Method: Fifty-five 6-week-old female Swiss mice were immunosuppressed. They were given tetracycline hydrochloride in their drinking water, then small cotton pads were soaked in a C. albicans cell suspension (107CFU/mL) and swabbed in the oral cavity to produce oral candidiasis. Photodithazine-mediated PDT was performed five days after Candida inoculation. The PS was applicated topically on the dorsum of the tongue of mice at concentrations 75, 100, 125 and 150mg/L for 20 minutes before the treatment (pre-irradiation time) followed by 14 minutes by illumination with red LED light (37,5J/cm2) at 660nm. After treatment the dorsum of the tongue was swabbed to recover C. albicans cells and the microbiological evaluation was performed. The yeast colony counts were quantified and the number of CFU/mL was determined and analyzed by ANOVA test (P<.05). Animals were killed 24 hours after treatment and the tongue of all mice were surgically removed for histological analysis.
Result: The results of this investigation demonstrated that PDT was effective in reducing C. albicans recovered from the tongue of mice (P<0.05) at concentrations 100, 125 and 150mg/L of PS when compared with the animals from the positive control group. There was no difference between these concentrations. Histological analyze was performed and no adverse effect on the tongue tissue was induced by PDT.
Conclusion: PDT was effective for inactivation of C. albicans without causing any harming effects on tissues.