A major global problem is the severe toxicity of conventional antifungal medications and multidrug resistance. Investigation of new substances with outstanding therapeutic potential is necessary. In this work, the antifungal potential of limonene, a secondary metabolite present in numerous essential oils derived from citrus plant, is assessed. It was tested for antifungal susceptibility, hydrolytic enzyme secretion, morphological transition, adhesion, and biofilm formation in in-vitro anti-Candida research. Further testing was conducted using docking tools, followed by MD simulations employing five main antifungal targets related with pathogenicity (Als3, Bcr1, Plb1, Sap2 and Tec1). It only results in 1% RBC cell lysis at MIC of 300 µg/ml. To buccal epithelial cells, limonene drastically decreased adherence. As well as being reduced by 73% and 53%, respectively, at MIC, were the hydrolytic enzymes proteinases and phospholipases. It was observed under a microscope that limonene administration prevents morphological change in C. albicans. Also decreased by 91% and 87%, respectively, were adhesion and biofilm development. Stable hydrophobic contacts with all of the target proteins, with the exception of Bcr1, are confirmed by docking and MD modelling experiments. According to the current research, C. albicans is inhibited by limonene's main virulence factors. Limonene is an excellent candidate to be researched as an antifungal medicine due to its low toxicity, ease of availability, and great antifungal potential. To comprehend the present work's mode of action and precise target sites, molecular and in vivo research are required.
Keywords- biofilms, Candida albicans, hydrolytic enzymes, Limonene