Neuroprotective effect of salvianolic acid B against cerebral ischemic injury in rats via the CD40/NF-κB pathway associated with suppression of platelets activation and neuroinflammation

Navigating neurological disorders: harnessing the power of natural compounds for innovative therapeutic breakthroughs

Novel treatments are needed as neurological issues become more frequent worldwide. According to the report, plants, oceans, microorganisms, and animals contain interesting drug discovery compounds. Alzheimer's, Parkinson's, and stroke reviews emphasize neurological disorders' complexity and natural substances' safety. Learn about marine-derived and herbal substances' neuroprotective characteristics and applications. Molecular pathways show these substances' neurological healing effects. This article discusses clinical usage of Bryostatin-1, Fucoidan, Icariin, Salvianolic acid, Curcumin, Resveratrol, etc. Their potential benefits for asthma and Alzheimer's disease are complex. Although limited, the study promotes rigorous scientific research and collaboration between traditional and alternative medical practitioners. Unexplored natural compounds, quality control, well-structured clinical trials, and interdisciplinary collaboration should guide future study. Developing and employing natural chemicals to treat neurological illnesses requires ethical sourcing, sustainability, and public awareness. This detailed analysis covers natural chemicals' current state, challenges, and opportunities in neurological disorder treatment. See also the graphical abstract(Fig. 1).

Injectable Hydrogels Based on Hyaluronic Acid and Gelatin Combined with Salvianolic Acid B and Vascular Endothelial Growth Factor for Treatment of Traumatic Brain Injury in Mice

Traumatic brain injury (TBI) leads to structural damage in the brain, and is one of the major causes of disability and death in the world. Herein, we developed a composite injectable hydrogel (HA/Gel) composed of hyaluronic acid (HA) and gelatin (Gel), loaded with vascular endothelial growth factor (VEGF) and salvianolic acid B (SAB) for treatment of TBI. The HA/Gel hydrogels were formed by the coupling of phenol-rich tyramine-modified HA (HA-TA) and tyramine-modified Gel (Gel-TA) catalyzed by horseradish peroxidase (HRP) in the presence of hydrogen peroxide (H2O2). SEM results showed that HA/Gel hydrogel had a porous structure. Rheological test results showed that the hydrogel possessed appropriate rheological properties, and UV spectrophotometry results showed that the hydrogel exhibited excellent SAB release performance. The results of LIVE/DEAD staining, CCK-8 and Phalloidin/DAPI fluorescence staining showed that the HA/Gel hydrogel possessed good cell biocompatibility. Moreover, the hydrogels loaded with SAB and VEGF (HA/Gel/SAB/VEGF) could effectively promote the proliferation of bone marrow mesenchymal stem cells (BMSCs). In addition, the results of H&E staining, CD31 and α-SMA immunofluorescence staining showed that the HA/Gel/SAB/VEGF hydrogel possessed good in vivo biocompatibility and pro-angiogenic ability. Furthermore, immunohistochemical results showed that the injection of HA/Gel/SAB/VEGF hydrogel to the injury site could effectively reduce the volume of defective tissues in traumatic brain injured mice. Our results suggest that the injection of HA/Gel hydrogel loaded with SAB and VEGF might provide a new approach for therapeutic brain tissue repair after traumatic brain injury.

Bone marrow mesenchymal stem cells therapy regulates sphingolipid and glycerophospholipid metabolism to promote neurological recovery in stroke rats: A metabolomics analysis

Bone marrow mesenchymal stem cells (BMSCs) have therapeutic potential in the subacute/chronic phase of acute ischemic stroke (AIS), but the underlying mechanisms are not yet fully elucidated. There is a knowledge gap in understanding the metabolic mechanisms of BMSCs in stroke therapy. In this study, we administered BMSCs intravenously 24 h after reperfusion in rats with transient cerebral artery occlusion (MCAO). The treatment with BMSCs for 21 days significantly reduced the modified neurological severity score of MCAO rats (P < 0.01) and increased the number of surviving neurons in both the striatum and hippocampal dentate gyrus region (P < 0.01, respectively). Moreover, BMSCs treatment resulted in significant enhancements in various structural parameters of dendrites in layer V pyramidal neurons in the injured hemispheric motor cortex, including total length (P < 0.05), number of branches (P < 0.05), number of intersections (P < 0.01), and spine density (P < 0.05). Then, we performed plasma untargeted metabolomics analysis to study the metabolic changes of BMSCs on AIS. There were 65 differential metabolites identified in the BMSCs treatment group. Metabolic profiling analysis revealed that BMSCs modulate abnormal sphingolipid metabolism and glycerophospholipid metabolism, particularly affecting core members such as sphingomyelin (SM), ceramide (Cer) and sphingosine-1-phosphate (S1P). The metabolic network analysis and pathway-based compound-reaction-enzyme-gene network analysis showed that BMSCs inhibited the Cer-induced apoptotic pathway and promoted the S1P signaling pathway. These findings suggest that the enhanced effects of BMSCs on neuronal survival and synaptic plasticity after stroke may be mediated through these pathways. In conclusion, our study provides novel insight into the potential mechanisms of BMSCs treatment in stroke and sheds light on the possible clinical translation of BMSCs.

Metabolomics: A useful tool for ischemic stroke research

Ischemic stroke (IS) is a multifactorial and heterogeneous disease. Despite years of studies, effective strategies for the diagnosis, management and treatment of stroke are still lacking in clinical practice. Metabolomics is a growing field in systems biology. It is starting to show promise in the identification of biomarkers and in the use of pharmacometabolomics to help patients with certain disorders choose their course of treatment. The development of metabolomics has enabled further and more biological applications. Particularly, metabolomics is increasingly being used to diagnose diseases, discover new drug targets, elucidate mechanisms, and monitor therapeutic outcomes and its potential effect on precision medicine. In this review, we reviewed some recent advances in the study of metabolomics as well as how metabolomics might be used to identify novel biomarkers and understand the mechanisms of IS. Then, the use of metabolomics approaches to investigate the molecular processes and active ingredients of Chinese herbal formulations with anti-IS capabilities is summarized. We finally summarized recent developments in single cell metabolomics for exploring the metabolic profiles of single cells. Although the field is relatively young, the development of single cell metabolomics promises to provide a powerful tool for unraveling the pathogenesis of IS.

Modulation of redox-sensitive transcription factors with polyphenols as pathogenetically grounded approach in therapy of systemic inflammatory response

One of the adverse outcomes of acute inflammatory response is progressing to the chronic stage or transforming into an aggressive process, which can develop rapidly and result in the multiple organ dysfunction syndrome. The leading role in this process is played by the Systemic Inflammatory Response that is accompanied by the production of pro- and anti-inflammatory cytokines, acute phase proteins, and reactive oxygen and nitrogen species. The purpose of this review that highlights both the recent reports and the results of the authors' own research is to encourage scientists to develop new approaches to the differentiated therapy of various SIR manifestations (low- and high-grade systemic inflammatory response phenotypes) by modulating redox-sensitive transcription factors with polyphenols and to evaluate the saturation of the pharmaceutical market with appropriate dosage forms tailored for targeted delivery of these compounds. Redox-sensitive transcription factors such as NFκB, STAT3, AP1 and Nrf2 have a leading role in mechanisms of the formation of low- and high-grade systemic inflammatory phenotypes as variants of SIR. These phenotypic variants underlie the pathogenesis of the most dangerous diseases of internal organs, endocrine and nervous systems, surgical pathologies, and post-traumatic disorders. The use of individual chemical compounds of the class of polyphenols, or their combinations can be an effective technology in the therapy of SIR. Administering natural polyphenols in oral dosage forms is very beneficial in the therapy and management of the number of diseases accompanied with low-grade systemic inflammatory phenotype. The therapy of diseases associated with high-grade systemic inflammatory phenotype requires medicinal phenol preparations manufactured for parenteral administration.

