Neuroprotective and neurorestorative therapy represent two major drug intervention strategies for ischemic stroke. Multiple factors such as excitotoxicity, inflammation, angiogenesis, and neurogenesis are the main pathological processes that underlie acute and chronic ischemic brain injury. Furthermore, their intimate interactions mediate blood-brain barrier permeability, increase neurovascular unit structural damage as well as a hemorrhagic transformation during ischemic stroke. We aimed to review the current understandings of the underlying mechanisms of neuroprotection and neurorestoration in ischemic stroke. Notably, traditional Chinese medicine (TCM) has notable advantages in the comprehensive treatment and overall regulation of multi-site and multi-target diseases. Therefore, we reviewed the recent advances in natural compounds from medicinal herbs that possess the bioactivities of simultaneously promoting neuroprotection (e.g., excitotoxicity, oxidative stress, apoptosis, inflammation, and autophagy) and neurorestoration (e.g., angiogenesis, neurogenesis, and axonal sprouting) following brain ischemia injury. These natural compounds were divided into glycosides (astragaloside IV, gastrodin, ginsenoside Rg1 and salidroside), flavonoids (baicalin, icariin, puerarin and breviscapine), phenols (resveratrol, curcumin and salvianolic acid B), and terpenes (ginkgolide B and catalpol). We found that all compounds exhibited anti-brain ischemia activities in vivo and in vitro experiments by promoting neuroprotection and, or neurorestoration. This review tracks and summarizes the progress of the past five years to explore the active compounds and the underlying molecular mechanisms of TCMs that produce pro-neuroprotection and pro-neurorestoration. Additionally, we provide another basis of reference supporting the advantages of TCMs, which could ultimately lead to the development of precise clinical medications for ischemic stroke treatment.

Nicotinamide phosphoribosyltransferase (NAMPT) maintains mitochondrial function and protects against cerebral ischemic injury by improving energy metabolism. Notoginsenoside R1 (R1), a unique constituent of Panax notoginseng, has been shown to promote the proliferation and tube formation of human umbilical vein endothelial cells. Whether R1 has proangiogenesis on the activation of NAMPT in ischemic stroke remains unclear. The purpose of this study was to investigate the pharmacodynamic effect and mechanism of R1 on angiogenesis after ischemic stroke. We used male Sprague-Dawley (SD) rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). R1 was administered via intraperitoneal (i.p.) injection immediately after ischemia induction. The promotion of R1 on angiogenesis were detected by immunofluorescence staining, 3D stereoscopic imaging and transmission electron microscopy detection. HBMEC cells were pretreated with different concentrations of R1 for 12 h before oxygen-glucose deprivation/reoxygenation (OGD/R) exposure. Afterward, scratch assay, EdU staining and tube formation were determined. Western blot analyses of proteins, including those involved in angiogenesis, NAMPT-SIRT1 cascade, VEGFR-2, and Notch signaling, were conducted. We showed that R1 significantly restored cerebral blood flow, improved mitochondrial energy metabolism and promoted angiogenesis. More importantly, incubation with 12.5-50 μM R1 significantly increased the migration, proliferation and tube formation of HBMECs in vitro. The promotion of R1 on angiogenesis were associated with the NAMPT-NAD⁺-SIRT1 cascade and Notch/VEGFR-2 signaling pathway, which was partially eliminated by inhibitors of NAMPT and SIRT1. We demonstrated that R1 promotes post-stroke angiogenesis via activating NAMPT-NAD⁺-SIRT1 cascade. The modulation of Notch signaling and VEGFR-2 contribute to the post-stroke angiogenesis. These findings offer insight for exploring new therapeutic strategies for neurorestoration via R1 treatment after ischemic stroke.

Ischemic stroke is a syndrome of severe neurological responses that cause neuronal death, damage to the neurovascular unit and inflammation. Notoginsenoside R1 (NG-R1) is a neuroprotective drug that is commonly used to treat neurodegenerative and cerebrovascular diseases. However, its potential mechanisms on the regulation of small molecule metabolism in ischemic stroke are largely unknown. The aim of this study was to explore the potential mechanisms of NG-R1 on the regulation of small molecule metabolism after ischemic stroke. Here, we found that NG-R1 reduced infarct size and improved neurological deficits by ameliorating neuronal damage and inhibiting glial activation in MCAO/R rats. Furthermore, using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), we clarified that NG-R1 regulated ATP metabolism, the tricarboxylic acid (TCA) cycle, the malate-aspartate shuttle, antioxidant activity, and the homeostasis of iron and phospholipids in the striatum and hippocampus of middle cerebral artery occlusion/reperfusion (MCAO/R) rats. In general, NG-R1 is a promising compound for brain protection from ischemic/reperfusion injury, possibly through the regulation of brain small molecule metabolism.