Effect of low-level laser therapy on the release of interleukin-6 and basic fibroblast growth factor from cultured human skin fibroblasts in normal and high glucose mediums

Introduction: This study evaluated the effects of low-level laser therapy (LLLT) on human skin fibroblasts (HSFs) that have been cultured in high glucose concentration media. Materials and methods: HSFs were cultured under physiological glucose condition medium, and then cultured in high glucose concentration medium (15 mM/L) for 1 or 2 weeks prior to LLLT. Experimental HSFs were irradiated with three energy densities (0.5, 1, and 2 J/cm(2)) once daily for three consecutive days. Release of interleukin-6 (IL-6) and basic fibroblast growth factor (bFGF) was evaluated using the enzyme-linked immunosorbent assay (ELISA) method. Results: Statistical analysis showed three doses of 0.5 (p = 0.049), 1 (p = 0.027), and 2 J/cm(2) (p - 0.004) stimulated the release of IL-6 in HSFs cultured in high glucose concentration medium compared with that of non-irradiated HSFs that were cultured in the same medium. LLLT with 2 J/cm(2) induced the release of bFGF from HSFs cultured in high glucose concentration medium for 1 or 2 weeks (both p = 0.04). Conclusion: Our study showed that LLLT stimulated the release of IL-6 and bFGF from HSFs cultured in high glucose concentration medium. LLLT was more effective in releasing IL-6 and bFGF while HSFs which were cultured in physiologic glucose concentration medium during laser irradiation.