Proteomics analysis of protein biomarkers in Astragalus membranaceus- and Astragaloside IV-treated brain tissues in ischemia-reperfusion injured rats

Astragaloside IV: A promising natural neuroprotective agent for neurological disorders

Neurological disorders are characterized by high morbidity, disability, and mortality rates, which seriously threaten human health. However, clinically satisfactory agents for treatment are still currently lacking. Therefore, finding neuroprotective agents with minimum side effects and better efficacy is a challenge. Chinese herbal medicine, particularly natural preparations extracted from herbs or plants, has become an unparalleled resource for discovering new agent candidates. Astragali Radix is an important Qi tonic drug in traditional Chinese medicine and has a long medicinal history. As a natural medicine, it has a good prevention and treatment effect on neurological disorders. Here, the role and mechanism of astragaloside IV in the treatment of neurological disorders were evaluated and discussed through previous research results. Related information from major scientific databases, such as PubMed, MEDLINE, Web of Science, ScienceDirect, Embase, BIOSIS Previews, and the Cochrane Central Register of Controlled Trials and Cochrane Library, covering between 2001 and 2021 was compiled, using "Astragaloside IV" and "Neurological disorders," "Astragaloside IV," and "Neurodegenerative diseases" as reference terms. By summarizing previous research results, we found that astragaloside IV may play a neuroprotective role through various mechanisms: anti-inflammatory, anti-oxidative, anti-apoptotic protection of nerve cells and regulation of nerve growth factor, as well as by inhibiting neurodegeneration and promoting nerve regeneration. Astragaloside IV is a promising natural neuroprotective agent. By determining its pharmacological mechanism, astragaloside IV may be a new candidate drug for the treatment of neurological disorders.

A New Therapeutic Trend: Natural Medicine for Ameliorating Ischemic Stroke via PI3K/Akt Signaling Pathway

Ischemic stroke (IS) is an acute cerebrovascular disease caused by sudden arterial occlusion, which is characterized by a high morbidity, mortality, and disability rate. It is one of the most important causes of nervous system morbidity and mortality in the world. In recent years, the search for new medicine for the treatment of IS has become an attractive research focus. Due to the extremely limited time window of traditional medicine treatment, some side effects may occur, and accompanied by the occurrence of adverse reactions, the frequency of exploration with natural medicine is significantly increased. Phosphatidylinositol-3-kinase/Protein kinase B (PI3K/Akt) signaling pathway is a classical pathway for cell metabolism, growth, apoptosis, and other physiological activities. There is considerable research on medicine that treats various diseases through this pathway. This review focuses on how natural medicines (including herbs and insects) regulate important pathophysiological processes such as inflammation, oxidative stress, apoptosis, and autophagy through the PI3K/Akt signaling pathway, and the role it plays in improving IS. We found that many kinds of herbal medicine and insect medicine can alleviate the damage caused by IS through the PI3K/Akt signaling pathway. Moreover, the prescription after their combination can also achieve certain results. Therefore, this review provides a new candidate category for medicine development in the treatment of IS.

Roots of Astragalus propinquus Schischkin Regulate Transmembrane Iron Transport and Ferroptosis to Improve Cerebral Ischemia-Reperfusion Injury

Background

The dried roots of the Astragalus propinquus Schischkin (RAP) plant, as a traditional Chinese medicine, has been widely used to treat stroke, cerebral ischemia, qi deficiency, and hypertension. Buyang Huanwu decoction is traditionally used to treat stroke in China for more than 200 years and has a significant effect on cerebral ischemia, and RAP is monarch medicine of Buyang Huanwu decoction. Therefore, this study was designed to observe the regulatory effect of RAP on transmembrane iron transporters and ferroptosis-related factors in cerebral ischemia-reperfusion injury (CIRI) in rats.

Methods

Middle cerebral artery occlusion (MCAO) was used to block blood flow in the blood supply area of the middle cerebral artery in seventy male SD rats to induce focal CIRI to establish a rat model of CIRI. RAP was administered to explore the regulatory effect of RAP on iron transmembrane transport under the condition of CIRI. The infarct size was measured using 2,3,5-triphenyl-tetrazolium chloride (TTC) staining, the pathological structure of brain tissue was observed by HE staining, and neuronal injury was evaluated by Nissl staining after treatment. Then, changes in the iron transporters ferritin (Fn), ferritin heavy chain (FHC), ferritin light chain (FLC), transferrin (Tf), transferrin receptor (TfR), divalent metal transporter 1 (DMT1), L-type calcium channel (LTCC), transient receptor potential canonical 6 (TRPC6), and ferroportin 1 (FPN1) were observed by immunohistochemistry staining (IHC) and Western blotting. The expression of key factors of ferroptosis, including the membrane sodium-dependent cystine/glutamate antiporter System Xc⁻ (System Xc⁻) light chain subunit (XCT) and heavy chain subunit (SLC3A2), glutathione peroxidase 4 (GPX4), nuclear factor erythroid 2-related factor (NRF2), heme oxygenase-1 (HO-1), and iron-responsive element-binding protein 2 (IREB2) in the brain tissues of rats was assessed by Western blotting. RAP decreased the infarct size and neuronal injury after CIRI in rats. Similarly, RAP treatment regulated the expression of iron transporters. As such, RAP was able to reduce the expression of Fn, FHC, FLC, Tf, TfR, DMT1, and TRPC6 and increase the expression of FPN1 through a Tf/TfR-independent pathway after CIRI in rats.

Conclusion

RAP stimulation inhibited ferroptosis by regulating the expression of the key ferroptosis factors XCT, SLC3A2, GPX4, NRF2, HO-1, and IREB2. In conclusion, RAP regulates transmembrane iron transport and ferroptosis to improve CIRI.

A Review of Traditional Chinese Medicine, Buyang Huanwu Decoction for the Treatment of Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) is often referred to as “collaterals disease” in traditional Chinese medicine (TCM), and commonly includes ischemic and hemorrhagic CSVD. TCM has a long history of treating CSVD and has demonstrated unique efficacy. Buyang Huanwu Decoction (BHD) is a classical TCM formula that has been used for the prevention and treatment of stroke for hundreds of years. BHD exerts its therapeutic effects on CSVD through a variety of mechanisms. In this review, the clinical and animal studies on BHD and CSVD were systematically introduced. In addition, the pharmacological mechanisms, active components, and clinical applications of BHD in the treatment of CSVD were reviewed. We believe that an in-depth understanding of BHD, its pharmacological mechanism, disease-drug interaction, and other aspects will help in laying the foundation for its development as a new therapeutic strategy for the treatment of CSVD.