Hydroxysafflor Yellow A Alleviates Acute Myocardial Ischemia/Reperfusion Injury in Mice by Inhibiting Ferroptosis via the Activation of the HIF-1α/SLC7A11/GPX4 Signaling Pathway.

Ferroptosis is closely associated with the pathophysiology of myocardial ischemia. Hydroxysafflor yellow A (HSYA), the main active ingredient in the Chinese herbal medicine safflower, exerts significant protective effects against myocardial ischemia/reperfusion injury (MI/RI). The aim of this study was to investigate the protective effects of HSYA against MI/RI and identify the putative underlying mechanisms. An in vivo model of acute MI/RI was established in C57 mice. Subsequently, the effects of HSYA on myocardial tissue injury were evaluated by histology. Lipid peroxidation and myocardial injury marker contents in myocardial tissue and serum and iron contents in myocardial tissue were determined using biochemical assays. Mitochondrial damage was assessed using transmission electron microscopy. H9C2 cardiomyocytes were induced in vitro by oxygen-glucose deprivation/reoxygenation, and ferroptosis inducer erastin was administered to detect ferroptosis-related indicators, oxidative-stress-related indicators, and expressions of ferroptosis-related proteins and HIF-1α. In MI/RI model mice, HSYA reduced myocardial histopathological damage, ameliorated mitochondrial damage in myocardial cells, and decreased total cellular iron and ferrous ion contents in myocardial tissue. HSYA increased the protein levels of SLC7A11, HIF-1α, and GPX4 and mitigated erastin- or HIF-1α siRNA-induced damage in H9C2 cells. In summary, HSYA alleviated MI/RI by activating the HIF-1α/SLC7A11/GPX4 signaling pathway, thereby inhibiting ferroptosis.

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.