Antibiofilm and anti-hyphal activity of a valencene-enriched fraction against Candida albicans.

In recent years, the emergence of azole-resistant Candida albicans strains has contributed to increased treatment failure with conventional antifungal therapies. Given the critical role of hyphal formation and biofilm development in C. albicans pathogenicity, this virulence traits represent important but challenging therapeutic targets. In this context, natural products have gained attention as potential sources of novel antivirulence agents. This study investigated the effects of a valencene-enriched fraction (VEF) derived from citrus fruits on the virulence characteristics of C. albicans. VEF significantly inhibited biofilm formation and reduced metabolic activity in vitro. Furthermore, it effectively suppressed the yeast-to-hyphal transition, preventing filamentation under both solid and liquid growth conditions. In an in vivo Caenorhabditis elegans infection model, VEF treatment significantly increased host survival compared to untreated infected controls. Importantly, VEF exhibited no observable toxicity toward nematodes, even at higher concentrations. At the molecular level, RT-PCR analysis revealed that VEF treatment significantly downregulated key hypha- and biofilm-associated genes, including hwp1, als3, egf1, and cph1 suggesting interference with the major regulatory pathways governing morphogenesis and virulence. Overall, these findings indicate that VEF possesses promising antibiofilm and anti-hyphal activities and supports its preliminary antivirulence potential. Rather than suggesting direct therapeutic applications, this study highlights VEF as a candidate for further antivirulence and mechanistic investigations. In particular, the results support valencene as a potential antivirulence scaffold for future research aimed at addressing antifungal resistance and pathogenicity in C. albicans.