Investigation of antifungal activity of stilbenes alone and in combination with fluconazole against candida albicans

Abstract

Objective: The objective of the present study was to evaluate the synergistic activity og two stilbenes in combination with fluconazole against candida albicans. Methods: In this study, we used two stilbenes [3,4',5-trihydroxystilbene (1) and 3,5-dihydroxy-4-isopropylstilbene (2)] purified from a bacterium associated with entomopathogenic nematode (EPN), to demonstrate both its intrinsic antifungal activity and its synergistic interaction with the fluconazole, in the treatment of C. albicans in vitro. The cytotoxicity of stilbenes was also tested against normal human cell line (FS normal fibroblast and L231 lung epithelial cell line). Results: Our results demonstrated that significant synergistic antifungal activity exists between the two stilbenes and fluconazole against C. albicans. The time kill assay also supports the synergistic activity. No cytotoxicity was recorded for stilbenes and stilbenes plus fluconazole up to 200 μg/mL. But fluconazole alone recorded significant cytotoxicity. Conclusion: These results suggest that stilbenes combined with antibiotics may be microbiologically beneficial. These findings have potential implications in delaying the development of resistance as the anticandidal effect is achieved with lower concentrations of both drugs.