中文摘要：黄曲霉是一种土传病原菌，因其产生致癌性霉菌毒素黄曲霉毒素B1（AFB1）而危害人和动物。减少这种真菌污染的方法主要是本身可能有毒的化学物质。因此，鉴定并表征抗黄曲霉毒素产生的天然产物就成为可持续发展的战略选择。先前的研究已证明，黑胡椒的主要成份胡椒碱是一种AFB1抑制剂；而其行为机理尚待阐明。本研究旨在评估胡椒碱对黄曲霉，特别是在氧化应激反应下活动的分子机理。研究表明当胡椒碱正调控黄曲霉抗氧化状态时，抑制了黄曲霉产生AFB1。
外文摘要：Aspergillus flavus, a soil-borne pathogen, represents a danger for humans and animals since it produces the carcinogenic mycotoxin Aflatoxin B1 (AFB1). Approaches aiming the reduction of this fungal contaminant mainly involve chemicals that may also be toxic. Therefore, identification and characterization of natural anti-aflatoxigenic products represents a sustainable alternative strategy. Piperine, a major component of black and long peppers, has been previously demonstrated as an AFB1-inhibitor; nevertheless its mechanism of action was yet to be elucidated. The aim of the present study was to evaluate piperine's molecular mechanism of action in A. flavus with a special focus on oxidative stress response. For that, the entire AFB1 gene cluster as well as a targeted gene-network coding for fungal stress response factors and cellular receptors were analyzed. In addition to this, fungal enzymatic activities were also characterized. We demonstrated that piperine inhibits aflatoxin production and fungal growth in a dose-dependent manner. Analysis of the gene cluster demonstrated that almost all genes participating in aflatoxin's biosynthetic pathway were down regulated. Exposure to piperine also resulted in decreased transcript levels of the global regulator veA together with an over-expression of genes coding for several basic leucine zipper (bZIP) transcription factors such as atfA, aftB and ap-1 and genes belonging to superoxide dismutase and catalase's families. Furthermore, this gene response was accompanied by a significant enhancement of catalase enzymatic activity. In conclusion, these data demonstrated that piperine inhibits AFB1 production while positively modulating fungal antioxidant status in A. flavus.
外文关键词：Aflatoxin B1；A. flavus；Inhibition；Oxidative stress；Gene expression；Piperine
作者：Caceres, I；El Khoury, R；Bailly, S；Oswald, IP；Puel, O；Bailly, JD；AF Caceres, Isaura；El Khoury, Rhoda；Bailly, Sylviane
作者单位：Univ Toulouse
期刊名称：FUNGAL GENETICS AND BIOLOGY
期刊影响因子：2.933
出版年份：2017
出版刊次：-
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