Jahanshiri Z, Shams-Ghahfarokhi M, Allameh A, Razzaghi-Abyaneh M
Dept. of Mycology and.
Iran J Public Health. 2012;41(6):72-9. Epub 2012 Jun 30.
The effect of curcumin as a natural safe compound with different biological activities was examined on fungal growth and aflatoxin production in Aspergillus parasiticus NRRL 2999.
The fungus was cultured in presence of serial two-fold concentrations of curcumin (125-2000 μg/ml) in yeast extract sucrose broth for 3 days at 28°C. Mycelia dry weight was determined as an index of fungal growth, while aflatoxin production was assessed by high performance liquid chromatography (HPLC). The expression of ver-1, nor-1, pksA, omtA and aflR genes in aflatoxin biosynthetic pathway was evaluated by real time PCR.
Curcumin strongly inhibited aflatoxin B(1) production in the range of 26.6 to 94.9% by serial two-fold concentrations from 125 to 2000 μg/ml. Fungal growth was also inhibited by the compound in the range of 34.0 to 60.8%. Analysis of the expression of aflatoxin pathway genes by real time PCR showed that curcumin inhibited the expression of ver-1, nor-1, pksA, omtA and aflR genes at concentrations of 250 and 1000 μg/ml. In concentration of 1000 μg/ml, gene expression was reduced by 31.3%, 44.6%, 57.1% 110.9% and 286.7% accordingly. Reduction in the expression of aflatoxin biosynthesis genes was significant only for aflR. In ferric reducing ability of plasma (FRAP) assay, curcumin showed strong antioxidant activity at all concentrations tested.
Curcumin may be employed successfully as a good candidate in controlling of toxigenic fungal growth on food and feed and subsequent contamination with aflatoxins in practice.
研究了姜黄素作为一种具有不同生物活性的天然安全化合物对寄生曲霉NRRL 2999真菌生长和黄曲霉毒素产生的影响。
将该真菌在酵母提取物蔗糖肉汤中，于28℃下，在一系列两倍浓度（125 - 2000μg/ml）的姜黄素存在下培养3天。测定菌丝体干重作为真菌生长指标，同时通过高效液相色谱法（HPLC）评估黄曲霉毒素的产生。通过实时PCR评估黄曲霉毒素生物合成途径中ver-1、nor-1、pksA、omtA和aflR基因的表达。
姜黄素以125至2000μg/ml的一系列两倍浓度，强烈抑制黄曲霉毒素B(1)的产生，抑制范围为26.6%至94.9%。该化合物也抑制真菌生长，抑制范围为34.0%至60.8%。通过实时PCR分析黄曲霉毒素途径基因的表达表明，姜黄素在250和1000μg/ml浓度下抑制ver-1、nor-1、pksA、omtA和aflR基因的表达。在1000μg/ml浓度下，基因表达相应降低了31.3%、44.6%、57.1%、110.9%和286.7%。黄曲霉毒素生物合成基因表达的降低仅对aflR有显著意义。在血浆铁还原能力（FRAP）测定中，姜黄素在所有测试浓度下均表现出强抗氧化活性。
在实践中，姜黄素可能成功用作控制食品和饲料中产毒真菌生长以及随后黄曲霉毒素污染的良好候选物。
