The essential oil extracted from the seeds of dill (Anethum graveolens L.) was demonstrated in this study as a potential source of an eco-friendly antifungal agent. To elucidate the mechanism of the antifungal action further, the effect of the essential oil on the plasma membrane and mitochondria of Aspergillus flavus was investigated. The lesion in the plasma membrane was detected through flow cytometry and further verified through the inhibition of ergosterol synthesis. The essential oil caused morphological changes in the cells of A. flavus and a reduction in the ergosterol quantity. Moreover, mitochondrial membrane potential (MMP), acidification of external medium, and mitochondrial ATPase and dehydrogenase activities were detected. The reactive oxygen species (ROS) accumulation was also examined through fluorometric assay. Exposure to dill oil resulted in an elevation of MMP, and in the suppression of the glucose-induced decrease in external pH at 4 µl/ml. Decreased ATPase and dehydrogenase activities in A. flavus cells were also observed in a dose-dependent manner. The above dysfunctions of the mitochondria caused ROS accumulation in A. flavus. A reduction in cell viability was prevented through the addition of L-cysteine, which indicates that ROS is an important mediator of the antifungal action of dill oil. In summary, the antifungal activity of dill oil results from its ability to disrupt the permeability barrier of the plasma membrane and from the mitochondrial dysfunction-induced ROS accumulation in A. flavus.
Research article: Tian J, Ban X, Zeng H, He J, Chen Y, et al. (2012) The Mechanism of Antifungal Action of Essential Oil from Dill (Anethum graveolens L.) on Aspergillus flavus. PLoS ONE 7(1): e30147. doi:10.1371/journal.pone.0030147
Read the full article here: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030147
Editor: Bob Lightowlers, Newcastle University, United Kingdom
Copyright: © 2012 Tian et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported by the National Mega Project on Major Drug Development (2011ZX09401-302), the Commonweal Specialized Research Fund of China Agriculture (201103016), the Key Program of Natural Science Foundation of Hubei Province of China (2010CBB02301), and the Fundamental Research Funds for the Central Universities (20103010101000185). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
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