Cellular, physiological and molecular approaches to investigate the antifungal and anti-aflatoxigenic effects of thyme essential oil on Aspergillus flavus. (15th June 2020)

• Record Type: Journal Article
• Authors: Oliveira, Rodrigo C.; Carvajal-Moreno, Magda; Correa, Benedito; Rojo-Callejas, Francisco
• Is Part Of: Food chemistry. Volume 315(2020)
• Publication Date: 2020-06-15
• Subjects: Essential oil -- Mycotoxins -- Apoptosis -- Gene expression -- Aflatoxins; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2019.126096
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Thyme essential oil could suppress growth and aflatoxin B1 production in A. flavus. Thyme essential oil induced apoptotic-like cell death on A. flavus . Gene laeA of fungal secondary metabolism was down-regulated by thyme essential oil. Abstract: Several approaches, including the detection of apoptotic-like cell death, aflatoxin B1 (AFB1 ) production and gene expression analysis, were carried out to provide insights into the antifungal and anti-aflatoxigenic effects of thyme essential oil (EO) on Aspergillus flavus . At 0.5 µL mL −1, thyme EO completely inhibited A. flavus growth. Furthermore, this antifungal activity triggered significant apoptosis, via nuclear condensation (87.5% of nuclei analyzed) and plasma membrane damage (in 100% of treated hyphae). Further analysis of AFB1 production and gene expression related to secondary metabolism ( laeA ) and the mechanism of virulence ( lipA and meT ) of A. flavus in the presence of thyme EO indicated important physiological changes related to its anti-aflatoxigenic property. These results highlight the potent antifungal abilities of thyme EO in controlling A. flavus and AFB1 production, especially the abilities that operate by exerting changes at the molecular level and inducing significant apoptotic-like cell death.