Assessing the efficacy of gutiferone E in photodynamic therapy for oral candidiasis

The rise in antifungal resistance and side effects of conventional treatments drive the search for innovative
therapies like Photodynamic Therapy (PDT). This study explored the efficacy of PDT mediated by gutiferone, an
isolated compound from red propolis, for candidiasis treatment. Multiple evaluation methods were employed,
including determining the minimum inhibitory concentration (MIC) via broth microdilution, quantifying
biomass using crystal violet detachment, and cell counting through total plate count. PDT mediated by gutiferone
was also assessed in five groups of mice, followed by histopathological examination and agar plating of lingual
tissue samples. Among the seven Candida species tested, gutiferone displayed efficacy against C. albicans, C.
glabrata, and C. tropicalis, with MIC values of 1000 μg/mL. In C. tropicalis biofilms, exposure to gutiferone led to a
reduction of 1.61 Log10 CFU/mL. PDT mediated by gutiferone achieved an average reduction of 3.68 Log10
CFU/mL in C. tropicalis biofilm cells, underscoring its potent fungicidal activity. Histopathological analysis
revealed fungal structures, such as pseudohyphae and hyphae, in infected groups (G2) and irradiated mice. In
contrast, groups treated with gutiferone or subjected to gutiferone-assisted PDT (G5) exhibited only few blastoconidia.
Furthermore, CFU/mL assessments in lingual tissue post-treatment demonstrated a significantly lower
count (0.30 Log10 CFU/mL) in the G5 group compared to G2 (2.43 Log10 CFU/mL). These findings highlight the
potential of PDT mediated by gutiferone as a promising alternative for managing denture stomatitis. Future
research and clinical investigations offer the promise of validating its clinical applicability and improving outcomes
in the treatment of oral candidiasis.