Sinomenine activation of Nrf2 signaling prevents inflammation and cerebral injury in a mouse model of ischemic stroke

Cell polarization in ischemic stroke: molecular mechanisms and advances

Ischemic stroke is a cerebrovascular disease associated with high mortality and disability rates. Since the inflammation and immune response play a central role in driving ischemic damage, it becomes essential to modulate excessive inflammatory reactions to promote cell survival and facilitate tissue repair around the injury site. Various cell types are involved in the inflammatory response, including microglia, astrocytes, and neutrophils, each exhibiting distinct phenotypic profiles upon stimulation. They display either proinflammatory or anti-inflammatory states, a phenomenon known as 'cell polarization.' There are two cell polarization therapy strategies. The first involves inducing cells into a neuroprotective phenotype in vitro, then reintroducing them autologously. The second approach utilizes small molecular substances to directly affect cells in vivo. In this review, we elucidate the polarization dynamics of the three reactive cell populations (microglia, astrocytes, and neutrophils) in the context of ischemic stroke, and provide a comprehensive summary of the molecular mechanisms involved in their phenotypic switching. By unraveling the complexity of cell polarization, we hope to offer insights for future research on neuroinflammation and novel therapeutic strategies for ischemic stroke.

Targeting the neurovascular unit: Therapeutic potential of traditional Chinese medicine for the treatment of stroke

Stroke poses a significant global health challenge due to its elevated disability and mortality rates, particularly affecting developing nations like China. The neurovascular unit (NVU), a new concept encompassing neurons, brain microvascular endothelial cells, pericytes, astrocytes, microglia, and the extracellular matrix, has gained prominence in recent years. Traditional Chinese medicine (TCM), deeply rooted in Chinese history, employs a combination of acupuncture and herbal treatments, demonstrating significant efficacy across all stages of stroke, notably during recovery. The holistic approach of TCM aligns with the NVU's comprehensive view of treating stroke by addressing neurons, surrounding cells, and blood vessels collectively. This review examines the role of NVU in stroke and endeavors to elucidate the mechanisms through which traditional Chinese medicine exerts its anti-stroke effects within the NVU framework. The NVU contributes to neuroinflammation, immune infiltration, blood-brain barrier permeability, oxidative stress, and Ca2+ overload during stroke occurs. Additionally, TCM targeting the NVU facilitates nerve repair post-stroke through various pathways and approaches. Specific herbs, including panax notoginseng, ginseng, and borneol, alleviate brain injury by enhancing brain-derived neurotrophic factor expression and targeting astrocytes and microglia to yield anti-inflammatory and antioxidant effects. Acupuncture, another facet of TCM, promotes brain injury repair by augmenting cerebral blood flow and improving circulation. This exploration aims to assess the viability of stroke treatment by directing TCM interventions toward the NVU, thus paving the way for its broader clinical application.

Investigating the therapeutic potential of sinomenine in rheumatoid arthritis: anti-inflammatory, antioxidant, and immunomodulatory mechanisms

An autoimmune disease, rheumatoid arthritis (RA) is characterized by the onset of inflammation and subsequent damage to the joints. Although several therapies are available for RA, none are effective, and many have undesirable side effects. The roots of Sinomenium acutum produce an alkaloid called Sinomenine (SIN), which has been used for centuries in Chinese medicine to treat arthritis due to its anti-inflammatory properties. This study aimed to explore the potential therapeutic benefits of SIN through oral administration following RA induction using Freund's complete adjuvant (FCA) injections. The study monitored changes in the arthritic index, hind paw volume, inflammation and oxidative stress markers. Results demonstrated that SIN effectively inhibited the activity of NF-κB and IKKβ in knee joint tissues, which led to a decrease in tissue levels of TNF-α, IL-6, IL-1β, and iNOS in RA-induced rats. The production of anti-inflammatory cytokines such as IL-10, Arg-1, and Fizz1 also increased. In rat knee joints, SIN elevated the expression of TIMP-1 and TIMP-3 and decreased the expression of MMP-2 and MMP-9. Additionally, SIN modulated the RANK/RANKL/OPG pathway in RA-induced rat knee joint tissues, reducing RANKL expression and increasing OPG. SIN also effectively decreased MDA, NO, and elevated antioxidant enzymes (SOD, CAT, GPx, and GSH) in RA-induced rats via Nrf2/Keap 1 signaling pathway activation. In conclusion, this study suggests that SIN possesses potential therapeutic benefits for treating RA by modulating the RANK/RANKL/OPG pathway, which may impact osteoclast activity, oxidative stress, and inflammation in knee joint tissues.

