Treatment with tanshinone IIA suppresses disruption of the blood-brain barrier and reduces expression of adhesion molecules and chemokines in experimental autoimmune encephalomyelitis

Revolutionizing Neuroimmunology: Unraveling Immune Dynamics and Therapeutic Innovations in CNS Disorders

Neuroimmunology is reshaping the understanding of the central nervous system (CNS), revealing it as an active immune organ rather than an isolated structure. This review delves into the unprecedented discoveries transforming the field, including the emerging roles of microglia, astrocytes, and the blood-brain barrier (BBB) in orchestrating neuroimmune dynamics. Highlighting their dual roles in both repair and disease progression, we uncover how these elements contribute to the intricate pathophysiology of neurodegenerative diseases, cerebrovascular conditions, and CNS tumors. Novel insights into microglial priming, astrocytic cytokine networks, and meningeal lymphatics challenge the conventional paradigms of immune privilege, offering fresh perspectives on disease mechanisms. This work introduces groundbreaking therapeutic innovations, from precision immunotherapies to the controlled modulation of the BBB using nanotechnology and focused ultrasound. Moreover, we explore the fusion of immune modulation with neuromodulatory technologies, underscoring new frontiers for personalized medicine in previously intractable diseases. By synthesizing these advancements, we propose a transformative framework that integrates cutting-edge research with clinical translation, charting a bold path toward redefining CNS disease management in the era of precision neuroimmunology.

Taraxacum coreanum (Korean Dandelion) Extract Protects Against Lipopolysaccharide-Induced Blood-Brain Barrier Destruction via Regulation of Tight Junctions and Inflammatory Responses in bEnd.3 Cells

Dysfunction of the blood-brain barrier (BBB) is closely related to neuroinflammation-mediated neurodegenerative disorders. Lipopolysaccharide (LPS), an endotoxin, can cause inflammation by impairing the brain endothelial barrier function and increasing the BBB permeability. Although Taraxacum coreanum NAKAI extract (TC), a traditional medicine widely used in Korea, has antioxidant and anti-inflammatory properties, the protective effects on neuroinflammation and BBB dysfunction are not fully understood. In the present study, bEnd.3 cerebral vascular endothelial cells were treated with TC followed by LPS exposure, and the effects on transendothelial electrical resistance (TEER) values, pro-inflammatory cytokine production, and expression of proteins related to inflammatory responses and tight junction integrity were assessed. The TC-treated group exhibited elevated TEER values in bEnd.3 monolayer compared to LPS-only treated group. In addition, TC treatment increased the expression of proteins involved in the tight junctions, such as ZO-1, claudin-5, and occludin. Furthermore, the TC-treated group suppressed the proteins expression-related to nuclear factor-κB (NF-κB) pathway. Taken together, TC attenuates LPS-induced neuroinflammatory responses by regulating NF-κB activation, which may contribute to protecting against BBB disruption. These findings suggest that TC may have the potential to be used as a material for functional foods to prevent neuroinflammation-related brain diseases.

Extracellular vesicles containing miR-181a-5p as a novel therapy for experimental autoimmune encephalomyelitis-induced demyelination

Multiple sclerosis (MS) is an inflammatory demyelinating disorder of the central nervous system. Recent research has revealed that mesenchymal stem cell-derived extracellular vesicles (MSC-EVs), containing specific miRNAs, possess immunomodulatory properties and have demonstrated therapeutic potential in the treatment of MS. This study aimed to investigate the role MSC-EVs, containing microRNA-181a-5p (miR-181a-5p) in both experimental autoimmune encephalomyelitis (EAE), an established animal model of MS, and lipopolysaccharide-stimulated BV2 microglia. We evaluated clinical symptoms and inflammatory responses in EAE mice following intrathecal injections of MSC-EVs. MSC-EVs containing miR-181a-5p were co-cultured with microglia to explore their impact on inflammation and cell pyroptosis. We validated the interaction between miR-181a-5p and its downstream regulators and conducted in vivo verification by injecting manipulated EVs containing miR-181a-5p into EAE mice. Our results demonstrated that MSC-EVs, containing miR-181a-5p reduced the clinical symptoms of EAE mice. Furthermore, we observed downregulation of miR-181a-5p in EAE model mice, and its expression was restored after treatment with MSC-EVs, which corresponded to suppressed microglial inflammation and pyroptosis. Additionally, EVs containing miR-181a-5p mitigated spinal cord injury and demyelination in EAE mice. Mechanistically, ubiquitin-specific protease 15 (USP15) exhibited high expression in EAE mice, and miR-181a-5p was specifically targeted and bound to USP15, thereby regulating the RelA/NEK7 axis. In conclusion, MSC-EVs containing miR-181a-5p inhibit microglial inflammation and pyroptosis through the USP15-mediated RelA/NEK7 axis, thus alleviating the clinical symptoms of EAE. These findings present a potential therapeutic approach for the treatment of MS.

Emerging concerns of blood-brain barrier dysfunction caused by neurotropic enteroviral infections

Enteroviruses (EVs), comprise a genus in the Picornaviridae family, which have been shown to be neurotropic and can cause various neurological disorders or long-term neurological condition, placing a huge burden on society and families. The blood-brain barrier (BBB) is a protective barrier that prevents dangerous substances from entering the central nervous system (CNS). Recently, numerous EVs have been demonstrated to have the ability to disrupt BBB, and further lead to severe neurological damage. However, the precise mechanisms of BBB disruption associated with these EVs remain largely unknown. In this Review, we focus on the molecular mechanisms of BBB dysfunction caused by EVs, emphasizing the invasiveness of enterovirus A71 (EVA71), which will provide a research direction for further treatment and prevention of CNS disorders.

