山柰酚对大鼠皮肤创面愈合和瘢痕增生的影响及其机制实验研究OA

Objective:To investigate the effects of kaempferol on skin wound healing and scar hyperplasia in rats and its possible mechanism of action.Methods:Twenty male SD rats were randomly selected from 100 rats as the normal group,and rats in the normal group only received back shaving treatment.The remaining 80 rats were used to establish the rat back skin wound model,and were randomly divided into model group,low-,medium-and high-dose kaempferol groups,with 20 rats in each group.Rats in the low-,medium-and high-dose kaempferol groups were giv-en intragastric administration at doses of 50,100 and 150 mg/kg,respectively,once daily.The model group and nor-mal group were given an equal volume of 0.9％sodium chloride solution by gavage during the same period.Each group was continuously administered until the wound was completely healed.On days 3,7 and 14 after administra-tion,the skin wound healing rate of rats was calculated.The complete healing time of skin wounds was observed,and the scar thickness was measured.HE staining was used to observe the pathological changes of rat skin wounds.ELISA was used to detect the levels of inflammatory factors interleukin-1β(IL-1β),IL-8 and tumor necrosis factor-α (TNF-α)in wound tissue.Western blot was used to detect the expression of vascular endothelial growth factor(VEGF),α-smooth muscle actin(α-SMA)and Toll-like receptor-9(TLR-9)/nuclear factor-κB(NF-κB)/IL-6 path-way-related proteins in wound tissue.Immunohistochemical staining was used to detect the positive areas of type Ⅰ collagen(Col Ⅰ)and ColⅢ and calculate their ratio.Results:On days 3,7 and 14 after administration,compared with the model group,the skin wound healing rates of rats in the low-,medium-and high-dose kaempferol groups in-creased sequentially(all P＜0.05).Compared with the model group,the complete skin wound healing time and scar thickness of rats in the low-,medium-and high-dose kaempferol groups decreased sequentially(all P＜0.05).In the model group,there were a large number of proliferating fibroblasts and significant inflammatory cell infiltration in the skin wound tissue,and collagen fiber proliferation with local degeneration was observed in the interstitium;the patho-logical changes of skin wound tissue in the low-,medium-and high-dose kaempferol groups were improved compared with the model group.Compared with the normal group,the levels of IL-1β,IL-8 and TNF-α,the expression levels of VEGF and α-SMA,the positive areas of Col Ⅰ and ColⅢ and the Col Ⅰ/ColⅢ ratio,the protein expression levels of TLR-9 and IL-6,and the p-NF-κB p65/NF-κB p65 ratio in the skin wound tissue of rats in the model group were in-creased(all P＜0.05).Compared with the model group,the levels of IL-1β,IL-8 and TNF-α,the expression level ofα-SMA,the positive area of Col I and the Col Ⅰ/ColⅢ ratio,the protein expression levels of TLR-9 and IL-6,and the p-NF-κB p65/NF-κB p65 ratio in the skin wound tissue of rats in the low-,medium-and high-dose kaempferol groups were decreased,while the expression level of VEGF was increased,in a dose-dependent manner(all P＜0.05).Com-pared with the model group,the positive area of ColⅢ in the skin wound tissue of rats in the medium-and high-dose kaempferol groups was decreased(all P＜0.05).Conclusion:Kaempferol can reduce the inflammatory response of skin wounds in rats,promote angiogenesis,and inhibit the excessive activation of myofibroblasts,thereby accelerating skin wound healing and inhibiting scar hyperplasia in rats,and its mechanism of action may be related to the down-regulation of the TLR-9/NF-κB/IL-6 signaling pathway.