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

Document Type : Full Research Paper

Authors

1 ,Department of Food Hygiene, Faculty of Veterinary Medicine, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Department of Food Science and Technology, Faculty of Agricultural Sciences and Food Industry, Science and Research Branch, Islamic Azad University, Tehran, Iran

3 Department of pathobiology school of veterinary science and research branch islamic azad university Tehran, Iran.

Abstract

Background and Objectives: 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.
Material and methods: 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.
Results: 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.
Conclusion: 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.   

Keywords


1. Abbaszadeh S, Sharifzadeh A, Shokri H, Khosravi A, Abbaszadeh A .2014 . .Antifungal efficacy of 
thymol, carvacrol, eugenol and menthol as alternative agents to control the growth of food-relevant fungi. Journal de mycologie medicale.2 4(2):e51-e56.
2. Ahmad A, Khan A, Akhtar F, Yousuf S, Xess I, Khan L, et al.2011  .Fungicidal activity of thymol and carvacrol by disrupting ergosterol biosynthesis and membrane integrity against Candida. European journal of clinical microbiology & infectious diseases .30(1):41-50.
3. Alizadeh-Salteh S. 2015 Growth inhibition of Aspergillus flavus isolated from pistachio by secondary metabolites. Journal of Nuts 6(2):85-94.
4. J.IPitt, J. C Basilico,M. L. Abarca,c. Lopez. 2000 . Mycotoxin and toxigenic fungi. Medical mycology.38: 41-46.
5. Bishop CD.  .1995Antiviral activity of the essential oil of Melaleuca alternifolia (maiden amp; Betche) Cheel (tea tree) against tobacco mosaic virus. Journal of Essential Oil Research. 7(6):641-4.
6. Bryden WL. .2007Mycotoxins in the food chain: human health implications. Asia Pacific journal of clinical nutrition.16(S1):95-101.
7. Hitokoto H, Morozumi S, Wauke T, Sakai S, Kurata H.. 1980 Inhibitory effects of spices on growth and toxin production of toxigenic fungi. Applied and Environmental Microbiology. 39(4):818-22.
8. Hu Y, Zhang J, Kong W, Zhao G, Yang M. .2017 Mechanisms of antifungal and anti-aflatoxigenic properties of essential oil derived from turmeric (Curcuma longa L.) on Aspergillus flavus. Food chemistry. 220:1-8.
9. López-Malo A, Alzamora SM, Palou E. .2002 Aspergillus flavus dose–response curves to selected natural and synthetic antimicrobials. International Journal of Food Microbiology. 73(2-3):213-8.
10. López-Malo A, Alzamora SM, Palou E.  .2005Aspergillus flavus growth in the presence of chemical preservatives and naturally occurring antimicrobial compounds. International Journal of Food Microbiology. 99(2):119-28.
11. L Shcherbakova, O Mikityuk, L Arslanova.2021. Studing the ability of Thymol to Improve fungicidal effects of Tebuconazole and Difenoconazole Against some plant pathogenic fungi in seed or foliar treatment. Frontiers in Microbiology.12,331
12. Mari M, Bertolini P, Pratella G.2003. Nonconventional methods for the control of post‐harvest pear diseases. Journal of Applied Microbiology. 94(5):761-6
13. Moon Y-S, Lee H-S, Lee S-E. . 2018Inhibitory effects of three monoterpenes from ginger essential oil on growth and aflatoxin production of Aspergillus flavus and their gene regulation in aflatoxin biosynthesis. Applied Biological Chemistry. 61(2):243-50.
14. Organization WHO. Food safety and foodborne illness. WHO fact sheet No. 237.
15. Passone MA, Rosso LC, Ciancio A, Etcheverry M. . 2010Detection and quantification of Aspergillus section Flavi spp. in stored peanuts by real-time PCR of nor-1 gene, and effects of storage conditions on aflatoxin production. International journal of food microbiology.138(3):276-81.
16. Pessoa L, Morais S, Bevilaqua C, Luciano J.  .2002Anthelmintic activity of essential oil of Ocimum gratissimum Linn and eugenol against Haemonchus contortus. Veterinary parasitology.109(1-2):59-63.
17.  P C Braga, M Alfieri, M  Culici. 2007. Inhibitory activity of thymol against the formation and viability of candida albicans hyphae. Mycoses.50 :502-506
18. Rasooli I, Abyaneh MR.  .2004Inhibitory effects of Thyme oils on growth and aflatoxin production by Aspergillus parasiticus. Food control.15(6):479-83.
19. Scherm B, Palomba M, Serra D, Marcello A, Migheli Q.  .2005Detection of transcripts of the aflatoxin genes aflD, aflO, and aflP by reverse transcription–polymerase chain reaction allows differentiation of aflatoxin-producing and non-producing isolates of Aspergillus flavus and Aspergillus parasiticus. International journal of food microbiology.98(2):201-10.
20. Skory CD, Chang P-K, Linz JE. .1993Regulated expression of the nor-1 and ver-1 genes associated with aflatoxin biosynthesis. Applied  and Environmental Microbiology.59(5):1642-6.
21. Tripathi P, Dubey N. . 2004 Exploitation of natural products as an alternative strategy to control postharvest fungal rotting of fruit and vegetables. Postharvest biology and Technology.32(3):235-45.
22. Yahyaraeyat R, Khosravi A, Shahbazzadeh D, Khalaj.  .2013The potential effects of Zataria multiflora Boiss essential oil on growth, aflatoxin production and transcription of aflatoxin biosynthesis pathway genes of toxigenic Aspergillus parasiticus. Brazilian Journal of Microbiology.44(2):649-55.
23. Yu J, Chang P-K, Ehrlich KC, Cary JW, Bhatnagar D, Cleveland TE, et al.  .2004Clustered pathway genes in aflatoxin biosynthesis. Applied andEnvironmental Microbiology.70(3):1253-62.
Zain ME..2011 Impact of mycotoxins on humans and animals. Journal of Saudi Chemical Society. 15(2):129-44.