Photodynamic antimicrobial chemotherapy (PACT) with methylene blue increases membrane permeability in Candida albicans

• DOI: 10.1007/s10103-007-0530-2
• Publication Date: 2007-12-21T09:52:13Z
• Authors: Ligia Maria Giroldo; Monalisa Poliana ...; Marco Antonio de ...; Egberto Munin; Leandro Procópio ...; Maricilia Silva C...
• Keywords: Methylene Blue; 0303 health sciences; 03 medical and health sciences; Cell Membrane Permeability; Photochemotherapy; Lasers; Candida albicans; Fluorometry; 3. Good health

Photodynamic antimicrobial chemotherapy (PACT) is a potential antimicrobial therapy that combines light and a photosensitizing drug, promoting a phototoxic effect on the treated cells, in general via oxidative damage. In this work we studied the effect of PACT, using methylene blue (MB), on the permeability of Candida albicans membrane. Our results demonstrated that the combination of MB and laser (684 nm) promoted a decrease in Candida growth. The inhibition was more pronounced in the presence of 0.05 mg/ml MB and with an energy density of 28 J/cm(2). The decrease in Candida growth was associated with an increase in membrane permeabilization. Thus, we suggest that a PACT mechanism using MB can be related to damage in the plasma membranes of the cells.