Dan-Deng-Tong-Nao softgel capsule promotes angiogenesis of cerebral microvasculature to protect cerebral ischemia reperfusion injury via activating HIF-1α-VEGFA-Notch1 signaling pathway

BACKGROUND: A proprietary Chinese herbal product called Dan-Deng-Tong-Nao softgel capsule (DDTNC) is used to treat ischemic stroke. However, the preventive mechanisms of DDTNC against cerebral ischemia reperfusion injury (CIRI) haven not been characterized. OBJECTIVE: To explore the mechanisms of protective effects of DDTNC against CIRI from both internal and external levels. METHODS: Chemical characterization was performed using UPLC. The potential protective mechanisms of DDTNC against CIRI were predicted using network pharmacology. Model of middle cerebral artery occlusion/reperfusion (MCAO/R) was established in rats. An model of brain microvascular endothelial cells (BMECs) induced by oxygen-glucose deprivation/reoxygenation (OGD/R) was also established. We evaluated neurological deficits, cerebral infarct volume, cortical neuron damage, and mitochondrial swelling in vivo. We evaluated the expression of VEGFR2, VEGFA, HIF-1α, CD31, and CD34 in ischemic cortex, and VEGF, bFGF, BDNF, angiostatin, and endostatin in serum of rats and in BMEC supernatants. We also evaluated cell viability, cytotoxicity, intracellular ROS, apoptosis, and migration ability in vitro. RESULTS: Seven components were detected in DDTNC. KEGG enrichment analysis showed that DDTNC may modulate angiogenesis via the HIF-1 signaling pathway. DDTNC treatment reduced neurological score and infarct volume, and improved cell morphology of damaged neurons. Transmission electron microscopy showed that DDTNC reduced mitochondria swelling in cortical neurons. Furthermore, DDTNC reduced intracellular ROS and inhibited apoptosis. DDTNC boosted the expression of CD31, CD34, VEGFR2, VEGFA and HIF-1α, highlighting its involvement in angiogenesis, according to immunofluorescence studies. Furthermore, DDTNC enhanced tube formation and migration of BMECs in vitro. ELISA and western blotting indicated that DDTNCCSF induced the expression of VEGF, BDNF and bFGF, reduced the level of angiostatin and endostatin, increased the protein expression of VEGFA, Notch1 and HIF-1α in vitro and in vivo. CONCLUSIONS: DDTNC promoted angiogenesis to protect brain tissue against MCAO/R, and exerted protective effects against OGD/R in BMECs via activating HIF-1α-VEGFA-NOTCH1 signal transduction pathway.