Ginkgolide C attenuates cerebral ischemia/reperfusion-induced inflammatory impairments by suppressing CD40/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba L. (Ginkgoaceae), a traditional Chinese medicine, has been applied for thousands of years for the treatment of cardio-cerebral vascular diseases in China. It is written in Compendium of Materia Medica that Ginkgo has the property of "dispersing poison", which is now referred to as anti-inflammatory and antioxidant. Ginkgolides are important active ingredients in Ginkgo biloba leaves and ginkgolide injection has been frequently applied in clinical practice for the treatment of ischemic stroke. However, few studies have explored the effect and mechanism of ginkgolide C (GC) with anti-inflammatory activity in cerebral ischemia/reperfusion injury (CI/RI).

AIM OF THE STUDY

The present study aimed to demonstrate whether GC was capable of attenuating CI/RI. Furthermore, the anti-inflammatory effect of GC in CI/RI was explored around the CD40/NF-κB pathway.

MATERIALS AND METHODS

In vivo, middle cerebral artery occlusion/reperfusion (MCAO/R) model was established in rats. The neuroprotective effect of GC was assessed by neurological scores, cerebral infarct rate, microvessel ultrastructure, blood-brain barrier (BBB) integrity, brain edema, neutrophil infiltration, and levels of TNF-α, IL-1β, IL-6, ICAM-1, VCAM-1, and iNOS. In vitro, rat brain microvessel endothelial cells (rBMECs) were preincubated in GC before hypoxia/reoxygenation (H/R) culture. The cell viability, levels of CD40, ICAM-1, MMP-9, TNF-α, IL-1β, and IL-6, and activation of NF-κB pathway were examined. In addition, the anti-inflammatory effect of GC was also investigated by silencing CD40 gene in rBMECs.

RESULTS

GC attenuated CI/RI as demonstrated by decreasing neurological scores, reducing cerebral infarct rate, improving microvessel ultrastructural features, ameliorating BBB disruption, attenuating brain edema, inhibiting MPO activity, and downregulating levels of TNF-α, IL-1β, IL-6, ICAM-1, VCAM-1, and iNOS. Coherently, in rBMECs exposed to H/R GC enhanced cell viability and downregulated levels of ICAM-1, MMP-9, TNF-α, IL-1β, and IL-6. Furthermore, GC suppressed CD40 overexpression and hindered translocation of NF-κB p65 from the cytosol to the nucleus, phosphorylation of IκB-α, and activation of IKK-β in H/R rBMECs. However, GC failed to protect rBMECs from H/R-induced inflammatory impairments and suppress activation of NF-κB pathway when CD40 gene was silenced.

CONCLUSIONS

GC attenuates cerebral ischemia/reperfusion-induced inflammatory impairments by suppressing CD40/NF-κB pathway, which may provide an available therapeutic drug for CI/RI.

Neuroprotective Effects of Geopung-Chunghyuldan Based on Its Salvianolic Acid B Content Using an In Vivo Stroke Model

BACKGROUND

Geopung-Chunghyuldan (GCD) has neuroprotective properties. Salviae miltiorrhizae Radix plays an essential role in GCD's effect. The Salviae miltiorrhizae Radix marker compound is salvianolic acid B; however, its content is not uniform among samples. This study aimed to evaluate the neuroprotective effects of GCD based on salvianolic acid B content.

METHODS

The neuroprotective effects of GCD based on the salvianolic acid B content were evaluated by measuring infarct volume 24 h after permanent middle cerebral artery occlusion in an in vivo stroke model. For the experimental group, each GCD was administered immediately before surgery. The control groups were administered distilled water and aspirin (30 mg/kg) in the same way. The salvianolic acid B content in five types of Salviae Miltiorrhizae Radix (two Chinese and three Korean regions) based on different cultivation regions was analyzed by high-performance liquid chromatography.

RESULTS

Three samples met the Korean and Chinese Pharmacopeia standards for salvianolic acid B. However, two samples did not. GCDs with high salvianolic acid B showed marked neuroprotective effects compared to the control groups, whereas GCDs with low salvianolic acid B did not.

CONCLUSIONS

The salvianolic acid B content of Salviae miltiorrhizae Radix affects the neuroprotection effect of GCD. Stable, raw Salviae miltiorrhizae Radix is essential for GCD homogenization.

The role of traditional herbal medicine for ischemic stroke: from bench to clinic-A critical review

BACKGROUND

Ischemic stroke (IS) is a leading cause of death and severe long-term disability worldwide. Over the past few decades, considerable progress has been made in anti-ischemic therapies. However, IS remains a tremendous challenge, with favourable clinical outcomes being generally difficult to achieve from candidate drugs in preclinical phase testing. Traditional herbal medicine (THM) has been used to treat stroke for over 2,000 years in China. In modern times, THM as an alternative and complementary therapy have been prescribed in other Asian countries and have gained increasing attention for their therapeutic effects. These millennia of clinical experience allow THM to be a promising avenue for improving clinical efficacy and accelerating drug discovery.

PURPOSE

To summarise the clinical evidence and potential mechanisms of THMs in IS.

METHODS

A comprehensive literature search was conducted in seven electronic databases, including PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, the Chinese National Knowledge Infrastructure, the VIP Information Database, the Chinese Biomedical Literature Database, and the Wanfang Database, from inception to 17 June 2022 to examine the efficacy and safety of THM for IS, and to investigate experimental studies regarding potential mechanisms.

RESULTS

THM is widely prescribed for IS alone or as adjuvant therapy. In clinical trials, THM is generally administered within 72 h of stroke onset and are continuously prescribed for over 3 months. Compared with Western medicine (WM), THM combined with routine WM can significantly improve neurological function defect scores, promote clinical total effective rate, and accelerate the recovery time of stroke with fewer adverse effects (AEs). These effects can be attributed to multiple mechanisms, mainly anti-inflammation, antioxidative stress, anti-apoptosis, brain blood barrier (BBB) modulation, inhibition of platelet activation and thrombus formation, and promotion of neurogenesis and angiogenesis.

CONCLUSIONS

THM may be a promising candidate for IS management to guide clinical applications and as a reference for drug development.