TGFβ1-induced hedgehog signaling suppresses the immune response of brain microvascular endothelial cells elicited by meningitic Escherichia coli

BACKGROUND

Meningitic Escherichia coli (E. coli) is the major etiological agent of bacterial meningitis, a life-threatening infectious disease with severe neurological sequelae and high mortality. The major cause of central nervous system (CNS) damage and sequelae is the bacterial-induced inflammatory storm, where the immune response of the blood-brain barrier (BBB) is crucial.

METHODS

Western blot, real-time PCR, enzyme-linked immunosorbent assay, immunofluorescence, and dual-luciferase reporter assay were used to investigate the suppressor role of transforming growth factor beta 1 (TGFβ1) in the immune response of brain microvascular endothelial cells elicited by meningitic E. coli.

RESULT

In this work, we showed that exogenous TGFβ1 and induced noncanonical Hedgehog (HH) signaling suppressed the endothelial immune response to meningitic E. coli infection via upregulation of intracellular miR-155. Consequently, the increased miR-155 suppressed ERK1/2 activation by negatively regulating KRAS, thereby decreasing IL-6, MIP-2, and E-selectin expression. In addition, the exogenous HH signaling agonist SAG demonstrated promising protection against meningitic E. coli-induced neuroinflammation.

CONCLUSION

Our work revealed the effect of TGFβ1 antagonism on E. coli-induced BBB immune response and suggested that activation of HH signaling may be a potential protective strategy for future bacterial meningitis therapy. Video Abstract.

Sodium Tanshinone IIA Sulfonate Protects Primary Cardiomyocytes Against Radiation-Induced Myocardial Injury via the p38 Pathway

Sodium tanshinone IIA sulfonate (STS), which is extracted from a Chinese medicinal herb, possesses many pharmacologic functions, such as coronary dilation, anti-inflammatory properties, and antiapoptotic and antioxidant effects. It remains unknown whether STS can protect cardiomyocytes injured after radiation therapy. An in vitro Sprague-Dawley (SD) rat neonatal cardiomyocyte system was established. Primary cardiomyocytes (PCMs) from neonatal SD rats were isolated under sterile conditions. PCM cells were divided into a control group (0 Gy/hour) and 5 experimental radiation therapy groups (0.25 Gy/hour, 0.5 Gy/hour, 1 Gy/hour, 2 Gy/hour, and 4 Gy/hour). Cell viability, the content of malondialdehyde (MDA), the lactate dehydrogenase (LDH) leakage rate, and superoxide dismutase (SOD) and glutathione (GSH) activities were recorded separately in each group after 7 days of culture. Western blot was used to detect the levels of p38, caspase-3 protein, and X protein (BAX) associated with B-cell lymphoma 2 (Bcl-2) in PCMs. X-rays inhibited cell growth, decreased cell viability, and induced an oxidative stress response in PCMs. STS and SB203580 (the inhibitor of P38 mitogen-activated protein kinase pathway) alleviated X-ray-induced damage to PCMs. An enzyme-linked immunosorbent assay showed that X-rays increased the cTnT level. STS and SB203580 ameliorated the X-ray-induced increase in cTnT leakage. X-rays enhanced the expression of p38/p-p38 and caspase-3 while reducing the expression of Bcl-2/BAX in PCMs, as demonstrated by western blotting. STS and SB203580 mitigated the changes in protein expression triggered by X-ray radiation. In conclusions, STS was shown to exert significant cardioprotective, anti-inflammatory, and antioxidant effects in PCMs by inhibiting the p38 mitogen-activated protein kinase pathway.

Tanshinone IIA Against Cerebral Ischemic Stroke and Ischemia- Reperfusion Injury: A Review of the Current Documents

Stroke is a well-known neurological disorder that carries significant morbidity and mortality rates worldwide. Cerebral Ischemic Stroke (CIS), the most common subtype of stroke, occurs when thrombosis or emboli form elsewhere in the body and travel to the brain, leading to reduced blood perfusion. Cerebral Ischemia/Reperfusion Injury (CIRI) is a common complication of CIS and arises when blood flow is rapidly restored to the brain tissue after a period of ischemia. The therapeutic approaches currently recognized for CIS, such as thrombolysis and thrombectomy, have notable side effects that limit their clinical application. Recently, there has been growing interest among researchers in exploring the potential of herbal agents for treating various disorders and malignancies. One such herbal agent with medicinal applications is tanshinone IIA, an active diterpene quinone extracted from Salvia miltiorrhiza Bunge. Tanshinone IIA has shown several pharmacological benefits, including anti-inflammatory, antioxidant, anti-apoptotic, and neuroprotective properties. Multiple studies have indicated the protective role of tanshinone IIA in CIS and CIRI. This literature review aims to summarize the current findings regarding the molecular mechanisms through which this herbal compound improves CIS and CIRI.

