Comparative Antifungal Activity of Medicinal Plant Extracts and Essential Oils Against Clinical Isolates of Candida albicans from Denture Stomatitis Patients

In this study, we investigated the antifungal potential of methanolic extracts and essential oils obtained from five medicinal plants (Salvadora persica, Mentha spicata, Achillea millefolium, Matricaria chamomilla, and Zingiber officinale) against 25 clinical isolates of Candida albicans collected from patients with denture stomatitis. Antifungal susceptibility was assessed using broth microdilution as the primary method, with agar diffusion assays performed to provide complementary visual confirmation. Nystatin was included as a reference control. Across the tested samples, essential oils consistently showed stronger antifungal effects than the corresponding methanolic extracts. Notably, Z. officinale essential oil exhibited the highest level of activity, inhibiting 15 out of 25 isolates and, in several cases, demonstrating efficacy comparable to or exceeding that of nystatin. Chemical profiling by GC–MS indicated that the ginger essential oil was dominated by sesquiterpene and monoterpene hydrocarbons, with zingiberene (21.49%) being the major constituent, followed by β-sesquiphellandrene, α-curcumene, sabinene, and α-citral. This terpene-rich composition may contribute to the observed antifungal activity, potentially through the disruption of fungal cell membrane integrity. Taken together, these results suggest that Z. officinale essential oil represents a promising natural antifungal candidate for the management of denture-associated C. albicans infections. Further studies, including biofilm-based assays and in vivo evaluations, will be necessary to confirm its clinical applicability. To the best of our knowledge, this study is among the first to comparatively assess these five medicinal plants against clinical C. albicans isolates derived specifically from denture stomatitis patients.