Steroid Receptor Coactivator-Interacting Protein (SIP) Alleviates Ischemic Cerebral Infarction Damage Through the NF-κB Pathway

Ischemic stroke leads to high mortality and disability rates in humans. Cerebral ischemic injury has a severe complex pathophysiological mechanism. The abnormal release of inflammatory cytokines will cause brain tissue damage and destroy the blood-brain barrier integrity, which aggravates the process of brain injury. Therefore, attenuating the level of inflammatory response is critical for the therapy of cerebral ischemia injury. This study examined the rule of SIP treatment to support neuron protective effect after cerebral injury in an animal model of middle cerebral artery occlusion (MCAO). After ischemia/reperfusion, neurological function, neuroglia cells activation, infarction volume, brain water content, brain tissue apoptosis ratio, and inflammatory response were assessed, and quantitative PCR and western blot were also detected, respectively. Treatment of SIP ameliorated neurological dysfunction, brain infarction, brain edema, and brain cell apoptosis after MCAO operation. Overexpression SIP also suppressed pro-inflammatory cytokines release. Furthermore, the protective effect of SIP on brain injury occurs through reduced neuroglia cells activation through downregulation of the NF-κB pathway. In summary, the present work indicated that SIP prevents ischemic cerebral infarction-induced inflammation and apoptosis by blocking inflammasome activation via NF-κB signaling pathway. Those results suggest that SIP treatment is an attractive strategy for prevention of ischemic cerebral infarction.

Erythrocyte Membrane-Enveloped Salvianolic Acid B Nanoparticles Attenuate Cerebral Ischemia-Reperfusion Injury

Purpose

Ischemic stroke is the second leading cause of death and the third leading cause of disability worldwide. Salvianolic acid B (SAB), a water-soluble phenolic acid derived from the traditional Chinese medicine Salvia miltiorrhiza, exerted protective effects on cerebral ischemia-reperfusion injury. However, the efficacy of SAB is seriously hindered by poor blood brain barrier (BBB) permeability and short biological half-life in plasma. Brain targeted biomimetic nanoparticle delivery systems offer much promise in overcoming these limitations.

Methods

A brain targeted biomimetic nanomedicine (RR@SABNPs) was developed, which comprised of SAB loaded bovine serum albumin nanoparticles and functionalized red blood cell membrane (RBCM) with Arg-Gly-Asp (RGD). The characterization parameters, including particle size, zeta potential, morphology, Encapsulation Efficiency (EE), Drug Loading (DL), release behavior, stability, and biocompatibility, were investigated. Moreover, the middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was used to assess the therapeutic efficacy of RR@SABNPs on ischemic stroke. Finally, the reactive oxygen species (ROS) levels and mitochondrial membrane potential (MMP) were detected by DHE and JC‑1 staining in oxygen-glucose deprivation/reperfusion (OGD/R) and H₂O₂ injured PC12 cells.

Results

RR@SABNPs exhibited spheric morphology with core-shell structures and good stability and biocompatibility. Meanwhile, RR@SABNPs can significantly prolong SAB circulation time by overcoming the reticuloendothelial system (RES) and actively targeting ischemic BBB. Moreover, RR@SABNPs had comprehensive protective effects on MCAO/R model mice, manifested as a reduced infarct volume and improved neurological and sensorimotor functions, and significantly scavenged excess ROS and maintained MMP.

Conclusion

The designed brain targeted biomimetic nanomedicine RR@SABNPs can significantly prolong the half-time of SAB, deliver SAB into the ischemic brain and exhibit good therapeutic effects on MCAO/R model mice.

Polyphenols for the Treatment of Ischemic Stroke: New Applications and Insights

Ischemic stroke (IS) is a leading cause of death and disability worldwide. Currently, the main therapeutic strategy involves the use of intravenous thrombolysis to restore cerebral blood flow to prevent the transition of the penumbra to the infarct core. However, due to various limitations and complications, including the narrow time window in which this approach is effective, less than 10% of patients benefit from such therapy. Thus, there is an urgent need for alternative therapeutic strategies, with neuroprotection against the ischemic cascade response after IS being one of the most promising options. In the past few decades, polyphenolic compounds have shown great potential in animal models of IS because of their high biocompatibility and ability to target multiple ischemic cascade signaling pathways, although low bioavailability is an issue that limits the applications of several polyphenols. Here, we review the pathophysiological changes following cerebral ischemia and summarize the research progress regarding the applications of polyphenolic compounds in the treatment of IS over the past 5 years. Furthermore, we discuss several potential strategies for improving the bioavailability of polyphenolic compounds as well as some essential issues that remain to be addressed for the translation of the related therapies to the clinic.

Naoxintong capsule limits myocardial infarct expansion by inhibiting platelet activation through the ERK5 pathway

BACKGROUND

In the clinic, Naoxintong capsule (NXT) has been applied in two level prevention of ischemic disease. However, its mechanism of action requires further study.

PURPOSE

This study investigated whether NXT could affect platelet function and activation under ischemic pathological conditions.

MATERIALS AND METHODS

Wistar rats were divided into six groups, sham, saline, NXT (250, 500, 1000 mg/kg), and aspirin group (10 mg/kg). For the pre-treatment assays, MI model was established after pre-administration of saline, NXT-L, NXT-M, NXT-H, and aspirin respectively for 14 days, and after surgery, there were no continuous treatments. For the post-treatment assay, rats were orally administered for 3 days after MI. FeCl3-induced thrombosis model was applied to determine the thrombus wet weight. Bleeding time was used to assess the ability of the platelets to develop a hemostatic plug.

RESULTS

NXT decreased infarct size, decreased LDH, CK, and CK-MB values, and improved cardiac function. NXT inhibited platelets activation through reducing CD62P-positive platelets and inhibited infarct expansion by decreasing the number of CD45-positive cells and the amount of MMP9 secreted into the heart tissue. Mechanistically, NXT inhibited platelets activation through decreasing ROS levels, decreasing ERK5 phosphorylation, and increasing RAC1 phosphorylation in MI rats. Pre-treatment with NXT decreased thrombus formation and had normal bleeding times.

CONCLUSION

NXT showed obviously preventive effects, which was associated with negative control of platelet activation. The above results provide a basis for clinically expanding application of NXT.

Astrocytic glycogen mobilization participates in salvianolic acid B-mediated neuroprotection against reperfusion injury after ischemic stroke

Astrocytic glycogen serves as an important glucose reserve, and its degradation provides extra support for neighboring neurons during energy deficiency. Salvianolic acid B (SAB) exerts a neuroprotective effect on reperfusion insult after cerebrovascular occlusion, but the effect of SAB on astrocytic glycogen and its relationship with neuroprotection are not completely understood. Here, we knocked down astrocyte-specific glycogen phosphorylase (GP, the rate-limiting enzyme in glycogenolysis) in vitro and in vivo and investigated the changes in key enzymes in glycogen metabolism by performing immunoblotting in vitro and immunofluorescence in vivo. Neurobehavioral and morphological assessments were conducted to uncover the outcomes during brain reperfusion. SAB accelerated astrocytic glycogenolysis by upregulating GP activity but not GP expression after reperfusion. Suppression of astrocytic glycogenolysis weakened SAB-mediated neuroprotection against the reperfusion insult. In addition, activation of glycogenolysis by SAB contributed to the survival of astrocytes and surrounding neurons by increasing antioxidant levels in astrocytes. Our data reveal that astrocytic GP represents an important metabolic target in SAB-induced protection against brain damage after cerebrovascular recanalization.

