Effect of low-level laser therapy on gene expression of vascular endothelial growth factor and interleukin-1 ß in scalpel-induced and laser-induced oral wounds in rats

Abstract

Introduction: The effect of low-level laser therapy (LLLT) on wound healing has been evaluated in several studies; however, little is known about the molecular mechanisms that underlies the biostimulatory effect of this treatment modality. Aim: to evaluate the effect of LLLT on gene expression of vascular endothelial growth factor (VEGF) and interleukin-1beta (IL-1 b) during healing of wounds created by surgical blade and by surgical laser in order to have a better image of their interactive role influenced by the laser irradiation. Materials and Methods: 40 male Wister rats were randomly assigned into four groups (A, B, C and D). In groups A and C, an incision was made in the gingival and mucosal tissues using a surgical scalpel. A similar incision was made in groups B and D using 980 nm diode laser. Group A and B were subjected twice to low level 870 nm diode laser 3 h and 24 h after the incision while group C and D served as controls. 30 min after the second irradiation, the rats belonging to all groups were euthanized, and the wound area was excised. Quantitative reverse-transcriptasepolymerase chain reaction was used to measure the gene expression of VEGF and IL-1b. Results and Discussion: LLLT caused an increase in VEGF gene expression in scalpel-induced wounds and a corresponding decrease in laser-induced wounds but without significant differences. LLLT inhibited the gene expression of IL-1b in both types of wounds, but this inhibition was only significant in scalpel wounds. Conclusion: Biostimulatory effect of LLLT could be mediated through modulation of the immune response by the inhibition of IL-1b.