Chemical Composition and Antibacterial Activity of the Essential Oil of <i>Dysphania ambrosioides</i> (L.) Mosyakin & Clemants from North Central Nigeria

Abstract

The chemical composition of the essential oil of Dysphania ambrosioides and the antibacterial properties of the oil against two clinical isolates and two typed isolates (one each of Gram positive and Gram negative bacteria) of Bacillus subtilis, Staphylococcus aureus ATCC 25923; Escherichia coli, Pseudomonas aeruginosa ATCC 27853 was studied. The essential oil was extracted from the fresh leaves of D. ambrosioides with the aid of a Clevenger apparatus by hydrodistillation after which the chemical composition of the oil was analyzed using the Shimadzu GCMS QP2010 plus. The minimum inhibitory concentration (MIC) of the oil against E. coli, S. aureus, B. subtilis and P. aureginosa as well as and the zones of inhibition compared with standard antibiotics was determined. The GC-MS analysis revealed a total of twenty (20) compounds in the oil, with alpha-terpinene (48.68%), o-Cymene (21.71%) and trans-beta-terpinyl butanoate (17.15%), ascaridole (5.67%), gamma-terpinene (2.16%) and D-limonene (1.83%) being the major compounds identified. The oil was active against E. coli, S. aureus, P. aureginosa andB. subtilis at MIC ranging from 10 to 20 μL/mL. The zones of inhibition revealed that the oil has a good microbial efficacy at 200μL/mL (ranging from 27.5 to 30mm) against E. coli, S. aureus, B. subtilis which is comparable to ciprofloxacin, better than vancomycin, ampicillin and amoxicillin/clavulanic acid, and a relatively lower activity against P. aeruginosa (11mm). The oil was rich in compounds that possessed antimicrobial activity.