Antifungal, Anti-aflatoxigenic, Antioxidant Activity and in vivo Efficacy of Essential Oil of the Aerial Parts of Thymus capitatus (L.) Hoffmanns & Link

Abstract

Aspergillus flavus has been reported to be the most common fungus used as food by human beings. This fungus may have the potential to produce aflatoxin B1 (AFB1), which is reported as being the most hepatotoxic, teratogenic, mutagenic, and immunosuppressive to humans and other livestock. Therefore, the objective of this work was to study the chemical profile of Thymus capitatus essential oil (EO) and the inhibition of growth of Aspergillus flavus E73 and AFB1 production by the EO. The antioxidant activity and phytotoxicity were also evaluated. The gas chromatography– mass spectrometry (GC–MS) analysis showed that the major components of Thymus capitatus EO were thymol (25.82%), linalool (23.40%), geraniol (14.22%), pcymen- 3-ol (8.93%), and p-cymene (6.76%). The results showed that the EO could inhibit the growth of Aspergillus flavus E73 in the range of 40.72 to 87.00%. The minimal inhibitory concentration (MIC) of Thymus capitatus EO against Aspergillus flavus E73 was found to be at 1.00 mg/ml. The oil revealed complete inhibition of dry mycelium weight and AFB1 production at 1.00 mg/ml. The EO revealed a broad spectrum of fungitoxicity against some fungi. The antioxidant activity was also assessed where IC50 (when initial concentration is reduced to half) and β- carotene/linoleic acid inhibition percentage of Thymus capitatus EO were 619.16 ± 3.94 μg/ml and 65.55%, respectively, while the total phenolic content was 21.45 μg/mg. The EO showed non-phytotoxicity on two varieties of wheat seeds. These findings demonstrated that EO could be good alternative to protect food.