The Recent Applications of PLGA-Based Nanostructures for Ischemic Stroke

With the accelerated development of nanotechnology in recent years, nanomaterials have become increasingly prevalent in the medical field. The poly (lactic acid-glycolic acid) copolymer (PLGA) is one of the most commonly used biodegradable polymers. It is biocompatible and can be fabricated into various nanostructures, depending on requirements. Ischemic stroke is a common, disabling, and fatal illness that burdens society. There is a need for further improvement in the diagnosis and treatment of this disease. PLGA-based nanostructures can facilitate therapeutic compounds' passage through the physicochemical barrier. They further provide both sustained and controlled release of therapeutic compounds when loaded with drugs for the treatment of ischemic stroke. The clinical significance and potential of PLGA-based nanostructures can also be seen in their applications in cell transplantation and imaging diagnostics of ischemic stroke. This paper summarizes the synthesis and properties of PLGA and reviews in detail the recent applications of PLGA-based nanostructures for drug delivery, disease therapy, cell transplantation, and the imaging diagnosis of ischemic stroke.

Therapeutic prospects of naturally occurring p38 MAPK inhibitors tanshinone IIA and pinocembrin for the treatment of SARS-CoV-2-induced CNS complications

P38 mitogen-activated protein kinase (p38 MAPK) signaling pathway is closely related to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) replication and hyperinflammatory responses in coronavirus disease 2019 (COVID-19). Therefore, blood-brain barrier-penetrating p38 MAPK inhibitors have good potential for the treatment of central nervous system (CNS) complications of COVID-19. The aim of the present study is the characterization of the therapeutic potential of tanshinone IIA and pinocembrin for the treatment of CNS complications of COVID-19. Studies published in high-quality journals indexed in databases Scopus, Web of Science, PubMed, and so forth were used to review the therapeutic capabilities of selected compounds. In continuation of our previous efforts to identify agents with favorable activity/toxicity profiles for the treatment of COVID-19, tanshinone IIA and pinocembrin were identified with a high ability to penetrate the CNS. Considering the nature of the study, no specific time frame was determined for the selection of studies, but the focus was strongly on studies published after the emergence of COVID-19. By describing the association of COVID-19-induced CNS disorders with p38 MAPK pathway disruption, this study concludes that tanshinone IIA and pinocembrin have great potential for better treatment of these complications. The inclusion of these compounds in the drug regimen of COVID-19 patients requires confirmation of their effectiveness through the conduction of high-quality clinical trials.

Exosomal miR-23b-3p from bone mesenchymal stem cells alleviates experimental autoimmune encephalomyelitis by inhibiting microglial pyroptosis

Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system and is marked by inflammation and damage to the myelin sheath surrounding nerve fibers. Recent studies have highlighted the therapeutic value of exosomes (Exos) obtained from bone marrow mesenchymal stem cells (BMSCs) in MS treatment. These BMSC-Exos contain biologically active molecules that show promising results in preclinical evaluations. The aim of this study was to investigate the mechanism of BMSC-Exos containing miR-23b-3p in both LPS-stimulated BV2 microglia and in experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Exos were isolated from BMSCs, and their effects were evaluated in vitro by co-culturing with BV2 microglia. The interaction between miR-23b-3p and its downstream targets was also explored. The efficacy of BMSC-Exos was further verified in vivo by injecting the Exos into EAE mice. The results showed that BMSC-Exos containing miR-23b-3p reduced microglial pyroptosis in vivo by specifically binding to and suppressing the expression of NEK7. In vivo, BMSC-Exos containing miR-23b-3p alleviated the severity of EAE by decreasing microglial inflammation and pyroptosis via the repression of NEK7. These findings provide new insights into the therapeutic potential of BMSC-Exos containing miR-23b-3p for MS.

Combination of puerarin and tanshinone IIA alleviates ischaemic stroke injury in rats via activating the Nrf2/ARE signalling pathway

CONTEXT

Puerarin (Pue) and tanshinone IIA (Tan IIA) are often used in combination in the treatment of cerebrovascular diseases.

OBJECTIVE

To investigate the neuroprotective effect and synergic mechanism of Pue-Tan IIA on the treatment of ischaemic stroke (IS).

MATERIALS AND METHODS

IS was induced in rats by middle cerebral artery occlusion (MCAO). Rats were intraperitoneally injected with Pue (36 mg/kg), Tan IIA (7.2 mg/kg), or Pue-Tan IIA (36 and 7.2 mg/kg) for five times [30 min before ischaemia, immediately after reperfusion (0 h), 24, 48, and 72 h after reperfusion]. After administration, neurological function assessment and histological changes in the brain were performed. S-100β and NSE levels were measured to determine the severity of brain injury. Oxidative stress parameters and inflammatory mediators were measured. The proteins involved in Nrf2/ARE signalling pathway were determined by qRT-PCR and western blot.

RESULTS

After administration, the neurological function scores, infarct volume, S-100β, and NSE levels were significantly reduced in MCAO rats, especially with Pue-Tan IIA treatment (p < 0.05). All treatments increased T-AOC, CAT, SOD, and GSH activities and reduced GSSG activity and MDA, TNF-α, IL-6, ICAM-1, and COX-2 levels in MCAO rats. Pue-Tan IIA significantly increased Nrf2 expression in the nucleus (1.81-fold) and decreased its expression in the cytoplasm (0.60-fold). Pue-Tan IIA significantly increased the expressions of HO-1 (1.87-fold) and NQO1 (1.76-fold) and decreased Keap1 expression (0.39-fold).

DISCUSSION AND CONCLUSIONS

The combination of Pue and Tan IIA could alleviate ischaemic brain injury by activating Nrf2/ARE signalling pathway, providing an experimental basis for clinical applications.