The therapeutic effect and mechanism of Qishen Yiqi dripping pills on cardiovascular and cerebrovascular diseases and diabetic complications

The alterations in vascular homeostasis is deeply involved in the development of numerous diseases, such as coronary heart disease, stroke, and diabetic complications. Changes in blood flow and endothelial permeability caused by vascular dysfunction are the common mechanisms for these three types of diseases. The disorders of glucose and lipid metabolism can result in changes of the energy production patterns in endothelium and surrounding cells which may consequently cause local energy metabolic disorders, oxidative stress and inflammatory responses. Traditional Chinese medicine (TCM) follows the principle of the "treatment by the syndrome differentiation". TCM considers of that coronary heart disease, stroke and diabetes complications all as the type of "Qi deficiency and Blood stasis" syndrome, which mainly happens to the vascular system. Therefore, the common pathogenesis of these three types of diseases suggests the treatment strategy by TCM should be in a close manner and named as "treating different diseases by the same treatment". Qishen Yiqi dripping pills is a modern Chinese herbal medicine which has been widely used for treatment of patients with coronary heart disease characterized as "Qi deficiency and blood stasis" in China. Recently, many clinical reports have demonstrated the potent therapeutic effects of Qishen Yiqi dripping pills on ischemic stroke and diabetic nephropathy. Based on these reports, we will summarize the clinical applications of Qishen Yiqi dripping pills on coronary heart disease, ischemic stroke and diabetic nephropathy, including the involved mechanisms with basic researches.

Research Progress on the Mechanism of Mitochondrial Autophagy in Cerebral Stroke

Mitochondrial autophagy is an early defense and protection process that selectively clears dysfunctional or excessive mitochondria through a distinctive mechanism to maintain intracellular homeostasis. Mitochondrial dysfunction during cerebral stroke involves metabolic disbalance, oxidative stress, apoptosis, endoplasmic reticulum stress, and abnormal mitochondrial autophagy. This article reviews the research progress on the mechanism of mitochondrial autophagy in ischemic stroke to provide a theoretical basis for further research on mitochondrial autophagy and the treatment of ischemic stroke.

HDAC3 Downregulation Improves Cerebral Ischemic Injury via Regulation of the SDC1-Dependent JAK1/STAT3 Signaling Pathway Through miR-19a Upregulation

Histone deacetylase (HDAC) inhibitors can protect the brain from ischemic injury. This study aimed to identify the regulation of HDAC3 in cerebral ischemic injury. Middle cerebral artery occlusion (MCAO) was performed to establish a mouse model with cerebral ischemic injury, in which expression of HDAC3 and miR-19a was evaluated using RT-qPCR. In MCAO mice with silencing of HDAC3, infarct volume was determined using 2,3,5-triphenyl tetrazolium chloride (TTC) staining, and serum levels of TNF-α, IL-6, and IL-8 were measured using ELISA. An in vitro model was constructed in human umbilical vein endothelial cells (HUVECs) with oxygen-glucose deprivation/reoxygenation (OGD/R), followed by gain- and loss-of-function experiments. Relationships among miR-19a, HDAC3, and syndecan-1 (SDC1) were explored using RIP, ChIP, and dual-luciferase reporter assays. The expression of HDAC3, SDC1, JAK1, and STAT3 along with the extent of JAK1 and STAT3 phosphorylation was measured by Western blot analysis. HUVEC viability, apoptosis, and angiogenesis were assessed by CCK-8, flow cytometry, and angiogenesis assays in vitro separately. We found elevated HDAC3 and downregulated miR-19a expression in the MCAO mice. Decreased TNF-α, IL-6, and IL-8 serum levels were observed in response to silencing of HDAC3. HDAC3 inhibited the expression of miR-19a, which in turn targeted SDC1, leading to JAK1/STAT3 signaling pathway activation. HDAC3 overexpression or miR-19a inhibition repressed HUVEC viability and angiogenesis but enhanced HUVEC apoptosis. Our data unraveled the mechanism whereby HDAC3 inhibition ameliorated cerebral ischemic injury by activating the JAK1/STAT3 signaling pathway through miR-19a-mediated SDC1 inhibition.

Omics and Transgenic Analyses Reveal that Salvianolic Acid B Exhibits its Anti-Inflammatory Effects through Inhibiting the Mincle-Syk-Related Pathway in Macrophages

Salvianolic acid B (Sal B), the main water-soluble compound in Salvia miltiorrhiza, is known to exhibit anti-inflammatory activity, however, the underlying mechanism(s) is not completely uncovered. In this study, Sal B inhibited lipopolysaccharide (LPS)-induced M1 activation and promoted the transformation of macrophages from M1- to M2-type polarization. The altered lipid profiles of LPS-induced RAW 264.7 macrophages were partly restored by Sal B treatment. At the proteomic level, a total of 5612 proteins were identified and 432 were significantly changed in macrophages under LPS treatment. The differential proteins were classified into four clusters according to their expression level in blank, LPS, and Sal B groups. LPS-induced proteins in Cluster IV including Kif14, Mincle, and Sec62 were significantly recovered to almost normal levels by Sal B treatment. Use of knockdown Mincle or picetannol (inhibitor of Syk) led to significant reductions in the gene expressions of IL-1β, iNOS, and IL-12 and the release of NO. The converse was, however, observed for overexpressed Mincle. In addition, LPS- or trehalose-6,6-dibehenate-induced phosphorylation of Syk and PKCδ was decreased by Sal B treatment. These results suggest that Sal B inhibition of LPS-induced inflammation might be through inhibition of the Mincle-Syk-PKCδ signaling pathway.

Danhong Injection Attenuates Cerebral Ischemia-Reperfusion Injury in Rats Through the Suppression of the Neuroinflammation

Neuroinflammation is one of the major causes of damage of the central nervous system (CNS) and plays a vital role in the pathogenesis of cerebral ischemia, which can result in long-term disability and neuronal death. Danhong injection (DHI), a traditional Chinese medicine injection, has been applied to the clinical treatment of cerebral stoke for many years. In this study, we investigated the protective effects of DHI on cerebral ischemia-reperfusion injury (CIRI) in rats and explored its potential anti-neuroinflammatory properties. CIRI in adult male SD rats was induced by middle cerebral artery occlusion (MCAO) for 1 h and reperfusion for 24 h. Results showed that DHI (0.5, 1, and 2 ml/kg) dose-dependently improved the neurological deficits and alleviated cerebral infarct volume and histopathological damage of the cerebral cortex caused by CIRI. Moreover, DHI (0.5, 1, and 2 ml/kg) inhibited the mRNA expressions of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), intercellular cell adhesion molecule-1 (ICAM-1), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in ischemic brains, downregulated TNF-α, IL-1β, and monocyte chemotactic protein-1 (MCP-1) levels in serum, and reduced the neutrophil infiltration (myeloperoxidase, MPO) in ischemic brains, in a dose-dependent manner. Immunohistochemical staining results also revealed that DHI dose-dependently diminished the protein expressions of ICAM-1 and COX-2, and suppressed the activation of microglia (ionized calcium-binding adapter molecule 1, Iba-1) and astrocyte (glial fibrillary acidic protein, GFAP) in the cerebral cortex. Western blot analysis showed that DHI significantly downregulated the phosphorylation levels of the proteins in nuclear factor κB (NF-κB) and mitogen-activated protein kinas (MAPK) signaling pathways in ischemic brains. These results indicate that DHI exerts anti-neuroinflammatory effects against CIRI, which contribute to the amelioration of CNS damage.

