Investigation of the Anti-Inflammatory Effects of Photobiomodulation Therapy on Human Gingival Fibroblasts (Hgf1-Pi1) Publisher Pubmed



Javani Jouni F ; Hashemzadeh S ; Rastegarpouyani N ; Mirzaei A ; Zafari J
Source: Molecular Biology Reports Published:2026

Abstract

Introduction: Periodontal disease [1] is a chronic inflammatory condition caused by pathogens such as Porphyromonas gingivalis (Pg), which leads to destruction of periodontal structures. Photobiomodulation therapy (PBMT) holds promise in alleviating inflammation and oxidative stress, yet optimal parameters remain debatable. This study investigates the effects of 660 nm and 970 nm lasers on viability, inflammatory gene expression, and cytokine secretion in human gingival fibroblasts (HGF1-PI1) to assess PBMT’s potential in PD treatment. Methods: Human Gingival Fibroblasts (HGF1-PI1) were cultured in DMEM supplemented with 10% FBS. An inflammatory model was established using Porphyromonas gingivalis-derived lipopolysaccharide (LPS), with optimal concentrations chosen according to ROS/IL-6 production and cell viability using the MTT assay. Cells were exposed to 660 nm (50 mW) or 970 nm (200 mW) lasers at 6, 12, and 18 J/cm². Gene expression study of inflammation-associated genes, IFN-γ, IL-6, and TNF-α, was performed using RT-qPCR, while cytokine levels were evaluated by the ELISA technique. Results: Findings from the MTT assay revealed no significant change in cell viability with laser treatment alone or combined with Pg.LPS, compared to the control group. Real-time PCR analysis for cytokine gene expression of IFN-γ, IL-6, and TNF-α indicating a decrease in gene expression in HGF cells treated with both Pg.LPS and laser. Inflammatory cytokine production, showed the highest levels in the Pg.LPS group, while the laser-treated and control groups demonstrated no significant difference. Conclusion: Photobiomodulation therapy using dual-wavelength diode lasers (660 and 970 nm) effectively attenuated Porphyromonas gingivalis LPS–induced inflammation in human gingival fibroblasts by downregulating key proinflammatory mediators, including IFN-γ, IL-6, and TNF-α. These findings suggest that PBMT may serve as a safe and supportive therapeutic approach for modulating inflammation in periodontal tissues. © The Author(s), under exclusive licence to Springer Nature B.V. 2025.