Antifungal Activity of Natural Thymol: Advances on Molecular Mechanisms and Therapeutic Potential

Currently, the increased incidence of invasive fungal infections globally is posing a significant challenge to public health. Due to drug resistance issues, the clinical efficacy of existing antifungal drugs is seriously insufficient, while new drug development progresses slowly. Consequently, there is an urgent need to discover and develop novel antifungal therapeutics. Natural products have the characteristics of wide sources and few adverse reactions and are one of the sources for developing antifungal drugs. Numerous studies have shown that many compounds isolated from plants and traditional Chinese medicine have antifungal activity and diverse antifungal mechanisms. Thymol, a monoterpene phenol compound from thyme (Lamiaceae), has multiple biological functions such as antibacterial, antioxidant, and anti-inflammatory. Recent research has found that thymol has strong antifungal activity, and its molecular mechanisms involve cell membrane rupture, interference with cell wall synthesis, disruption of mitochondrial function and energy metabolism, inhibition of biofilm, inhibition of virulence factor expression, inhibition of key enzymes, and induction of cell apoptosis. This review aimed to summarize the antifungal activity of thymol and the underlying molecular mechanisms, safety, and potential clinical applications. Emerging technologies in thymol delivery systems and future research directions are also discussed. The comprehensive analysis aims to provide a detailed understanding of fungal infections and the role of thymol in antifungal treatment, offering insights for further research and clinical practice.