Allium macrostemon Saponin Inhibits Activation of Platelet via the CD40 Signaling Pathway

Allium macrostemon saponin is a traditional Chinese medicine that exhibits anti-atherosclerosis effects. However, the mechanism of its action has not been fully clarified. Platelet activation induced by CD40L plays an important role in the process of atherosis. In the present study, we demonstrate for the first time that A. macrostemon saponin inhibits platelet activation induced by CD40L. Moreover, the effects of saponin on platelet activation were achieved by activation of the classical CD40L-associated pathway, including the PI3K/Akt, MAPK and NF-κB proteins. In addition, the present study further demonstrated that saponin exhibited an effect on the TRAF2-mediated ubiquitination degradation, which contributed to the inhibition of the CD40 pathway and its downstream members. The findings determine that A. macrostemon saponin inhibits activation of platelets via activation of downstream proteins of the CD40 pathway. This in turn affected TRAF2-associated ubiquitination degradation and caused an anti-thrombotic effect.

Boeravinone B Protects Brain against Cerebral Ichemia Reperfusion Injury in Rats: Possible Role of Anti-inflammatory and Antioxidant

It is well known that inflammatory reactions and oxidative stress play a key role in the pathogenesis of cerebral ischemia and secondary injury. Boeravinone B (BB) proofed their anti-inflammatory and antioxidant effect, but their neuroprotective effects still unknown. In this experimental study, we explore the neuro-protective effect of Boeravinone B on the ischemia/reperfusion and explore the possible mechanism. Male Wistar rats were used for the current experimental study. First induces natural I/R injury in rats and treated with BB and nifedipine, respectively. Rats were subjected to ischemia after 6 consecutive days by occlusion of the bilateral common carotid arteries (BCCAO). Neurological score, biochemical, antioxidant, pro-inflammatory cytokines and inflammatory parameters were estimated in the serum and brain tissue. BB treatment significantly (p < 0.001) suppressed neuronal injury, dose-dependently decreased the cerebral water content. BB treatment altered the pro-inflammatory cytokines, antioxidant and inflammatory mediators in the serum and brain tissue. BB regulated the expression of glycine (Gly), glutamic acid (Glu), taurine (Tau), aspartic acid (Asp) and γ-aminobutyric acid (GABA) and enhanced the activity of Na+, K+ ATPase and Ca2+ ATPase. BB significantly (p < 0.001) reduced antioxidant enzymes such as glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), malondialdehyde (MDA), glutathione reductase (GR); inflammatory cytokines include interleukin-4 (IL-4), interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), interleukin-6 (IL-6) and interleukin-1β (IL-1β); inflammatory mediators include prostaglandin (PGE2), nuclear kappa factor B (NF-κB) and cyclooxygenase-2 (COX-2), respectively. In this study, we have found that Boeravinone B exhibited protection against cerebral I/R by reducing oxidative stress and inflammatory reaction.

Pharmacological Effects of Salvianolic Acid B Against Oxidative Damage

Salvianolic acid B (Sal B) is one of the main active ingredients of Salvia miltiorrhiza, with strong antioxidant effects. Recent findings have shown that Sal B has anti-inflammatory, anti-apoptotic, anti-fibrotic effects and can promote stem cell proliferation and differentiation, and has a beneficial effect on cardiovascular and cerebrovascular diseases, aging, and liver fibrosis. Reactive oxygen species (ROS) include oxygen free radicals and oxygen-containing non-free radicals. ROS can regulate cell proliferation, survival, death and differentiation to regulate inflammation, and immunity, while Sal B can scavenge oxygen free radicals by providing hydrogen atoms and reduce the production of oxygen free radicals and oxygen-containing non-radicals by regulating the expression of antioxidant enzymes. The many pharmacological effects of Sal B may be closely related to its elimination and inhibition of ROS generation, and Nuclear factor E2-related factor 2/Kelch-like ECH-related protein 1 may be the core link in its regulation of the expression of antioxidant enzyme to exert its antioxidant effect. What is confusing and interesting is that Sal B exhibits the opposite mechanisms in tumors. To clarify the specific target of Sal B and the correlation between its regulation of oxidative stress and energy metabolism homeostasis will help to further understand its role in different pathological conditions, and provide a scientific basis for its further clinical application and new drug development. Although Sal B has broad prospects in clinical application due to its extensive pharmacological effects, the low bioavailability is a serious obstacle to further improving its efficacy in vivo and promoting clinical application. Therefore, how to improve the availability of Sal B in vivo requires the joint efforts of many interdisciplinary subjects.

Salvianolic Acid B Improves Chronic Mild Stress-Induced Depressive Behaviors in Rats: Involvement of AMPK/SIRT1 Signaling Pathway

Introduction

Depression is one of the most common neuropsychiatric illnesses which leads to a huge social and economic burden on modern society. So, it is necessary to develop an effective and safe pharmacological intervention for depression. Accumulating evidence has shown that adenosine monophosphate-activated protein kinase/sirtuin 1 (AMPK/SIRT1) signaling pathway plays a pivotal role in the development of depression. Our present study aimed to investigate the antidepressant effect and possible mechanisms of salvianolic acid B (SalB) in a chronic mild stress (CMS)-induced depression model in rats.

Materials and Methods

The rats were randomly divided into three groups: control group with no stressor, CMS group and CMS+SalB (30 mg/kg/d) group. After administration for 28 consecutive days, the behavior tests were performed. The rats were sacrificed after behavior tests, and the brain tissues were collected for biochemical analysis.

Results

It was observed that the administration of SalB for 28 consecutive days successfully corrected the depressive-like behaviors in CMS-treated rats. SalB could effectively reduce the gene expression of pro-inflammatory cytokines such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α), as well as nuclear factor-kappa B (NF-κB) p65 protein. In addition, inhibitor of NF-κB (IκB) protein expression was significantly increased after the administration of SalB. Moreover, SalB could effectively decrease protein expression of oxidative stress markers such as 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA) and increase the activity of catalase (CAT). SalB treatment also reversed CMS-induced inhibition of Nrf2 signaling pathway, along with increasing the mRNA expression of NAD(P)H:quinone oxidoreductase (NQO-1) and heme oxygenase 1 (HO-1). Regarding the endoplasmic reticulum (ER) stress markers, the protein expressions of C/EBP-homologous protein (CHOP) and glucose-regulated protein 78 kD (GRP78) were also significantly reduced after SalB administration. Furthermore, the supplementation of SalB could effectively activate the AMPK/SIRT1 signaling pathway, which indicated significant increase in pAMPK/AMPK ratio and SIRT1 protein expression.

Conclusion

Our study demonstrated that SalB relieved CMS-induced depressive-like state through the mitigation of inflammatory status, oxidative stress, and the activation of AMPK/SIRT1 signaling pathway.

