Abstract:

Objective To investigate the effects of topical application of oleic acid on inflammatory response and wound healing in diabetic mice. Methods The diabetic models were established by peritoneal injection of streptozocin in 84 C57BL/6 mice. One month after model establishment, full-thickness skin wounds with diameter of 1 cm were prepared in the dorsal region of mice. All the mice were divided into oleic acid group (30 mmol/L oleic acid solution) and control group (same amount of solvent instead of oleic acid solution), with 42 mice in each group. The wound sites were digitally photographed to calculate the percentage of wound closure using computer image analysis software. The wound specimens were also obtained for detecting the infiltration of polymorphonuclear neutrophils (PMN) and macrophages (Mφ) using immunohistological technique. The expression of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in wound tissues was determined by ELISA. Results From the fifth day after surgery, the percentages of wound closure in oleic acid group were significantly higher than those in control group (P<0.01). The wound closure time in oleic acid group and control group was (17.2±2.6) d and (19.5±1.9) d respectively (P<0.05). The levels of PMN 12 and 24 h after surgery and those of Mφ 3 and 5 d after surgery in oleic acid group were significantly higher than those in control group (P<0.01), while the levels of PMN and Mφ 10 and 15 d after surgery in oleic acid group were significantly lower than those in control group (P<0.05 or P<0.01). The expression of TNF-α in wound tissues 3 d after surgery and the expression of IL-6 in wound tissues 12 h, 24 h and 3 d after surgery in oleic acid group was significantly higher than that in control group (P<0.05 or P<0.01), while the expression of TNF-α and IL-6 in wound tissues 10 d after surgery was significantly lower than that in control group (P<0.05 or P<0.01). Conclusion For the wounds of diabetic mice, oleic acid may accelerate the inflammatory response in the early phase and prevent the persistence of inflammatory response in the later phase to promote the wound healing.

Key words: wound healing, diabetes mellitus, inflammation, oleic acid