Antifungal properties and inhibitory effects upon aflatoxin production of Thymus vulgaris L. by Aspergillus flavus Link

Abstract

The antifungal and antiaflatoxigenic properties of Thymus vulgaris essential oil (TEO) were evaluated upon Aspergillus flavus "in vitro". Suspension containing 10(6) of A. flavus were cultivated with TEO in concentrations ranging from 50 to 500 μg/mL. TEO reached minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) at 250 μg/mL. Inhibition of ergosterol biosynthesis was detected at a concentration of 100 μg/mL of TEO. Morphological evaluation performed by both light microscopy and scanning electron microscopy showed that antifungal activity of TEO could be detected starting at a concentration of 50 μg/mL and the fungicide effect at a concentration of 250 μg/mL. TEO completely inhibited production of both B1 and B2 aflatoxins (AFB1 and AFB2) at a concentration of 150 μg/mL. This way, fungal biomass development and aflatoxin production were dependent on TEO concentration. Therefore, TEO was capable of controlling the growth of A. flavus and its production of aflatoxins.

Essential oils of Moldavian Thymus species: Chemical composition, antioxidant, anti‐Aspergillus and antigenotoxic activities

“…In addition, Kohiyama et al. reported that T. vulgaris EO (40.6% borneol, 19.9% α‐terpineol) inhibited A. flavus growth (MIC=250 μg/ml) and aflatoxin production . With respect to T. vulgaris EO (density=0.92 g/ml, at 20°C), we found a MIC value close to that reported by Kohiyama et al.…”

“…34 Antioxidant aromatic compounds such as thymol and p-cymene were detected in higher levels in T. citriodorus 'Aureus' EO than in T. aflatoxin production. 36 With respect to T. vulgaris EO (density=0.92 g/ml, at 20°C), we found a MIC value close to that reported by (Table 3). (Figure 1, Figure 2 μM of thymol produced DNA damaging effects.…”

“…(230 vs . 250 μg/ml) . The differences that occur between the reported values can be explained by the sensitivity of the fungal strain, methodology and chemical composition of Thymus EOs.…”

Inhibiting Microbial Toxins Using Plant-Derived Compounds and Plant Extracts

“…In addition, histological analysis of liver from chickens fed with plant compounds revealed significantly lesser hepatocellular degeneration, inflammation and necrosis as compared to control birds [175]. Similar inhibitory effect on aflatoxins production was obtained with other plant-derived antimicrobials, namely Thymus eriocalyx [176], Thymus vulgaris [177], thyme , anise , cinnamon , and spearmint [178]. These results suggest that plant compounds could be used as feed/food additives to control aflatoxins contamination in food products or animal feed.…”

Identification of the Anti-Aflatoxinogenic Activity of Micromeria graeca and Elucidation of Its Molecular Mechanism in Aspergillus flavus

“…As plants grow, they produce many metabolites that serve as a defense against a number of environmental stresses. Therefore, plant extracts have long been studied as protective bioactive agents and it was demonstrated that some of them have antifungal or anti-toxinogenic properties [19,20]. …”