Evaluation effect of low level Helium-Neon laser and Iranian propolis extract on Collagen Type I gene expression by human gingival fibroblasts: an in vitro study

Background and aim: production of collagen by fibroblast cells is a key component in wound healing. Several studies have shown that low level laser therapy (LLLT) and propolis extract stimulate collagen Type I production. The aim of this study is to evaluation the combined effect of LLL helium neon (632.8 nm) and Iranian propolis extract on collagen Type I gene expression by human gingival fibroblasts (HGF3-PI 53). Methods and materials:Human gingival fibroblasts after culturing divided into six experimental groups: G1-control group, which received no irradiation and propolis extract, G2-irradiated at1.5 J/cm², G3-irradiated at 0.15 J/cm², G4-recived extract of propolis, G5- combined extract of propolis and 1.5 J/cm² laser irradiation and G6- combined extract of propolis and 0.15 J/cm² laser irradiation. The experiments were conducted in triplicate. After 24 hour, the total RNA was extracted and cDNA synthesis was performed. Type I collagen mRNA expression was determined with real time PCR. Results:The obtained results illustrated a statistically significant difference between G3 (0.15 J/cm²) and G1 (control group) in levels of collagen Type I messenger RNA (mRNA) expression (p