Nose to brain drug delivery - A promising strategy for active components from herbal medicine for treating cerebral ischemia reperfusion

Cerebral ischemia reperfusion injury (CIRI), one of the major causes of death from stroke in the world, not only causes tremendous damage to human health, but also brings heavy economic burden to society. Current available treatments for CIRI, including mechanical therapies and drug therapies, are often accompanied by significant side-effects. Therefore, it is necessary to discovery new strategies for treating CIRI. Many studies have confirmed that the herbal medicine has the advantages of abundant resources, good curative effect and little side effects, which can be used as potential drug for treatment of CIRI through multiple targets. It's known that oral administration commonly has low bioavailability, and injection administration is inconvenient and unsafe. Many drugs can't delivery to brain through routine pathways due to the blood-brain-barrier (BBB). Interestingly, increasing evidences have suggested the nasal administration is a potential direct route to transport drug into brain avoiding the BBB and has the characteristics of high bioavailability for treating brain diseases. Therefore, intranasal administration can be treated as an alternative way to treat brain diseases. In the present review, effective methods to treat CIRI by using active ingredients derived from herbal medicine through nose to brain drug delivery (NBDD) are updated and discussed, and some related pharmacological mechanisms have also been emphasized. Our present study would be beneficial for the further drug development of natural agents from herbal medicines via NBDD.

Salvia miltiorrhiza stem-leaf active components of salvianolic acids and flavonoids improved the hemorheological disorder and vascular endothelial function on microcirculation dysfunction rats

Microcirculation, which connects macrocirculation and cells between arterioles and venules, plays a major role in the early onset of a variety of diseases. In this article, a dextran-induced microcirculation dysfunction (MCDF) model rats were adopted to evaluate the effects and mechanism of Salvia miltiorrhiza stem-leaf extracts based on plasma and urine metabonomics. The results showed the effective components of S. miltiorrhiza stem-leaf could significantly improve the hemorheology and coagulation index of MCDF rats and callback the expression of endothelin-1 (ET-1), induciblenitric oxide synthase (iNOS), vascularendothelial growth factor (VEGF), P-Selectin, thromboxane A2, 6-keto-PGF_1α , TNF-α, and interleukin-1β to control group in MCDF rats. The decrease of microvessel density (MVD) in lung and thymus caused by MCDF was upgraded by Salvia miltiorrhiza stem-leaf. Based on the plasma and urine metabolic data, 20 potential biomarkers were identified. These biomarkers are mainly related to linoleic acid metabolism, glutathione metabolism, pantothenate and coenzyme A biosynthesis, pentose and glucuronate interconversions, pyruvate metabolism, glyoxylate and dicarboxylate metabolism, beta-alanine metabolism, and citrate cycle. The results indicated that the effective components of S. miltiorrhiza stem-leaf can improve the hemorheological disorder and vascular endothelial function. Meanwhile, the effective components can regulate potential biomarkers and correlated metabolic pathway, which can provide guidance for the research and development of new drugs for MCDF.

Salvianolic Acid D Alleviates Cerebral Ischemia-Reperfusion Injury by Suppressing the Cytoplasmic Translocation and Release of HMGB1-Triggered NF-κB Activation to Inhibit Inflammatory Response

Inflammatory response participates in the overall pathophysiological process of stroke. It is a promising strategy to develop antistroke drugs targeting inflammation. This study is aimed at investigating the therapeutic effect and anti-inflammatory mechanism of salvianolic acid D (SalD) against cerebral ischemia/reperfusion (I/R) injury. A rat middle cerebral artery occlusion/reperfusion (MCAO/R) injury model was established, and an oxygen-glucose deprivation/reoxygenation (OGD/R) injury model was established in PC12 cells. Neurological deficit score, cerebral infarction, and edema were studied in vivo. Cell viability was achieved using the MTT method in vitro. The Bax, Bcl-2, cytochrome c, HMGB1, TLR4, TRAF6, NF-κB p65, p-NF-κB p65, and cleaved caspase-3 and -9 were tested via the Western blot method. Cytokines and cytokine mRNA, including TNF-α, IL-1β, and IL-6, were studied via ELISA and PCR methods. The translocation of HMGB1 and NF-κB were studied by immunofluorescence assay. The HMGB1/NeuN, HMGB1/GFAP, and HMGB1/Iba1 double staining was carried out to observe the localization of HMGB1 in different cells. Results showed that SalD alleviated neurological impairment, decreased cerebral infarction, and reduced edema in I/R rats. SalD improved OGD/R-downregulated PC12 cell viability. SalD also promoted Bcl-2 expression and suppressed Bax, cytochrome c, and cleaved caspase-3 and -9 expression. SalD decreased the intensity of TLR4, MyD88, and TRAF6 proteins both in vivo and in vitro, and significantly inhibited the NF-κB nuclear translocation induced by I/R and OGD/R. What's more, SalD inhibited HMGB1 cytoplasmic translocation in neurons, astrocytes, and microglia in both the cortex and hippocampus regions of I/R rats. In conclusion, SalD can alleviate I/R-induced cerebral injury in rats and increase the PC12 cell viability affected by OGD/R. The anti-inflammatory mechanism of SalD might result from the decreased nuclear-to-cytoplasmic translocation of HMGB1 and the inhibition on its downstream TLR4/MyD88/NF-κB signaling.

Qingkailing injection ameliorates cerebral ischemia-reperfusion injury and modulates the AMPK/NLRP3 Inflammasome Signalling pathway

Background

Cerebral ischemia is the second-leading cause of death and the main cause of permanent adult disabilities worldwide. Qingkailing (QKL) injection, a patented Chinese medicine approved by the China Food and Drug Administration, has been widely used in clinical practice to treat cerebral ischemia in China. The NOD-like receptor pyrin 3 (NLRP3) inflammasome is activated in cerebral ischemia and thus, is an effective therapeutic target. AMP-activated protein kinase (AMPK) is an important regulator inhibiting NLRP3 inflammasome activation.

Methods

We investigated the potential of QKL injection to provide neuroprotection after cerebral ischemia in a rat model of middle cerebral artery occlusion (MCAO). Adult male Sprague-Dawley rats (210–230 g) were randomly divided into three groups which consist of sham, MCAO and 3 ml/kg QKL. Rats in the QKL group received intraperitoneal injections of 3 ml/kg QKL, while rats in other groups were given saline in the same volumes. After 90 min ischemia and 24 h reperfusion, neurological function, laser speckle imaging, brain infarction, brain water content and brain blood barrier permeability were examined and cell apoptosis at prefrontal cortex were evaluated 24 h after MCAO, and western blot and real-time quantitative polymerase chain reaction was also researched, respectively.

Results

Intraperitoneal administration of QKL alleviated neurological deficiencies, cerebral infarction, blood-brain barrier permeability, brain oedema and brain cell apoptosis after MCAO induction. QKL decreased pro-inflammatory cytokines, TNF-α, IL-6 and IL-1β, and increased anti-inflammatory cytokines, IL-4 and IL-10. Furthermore, QKL activated phosphorylated AMPK, decreased oxidative stress and decreased NLRP3 inflammasome activation.

Conclusions

QKL relieved cerebral ischemia reperfusion injury and suppressed the inflammatory response by inhibiting AMPK-mediated activation of the NLRP3 inflammasome. These results suggest that QKL might have potential in treating brain inflammatory response and attenuating the cerebral ischemia-reperfusion injury.