Research progress of mechanisms for tight junction damage on blood-brain barrier inflammation

Inflammation in the central nervous system (CNS) contributes to disease pathologies by disrupting the integrity of the blood-brain barrier (BBB). Tight junctions (TJ) are a key component of the BBB. Following hypoxic-ischaemic or mechanical injury to the brain, inflammatory mediators are released such as cytokines, chemokines, and growth factors. Simultaneously, matrix metalloproteinases (MMPs) are released which can degrade TJ proteins. Subsequently, the function and morphology of the BBB are disrupted, which allows immune cells an opportunity to enter into the brain parenchyma. This review summarises the information on the role of TJ protein families in the BBB and provides a comprehensive summary of the mechanisms whereby inflammation breaks down the BBB by increasing degradation of TJ proteins.

Simultaneous Determination of Seven Lipophilic and Hydrophilic Components in Salvia miltiorrhiza Bunge by LC-MS/MS Method and Its Application to a Transport Study in a Blood-Brain-Barrier Cell Model

Salvia miltiorrhiza Bunge (SM) has been extensively used in Alzheimer’s disease treatment, the permeability through the blood-brain barrier (BBB) determining its efficacy. However, the transport mechanism of SM components across the BBB remains to be clarified. A simple, precise, and sensitive method using LC-MS/MS was developed for simultaneous quantification of tanshinone I (TS I), dihydrotanshinone I (DTS I), tanshinone IIA (TS IIA), cryptotanshinone (CTS), protocatechuic aldehyde (PAL), protocatechuic acid (PCTA), and caffeic acid (CFA) in transport samples. The analytes were separated on a C18 column by gradient elution. Multiple reaction monitoring mode via electrospray ionization source was used to quantify the analytes in positive mode for TS I, DTS I, TS IIA, CTS, and negative mode for PAL, PCTA, and CFA. The linearity ranges were 0.1–8 ng/mL for TS I and DTS I, 0.2–8 ng/mL for TS IIA, 1–80 ng/mL for CTS, 20–800 ng/mL for PAL and CFA, and 10–4000 ng/mL for PCTA. The developed method was accurate and precise for the compounds. The relative matrix effect was less than 15%, and the analytes were stable for analysis. The established method was successfully applied for transport experiments on a BBB cell model to evaluate the apparent permeability of the seven components.

Tanshinone IIA: A phytochemical as a promising drug candidate for neurodegenerative diseases

Tanshinones, lipophilic diterpenes isolated from the rhizome of Salvia miltiorrhiza, have diverse pharmacological activities against human ailments including neurological diseases. In fact, tanshinones have been used to treat heart diseases, stroke, and vascular diseases in traditional Chinese medicine. During the last decade, tanshinones have been the most widely studied phytochemicals for their neuroprotective effects against experimental models of cerebral ischemia and Alzheimer's diseases. Importantly, tanshinone IIA, mostly studied tanshinone for biological activities, is recently reported to attenuate blood-brain barrier permeability among stroke patients, suggesting tanshinone IIA as an appealing therapeutic candidate for neurological diseases. Tanshinone I and IIA are also effective in experimental models of Parkinson's disease, Multiple sclerosis, and other neuroinflammatory diseases. In addition, several experimental studies suggested the pleiotropic neuroprotective effects of tanshinones such as anti-inflammatory, antioxidant, anti-apoptotic, and BBB protectant further value aiding to tanshinone as an appealing therapeutic strategy in neurological diseases. Therefore, in this review, we aimed to compile the recent updates and cellular and molecular mechanisms of neuroprotection of tanshinone IIA in diverse neurological diseases.

Pharmacological basis of tanshinone and new insights into tanshinone as a multitarget natural product for multifaceted diseases

Drug development has long included the systematic exploration of various resources. Among these, natural products are one of the most important resources from which novel agents are developed due to the multiple pharmacologic effects of these natural products on diseases. Tanshinone, a representative natural product, is the main compound extracted from the dried root and rhizome of Salvia miltiorrhiza Bge. Research on tanshinone began in the early 1930s. With the in-depth investigation of an increasing number of identified analogs, tanshinone has demonstrated a wide variety of bioactivities and contradicted the saying, 'You can't teach an old dog new tricks'. This review is focused on the pharmacological action of tanshinone and status of research on tanshinone in recent years. The mechanism of tanshinone has also drawn much attention, with the findings of representative targets and pathways of tanshinone. The most recent studies have comprehensively shown that tanshinone can be used to treat leukemia and solid carcinoma, protect against cardiovascular and cerebrovascular diseases, and alleviate liver- and kidney-related diseases, among its other effects. Multiple signaling pathways, including antiproliferative, antiapoptotic, anti-inflammatory, and antioxidative stress pathways, are involved in its actions.

Salvia bowleyana Dunn root is a novel source of salvianolic acid B and displays antitumor effects against gastric cancer cells

Salvianolic acid B (Sal-B) is widely used in China for the treatment of numerous diseases. Currently, Salvia miltiorrhiza Bunge is the main source of this compound, but Salvia bowleyana Dunn, a surrogate of S. miltiorrhiza Bge, may provide a novel source for obtaining more Sal-B. In the present study, a simple method for separation and purification of phenolic compounds from S. bowleyana Dunn roots was employed. Sal-B was subsequently purified and its inhibitory effect on the gastric cancer HGC-27 and AGS cell lines was investigated. Sal-B extracted from S. bowleyana Dunn displayed significant antitumor activity in proliferation and apoptosis assays. Overall, it was found that S. bowleyana Dunn has a higher Sal-B content than S. miltiorrhiza Bge and may be used as a novel source of this potential anti-gastric cancer compound.

