Effects of Chinese herbal medicine Yiqi Huayu formula on substance P expression in skin ulcers of rats with diabetes mellitus

OBJECTIVE: To investigate the effects of Chinese herbs for replenishing qi (Yiqi) and dissolving stasis (Huayu) on substance P expression in granulation tissue of skin ulcers in rats with diabetes mellitus. METHODS: One hundred male Sprague-Dawley rats with back full-thickness skin lesion were randomly divided into five groups: ulcer control group, diabetic ulcer group, Yiqi Huayu herb group, Yiqi herb group, and Huayu herb group. Except ulcer control group, the other rats were also injected streptozotocin to induce diabetes mellitus. Rats in each group were given normal saline or herbal drugs for 15 d and the wound healing rate of the rats was observed on days 8 and 15, respectively. After treatment, the expression of substance P in granulation tissues of the rats was tested with immunohistochemical method and the immunohistochemical index was calculated. RESULTS: On the 8th and 15th days after treatment, the wound healing rate of the ulcer control group was higher than that of the diabetic ulcer group (P<0.01); the wound healing rates of all the treated groups were higher than that of the diabetic ulcer group (P<0.05); the wound healing rate of the Yiqi Huayu herb group was higher than those of the Yiqi herb group and the Huayu herb group (P<0.05). Compared with the diabetic ulcer group, the expression of substance P of the ulcer control group was increased (P<0.05); the expressions of substance P of the Yiqi Huayu herb group and the Huayu herb group were higher than that of the diabetic ulcer group (P<0.05). CONCLUSION: Yiqi Huayu herbs can promote wound healing in rats with diabetes mellitus by up-regulating the expression of substance P.