Rhoa/ROCK, mTOR and Secretome-Based Treatments for Ischemic Stroke: New Perspectives

Ischemic stroke triggers a complex cascade of cellular and molecular events leading to neuronal damage and tissue injury. This review explores the potential therapeutic avenues targeting cellular signaling pathways implicated in stroke pathophysiology. Specifically, it focuses on the articles that highlight the roles of RhoA/ROCK and mTOR signaling pathways in ischemic brain injury and their therapeutic implications. The RhoA/ROCK pathway modulates various cellular processes, including cytoskeletal dynamics and inflammation, while mTOR signaling regulates cell growth, proliferation, and autophagy. Preclinical studies have demonstrated the neuroprotective effects of targeting these pathways in stroke models, offering insights into potential treatment strategies. However, challenges such as off-target effects and the need for tissue-specific targeting remain. Furthermore, emerging evidence suggests the therapeutic potential of MSC secretome in stroke treatment, highlighting the importance of exploring alternative approaches. Future research directions include elucidating the precise mechanisms of action, optimizing treatment protocols, and translating preclinical findings into clinical practice for improved stroke outcomes.

Obacunone Alleviates Inflammatory Pain by Promoting M2 Microglial Polarization and by Activating Nrf2/HO-1 Signaling Pathway

Background

Treating inflammatory pain (IP) continues to pose clinical challenge, because of the lack of effective pharmacological interventions. Microglial polarization serves as pivotal determinant in IP progress. Obacunone (OB), a low-molecular-weight compound with a diverse array of biological functions, having reported as an activator of nuclear factor E2-related factor 2 (Nrf2), exhibits anti-inflammatory property. However, it remains uncertain whether OB can alleviate IP by facilitating the transition of microglial polarization from the M1 to M2 state through modulating Nrf2/ heme oxygenase-1 (HO-1) pathway.

Methods

We induced an mice IP model by subcutaneously administering Complete Freund's Adjuvant (CFA) into the hind paw. Paw withdrawal latency (PWL) in seconds (s) and paw withdrawal frequency (PWF) were employed to evaluate the establishment of the IP model, while a caliper was used to measure the maximal dorsoventral thickness of the mice paw. Nerve injury was assessed by Hematoxylin-Eosin (HE) Staining. Western blot and got conducted for detection of M1/M2 microglial polarization markers, Nrf2 and HO-1 in spinal cord tissues respectively.

Results

In comparison to the control cohort, PWF, M1 phenotype marker iNOS, CD86, paw thickness increased significantly within CFA cohort, while PWL, M2 phenotype marker Arg-1, interleukin-10 (IL-10) decreased in the CFA group. In comparison to model cohort, OB treatment decreased PWF, paw thickness, M1 phenotype marker iNOS, CD86 significantly, while PWL, M2 phenotype marker Arg-1, IL-10, Nrf2, HO-1 increased significantly. The morphological injuries of sciatic nerve in CFA mice were obviously improved by OB treatment. OB inhibited the release of M1-related IL-1β, CXCL1 but promoted M2-related TGF-β, IL-10 in serum in CFA mice. The intervention of the Nrf2 inhibitor ML385 mitigated analgesic effect of OB.

Conclusion

We demonstrate that OB is able to attenuate inflammatory pain via promoting microglia polarization from M1 to M2 and enhancing Nrf2/HO-1 signal. OB treatment may be a potential alternative agent in the treatment of IP.

