Therapeutic targets of neuroprotection and neurorestoration in ischemic stroke: Applications for natural compounds from medicinal herbs

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.