Investigation of Antifungal Activity of Stilbenes Alone and in Combination with Clotrimazole against Candida albicans

Candidiasis is a term describing infections by yeasts from the genus Candida, and the type of infection encompassed by candidiasis ranges from superficial to systemic. Treatment of such infections often requires antifungal agents such as clotrimazole, but increased use of these drugs has led to a selection of Candida sp. with increased resistance to these drugs. Antibiotics have been effective in treating infectious diseases, but resistance to these drugs has led to the emergence of new and the reemergence of old infectious diseases. 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 synergy with the clotrimazole, in the treatment of Candida albicans in vitro. Our results demonstrated that significant synergistic effect exists between stilbenes and Clotrimazole against C. albicans. The time kill assay also supports the synergistic activity. The cytotoxicity of stilbenes was also tested against normal human cell lines (L231 lung epithelial and folliculo-stellate (FS) normal fibroblast) and no cytotoxicity was recorded for stilbenes up to 200 μg/mL. _____________________________________________________________________________________________________________