α-Pinene: Docking Study, Cytotoxicity, Mechanism of Action, and Anti-Biofilm Effect against Candida albicans
Daniela Bomfim Barros, Luanna de Oliveira e Lima, Larissa Alves da Silva, Mariana Cavalcante Fonseca, Rafael Carlos Ferreira, Hermes Diniz Neto, Danielle da Nóbrega Alves, Walicyranison Plinio da Silva Rocha, Luciana Scotti, Edeltrudes de Oliveira Lima, Marianna Vieira Sobral, Lúcio Roberto Cançado Castellano, Juliana Moura Mendes, Felipe Queiroga Sarmento Guerra, Márcia Vanusa da Silva
Abstract
Candida albicans is associated with serious infections in immunocompromised patients. Terpenes are natural-product derivatives, widely studied as antifungal alternatives. In a previous study reported by our group, the antifungal activity of α-pinene against C. albicans was verified; α-pinene presented an MIC between 128–512 µg/mL. In this study, we evaluate time-kill, a mechanism of action using in silico and in vitro tests, anti-biofilm activity against the Candida albicans, and toxicity against human cells (HaCaT). Results from the molecular-docking simulation demonstrated that thymidylate synthase (−52 kcal mol−1), and δ-14-sterol reductase (−44 kcal mol−1) presented the best interactions. Our in vitro results suggest that α-pinene’s antifungal activity involves binding to ergosterol in the cellular membrane. In the time-kill assay, the antifungal activity was not time-dependent, and also inhibited biofilm formation, while rupturing up to 88% of existing biofilm. It was non-cytotoxic to human keratinocytes. Our study supports α-pinene as a candidate to treat fungal infections caused by C. albicans.