Crosstalk between Nrf2 signaling pathway and inflammation in ischemic stroke: Mechanisms of action and therapeutic implications

One of the major causes of long-term disability and mortality is ischemic stroke that enjoys limited treatment approaches. On the one hand, oxidative stress, induced by excessive generation of reactive oxygen species (ROS), plays a critical role in post-stroke inflammatory response. Increased ROS generation is one of the basic factors in the progression of stroke-induced neuroinflammation. Moreover, intravenous (IV) thrombolysis using recombinant tissue plasminogen activator (rtPA) as the only medication approved for patients with acute ischemic stroke who suffer from some clinical restrictions it could not cover the complicated episodes that happen after stroke. Thus, identifying novel therapeutic targets is crucial for successful preparation of new medicines. Recent evidence indicates that the transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2) contributes significantly to regulating the antioxidant production in cytosol, which causes antiinflammatory effects on neurons. New findings have shown a relationship between activation of the Nrf2 and glial cells, nuclear factor kappa B (NF-κB) pathway, the nucleotide-binding domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome signaling, and expression of inflammatory markers, suggesting induction of Nrf2 activation can represent a promising therapeutic alternative as the modulators of Nrf2 dependent pathways for targeting inflammatory responses in neural tissue. Hence, this review addresses the relationship of Nrf2 signaling with inflammation and Nrf2 activators' potential as therapeutic agents. This review helps to improve required knowledge for focused therapy and the creation of modern and improved treatment choices for patients with ischemic stroke.

Sinomenine regulates the cholinergic anti-inflammatory pathway to inhibit TLR4/NF-κB pathway and protect the homeostasis in brain and gut in scopolamine-induced Alzheimer's disease mice

Sinomenine (SIN), an alkaloid extracted from the Chinese herbal medicine Sinomenium acutum, has great potential in anti-inflammatory, immune regulation, analgesic and sedative, and is already a clinical drug for the treatment of rheumatoid arthritis in China. Our previous studies show SIN inhibits inflammation by regulating ɑ7nAChR, a key receptor of cholinergic anti-inflammatory pathway (CAP), which plays an important role in regulating peripheral and central nervous system inflammation. Growing evidence supports the cholinergic dysregulation and inflammatory responses play the key role in the pathogenesis of AD. The intervention effects of SIN on AD by regulating CAP and homeostasis in brain and gut were analyzed for the first time in the present study using scopolamine-induced AD model mice. Behavioral tests were used to assess the cognitive performance. The neurons loss, cholinergic function, inflammation responses, biological barrier function in the mouse brain and intestinal tissues were evaluated through a variety of techniques, and the gut microbiota was detected using 16SrRNA sequencing. The results showed that SIN significantly inhibited the cognitive decline, dysregulation of cholinergic system, peripheral and central inflammation, biological barrier damage as well as intestinal flora disturbance caused by SCOP in mice. More importantly, SIN effectively regulated CAP to suppress the activation of TLR4/NF-κB and protect the homeostasis in brain and gut to alleviate cognitive impairment.

Bioactivities and Mechanisms of Action of Sinomenine and Its Derivatives: A Comprehensive Review

Sinomenine, an isoquinoline alkaloid extracted from the roots and stems of Sinomenium acutum, has been extensively studied for its derivatives as bioactive agents. This review concentrates on the research advancements in the biological activities and action mechanisms of sinomenine-related compounds until November 2023. The findings indicate a broad spectrum of pharmacological effects, including antitumor, anti-inflammation, neuroprotection, and immunosuppressive properties. These compounds are notably effective against breast, lung, liver, and prostate cancers, exhibiting IC50 values of approximately 121.4 nM against PC-3 and DU-145 cells, primarily through the PI3K/Akt/mTOR, NF-κB, MAPK, and JAK/STAT signaling pathways. Additionally, they manifest anti-inflammatory and analgesic effects predominantly via the NF-κB, MAPK, and Nrf2 signaling pathways. Utilized in treating rheumatic arthritis, these alkaloids also play a significant role in cardiovascular and cerebrovascular protection, as well as organ protection through the NF-κB, Nrf2, MAPK, and PI3K/Akt/mTOR signaling pathways. This review concludes with perspectives and insights on this topic, highlighting the potential of sinomenine-related compounds in clinical applications and the development of medications derived from natural products.

