In vitro antifungal activities of essential oil from Nigerian medicinal plants against toxigenic Aspergillus flavus

Abstract

The aim of this study is to determine the sensitivity profile of toxigenic mould strain isolated from poultry feed to some essential oils. Essential oils extracted from eight medicinal plants collected from South-West Nigeria were screened for their activity against toxigenic Aspergillus flavus by disc diffusion method. Minimum inhibitory concentrations (MICs) of oils (%v/v) against A. flavus done by agar dilution method and minimum fungicidal concentration (MFCs) data (%v/v) obtained by the broth micro dilution method. Different concentrations of the essential oils were also tested for spore germination of the assayed mould strains. In addition, the essential oils were able to inhibit the mould spores germination when assayed at different concentrations. The results showed that the maximum antifungal activity, MIC and reduction in spore germination was demonstrated by oils of Cymbopogon citratus, Allium sativum and Ocimum basilicum as compared to control, which showed activity similar to control (miconazole nitrate). The essential oils of Zingiber officialis, Citrus limon and Citrus aurantifolia exhibited moderate activity. The oils of Citrus sinensis demonstrated comparatively low activity against the isolate as compared to control while the oil of Pimenta racemosa did not show any activity against the isolate. These results support the plant oils can be used to cure infections caused by toxigenic A. flavus and plant oils may have role as pharmaceutical and preservatives.