Detoxification of Aflatoxin with Herbal compounds

Introduction: Aflatoxins are mainly produced by Aspergillus species which are the highly toxic secondary metabolites. These species often contaminate food and agricultural products including cereals, peanuts, and crops in the field. Recently, a number of studies have been carried out on the elimination of aflatoxin, and the antifungal effects of medicinal herbals. In this study, the effects of aqueous extracts as natural compounds such as Perrsian hogweed, Coriander, Fenel, Anise, Cumin, Dill, peper mint and Mullein were examined on aflatoxins production and the aflR gene expression in Aspergillus parasiticus. Methods: Aspergillus parasitius (ATCC15517) was incubated at 30°C for 2 days on Sabouraud Dextrose Agar. The concentration of fungal spores was calculated using the 0.5 McFarland turbidity and then adjusted in such a way that each test well contained 5×104CFUs/mL. In vitro antifungal susceptibility testing for determination of MIC was performed according to CLSI document M38-A2. Herbal extract were dissolved in sterile diluted water to get a concentration of 1g/mL, and then diluted to the final concentrations of 15.62–500mg/mL in RPMI medium. Real-time PCR assay were used for analyzing of changing in expression of the aflR gene. Result: Results indicated that minimal inhibitory concentration (MIC) in the extracts against A. parasiticus growth were 200mg/ml (Cumin), 150mg/ml (Coriander), 125mg/ml (Fenel and peper mint), 100mg/ml (Perrsian hogweed and Anise), and 50mg/ml (Dill and Mullein). Conclusion: Herbal extracts have antitoxic properties. In this study, antifungal activities of eight herbal extract was evaluated against an aflatoxin-producing A.parasiticus in relation to the reduction of the expression of aflR which is important key gene of aflatoxin. Moreover, some of them effectively decrease aflatoxin production. The level of aflR gene expression was decreased significantly after the exposure of fungal cells to the Dill and Mullein extracts. The lowest inhibition was observed in MIC= 200 mg/ml of Cumin. According to the results, it can be suggested that some of these herbal extracts may have antifungal potential to be used in medicine or agriculture.

Keywords:

Aflatoxin , Aspergillus parasiticus , Herbal Extracts , Aflatoxin