Nuclear factor-kappa β as a therapeutic target for Alzheimer's disease

Alzheimer's disease (AD) is a typical progressive, chronic neurodegenerative disorder with worldwide prevalence. Its clinical manifestation involves the presence of extracellular plaques and intracellular neurofibrillary tangles (NFTs). NFTs occur in brain tissues as a result of both Aβ agglomeration and Tau phosphorylation. Although there is no known cure for AD, research into possible cures and treatment options continues using cell-cultures and model animals/organisms. The nuclear factor-kappa β (NF-κβ) plays an active role in the progression of AD. Impairment to this signaling module triggers undesirable phenotypic changes such as neuroinflammation, activation of microglia, oxidative stress related complications, and apoptotic cell death. These imbalances further lead to homeostatic abnormalities in the brain or in initial stages of AD essentially pushing normal neurons toward the degeneration process. Interestingly, the role of NF-κβ signaling associated receptor-interacting protein kinase is currently observed in apoptotic and necrotic cell death, and has been reported in brains. Conversely, the NF-κβ signaling pathway has also been reported to be involved in normal brain functioning. This pathway plays a crucial role in maintaining synaptic plasticity and balancing between learning and memory. Since any impairment in the pathways associated with NF-κβ signaling causes altered neuronal dynamics, neurotherapeutics using compounds including, antioxidants, bioflavonoids, and non-steroidal anti-inflammatory drugs against such abnormalities offer possibilities to rectify aberrant excitatory neuronal activity in AD. In this review, we have provided an extensive overview of the crucial role of NF-κβ signaling in normal brain homeostasis. We have also thoroughly outlined several established pathomechanisms associated with NF-κβ pathways in AD, along with their respective therapeutic approaches.

Neuroprotective Effects of Ginsenosides against Cerebral Ischemia

Ginseng has been used worldwide as traditional medicine for thousands of years, and ginsenosides have been proved to be the main active components for their various pharmacological activities. Based on their structures, ginsenosides can be divided into ginseng diol-type A and ginseng triol-type B with different pharmacological effects. In this study, six ginsenosides, namely ginsenoside Rb1, Rh2, Rg3, Rg5 as diol-type ginseng saponins, and Rg1 and Re as triol-type ginseng saponins, which were reported to be effective for ischemia-reperfusion (I/R) treatment, were chosen to compare their protective effects on cerebral I/R injury, and their mechanisms were studied by in vitro and in vivo experiments. It was found that all ginsenosides could reduce reactive oxygen species (ROS), inhibit apoptosis and increase mitochondrial membrane potential in cobalt chloride-induced (CoCl₂-induced) PC12 cells injury model, and they could reduce cerebral infarction volume, brain neurological dysfunction of I/R rats in vivo. The results of immunohistochemistry and western blot showed that the expression of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), silencing information regulator (SIRT1) and nuclear transcription factor P65 (NF-κB) in hippocampal CA1 region of some ginsenoside groups were also reduced. In general, the effect on cerebral ischemia of Rb1 and Rg3 was significantly improved compared with the control group, and was the strongest among all the ginsenosides. The effect on SIRT1 activation of ginsenoside Rb1 and the inhibition effect of TLR4/MyD88 protein expression of ginsenoside Rb1 and Rg3 were significantly stronger than that of other groups. The results indicated that ginsenoside Rg1, Rb1, Rh2, Rg3, Rg5 and Re were effective in protecting the brain against ischemic injury, and ginsenoside Rb1 and Rg3 have the strongest therapeutic activities in all the tested ginsenosides. Their neuroprotective mechanism is associated with TLR4/MyD88 and SIRT1 activation signaling pathways, and they can reduce cerebral ischemic injury by inhibiting NF-κB transcriptional activity and the expression of proinflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6).

Salvianolic Acid B-Alleviated Angiotensin II Induces Cardiac Fibrosis by Suppressing NF-κB Pathway In Vitro

BACKGROUND Salvianolic acid B (SalB) is the representative component of phenolic acids derived from the roots and rhizomes of Salvia miltiorrhiza Bge (Labiatae), which has been used widely in Asian countries for clinical therapy of various cardiovascular dysfunction-related diseases. However, cardiac protection effects and the underlying mechanism for clinical application are still poorly understood. Here, we investigated the potential anti-myocardial fibrosis effect and mechanism of SalB on Angiotensin II (Ang II)-induced cardiac fibrosis in vitro. MATERIAL AND METHODS The proliferation and migration capacity of cardiac fibroblasts (CFBs) were measured by MTT assay and scratch analysis, respectively. The colorimetric assay determined the hydroxyproline content in medium. Western blotting detected the protein expressions of nuclear transcription factor-kappa B (NF-κB) pathway-associated proteins, fibronectin (FN), collagen type I (Coll I), α-smooth muscle actin (α-SMA), and connective tissue growth factor (CTGF). The expression of α-SMA protein was observed by immunofluorescence staining. qRT-PCR detected the mRNA expression of NF-κB. RESULTS SalB attenuated Ang II-induced the proliferation and the migration ability of CFBs. Ang II-induced the extracellular matrix protein Coll I, FN, and α-SMA, the pro-fibrotic cytokine CTGF protein expression was inhibited, and the nuclear translocation of NF-κB p65 subunit was reduced by SalB. Western blotting and qRT-PCR confirmed that SalB blocked the activation of NF-κB induced by Ang II. PDTC (the NF-κB inhibitor) also inhibited proliferation of CFBs and reduced α-SMA and Coll I expression induced by Ang II. CONCLUSIONS SalB can alleviate Ang II-induced cardiac fibrosis via suppressing the NF-κB pathway in vitro.

Design of multi-drug combinations for poly-pharmacological effects using composition-activity relationship modeling and multi-objective optimization approach: Application in traditional Chinese medicine

In recent years, multi-component therapies are increasingly utilized to treat complex diseases such as cancer, diabetes, and other chronic complex diseases. Here, we proposed the protocol for rational design of drug combination with poly-pharmacological effects by integration of design of experiments (DOE), computational modeling, and multiple-objective optimization algorithm. Here, we introduce a common workflow for modeling quantitative relationship of chemical composition and multiple activities of drug combinations. As an example, anti-oxidation, neuroprotective, and anti-platelet activities of three different salvia polyphenols were measured, which were mathematically represented by multivariant regression models to evaluate the effect of combination. In validation, the optimized combination which obtained by weighed-sum method showed good activities in all three models. Our results demonstrate that the multiple-objective optimization strategy is suitable to optimize the ratio of the compounds so to induce the best therapeutic action.

Microglia TREM2 is required for electroacupuncture to attenuate neuroinflammation in focal cerebral ischemia/reperfusion rats

Neuroinflammation plays a critical role in ischemic stroke pathology and could be a promising target in ischemic stroke. Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglia-specific receptor in the CNS that is involved in regulating neuroinflammation in cerebral ischemia. However, the role of TREM2 in ischemic stroke is controversial. Electroacupuncture (EA) is an effective therapy for alleviating stroke-induced neuroinflammation. Here, we found that ischemic stroke induced an increased microglial TREM2 expression, and EA treatment can further promote microglial TREM2 expression following cerebral ischemia. TREM2 overexpression was observed to play a neuroprotective role by improving the neurobehavioral deficit and reducing the cerebral infarct volume 72 h after reperfusion, whereas TREM2 silencing had the opposite effects. Moreover, the effects of EA on improving stroke outcome and suppressing neuroinflammation in the brain were reversed by TREM2 silencing. Finally, TREM2 silencing also suppressed the ability of EA to regulate the PI3K/Akt and NF-κB signaling pathways. Altogether, the results show that TREM2 could be a potential target in EA treatment for attenuating inflammatory injury following cerebral ischemia/reperfusion.