Sinomenine accelerate wound healing in rats by augmentation of antioxidant, anti-inflammatory, immunuhistochemical pathways

Sinomenine (SN) is a well-documented unique plant alkaloid extracted from many herbal medicines. The present study evaluates the wound healing potentials of SN on dorsal neck injury in rats. A uniform cut was created on Sprague Dawley rats (24) which were arbitrarily aligned into 4 groups receiving two daily topical treatments for 14 days as follows: A, rats had gum acacia; B, rats addressed with intrasite gel; C and D, rats had 30 and 60 mg/ml of SN, respectively. The acute toxicity trial revealed the absence of any toxic signs in rats after two weeks of ingestion of 30 and 300 mg/kg of SN. SN-treated rats showed smaller wound areas and higher wound closure percentages compared to vehicle rats after 5, 10, and 15 days of skin excision. Histological evaluation of recovered wound tissues showed increased collagen deposition, fibroblast content, and decreased inflammatory cells in granulated tissues in SN-addressed rats, which were statistically different from that of gum acacia-treated rats. SN treatment caused positive augmentation of Transforming Growth Factor Beta 1 (angiogenetic factor) in wound tissues, denoting a higher conversion rate of fibroblast into myofibroblast (angiogenesis) that results in faster wound healing action. Increased antioxidant enzymes (SOD and CAT), as well as decreased MDA contents in recovered wound tissues of SN-treated rats, suggest the antioxidant potentials of SN that aid in faster wound recovery. Wound tissue homogenates showed higher hydroxyproline amino acid (collagen content) values in SN-treated rats than in vehicle rats. SN treatment suppressed the production of pro-inflammatory cytokines and increased anti-inflammatory cytokines in the serum of wounded rats. The outcomes present SN as a viable pharmaceutical agent for wound healing evidenced by its positive modulation of the antioxidant, immunohistochemically proteins, hydroxyproline, and anti-inflammatory cytokines.

Exploring the molecular mechanism of Yinao Fujian formula on ischemic stroke based on network pharmacology and experimental verification

Background

Ischemic stroke (IS) is a leading cause of long-term disability and even mortality, threatening people's lives. Yinao Fujian (YNFJ) formula is a Traditional Chinese Medicine formula that has been widely used to treat patients with IS. However, the molecular mechanism of YNFJ for the treatment of IS is still elusive. Our study aimed to explore the potential protective effect and the underlying mechanisms of YNFJ on IS using a network pharmacology approach coupled with experimental validation.

Materials and methods

Effective compounds of YNFJ were collected from BATMAN-TCM and TCMSP databases, while IS targets were obtained from GeneCards, OMIM, TTD and DrugBank databases. The protein-protein interaction (PPI) network was constructed to further screen the hub targets of YNFJ in IS treatment. GO and KEGG enrichment analyses were used to identify the critical biological processes and signaling pathways of YNFJ for IS. Moreover, Nissl staining, HE, TTC staining and Tunel staining were used in the MCAO model to prove the neuroprotective effect of YNFJ. Oxidative damage, inflammatory factor release and related pathways were tested in MCAO rat model and hypoxia-induced BV2 cell model, respectively.

Results

We found that YNFJ treatment significantly alleviated MCAO-induced nerve damage and apoptosis. Then, network pharmacology screening combined with literature research revealed IL6, TNF, PTGS2, NFKBIA and NFE2L2 as the critical targets in a PPI network. Moreover, the top 20 signaling pathways and biological processes associated with the protective effects of YNFJ on IS were enriched through GO and KEGG analyses. Further analysis indicated that NF-κB and Nrf2/HO-1 signaling pathways might be highly involved in the protective effects of YNFJ on IS. Finally, in vitro and in vivo experiments confirmed that YNFJ inhibited the release of inflammatory factors (IL-6 and TNF-α) and MDA content, and increased the activity of SOD. In terms of the mechanism, YNFJ inhibited the release of inflammatory factors by suppressing the NF-κB pathway and decreased the expression of iNOS and COX-2 to protect microglia from inflammation damage. In addition, YNFJ initiated the dissociation of Keap-1 and Nrf2, and activated the downstream protein HO-1, NQO1, thus decreasing oxidative stress.

