The Antifungal Efficacy of Clove Oil Nanoemulsions and Their Chemical Constituents in Mitigating Fusarium Mycotoxins

Abstract

We conducted in vitro studies to assess the effectiveness of clove oil and their chemical constituents to control Fusarium isolates such as 10–124–1 and 10–125–1 and their respective mycotoxins. Among the tested compounds, β-caryophyllene showed no antifungal activity, while eugenol exhibited the strongest inhibitory effects on mycelial growth and spore germination, followed by clove oil and eugenol acetate. These effects were likely due to cell membrane disruption and subsequent loss of cytoplasmic content, as evidenced by scanning electron microscopy (SEM). Regarding the mycotoxin inhibitory efficacy of the four nanoemulsions, all except β-caryophyllene significantly reduced mycotoxin production. Four nanoemulsions disrupting the biosynthetic pathway of DON production at the genetic level were investigated and the results indicated that all compounds, except β-caryophyllene, downregulated the expression of key biosynthetic genes (Tri3, Tri4, and Tri5) in isolate 10–124–1 while upregulating these genes in isolate 10–125–1. Overall, our results support optimizing clove oil formulations.