GC-MS Analysis and in Vitro Antimicrobial Susceptibility of Foeniculum vulgare Seed Essential Oil

Essential oil from seeds of Foeniculum vulgare was extracted on Clevenger apparatus. Essential oil was analyzed on Gas-Chromatography-Mass spectrometry (GC-MS) from which thirty six components were identified, among which 6 major and 30 minor components having different structural formulae and molecular weight representing total 99.98% of oil. Essential was investigated for its antibacterial and antifungal activity against seven infectious microbial pathogens. Paper disc diffusion and serial micro-dilution assays were performed for the determination of inhibition zone (DIZ) diameters and minimal inhibitory concentration, respectively. The Foeniculum vulgare essential oil showed the Diameter of Inhibition Zone (DIZ) ranging from 19.4 ± 0.07 - 26.4 ± 0.09 mm at a concentration level of 28 μg/disc in all the ten strains tested. The minimum inhibitory concentration (MIC) of essential oil against bacterial and fungal strains was obtained in the range of 7.0 - 56 μg/ml. Antibacterial and antifungal activity of Foeniculum vulgare essential oil is due to the presence of certain secondary plant metabolites such as terpenoids, steroids and flavonoids, esters and acids which are identified in the essential oil. The oil components can be further studied for their biological activity and overcome the problem of drug resistance in microbes.