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Effects of HeNe laser irradiation on experimental paracoccidioidomycotic lesions
Maria Carolina Ferreira1, Vânia Nieto Brito, Jacy Gameiro
1Department of Microbiology and Immunology, Institute of Biology, State University at Campinas (UNICAMP), Caixa Postal 6109, 13083-970 Campinas, São Paulo, Brazil.
Abstract:
Paracoccidioidomycosis (PCM) is the most prevalent human mycosis in Latin America. The infection is thought to take place firstly in the lungs and then may disseminate to other organs and tissues. Treatment by currently available antifungals is lengthy, the drugs may have undesirable side effects, and some are costly. Occasional resistant strains of Paracoccidioides brasiliensis, the causative agent of PCM, have been reported. So, the search for more efficient treatments or adjuvant therapies has to be continued. In this work, we evaluated the effects of HeNe laser irradiation on cutaneous inflammatory lesions caused by the inoculation of 5 x 10(6)/0.1ml yeasts cells into the back footpad of Balb/c mice. HeNe irradiation (lambda=632.8nm, 3mW, incident energy of 3J/cm(2)) was applied at days 7, 8 and 9 post-infection and histological and immunohistochemical analysis were done. Unirradiated animals were used as controls. The results showed that laser-treated mice presented reduction of footpad edema, faster cutaneous wound healing, confluent granuloma, diffuse- and more loosely distributed immunolabeling for TNF-alpha, enhanced labeling of IFN-gamma and any P. brasiliensis form detected, whereas multiple viable fungi were seen in diffuse widespread granulomas obtained from non-treated mice foot-pad. Fungi that were harvested from laser-treated animals presented no capability of growth in vitro as compared to those obtained from non-treated mice. We conclude that HeNe laser irradiation was able to inhibit the progress of inflammatory local reaction produced by P. brasiliensis infection and influence local cytokines production. We suggest that this treatment modality can be a useful coadjuvant tool to be combined with antifungal agents in the treatment of PCM ulcerations. The mechanisms involved in laser therapy of PCM lesions need further investigation.
Insights
Helium-Neon laser irradiation effectively reduced inflammation and promoted healing in Paracoccidioidomycosis (PCM) lesions in mice. This novel therapy inhibited fungal growth, suggesting its potential as an antifungal adjuvant treatment.
Area of Science:
- Mycology
- Dermatology
- Biomedical Engineering
Background:
- Paracoccidioidomycosis (PCM) is a prevalent fungal infection in Latin America, often requiring lengthy treatments with potential side effects and drug resistance.
- Current antifungal therapies for PCM are limited by duration, side effects, cost, and emerging resistant strains of Paracoccidioides brasiliensis.
- There is a continuous need for novel and effective therapeutic strategies or adjuvant treatments for PCM.
Purpose of the Study:
- To investigate the efficacy of Helium-Neon (HeNe) laser irradiation as a therapeutic intervention for cutaneous inflammatory lesions caused by P. brasiliensis.
- To evaluate the impact of HeNe laser treatment on the inflammatory response, fungal burden, and healing process in a murine model of PCM.
- To explore the potential of HeNe laser therapy as an adjuvant treatment for PCM ulcerations.
Main Methods:
- Balb/c mice were infected with P. brasiliensis yeast cells in the footpad.
- HeNe laser irradiation (632.8nm, 3mW) was applied on days 7, 8, and 9 post-infection.
- Histological and immunohistochemical analyses were performed, alongside in vitro fungal growth assays.
Main Results:
- Laser-treated mice showed reduced footpad edema and accelerated cutaneous wound healing.
- Histological analysis revealed confluent granulomas and altered cytokine expression (reduced TNF-alpha, enhanced IFN-gamma) in laser-treated lesions.
- Fungi isolated from laser-treated mice exhibited significantly reduced in vitro growth compared to controls, indicating fungal inhibition.
Conclusions:
- HeNe laser irradiation effectively inhibited the local inflammatory response and fungal progression in P. brasiliensis-induced lesions.
- The treatment modulated local cytokine production, influencing the host's immune response.
- HeNe laser therapy shows promise as a coadjuvant treatment to conventional antifungal agents for PCM ulcerations, warranting further investigation into its mechanisms.
