Photodynamic therapy has antifungal effect and reduces inflammatory signals in Candida albicans-induced murine vaginitis

• Photodynamic therapy with methylene blue and red laser is able to reduce fungal load in vaginal candidiasis (VC).
• Photodynamic therapy is a suitable approach to diminish inflammatory signals associated with VC.
• Photodynamic therapy is a new promising treatment for VC.

SummaryBackgroundVaginal candidiasis (VC) is a disease that affects thousands of women of childbearing age, mainly caused by Candida albicans fungus. Photodynamic therapy (PDT) uses photosensitizing substances that are nontoxic in the dark, but able to produce reactive oxygen species when they are subjected to a light source. In this work our purpose was to investigate PDT effects on fungal burden and inflammatory cells in a murine model of C. albicans-induced vaginal candidiasis.MethodsFemale BALB/c mice 6–10 weeks were estrogenized and maintained in this state during all experiment. After 72 h, mices were inoculated intravaginally (IV) with 20 μL of 2 × 105C. albicans cells suspension. Mice were separated into 5 groups after five days: H (healthy), PBS (control), laser, MB (methylene blue) and PDT. PDT and MB groups received IV 20 μL solution with 1 mM of MB, others received PBS. PDT and laser groups were irradiated with a red laser (100 mW, 660 nm) in one (36 J, 6 min) or two sessions (18 J, 3 min). After the end of treatment, mice were submitted to microbiological and histomorphometric analysis with ImageJ software. Data were plotted by mean values and standard deviations of CFU/mL and percentage of inflammatory cells area. ANOVA and Bonferroni post-test were used and data were considered significant when p < 0.05.ResultsPDT significantly reduced C. albicans after the two tested protocols, however, percentage area of inflammatory cells was significantly reduced just with two sessions of PDT.ConclusionsPDT with MB and red laser is a promising therapy for VC. It is able to reduce fungal infection in biofilm and inflammatory signals associated with VC in a murine model of vaginitis.