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OBJECTIVE To investigate the effect and mechanism of Panax notoginseng saponins （PNS） on wound healing after anal fistula surgery in rats by regulating the hypoxia-inducible factor-1α （HIF-1α）/vascular endothelial growth factor （VEGF）/ vascular endothelial growth factor receptor-2 （VEGFR2） signaling pathway. METHODS SD rats were selected to establish a postoperative rat model of anal fistula by infecting wound with Escherichia coli. The model rats were randomly grouped into model group， PNS low-dose and high-dose groups （15， 30 mg/cm2）， high-dose of PNS+2-methoxyestradiol （2ME2） group （PNS 30 mg/cm2+HIF-1α inhibitor 2ME2 4 mg/kg）， with 10 rats in each group. Another 10 normal rats were selected for back hair removal treatment as the control group. Each drug group was injected with the corresponding drug solution intramuscularly or （and） intraperitoneally， once a day， for 3 weeks. After the last administration， the wound healing rate （excluding the control group）， microvascular density （MVD）， the expression of collagen Ⅰ and fibronectin （FN） in the wound tissue were detected in each group； the levels of angiogenic factors [VEGF， E-mail：842710813@qq.com angiopoietin-Ⅰ （Ang-Ⅰ）， Ang-Ⅱ] in serum， the levels of inflammatory factors [interleukin-6 （IL-6） and IL-2] in serum binggui7183@163.com and wound tissue as well as the expressions of the related proteins of HIF-1α/VEGF/VEGFR2 signaling pathway in the wound tissue of rats were also detected in each group. RESULTS The MVD， the expression of collagen Ⅰ and FN in the wound tissue， and the levels of IL-6 and IL-2 in serum and wound tissue of rats increased significantly in the model group， compared to the control group （P＜0.05）， while the serum levels of VEGF， Ang- Ⅰ and Ang-Ⅱ decreased significantly （P＜0.05）. The wound healing rate， the MVD in wound tissue， the serum levels of VEGF， Ang-Ⅰ and Ang-Ⅱ， the expressions of collagen Ⅰ and FN in the wound tissue， and protein expressions of HIF-1α， VEGF and VEGFR2 in the PNS low-dose and high-dose groups increased significantly， compared to the model group （P＜0.05）， while the levels of IL-6 and IL-2 in serum and wound tissue decreased significantly （P＜0.05）； the high-dose PNS had a stronger effect （P＜ 0.05）. 2ME2 could weaken the effect of PNS on above indicators of rats after anal fistula surgery （P＜0.05）. CONCLUSIONS PNS can promote the production of angiogenic factors and inhibit the production of pro-inflammatory factors， thereby promoting wound healing in rats after anal fistula surgery. The above effects are related to the activation of HIF-1α/VEGF/VEGFR2 signaling pathway.
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OBJECTIVE To explore the effects of pterostilbene （PTE） on wound healing in diabetic skin ulcer model rats and its mechanism. METHODS Ten SD rats were grouped into control group； after diabetic skin ulcer model of other rats was induced by giving high-fat and high-sugar diet+intraperitoneal injection of streptozotocin+cutting off the skin and subcutaneous tissue in the marked area of the back， model rats were randomly divided into model group， PTE low-dose group （40 mg/kg）， PTE high-dose group （80 mg/kg）， PTE high-dose+PP2 group （80 mg/kg PTE+2 mg/kg SRC inhibitor PP2）， with 10 rats in each group. On the second day after modeling， the rats in each drug group were intraperitoneally injected with corresponding drug solutions， while the rats in control group and model group were intraperitoneally injected with normal saline， once a day， for 14 consecutive days. The wound healing rate of rats in each group was measured on the 7th and 14th day of administration； the contents of interleukin-1β （IL-1β）， IL-6， tumor necrosis factor-α （TNF-α） and vascular endothelial growth factor （VEGF） in the serum of rats were detected； the pathological changes of wound granulation tissue were observed， and the expressions of SRC/mitogen-activated protein kinase kinase （MEK）/extracellular signal-regulated kinase （ERK） signaling pathway-related proteins in wound granulation tissue were detected. RESULTS Compared with control group， the wound healing rate， serum content of VEGF， the phosphorylation levels of SRC， MEK1/2 and ERK1/2 were decreased significantly （P＜0.05）， while serum contents of IL- 1β， IL-6 and TNF-α were increased significantly （P＜0.05）； there was obvious infiltration of inflammatory cells in the wound granulation tissue， and the number of new blood vessels decreased. Compared with model group， above indexes of PTE low-dose and high-dose groups were improved significantly （P＜0.05）， and the pathological injury of granulation tissue in wound was improved. PP2 significantly reversed the improvement effects of PTE on the above indexes （P＜0.05）. CONCLUSIONS PTE can promote the wound healing of diabetic skin ulcer model rats， the mechanism of which may be related to activating SRC/MEK/ERK signaling pathway.