Background. Naoluo Xintong decoction (NLXTD) is a traditional Chinese medicine (TCM) formula which has been used to improve neuronal functional recovery after cerebral ischemic stroke. However, the molecular mechanism underlying NLXTD’s amelioration of ischemic stroke remains unclear. The present study was designed to explore the effect and mechanism of NLXTD on brain angiogenesis in a rat model with cerebral ischemia-reperfusion (I/R) injury targeting the hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) pathway. Materials and Methods. Cerebral I/R model was established by the classical middle cerebral artery occlusion (MCAO) method. Sprague-Dawley (SD) male rats (n = 80) were randomly divided into the sham-operation group, the model group, the HIF-1α inhibitor 2-methoxyestradiol (2ME2) group, the 2ME2 with NLXTD group, and the NLXTD group. Neurological deficit test, TTC staining, H&E staining, TUNEL staining, immunohistochemistry (IH), immunofluorescence (IF), western blot, and quantitative RT-PCR were performed to evaluate the effect of NLXTD after MCAO. Results. Administration of NLXTD significantly decreased neuron deficiency scores, reduced brain infarct volume, and lowered damaged and apoptotic cells after brain I/R injury in rats. Meanwhile, NLXTD had a protective effect on angiogenesis by increasing the MVD and the expressions of BrdU and CD34, which enhanced the number of endothelial cells in the ischemic penumbra brain. NLXTD treatment significantly raised the protein and mRNA levels of HIF-1α, VEGF, VEGFR2, and Notch1 compared with the model treatment. In contrast, a specific HIF-1α inhibitor, 2ME2, inhibited the improvement of neurological function and angiogenesis in NLXTD-induced rats with cerebral I/R injury, suggesting that NLXTD played a positive role in ischemic brain injury by activating the HIF-1α/VEGF signaling pathway. Conclusions. NLXTD exerts neuroprotection targeting angiogenesis by upregulating the HIF-1α/VEGF signaling pathway on cerebral I/R injury rats.

中文翻译：

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脑络心痛汤通过激活大鼠HIF-1α/VEGF信号通路促进血管生成改善脑缺血再灌注损伤

背景。脑络心痛汤 (NLXTD) 是一种中药 (TCM) 配方，已用于改善脑缺血性卒中后神经元功能的恢复。然而，NLXTD 改善缺血性卒中的分子机制仍不清楚。本研究旨在探讨 NLXTD 对针对缺氧诱导因子 1 α (HIF-1 α )/血管内皮生长的脑缺血再灌注 (I/R) 损伤大鼠模型中脑血管生成的影响和机制。因子（VEGF）途径。材料和方法。采用经典大脑中动脉闭塞（MCAO）方法建立脑I/R模型。Sprague-Dawley (SD) 雄性大鼠 ( n = 80）随机分为假手术组、模型组、HIF- 1α抑制剂2-甲氧基雌二醇（2ME2）组、2ME2加NLXTD组、NLXTD组。进行神经功能缺损试验、TTC 染色、H&E 染色、TUNEL 染色、免疫组织化学 (IH)、免疫荧光 (IF)、蛋白质印迹和定量 RT-PCR 以评估 MCAO 后 NLXTD 的作用。结果. NLXTD 的给药显着降低了大鼠脑 I/R 损伤后的神经元缺陷评分，减少了脑梗死体积，并降低了受损和凋亡细胞。同时，NLXTD通过增加MVD和BrdU和CD34的表达对血管生成具有保护作用，从而增加缺血半影脑内皮细胞的数量。与模型治疗相比， NLXTD 治疗显着提高了 HIF-1 α、VEGF、VEGFR2 和 Notch1 的蛋白质和 mRNA 水平。相比之下，特异性 HIF-1 α抑制剂 2ME2 抑制 NLXTD 诱导的脑 I/R 损伤大鼠神经功能和血管生成的改善，表明 NLXTD 通过激活 HIF-1 在缺血性脑损伤中发挥积极作用α/VEGF 信号通路。结论。NLXTD 通过上调脑 I/R 损伤大鼠的 HIF-1 α /VEGF 信号通路发挥靶向血管生成的神经保护作用。