Effects of patchouli and cinnamon essential oils on biofilm and hyphae formation by Candida species

The prevalence and fatality rates with biofilm-associated candidal infections have remained a challenge to the medical fraternity despite major advances in the field of antifungal therapy. Traditionally, essential oils (EOs) from the aromatic plants have been found to be excellent therapeutic agents to treat fungal ailments. The present study explores the antivirulent and antibiofilm effects of under explored leaf EOs of Indian patchouli EO extracted from Pogostemon heyneanus (PH), Indian cassia from Cinnamomum tamala (CT) and camphor EO from C. camphora (CC) against Candida species. The EOs were investigated for its efficacy to disrupt the young and preformed Candida spp. biofilms and to inhibit the yeast to hyphal transition, a hallmark virulent trait of C. albicans. The ability of these EOs to inhibit metabolically active cells was assessed through XTT assay. Of these three EOs, CT EO showed enhanced biofilm inhibition than others and hence it was further selected to study its biomass inhibition potential and exopolysaccharide layer disruption ability. The CT EO reduced the biomass of the preformed biofilms of all three Candida strains, which was supported by confocal microscopy. It also disrupted the exopolysaccharide layer of the Candida strains as shown by scanning electron microscopy. The present findings validate the effectiveness of EOs against the virulence of Candida spp. and emphasize the pharmaceutical potential of several native but yet unexplored wild aromatic plants in the prospect of therapeutic application.