Pharmacological potential of the combination of Salvia miltiorrhiza (Danshen) and Carthamus tinctorius (Honghua) for diabetes mellitus and its cardiovascular complications

Metabolic syndrome, such as diabetes mellitus, obesity, atherosclerosis, and high blood pressure (HBP), are closely linked pathophysiologically. However, current monotherapies for metabolic syndrome fail to target the multifactorial pathology via multiple mechanisms, as well as resolving the dysfunctionality of the cells and organs of the body. We aimed to provide a comprehensive and up-to-date review of the pharmacological advances, therapeutic potential, and phytochemistry of Salvia miltiorrhiza, Carthamus tinctorius, and Danhong injection (DHI). We discussed the molecular mechanisms of the bioactive constituents relating to diabetes mellitus and metabolic disease for further research and drug development. Interestingly, Salvia miltiorrhiza, Carthamus tinctorius, and DHI have anti-inflammatory, anti-glycemic, anti-thrombotic, and anti-cancer properties; and they mainly act by targeting the dysfunctional vasculatures including the inflammatory components of the disease to provide vascular repair as well as resolving oxidative stress. The major bioactive chemical constituents of these plants include polyphenolic acids, diterpene compounds, carthamin, and hydroxysafflor yellow A. Treatment of diabetes mellitus and its associated cardiovascular complication requires a comprehensive approach involving the use of appropriate traditional Chinese medicine formula. Danshen, Honghua, and DHI target the multiple risk factors regulating the physiologic function of the body and restore normalcy, apart from the traditional advice on exercise and diet control as treatment options in a metabolic syndrome patient.

Ghrelin Attenuates Neuroinflammation and Demyelination in Experimental Autoimmune Encephalomyelitis Involving NLRP3 Inflammasome Signaling Pathway and Pyroptosis

Multiple sclerosis (MS) is a chronic autoimmune and degenerative disease of the central nervous system, and conventional treatments have limited efficacy or side effects. Ghrelin, a 28-amino acid octanoylated peptide, has been reported to have neuroprotective effects, including anti-oxidation, anti-inflammation, and anti-apoptosis. Pyroptosis, also called inflammatory cell death, is triggered by overly active inflammasomes and accompanied by the production of numerous cytokines. As immune dysfunction is primarily involved in the pathogenesis of MS, this study aimed to explore the therapeutic effects and precise functional mechanisms of ghrelin against the nod-like receptor protein 3 (NLRP3) inflammasome and pyroptosis in experimental autoimmune encephalomyelitis (EAE). Sprague Dawley rats were immunized with guinea pig spinal cord homogenates and pertussis toxin to develop an EAE model. All rats were randomly divided into four groups: normal control group, EAE group, EAE + ghrelin group, and ghrelin control group. EAE rats showed abnormal behavioral scores and body weight changes. Histologic analysis displayed severe inflammatory infiltration and demyelination in the brain and spinal cord of EAE rats. Ghrelin treatments potently restored these abnormal changes. In addition, the ghrelin-treated EAE group showed significantly downregulated expression of inflammatory cytokines. The expression of proteins involved in the NLRP3 signaling pathway and pyroptosis was decreased as well. We also found that the anti-inflammatory effect of ghrelin was associated with inhibition of nuclear factor (NF)-κB activation. Compared with rats in the healthy control group, rats in the ghrelin control group did not show statistically significant changes in histologic examinations, pro-inflammatory cytokines production, or molecules involved in the NLRP3 signaling pathway, which indicated that ghrelin induced no side effects in the animals of our study. Our findings provide more insight into the use of ghrelin as a novel candidate for MS.

Natural products as a potential modulator of microglial polarization in neurodegenerative diseases

Neurodegenerative diseases (NDs) are characterized by the progressive loss of structure and function of neurons most common in elderly population, mainly including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). Neuroinflammation caused by microglia as the resident macrophages of the central nervous system (CNS) plays a contributory role in the onset and progression of NDs. Activated microglia, as in macrophages, to be heterogeneous, can polarize into M1 (pro-inflammatory) and M2 (anti-inflammatory) functional phenotypes. The former elaborate pro-inflammatory mediators promoting neuroinflammation and neuronal damage. In contrast, the latter generate anti-inflammatory mediators and neurotrophins that inhibit neuroinflammation and promote neuronal healing. Consistently, the regulation of microglial polarization from M1 to M2 phenotype appears as an outstanding therapeutic and preventive approach for NDs treatment. Although non-steroidal anti-inflammatory drugs (NSAIDs) currently used to alleviate M1 microglia-associated neuroinflammation responsible for the development of NDs, these drugs have different degrees of adverse effects and limited efficacy. As the advantages of novel structure, multi-target, high efficiency and low toxicity, natural products as the modulators of microglial polarization have attracted considerable concerns in the therapeutic areas of NDs. In this review, we mainly summarized the therapeutic potential of natural products and their various molecular mechanisms for NDs treatment through modulating microglial polarization. The aim of the current review is expected to be useful to develop innovative modulators of microglial polarization from natural products for the amelioration and treatment of NDs.

