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.

BACK GROUND 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/cm[2], G3-irradiated at 0.15 J/cm[2], G4-recived extract of propolis, G5- combined extract of propolis and 1.5 J/cm[2] laser irradiation and G6- combined extract of propolis and 0.15 J/cm[2] 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/cm[2]) and G1 (control group) in levels of collagen Type I messenger RNA (mRNA) expression (p<0.05). The irradiated cells showed a 1.4 times increase in mRNA expression of the collagen Type I gene. Expression of this gene decreases in other groups that this difference was statistically significant. CONCLUSION: LLLT in different dosage and propolis extract may result in decreased or increased collagen type I gene expression. However this effect should be investigated in clinical studies.