Conclusion

Taken together, the findings in our research showed that the protective effects of YNFJ on IS were mainly achieved by regulating the NF-κB and Nrf2/HO-1 signaling pathways to inhibit oxidative stress damage and inflammatory damage of microglia.

Sinomenine attenuates lipopolysaccharide-induced inflammation and apoptosis of WI-38 cells by reducing glutathione S-transferase M1 expression

Pediatric pneumonia is an infectious lung disease with high morbidity and mortality. Sinomenine, an alkaloid extracted from Caulis Sinomenii, exerts anti-inflammatory and anti-apoptotic activities. Lipopolysaccharide (LPS) is widely used for the establishment of an inflammatory model. This research aimed to explore the influences of sinomenine on LPS-caused inflammatory injuries in fetal lung WI-38 cells. WI-38 cells were treated with LPS to establish a cellular model of pediatric pneumonia. Cell viability was evaluated using CCK-8 assay. Apoptosis was evaluated using TUNEL staining and caspase-3 activity assays. Inflammatory cytokines and NF-κB p65 phosphorylation levels were measured by Enzyme-Linked Immunosorbent Assay. Glutathione S-transferase M1 (GSTM1) expression was detected by western blotting. Results showed that LPS reduced WI-38 cell viability, and sinomenine protected cells against LPS-induced viability reduction. Sinomenine concentration-dependently attenuated LPS-induced inflammation by reducing TNF-α, IL-1β and MCP-1, and increasing IL-10 levels. Sinomenine mitigated LPS-induced apoptosis. GSTM1 was screened by matching the targets of sinomenine and pediatric pneumonia. GSTM1 was upregulated in LPS-treated WI-38 cells, and this effect was attenuated after sinomenine treatment. GSTM1 was upstream of NF-κB pathway. Overexpression of GSTM1 reversed the suppressive functions of sinomenine on LPS-stimulated inflammation and apoptosis. Overall, sinomenine attenuates inflammation and apoptosis in WI-38 cells stimulated by LPS via inhibiting GSTM1 expression, indicating the therapeutic potential of sinomenine in pediatric pneumonia.

Effect of Jin three needles combined with Tong Qiao and blood activation Tang on neurological function, coagulation function and serum level in stroke patients

To investigate the efficacy and safety of Jin three needles combined with Tong Qiao Wu Blood-streaming Tang in patients with acute ischemic stroke (AIS), this retrospective study analyzed the data of patients with AIS between January 2017 and December 2022. The National Institutes of Health Stroke Scale (NIHSS) scores, blood neuron-specific enolase, S100β protein (S100β), fibrinogen (FIB), cerebral infarct volume, D-dimer (D-D), prothrombin time (PT), activated partial thromboplastin time, hypersensitive c-reactive protein (hs-CRP), serum tumor necrosis factor-α (TNF-α), and homocysteine (Hcy) were compared between the 2 groups. The treatment effect was significantly better in the observation group than in the comparison group (P < .05). The NIHSS score, neuron-specific enolase, S100β, and cerebral infarct volume were significantly lower in both groups after treatment than before treatment (P < .05). FIB and D-D levels were significantly lower and APTT and PT levels were significantly higher in both groups after treatment than before treatment (P < .05). TNF-α, hs-CRP, and Hcy were significantly lower in both groups after treatment than before treatment, and TNF-α, hs-CRP and Hcy were significantly lower in the observation group than in the comparison group (P < .05). No statistically significant difference in the incidence of adverse reactions occurred between the 2 groups (P > .05). Combining Jin three needles can improve the therapeutic effect in patients with AIS, promote the recovery of neurological function, improve coagulation function, and reduce the inflammatory response with good safety.

Regulation of microglia polarization after cerebral ischemia

Stroke ranks second as a leading cause of death and permanent disability globally. Microglia, innate immune cells in the brain, respond rapidly to ischemic injury, triggering a robust and persistent neuroinflammatory reaction throughout the disease's progression. Neuroinflammation plays a critical role in the mechanism of secondary injury in ischemic stroke and is a significant controllable factor. Microglia activation takes on two general phenotypes: the pro-inflammatory M1 type and the anti-inflammatory M2 type, although the reality is more complex. The regulation of microglia phenotype is crucial to controlling the neuroinflammatory response. This review summarized the key molecules and mechanisms of microglia polarization, function, and phenotypic transformation following cerebral ischemia, with a focus on the influence of autophagy on microglia polarization. The goal is to provide a reference for the development of new targets for the treatment for ischemic stroke treatment based on the regulation of microglia polarization.