Exosomes derived from mesenchymal stem cells attenuate inflammation and demyelination of the central nervous system in EAE rats by regulating the polarization of microglia

Multiple sclerosis (MS) is a chronic demyelinating disease caused by central nervous system (CNS) inflammation and immune dysfunction, which often leaves patients with severe physical disabilities. Microglia function in the surveillance of the CNS, and an imbalance in the M1/M2 phenotypes of microglia contribute to the progression of MS. Recent studies indicate that exosomes secreted by bone marrow mesenchymal stem cells (BMSCs) play therapeutic roles in many autoimmune diseases and aid in tissue repair. However, it is not clear whether BMSC-derived exosomes can attenuate MS-associated inflammation and immune dysfunction, or how BMSC exosomes protect neurons. The experimental autoimmune encephalomyelitis (EAE) rat model was used to investigate the effect of exosomes on microglia polarization and inflammation in CNS. The results showed that exosome treatment significantly decreased neural behavioral scores, reduced the infiltration of inflammatory cells into the CNS, and decreased demyelination in comparison to untreated EAE rats. In addition, exosome treatment resulted in significant increases in the levels of M2-related cytokines such as interleukin (IL)-10 and transforming growth factor (TGF)-β, whereas M1-related tumor necrosis factor (TNF)-α and IL-12 levels decreased significantly. Moreover, compared with the untreated EAE group, the exosome group displayed significantly increased protein and mRNA expression levels of M2 phenotype markers, whereas M1 marker expression decreased. Our findings were further confirmed in an in vitro HAPI microglia cell line model. In conclusion, these findings indicate that BMSC-derived exosomes can attenuate inflammation and demyelination of the CNS in the EAE rat model by regulating the polarization of microglia. Therefore, the use of BMSC-derived exosomes may be a potential therapeutic approach for the treatment of autoimmune and inflammatory diseases.

Comparative in vivo constituents and pharmacokinetic study in rats after oral administration of ultrafine granular powder and traditional decoction slices of Chinese Salvia

Salvia miltiorrhiza, one of the most well-known herbal medicines, is commonly used for the treatment of coronary heart diseases in China. Besides traditional decoction slices (TDS), another relatively new product of S. miltiorrhiza, ultrafine granular powder (UGP; D90 < 45 μm), is also increasingly being used. In this paper, a UHPLC-LTQ-Orbitrap MS technique was developed for a metabolite profile study after oral administration of UGP and TDS of S. miltiorrhiza. The results showed that the number of in vivo absorbed compounds from UGP was much greater than that from TDS, and different types of products from S. miltiorrhiza will have different metabolic processes in vivo. Furthermore, a UHPLC-Q-Trap MS/MS method for simultaneously determining four tanshinones (tanshinone IIA, dihydrotanshinone I, tanshinone I and cryptotanshinone) was established and applied to assess the pharmacokinetics of the two types of products. All of the analytes displayed significant higher area under the concentration-time curve and peak concentration after oral administration of UGP than after TDS, indicating that ultrafine powder product could improve the bioavailability and absorption of cryptotanshinon,tanshinone II A,dihydrotanshinonE I and tanshinone I in vivo. The present study provides scientific information for further exploration of the pharmacology of these two types of S. miltiorrhiza and offers a reference for clinical administration of S. miltiorrhiza.

Tanshinone IIA Sodium sulfonate regulates antioxidant system, inflammation, and endothelial dysfunction in atherosclerosis by downregulation of CLIC1

BACKGROUND

Tanshinone IIA Sodium sulfonate (STS) is clinically used for treating cardiovascular diseases in Traditional Chinese Medicine due to its antioxidation and anti-inflammation activities. Intracellular chloride channel 1 (CLIC1) participates in the regulation of oxidative stress and inflammation. This study investigates whether CLIC1 mediates the cardioprotective effects of STS.

METHODS

STS were used to treat atherosclerosis (AS) induced by feeding Apolipoprotein E-deficient (ApoE^-/-) mice with a high-fat, cholesterol-rich diet. In addition, normal and CLIC1^-/- human umbilical vein endothelial cells were treated with STS after exposure to H₂O₂ for 12h. The oxidative status was determined by analyzing reactive oxygen species(ROS) and malondialdehyde (MDA) levels. ELISA, qRT-PCR and Western blot were used to determine the levels of TNF-α, IL-6, ICAM-1 and VCAM-1. CLIC1 cellular localization was examined by immunofluorescence. Chloride ion concentration was detected with chloride ion quenchers (MQAE).

RESULTS

STS treatment decreased atherosclerotic lesion area by 3.5 times (P = 0.001) in vivo. Meanwhile, STS reduced MDA production (13.6%, P = 0.008), increased SOD activity (113.6%, P = 0.008), decreased TNF-α (38.6%, P = 0.008) and IL-6 (43.0%, P = 0.03) levels, and downregulated the expression of CLIC1, ICAM-1, and VCAM-1 in the atherosclerotic mice. The dose-dependent anti-oxidative and anti-inflammatory effects of STS were further confirmed in vitro. Furthermore, CLIC1 depletion abolished the STS-mediated decrease of ROS and MDA production in HUVEC cells. Additionally, STS inhibited both CLIC1 membrane translocation and chloride ion concentration.

CONCLUSION

The anti-oxidant, and anti-inflammation properties of STS in preventing AS is mediated by its inhibition of CLIC1 expression and membrane translocation.

Kv1.3 channel blocker (ImKTx88) maintains blood-brain barrier in experimental autoimmune encephalomyelitis

BACKGROUND

Disruption of blood-brain barrier (BBB) and subsequent infiltration of auto-reactive T lymphocytes are major characteristics of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). Kv1.3 channel blockers are demonstrated potential therapeutic effects on MS patients and EAE models, maybe via reducing activation of T cells. However, it remains to be explored whether Kv1.3 channel blockers maintain integrity of BBB in MS model.

