herbal medicine for the treatment of bacterial-based infections.