Photobiomodulation Exerts Anti-Inflammatory and Antioxidant Effects Reducing the Development of Tumors Elicited by 4-NQO in the Mice Tongue

Objective

Evaluate the influence of photobiomodulation in a model of oral carcinogenesis induced by 4-nitroquinoline-n-oxide (4-NQO).

Subjective

Ninety-six Swiss mice received topical application of 1% 4-NQO on tongue dorsum, for 20 weeks. The tongue was subjected to photobiomodulation with red (71.4 J/cm²) and infrared laser (142.8 J/cm²) starting at week 0, 12, and 16. After 20 weeks, tongues were removed for the following analyzes: histological assessment, immunohistochemical reactions (cyclin D1/Ki-67/TGF-β1), quantification of MPO, n-AG, MDA, GSH, total proteins, TNF-α, IL-1β, and IL-6 levels.

Results

4-NQO showed significant increase in the frequency of carcinoma (p < 0.001), and in the immunostaining for cyclin D1/Ki-67/TGF-β1 (p < 0.005), along with increased levels of TNF- α, IL-1β, IL-6, MPO, n-AG, MDA, and total proteins (p < 0.001), that were reduced by photobiomodulation with red and infrared lasers (p < 0.005).

Conclusion

Photobiomodulation reduces tumor development, accompanied by reduced inflammatory cells and content of cytokines and oxidative markers associated with carcinogenesis.