RESULTS

In this study, ImKTx88, a highly selective Kv1.3 channel blocker, was used to determine the role of Kv1.3 channel in the pathogenesis of EAE, particularly in the maintenance of BBB. ImKTx88 ameliorated pathological severity in the EAE rats, and reduced extravasation into CNS. ImKTx88 also ameliorated the severity of loss or redistribution of tight junction proteins, and inhibited over-expression of ICAM-1 and VCAM-1 in the brain from EAE rats. Furthermore ImKTx88 protection was associated with activation of Ang-1/Tie-2 axis, and might be due to decreased IL-17 production.

CONCLUSIONS

ImKTx88 may be a novel therapeutic agent for MS treatment by stabilizing the BBB.

Sodium Tanshinone IIA Sulfonate Enhances Effectiveness Rt-PA Treatment in Acute Ischemic Stroke Patients Associated with Ameliorating Blood-Brain Barrier Damage

Treatment with sodium tanshinone IIA sulfonate (STS) may ameliorate blood-brain barrier (BBB) damage in acute ischemic stroke patients receiving recombinant tissue plasminogen activator (rt-PA) thrombolysis and improve stroke patients’ outcome. This randomized, single-center, placebo-controlled clinical trial investigated the potential effects and underlying mechanisms of STS. Forty-two acute ischemic stroke patients receiving intravenous rt-PA thrombolysis were randomized to intravenous administration either with STS (60 mg/day) (n = 21) or with equivalent volume of saline as a placebo (n = 21) after randomization for 10 days. Clinical outcomes, computer tomography perfusion (CTP) imaging with permeability-surface area product (PS) maps and serum levels of BBB damage biomarkers, were compared between the two groups. The percentage of patients with excellent functional outcome indicated by a 90-day mRS ≤1 was significantly higher in the STS group than in the placebo group (p = 0.028). For patients with CTP imaging (n = 30), PS in the ipsilateral lesion (p = 0.034) and relative PS (p = 0.013) were significantly lower in the STS group than that in placebo. STS-treated patients also had lower levels of matrix metalloproteinase (MMP)-9 (p = 0.036) and claudin-5 (p = 0.026), but higher levels of tissue inhibitor of metalloproteinase (TIMP)-1 (p = 0.040) than those in the placebo group. Post-stroke STS treatment could improve neurologic functional outcomes for acute ischemic stroke patients following rt-PA treatment by reducing BBB leakage and damage, which might be mechanistically associated with MMP-9 inhibition.

Antioxidants and Dementia Risk: Consideration through a Cerebrovascular Perspective

A number of natural and chemical compounds that exert anti-oxidative properties are demonstrated to be beneficial for brain and cognitive function, and some are reported to reduce the risk of dementia. However, the detailed mechanisms by which those anti-oxidative compounds show positive effects on cognition and dementia are still unclear. An emerging body of evidence suggests that the integrity of the cerebrovascular blood-brain barrier (BBB) is centrally involved in the onset and progression of cognitive impairment and dementia. While recent studies revealed that some anti-oxidative agents appear to be protective against the disruption of BBB integrity and structure, few studies considered the neuroprotective effects of antioxidants in the context of cerebrovascular integrity. Therefore, in this review, we examine the mechanistic insights of antioxidants as a pleiotropic agent for cognitive impairment and dementia through a cerebrovascular axis by primarily focusing on the current available data from physiological studies. Conclusively, there is a compelling body of evidence that suggest antioxidants may prevent cognitive decline and dementia by protecting the integrity and function of BBB and, indeed, further studies are needed to directly examine these effects in addition to underlying molecular mechanisms.

Tanshinones and mental diseases: from chemistry to medicine

The prevalence of mental diseases, especially neurodegenerative disorders, is ever-increasing, while treatment options for such disorders are limited and insufficient. In this scarcity of available medication, it is a feasible strategy to search for potential drugs among natural compounds, such as those found in plants. One such plant source is the root of Chinese sage, Salvia miltiorrhiza Bunge (Labiatae), which contains several compounds reported to possess neuroprotective activities. The most important of these compounds are tanshinones, which have been reported to possess ameliorative activity against a myriad of mental diseases such as Alzheimer’s disease, cerebral ischemia/reperfusion injury, and glioma, along with promoting neuronal differentiation and manifesting antinociceptive and anticonvulsant outcomes. This review offers a critical evaluation of the utility of tanshinones to treat mental illnesses, and sheds light on the underlying mechanisms through which these naturally occurring compounds confer neuroprotection.

Simultaneous Determination of Four Tanshinones by UPLC-TQ/MS and Their Pharmacokinetic Application after Administration of Single Ethanol Extract of Danshen Combined with Water Extract in Normal and Adenine-Induced Chronic Renal Failure Rats

Salvia miltiorrhiza, one of the major traditional Chinese medicines, is commonly used and the main active ingredients—tanshinones—possess the ability to improve renal function. In this paper, the UPLC-TQ/MS method of simultaneously determining four tanshinones—tanshinone IIA, dihydrotanshinone I, tanshinone I, and cryptotanshinone—was established and applied to assess the pharmacokinetics in normal and chronic renal failure (CRF) rat plasma. The pharmacokinetics of tanshinones in rats were studied after separately intragastric administration of Salvia miltiorrhiza ethanol extract (SMEE) (0.65 g/kg), SMEE (0.65 g/kg) combined with Salvia miltiorrhiza water extract (SMWE) (1.55 g/kg). The results showed C_max and AUC_0–t of tanshinone IIA, tanshinone I, cryptotanshinone reduced by 50%~80% and CLz/F increased by 2~4 times (p < 0.05) in model group after administrated with SMEE. Nevertheless, after intragastric administration of a combination of SMWE and SMEE, the C_max and AUC_0–t of four tanshinones were upregulated and CLz/F was downregulated, which undulated similarity from the model group to the normal group with compatibility of SMEE and SMWE. These results hinted that SMWE could improve the bioavailability of tanshinones in CRF rats, which provides scientific information for further exploration the mechanism of the combination of SMWE and SMEE and offers a reference for clinical administration of Salvia miltiorrhiza.

