Evaluation the antifungal effect of thymol and its effect on NOR1 gene expression in Aspergillus flavus isolates

Phenolic compounds are known as the most important substance with antimicrobial properties and also as active components of essential oils such as thyme and savory. The aim of this study was to evaluate the effect of thymol on the growth and expression of nor1 gene in Aspergillus flavus isolates.

In this study, the antifungal effect of thymol on Aspergillus flavus was evaluated. Also, evaluation of nor1 gene expression of samples treated with thymol after culture in YES specific medium was determined by Real Time-PCR.

The minimum inhibitory  concentration (MIC) of thymol on Aspergillus flavus isolates ranged from 400 to 200 g / ml. Analysis of gene expression by Real Time-PCR method showed that thymol reduced the expression of nor1 gene in Aspergillus flavus isolates.  The expression of nor1 gene in each of the sensitive and resistant isolates was calculated to be 0.06% and 1.69%, respectively.

Due to the fact that the first step in the production of this toxin is the expression of a reductase enzyme of the nor1 gene to convert NOR1 (norsuluronic acid) to aflatoxin. Therefore, the lack of expression of this gene  inhibit the production of toxins. In this study, it was shown that thymol can have inhibitory effects on the growth and expression of nor1 gene  Because food contamination with aflatoxins is a threat to public health, the use of natural compounds and products is essential to reduce food contamination.