What is the role of photobiomodulation in reducing inflammation?

• A. It reduces inflammatory mediators through thermal effects
• B. It directly increases immune cell counts in the treated area
• C. It modulates cellular signaling to reduce inflammatory mediators and promote tissue repair
• D. It replaces the need for physical therapy

Answer: (C)

Photobiomodulation reduces inflammation by triggering photochemical changes in cells that shift signaling toward anti-inflammatory and repair processes. Light interacts with mitochondrial chromophores (notably cytochrome c oxidase), boosting cellular energy and modulating reactive oxygen species and nitric oxide. This leads to altered gene expression and signaling pathways that lower pro-inflammatory mediators while promoting tissue repair and regeneration. The best answer captures this mechanism: by modulating cellular signaling to reduce inflammatory mediators and support healing, rather than relying on heat, directly increasing immune cell counts, or replacing physical therapy.