Effect of Helium-Neon (HeNe) laser irradiacation on lesions in experimental paracoccidioidomycosis

ABSTRACT

Cutaneous lesions caused by the fungus Paracoccidioides brasiliensis lead to ulcerative wounds, which are difficult to be cured by conventional treatment with anti-fungal drugs due to their adverse effects and the multidrug resistance that some fungal isolates present. So, the laser therapy emerges as an alternative treatment since its anti-inflammatory effects and wound healing properties are already known. In this work, we showed that lesions caused by the inoculation of yeast cells into the back foot-pad of BALB/c mice and treated with HeNe laser present greater histologic organization, milder inflammatory infiltrate, higher organization of the granulation tissue around the lesion, and enhanced immunolabeling for iNOS. In addition, an increased SOD activity and NO concentration, higher percentage of macrophages, and lower neutrophil numbers were observed. The percentage of NK and NKT cells were also slightly higher after the first laser session. Altogether these results point towards a dual effect of the laser treatment, decreasing the inflammatory response and accelerating the wound healing of the lesions. In this sense, the HeNe laser can be considered as an effective adjunctive treatment to be combined with pharmacologic therapies for Effect of Helium-Neon (HeNe) laser irradiation on lesions in experimental paracoccidioidomycosis improving the treatment of painful non-healing paracoccidioidomycotic wounds.