Antagonizing peroxisome proliferator-activated receptor γ facilitates M1-to-M2 shift of microglia by enhancing autophagy via the LKB1-AMPK signaling pathway

Microglia‐mediated neuroinflammation plays a dual role in various brain diseases due to distinct microglial phenotypes, including deleterious M1 and neuroprotective M2. There is growing evidence that the peroxisome proliferator‐activated receptor γ (PPARγ) agonist rosiglitazone prevents lipopolysaccharide (LPS)‐induced microglial activation. Here, we observed that antagonizing PPARγ promoted LPS‐stimulated changes in polarization from the M1 to the M2 phenotype in primary microglia. PPARγ antagonist T0070907 increased the expression of M2 markers, including CD206, IL‐4, IGF‐1, TGF‐β1, TGF‐β2, TGF‐β3, G‐CSF, and GM‐CSF, and reduced the expression of M1 markers, such as CD86, Cox‐2, iNOS, IL‐1β, IL‐6, TNF‐α, IFN‐γ, and CCL2, thereby inhibiting NFκB–IKKβ activation. Moreover, antagonizing PPARγ promoted microglial autophagy, as indicated by the downregulation of P62 and the upregulation of Beclin1, Atg5, and LC3‐II/LC3‐I, thereby enhancing the formation of autophagosomes and their degradation by lysosomes in microglia. Furthermore, we found that an increase in LKB1–STRAD–MO25 complex formation enhances autophagy. The LKB1 inhibitor radicicol or knocking down LKB1 prevented autophagy improvement and the M1‐to‐M2 phenotype shift by T0070907. Simultaneously, we found that knocking down PPARγ in BV2 microglial cells also activated LKB1–AMPK signaling and inhibited NFκB–IKKβ activation, which are similar to the effects of antagonizing PPARγ. Taken together, our findings demonstrate that antagonizing PPARγ promotes the M1‐to‐M2 phenotypic shift in LPS‐induced microglia, which might be due to improved autophagy via the activation of the LKB1–AMPK signaling pathway.

Synergistic Effects of Salvianolic Acid B and Puerarin on Cerebral Ischemia Reperfusion Injury

Ischemic stroke (IS) is characterized by the sudden loss of blood circulation to an area of the brain, resulting in a corresponding loss of neurologic function. It has been a worldwide critical disease threatening to the health and life of human beings. Despite significant progresses achieved, effective treatment still remains a formidable challenge due to the complexity of the disease. Salvianolic acid B (Sal-B) and Puerarin (Pue) are two active neuroprotectants isolated from traditional Chinese herbs, Salvia miltiorrhiza and Kudzu root respectively, which have been used for the prevention and treatment of IS for thousands of years in China. The activities of two compounds against cerebral ischemia reperfusion injury have been confirmed via various pathways. However, the therapeutic efficacy of any of the two components is still unsatisfied. In the present study, the effect of the combination of Sal-B and Pue on IS was evaluated and validated in vitro and in vivo. The ratio of two compounds was firstly optimized based on the results of CoCl₂ damaged PC12 cells model. The co-administration exhibited significantly protective effect in CoCl₂ induced PC12 cells injury model by reducing ROS, inhibiting apoptosis and improving mitochondrial membrane potential in vitro. Moreover, Sal-B + Pue significantly relieved neurological deficit scores and infarct area than Sal-B or Pue alone in vivo. The results indicated that neuroprotection mechanism of Sal-B + Pue was related to TLR4/MyD88 and SIRT1 activation signaling pathway to achieve synergistic effect, due to the inhibition of NF-κB transcriptional activity and expression of pro-inflammatory cytokine (TNF-α, IL-1β, IL-6). In conclusion, the combination of Sal-B and Pue exerted much stronger neuroprotective effect than Sal-B or Pue alone, which provides a potential new drug and has great significance for the treatment of IS.

Molecular Pharmacology of Rosmarinic and Salvianolic Acids: Potential Seeds for Alzheimer's and Vascular Dementia Drugs

Both caffeic acid and 3,4-dihydroxyphenyllactic acid (danshensu) are synthesized through two distinct routs of the shikimic acid biosynthesis pathway. In many plants, especially the rosemary and sage family of Lamiaceae, these two compounds are joined through an ester linkage to form rosmarinic acid (RA). A further structural diversity of RA derivatives in some plants such as Salvia miltiorrhiza Bunge is a form of RA dimer, salvianolic acid-B (SA-B), that further give rise to diverse salvianolic acid derivatives. This review provides a comprehensive perspective on the chemistry and pharmacology of these compounds related to their potential therapeutic applications to dementia. The two common causes of dementia, Alzheimer's disease (AD) and stroke, are employed to scrutinize the effects of these compounds in vitro and in animal models of dementia. Key pharmacological mechanisms beyond the common antioxidant and anti-inflammatory effects of polyphenols are highlighted with emphasis given to amyloid beta (Aβ) pathologies among others and neuronal regeneration from stem cells.

Myricetin against ischemic cerebral injury in rat middle cerebral artery occlusion model

The purpose of the present study was to examine the effects of myricetin on reducing cerebral ischemia injury in a rat model. A rat model of permanent middle cerebral artery occlusion (pMCAO) was used in the present study. Rats were randomized into the following five groups: Sham, model, low‑myricetin (1 mg/kg), medium‑myricetin (5 mg/kg) and high‑myricetin (25 mg/kg) groups. Neurological deficit scores were evaluated by an examiner blinded to the experimental groups. Brain infarct size was estimated macroscopically using 2,3,5‑triphenyltetrazolium chloride staining. The levels of inflammatory factors tumor necrosis factor (TNF)‑α, interleukin (IL)‑6 and IL‑1β, and oxidative stress index superoxide dismutase (SOD), malondiadehyde (MDA), and the glutathione/glutathione disulfide (GSH/GSSG) ratio were measured by ELISA. The degree of brain cell apoptosis was determined using a terminal deoxynucleotidyl transferase dUTP nick‑end labeling assay. Protein expression levels of total or phosphorylated p38 mitogen activated protein kinase (MAPK), nuclear factor (NF)‑κB/p65 and protein kinase B (AKT) were determined using a western blotting assay. The neurological deficit score and infarct area induced by pMCAO decreased in a dose‑dependent manner following myricetin treatment. Furthermore, myricetin reduced the expression levels of IL‑1β, IL‑6, TNF‑α, and MDA, and increased GSH/GSSG ratio and SOD activity. A significant decrease in cell apoptosis was observed in response to myricetin. In addition, myricetin significantly increased the level of phosphorylated AKT protein, and decreased the phosphorylation of p38 MAPK and the level of NF‑κB/p65. Overall, the results of the present study suggested that myricetin exhibits a therapeutic effect by reducing ischemic cerebral injury, and the protective effect of myricetin may be associated with the p38 MAPK, NF‑κB/p65 and AKT signaling pathways.