Effect of curcumin on wound healing and its mechanism

Objective To observe the effect of curcumin on wound healing in a rat model and the mechanisms involved. Methods Thirty male Sprague Dawley rats were used in the study, and four 6 mm diameter size wound were made by puncher on the back of rats.Curcumin of different concentrations(30、15 and 0 mg/mL)and PBS were used to treat wound of rats everyday, respectively.On postinjury day1, 3, 7, 10 and 14, respectively, 6 rats of injury group weres randomized chosen to measure the size of wound area.The expression of(vascular endothlial growth factor)VEGF and (basic fibroblast growth factor)bFGF in the wound tissue was observed with immunohistochemical staining.The content of M1 and M2 in the wound tissue was observed with immunofluorescence staining. Result The solvent had no effect on wound healing.Compared with control group, the wounds of group Cur15 and Cur30 healed significantly earlier.The results of wound VEGF mean optical density in group Cur15 and Cur30 were higher than these in group Cur0 and PBS on days 7 and 10 after operation (P<0.05). The results of bFGF immunohistochemical average optical density in group Cur15 on days 3, 7and 10 after operation and group Cur30 on days 7and 10 after operation were more than those in group Cur0 and PBS at the same time (P<0.05). The percentage of wound CD68 and inducible nitric oxide synthase (iNOS) double positive cells was less than that in group Cur0 and PBS on days 3 and 7 after operation (P<0.05). The percentage of wound CD68 and(arginase-1, Arg-1)double positive cells in group Cur15 and group Cur 30 respectively on days 3 , 7 and 3, 7, 10, 14 after operation was higher than that in group Cur0 and PBS (P<0.05). Conclusions Curcumin could promote polarization of macrophages from M1 to M2 phenotype and exert protective effects on skin wound healing in rats. Key words: Curcumin; Wound healing; Macrophage; Polarization