Oxidative Stress and Salvia miltiorrhiza in Aging-Associated Cardiovascular Diseases

Aging-associated cardiovascular diseases (CVDs) have some risk factors that are closely related to oxidative stress. Salvia miltiorrhiza (SM) has been used commonly to treat CVDs for hundreds of years in the Chinese community. We aimed to explore the effects of SM on oxidative stress in aging-associated CVDs. Through literature searches using Medicine, PubMed, EMBASE, Cochrane library, CINAHL, and Scopus databases, we found that SM not only possesses antioxidant, antiapoptotic, and anti-inflammatory effects but also exerts angiogenic and cardioprotective activities. SM may reduce the production of reactive oxygen species by inhibiting oxidases, reducing the production of superoxide, inhibiting the oxidative modification of low-density lipoproteins, and ameliorating mitochondrial oxidative stress. SM also increases the activities of catalase, manganese superoxide dismutase, glutathione peroxidase, and coupled endothelial nitric oxide synthase. In addition, SM reduces the impact of ischemia/reperfusion injury, prevents cardiac fibrosis after myocardial infarction, preserves cardiac function in coronary disease, maintains the integrity of the blood-brain barrier, and promotes self-renewal and proliferation of neural stem/progenitor cells in stroke. However, future clinical well-designed and randomized control trials will be necessary to confirm the efficacy of SM in aging-associated CVDs.

Tanshinone IIA Prevent Tendon Adhesion in the Rat Achilles Tendon Model

Background: Tendon adhesion between the sheath and tendon surface is a common clinical problem. Orthopedist makes the improvement of repair techniques and rehabilitation to treat tendon adhesion, but it fails to cure completely. TSA was one of the major active phytochemicals because of its anti-inflammatory activity. We used tanshinone IIA (TSA) for the prevention of tendon adhesion in the rat Achilles tendon model and investigated the possible mechanisms, including microRNAs (miRNAs) and protein expression via TGF-β/Smad signaling pathway. Method: Sprague-Dawley (SD) rat Achilles tendons were half partial lacerated and sutured by a modified Kessler's technique, with TSA and normal saline for control. Macroscopic and histological evaluations were applied to examine the injured tendon six weeks after surgery. We evaluated the degree of adhesion in Gross observation and the remodeling of collagen fibers by observing microscopically and determining the amount of scar formation. The expression of microRNAs (miRNAs) was quantified by real-time PCR detection and protein expression were quantified by western blotting detection. Results: In gross evaluation of tendon adhesion, the TSA group had less adhesion appeared. No evidences of tendon rupture or local infection were observed. The content of collagen fibers in tendon tissue was decreased in TSA group compared with the control group, it indicated a significant difference from the control group, P = 0.0004. The expression of miRNAs including miR-155, miR-29b, miR21, miR-133b and let7 were detected in the repaired tendon tissue, and only miR-29b treated with TSA was observed significantly higher than control group, P <0.0001. The protein expression of TGF-β1 and p-Smad3 treated with TSA was lower than control group. Conclusions: The usage of TSA may be an efficient approach for preventing tendon adhesion.

Resveratrol defends blood-brain barrier integrity in experimental autoimmune encephalomyelitis mice

The mouse autoimmune encephalomyelitis (EAE), an experimental model of multiple sclerosis (MS), is primarily characterized as dysfunction of the blood-brain barrier (BBB). Resveratrol exhibits anti-inflammatory, antioxidative, and neuroprotective activities. We investigated the beneficial effects of resveratrol in protecting the integrity of the BBB in EAE mice and observed improved clinical outcome in the EAE mice after resveratrol treatment. Evans blue (EB) extravasation was used to detect the disruption of BBB. Western blot were used to detected the tight junction proteins and adhesion molecules zonula occludens-1 (ZO-1), occludin, ICAM-1, and VCAM-1. Inflammatory factors inducible nitric oxide synthase (iNOS), IL-1β, and arginase 1 were evaluated by quantitative RT-PCR (qPCR) and IL-10 by ELISA. NADPH oxidase (NOX) levels were evaluated by qPCR, and its activity was analyzed by lucigenin-derived chemiluminescence. Resveratrol at doses of 25 and 50 mg/kg produced a dose-dependent decrease in EAE paralysis and EB leakage, ameliorated EAE-induced loss of tight junction proteins ZO-1, occludin, and claudin-5, as well as repressed the EAE-induced increase in adhesion proteins ICAM-1 and VCAM-1. In addition, resveratrol suppressed the EAE-induced overexpression of proinflammatory transcripts iNOS and IL-1β and upregulated the expression of anti-inflammatory transcripts arginase 1 and IL-10 cytokine in the brain. Furthermore, resveratrol downregulated the overexpressed NOX2 and NOX4 in the brain and suppressed NADPH activity. Resveratrol ameliorates the clinical severity of MS through maintaining the BBB integrity in EAE mice.