[Effects of Coriaria Sinica Maxim's extract on microcirculation and oxidative stress of wounds in rats with deep second-degree burn].

OBJECTIVE: To investigate the effects of Coriaria Sinica Maxim's extract(CSME) on microcirculation and oxidative stress of wounds in rats with deep second-degree burn.

METHODS: One hundred and eighty rats were randomly divided into normal saline group(NS), white petroleum group(WPL), silver sulfadiazine group (SSD), Coriariasinica Maxim's extract group which were divided into low dose(CSME-L),middle dose(CSME-M) and high dose(CSME-H). After anesthesia with burn instrument to burn the hair removal area of rats, these wounds were confirmed by pathological results with deep second degree burns.And then,those drugs were applied respectively on the wounds,such as NS、WPL、SSD and different concentrations of CSME. After injury at 48 h, 7 d, 14 d and 21 d,the healing rate(HR) of wound was measured, and the microvessel density (MVD), tissue moisture (TM), vascular endothelial growth factor (VEGF), model driven architecture (MDA), superoxide dismutase(SOD) and hydroxyproline(HYP) were detected, too. All pathological sections of the wound tissue were observed.

RESULTS: The HR of CSME groups were obviously increased with a dose-dependent manner, which was significantly higher than that of NS and WPL ( P <0.05); On the 21st day, the diameter, number, distribution of the vessels and and the TM were less than other groups with a dose-dependent manner; On the 7th and 14th day after injury, CSME groups were significantly higher than the NS, WPL and SSD with a dose-dependent manner ( P <0.05), but, on the 21st day after injury, they were lower than NS, WPL and SSD with a dose-dependent ( P <0.05) manner. The levels of SOD, HYP, NO and ET in CSME groups were higher than those in other groups with dose-dependent on SOD activity, HYP, NO and ET content ( P <0.05), while MDA activity was weaker than other groups ( P <0.05). Similarly, pathological findings were also shown that CSME groups were better than other groups with a dose-dependent manner in decrease decreasing of wound repair time and hyperplasia of scar tissue.

CONCLUSIONS: CSME can relieve tissue edema, promote wound contraction, speed up the formation of eschar and accelerate the proliferation of granulation tissue, which are beneficial to the wound healing in the early stages. But, it can inhibit the hyperplasia of granulation tissue to prevent the excessive scar hyperplasia of burn wound in the later stages. Its mechanism is related to regulation what microcirculation, oxidativestress, NO and VEGF.