BACKGROUND Corydalis yanhusuo W.T. Wang (YHS) is a well-known Chinese flowering herbal plant commonly used for centuries in functional food and traditional Chinese medicine. In the present study, we have identified and characterized a novel inhibitor of vascular endothelial growth factor receptor 2 (VEGFR2) with low toxicity, alkaloid extract of YHS, which suppressed angiogenesis that plays a fundamental role in a wide spectrum of physiological functions and pathological processes. METHODS Proliferative ability of human umbilical vascular endothelial cells (HUVECs) was assessed using MTT assay and Ki67 immunofluorescence staining. Migration ability of HUVECs was evaluated by wound healing and transwell assays. In vitro angiogenesis was tested by spheroid sprouting and tube formation assays. In vivo vascularization was examined using Matrigel plug and chick chorioallantoic membrane (CAM) models. Protein expression and phosphorylation levels of VEGFR2, AKT, ERK and STAT3 were determined by Western blot assay. RESULTS We demonstrated that alkaloid extract of YHS significantly inhibited a variety of VEGF-induced angiogenesis processes including proliferation, migration, sprouting, and tube formation of HUVECs. Moreover, alkaloid extract of YHS contributed to reduced in vivo neo-vessel formation in Matrigel plugs of mice and CAM models. Further mechanistic studies revealed that alkaloid extract of YHS suppressed VEGF-induced signaling pathway as evaluated by diminished phosphorylation of VEGFR2 and subsequently attenuated its downstream regulators including phospho-ERK1/2, phospho-AKT and phospho-STAT3 levels in HUVECs. CONCLUSION Collectively, these preclinical findings indicate that alkaloid extract of YHS remarkably limits angiogenesis and may serve as a promising anti-angiogenic drug candidate.

中文翻译：

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延胡索生物碱提取物通过靶向血管内皮生长因子受体信号转导抑制血管生成。

背景技术延胡索延胡索（YHS）是一种著名的中草药开花植物，通常在功能性食品和中药中已有数百年历史。在本研究中，我们已经鉴定并鉴定了一种具有低毒性的新型血管内皮生长因子受体2（VEGFR2）抑制剂，YHS生物碱提取物，该抑制剂可抑制在广泛的生理功能和病理过程中起重要作用的血管生成。方法采用MTT法和Ki67免疫荧光染色法评估人脐血管内皮细胞（HUVECs）的增殖能力。HUVEC的迁移能力通过伤口愈合和transwell分析进行评估。通过球体发芽和试管形成试验测试了体外血管生成。使用Matrigel塞和鸡绒膜尿囊膜（CAM）模型检查了体内血管形成。通过蛋白质印迹法测定VEGFR2，AKT，ERK和STAT3的蛋白表达和磷酸化水平。结果我们证明，YHS生物碱提取物可显着抑制多种VEGF诱导的血管生成过程，包括HUVEC的增殖，迁移，发芽和管形成。此外，YHS的生物碱提取物有助于减少小鼠和CAM模型的Matrigel栓塞中的体内新血管形成。进一步的机理研究表明，通过减少VEGFR2的磷酸化评估，YHS的生物碱提取物可抑制VEGF诱导的信号传导途径，并随后减弱其下游调节剂，包括HUVEC中的磷酸化ERK1 / 2，磷酸化AKT和磷酸化STAT3水平。