A review on pharmacokinetics of sinomenine and its anti-inflammatory and immunomodulatory effects

Autoimmune diseases (ADs), with significant effects on morbidity and mortality, are a broad spectrum of disorders featured by body's immune responses being directed against its own tissues, resulting in chronic inflammation and tissue damage. Sinomenine (SIN) is an alkaloid isolated from the root and stem of Sinomenium acutum which is mainly used to treat pain, inflammation and immune disorders for centuries in China. Its potential anti-inflammatory role for treating immune-related disorders in experimental animal models and in some clinical applications have been reported widely, suggesting an inspiring application prospect of SIN. In this review, the pharmacokinetics, drug delivery systems, pharmacological mechanisms of action underlying the anti-inflammatory and immunomodulatory effects of SIN, and the possibility of SIN as adjuvant to disease-modifying anti-rheumatic drugs (DMARDs) therapy were summarized and evaluated. This paper aims to reveal the potential prospects and limitations of SIN in the treatment of inflammatory and immune diseases, and to provide ideas for compensating its limitations and reducing the side effects, and thus to make SIN better translate to the clinic.

Sinomenine Protects against Early Brain Injury by Inhibiting Microglial Inflammatory Response via Nrf2-Dependent Pathway after Subarachnoid Hemorrhage

Microglial activation and sustained inflammation plays an important role in the processes of early brain injury (EBI) after subarachnoid hemorrhage (SAH). Sinomenine (SIN) has been demonstrated to have neuroprotective effects in the traumatic brain injury (TBI) model. However, the role of SIN in SAH-induced EBI and its latent mechanisms remain unclear. This study was carried out to explore the role of SIN on SAH-induced EBI and its effects on the microglial inflammatory response following SAH. In this study, a model of SAH in rats was established. Modified neurological severity scores (mNSS), encephaledema, and Nissl staining were employed to determine the effects of SIN. Western blot and immunofluorescence analysis were performed to evaluate nuclear factor erythroid 2-related factor 2 (Nrf2) expression. Nrf2-related downstream proteins, including heme oxygenase-1 (HO-1) and quinine oxidoreductase-1 (NQO-1), were detected with immunohistochemistry analyses and Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR). Microglia activation and associated inflammatory factors, factor-kappa B (NF-κB), interleukin-1β (IL-1β), and interleukin-6 (IL-6), were assessed after SAH. The results showed that SIN administration improved neurobehavior function, and attenuated neural apoptosis and brain edema after SAH. In addition, SIN inhibited microglial action and the subsequent inflammatory response after SAH through the upregulated expression of HO-1 and NQO-1 via activation of the Nrf2 pathway. These results demonstrated that SIN supplementation provided protection against SAH-induced neuronal apoptosis by microglial inflammatory response regulation and possible involvement of the Nrf2 pathway.

Transcutaneous Electrical Acupoint Stimulation Pretreatment Alleviates Cerebral Ischemia-Reperfusion Injury in Rats by Modulating Microglia Polarization and Neuroinflammation Through Nrf2/HO-1 Signaling Pathway

Cerebral ischemia-reperfusion injury (CIRI) may lead to severe disability even death, but the strategies for prevention and treatment are still limited. Transcutaneous electrical acupoint stimulation (TEAS) has been reported to have a significant neuroprotection against CIRI, but the underlying mechanisms remain obscure. In this study, we established a focal cerebral ischemia-reperfusion model in male Sprague-Dawley rats. TEAS pretreatment was applied to Baihui (GV20), Sanyinjiao (SP6) and Zusanli (ST36) acupoints for 5 consecutive days before CIRI. After 24 h reperfusion, the brain damage was assessed using Zea-Longa score, brain water content (BWC) and infarct volume. Meanwhile, the number of activated microglia and the TNF-α were detected by immunofluorescence and ELISA respectively. Moreover, Western Blot and RT-qPCR were conducted to detect the proteins and mRNA expressions of Nrf2, HO-1, iNOS and Arg-1. We found that TEAS pretreatment significantly reduced Longa score, BWC, infarct volume and the number of activated microglia. Besides, TEAS pretreatment increased Nrf2 and HO-1 levels, while lowered the expression of TNF-α. Subsequently, we also discovered that the microglia M1 phenotype maker iNOS decreased and the M2 maker Arg-1 increased after TEAS pretreatment. However, these effects of TEAS pretreatment were markedly eliminated by brusatol. These findings clearly suggested that TEAS pretreatment exerted neuroprotection against CIRI, which might be related to modulating microglia polarization and neuroinflammation via Nrf2/HO-1 pathway.

