Effect of photobiomodulation (670nm) associated with vitamin A on the inflammatory phase of wound healing

Wound healing is a complex biological process with specific phases. Photobiomodulation (PBM) decreases the inflammatory infiltrate, stimulating fibroblast proliferation and angiogenesis, and therefore, is indicated for wound healing. Vitamin A is used to reverse the inhibitory effects on wound healing and accelerate the healthy granulation tissue. The study aimed to evaluate the effect of topical vitamin A and PBM (GaAlAs) in inflammatory phase of cutaneous wounds. Forty Wistar male rats were separated into four groups: (1) control (CG); (2) laser group (LG) GaAlAs, 670nm, 30mW, energy per point of 0.9J, radiating by 1 point in 30s; (3) vitamin A group (VitAG); and (4) laser group plus vitamin A (LG+VitAG). Wounds were surgically made by a punch biopsy with 10mm of diameter on the back of the animals and all treatments were started according to the experiment. The treatments were administered for four consecutive days and biopsy was performed on day 4. We performed both H&E and immunohistochemistry analysis. The results were compared between groups by one-way analysis of variance ANOVA test with post hoc Tukey (p<0.05). Inflammatory infiltrate increased significantly in LG compared to CG and VitAG (p<0.05). Regarding angiogenesis, VEGF expression was increased significantly in LG and LG+VitAG groups, p<0.01. The results indicate that proposed treatments were effective on the healing process improved by LG and LG+VitAG. We show that laser plus vitamin A enhances healing by reducing the wound area and may have potential application for clinical management of cutaneous wounds.