Essential Oils as Natural Inhibitors of Candida albicans Proteases: In-silico and In-vitro Evaluation

Abstract

Candida albicans is a common opportunistic fungal pathogen that causes mucosal and systemic infections, especially in immunocompromised persons. Hydrolytic enzymes including secreted aspartyl proteases (SAPs) and sterol 14α-demethylase (CYP51) contribute to the pathogen's pathogenicity by facilitating tissue invasion, biofilm development, and immune evasion. In this study, chosen essential oils lemongrass, thyme, and tea tree were investigated for their inhibitory ability against SAP5 and CYP51 using in-silico docking and in-vitro antifungal tests. Molecular docking indicated that substances such as thymol, geraniol, citral, and citronellol had high binding affinities and hydrogen bond interactions with critical SAP5 and CYP51 active site residues. Subsequent enzyme inhibition assays and microbiological casein agar plate tests proved that lemongrass and thyme oils had strong antifungal action, whereas tea tree oil had comparatively weaker effects. These findings imply that essential oils, notably lemongrass and thyme, have potential as natural antifungal agents by targeting important C. albicans proteases. Further research into identified active chemicals may lead to new therapy options for Candida infections that are resistant.