Photodynamic Inactivation in Vitro of the Pathogenic Fungus Paracoccidioides brasiliensis

Paracoccidioidomycosis (PCM) is a disease caused by the fungus Paracoccidioides brasiliensis (Pb), manifesting as a systemic mycosis, which can lead to death. This study evaluated the action of in vitro Photodynamic Inativation (PDI) on Pb yeast cells through the LED light source (LEC Prime WL—MMOptics: 455 nm, 0.8 W/cm² and 0.2 W with 6 mm tip) associated with the photosensitizer (Fs) curcumin 98%. The photodynamic action was performed with 4 groups and 6 application cycles of the technique, fractionated every 5 min, for a total cycle of 30 min. The tests were performed in quintuplicate and the groups were divided into: group 1—without Fs in its composition and without LED irradiation (L−F−); group 2—without Fs and with exposure to irradiation (L+F−); group 3—with Fs and without exposure to LED irradiation (L−F+); and group 4—composed with Fs and exposed to LED irradiation (L+F+). The results showed that the reduction of Pb, measured by the means of CFU Log, was significantly higher in group 4 (0.7748 ± 0.1876) when related to group 1 (2.399 ± 0.09470) (p < 0.001), group 2 (2.178 ± 0.08214) (p < 0.001) and group 3 (1.818 ± 0.09987) (p < 0.001). There was elimination of the fungus P. brasiliensis from the 20th minute of irradiation in the group exposed to the LED associated to the presence of Fs (p < 0.001). We concluded that PDI associated with the administration of curcumin 98% is capable of promoting the in vitro elimination of the pathogenic fungus Paracoccidioides brasiliensis.