Treatment of oral candidiasis with methylene blue-mediated photodynamic therapy in an immunodeficient murine model.
Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics
confidence
Key findings
MB photodynamic therapy showed dose-dependent antifungal effect; 450-500 µg/mL fully eradicated C. albicans from oral cavity.
View source on PubMed (PMID 11862203) ↗
- Sample size
- 75 mice
- Population
- Immunodeficient (SCID) mice with oral candidiasis induced by Candida albicans
- Dosing
- 0.05 mL MB at 250, 275, 300, 350, 400, 450, or 500 µg/mL
- Duration
- 4-week inoculation period; 10-minute MB pre-treatment before light activation
- Route
- Topical oral cavity administration with 664 nm diode laser activation
- Blinding
- not_reported
- Controls
- none
- Drug class
- nootropic
Measured endpoints
- Candida albicans fungal growth (colony-forming units per milliliter)Decreasedantimicrobialnot_reportedeffect: Reductions from 2.5 log10 and 2.74 log10 to 0 at 450 and 500 µg/mL; partial reduction at 250-400 µg/mL
Full abstract
The purpose of this study was to evaluate the efficacy of using methylene blue (MB)-mediated photodynamic therapy to treat oral candidiasis in an immunosuppressed murine model, mimicking what is found in human patients. Seventy-five experimental mice with severe combined immunodeficiency disease were inoculated orally with Candida albicans by swab 3 times a week for a 4-week period. On treatment day, mice were cultured for baseline fungal growth and received a topical oral cavity administration of 0.05 mL MB solution at one of the following concentrations: 250, 275, 300, 350, 400, 450, or 500 microgram/mL. After 10 minutes the mice were recultured and underwent light activation with 664 nm of diode laser light with a cylindrical diffuser. After photodynamic therapy the mice were cultured again for colony-forming units per milliliter and then killed, their tissue harvested for histopathology. The results indicate an MB dose-dependent effect. Concentrations from 250 to 400 microgram/mL reduced fungal growth but did not eliminate Candida albicans. MB concentrations of 450 and 500 microgram/mL totally eradicated Candida albicans from the oral cavity, resulting in reductions from 2.5 log(10) and 2.74 log(10) to 0, respectively. These results suggest that MB-mediated photodynamic therapy can potentially be used to treat oral candidiasis in immunodeficient patients.