The Effect of 630 nm Photobiomodulation on the Anti-Inflammatory Effect of Human Gingival Fibroblasts

Periodontal disease is the most common oral chronic inflammatory disease in humans. Recent studies have indicated that red light Photobiomodulation (PBM) could inhibit cell inflammation effectively, but the effect of different doses of PBM on the treatment of inflammation has to be improved. Thus, this study was aimed to investigate the effects of various doses of PBM (630 ± 30 nm, (1) 5 mW/cm2, 1 J/cm2, 200 s; (2) 5 mW/cm2, 3 J/cm2, 600 s; (3) 5 mW/cm2, 9 J/cm2, 1800 s; (4) 5 mW/cm2, 18 J/cm2, 3600 s; (5) 5 mW/cm2,36 J/cm2, 7200 s) on the anti-inflammatory response of human gingival fibroblasts. Our results suggested that PBM (630 ± 30 nm) with doses of 18 J/cm2 and 36 J/cm2 could significantly inhibit the production of inflammatory cytokines such as Prostaglandin E2 (PGE2) and IL-8, presumably due to the fact that a high dose of PBM treatment could reduce intracellular Reactive oxygen species (ROS) in human gingival fibroblasts, thus reducing the expression of COX-2 enzyme. In addition, it was found that treatment with different doses of PBM (630 ± 30 nm) did not result in reduced mitochondrial membrane potential and mitochondrial dysfunction in human gingival fibroblasts. Our study provides a theoretical reference for the selection of PBM parameters and the application of PBM in the clinical treatment of periodontitis.