The Inhibitory Effect of Three Essential Oils on Candida rugosa Lipase: In Vitro and In Silico Studies

Background: Essential oils have been used for centuries. EOs are gaining increasing interest because of their acceptance by consumers and their safe status. For the first time, the effect of essential oils on the inhibition of lipases has been investigated in this work. Objective: We aimed in this study to investigate in vitro the inhibitory effects of the three essential oils of most used spices: Peppermint (Mentha piperita L.), cinnamon (Cinnamomum zeylanicum L.) and Cloves (Syzygium aromaticum L. Merr. et Perry) against Candida rugose lipase. In silico studies using molecular docking have been achieved to study the inhibition mechanism of major compounds of EO: menthol, carvacrol, eugenol and cinnamylaldehyde toward CRL. Methods: The inhibitory effect of three essential oils were determined by candida rugosa enzyme and pNP-L as substrate using spectrophotometry. Autodock vina was used for molecular docking with 50 runs. Results: We have found that these essential oils have a strong inhibitory effect with IC50 values 1.09, 1.78 and 1.13 mg/ml compared with Orlistat 0.06 mg/ml. The results show competitive inhibition for the three major compounds Menthol, Carvacrol and Eugenol with uncompetitive inhibition for Cinnamaldehyde. Different repetition ratios of hydrogen bonds and hydrophobic interactions were observed. The saved interactions were with His449, Ser209, Gly123, Gly124 and Phe344 for all molecules. Conclusion: These observations support using and considering essential oils and their major compounds as good sources for design new drugs to treat candidiasis and other diseases related to Lipases.