The Regulatory Effect of Phytochemicals on Chronic Diseases by Targeting Nrf2-ARE Signaling Pathway

Redox balance is essential to maintain the body's normal metabolism. Once disrupted, it may lead to various chronic diseases, such as diabetes, neurodegenerative diseases, cardiovascular diseases, inflammatory diseases, cancer, aging, etc. Oxidative stress can cause or aggravate a series of pathological processes. Inhibition of oxidative stress and related pathological processes can help to ameliorate these chronic diseases, which have been found to be associated with Nrf2 activation. Nrf2 activation can not only regulate the expression of a series of antioxidant genes that reduce oxidative stress and its damage, but also directly regulate genes related to the above-mentioned pathological processes to counter the corresponding changes. Therefore, targeting Nrf2 has great potential for the prevention or treatment of chronic diseases, and many natural phytochemicals have been reported as Nrf2 activators although the defined mechanisms remain to be elucidated. This review article focuses on the possible mechanism of Nrf2 activation by natural phytochemicals in the prevention or treatment of chronic diseases and the regulation of oxidative stress. Moreover, the current clinical trials of phytochemical-originated drug discovery by targeting the Nrf2-ARE pathway were also summarized; the outcomes or the relationship between phytochemicals and chronic diseases prevention are finally analyzed to propose the future research strategies and prospective.

Sinomenine regulates immune cell subsets: Potential neuro-immune intervene for precise treatment of chronic pain

Chronic pain is a disease of long-lasting pain with unpleasant feelings mediated by central and (or) peripheral sensitization, its duration usually lasts more than 3 months or longer than the expected recovery time. The patients with chronic pain are manifested with enhanced sensitivity to noxious and non-noxious stimuli. Due to an incomplete understanding of the mechanisms, patients are commonly insensitive to the treatment of first line analgesic medicine in clinic. Thus, the exploration of non-opioid-dependent analgesia are needed. Recent studies have shown that "sinomenine," the main active ingredient in the natural plant "sinomenium acutum (Thunb.) Rehd. Et Wils," has a powerful inhibitory effect on chronic pain, but its underlying mechanism still needs to be further elucidated. A growing number of studies have shown that various immune cells such as T cells, B cells, macrophages, astrocytes and microglia, accompanied with the relative inflammatory factors and neuropeptides, are involved in the pathogenesis of chronic pain. Notably, the interaction of the immune system and sensory neurons is essential for the development of central and (or) peripheral sensitization, as well as the progression and maintenance of chronic pain. Based on the effects of sinomenine on immune cells and their subsets, this review mainly focused on describing the potential analgesic effects of sinomenine, with rationality of regulating the neuroimmune interaction.

Potential role of nutraceuticals via targeting a Wnt/β-catenin and NF-κB pathway in treatment of osteoarthritis

Osteoarthritis (OA) is a disease due to the aging of the articular cartilage, a post-mitotic tissue that stays functioning until primary homeostatic processes fail. Because of pain and disability, OA significantly influences national healthcare expenses and patient quality of life. It is a whole-joint illness characterized by inflammatory and oxidative signaling pathways and significant epigenetic alterations that cause cartilage extracellular matrix degradation. The canonical Wnt pathway (Wnt/β-catenin pathway) and nuclear factor kappa B (NF-κB) signaling pathways may function in joint tissues by modulating the activity of synovial cells, osteoblasts, and chondrocytes. However, finding innovative ways to treat osteoarthritis and get the joint back to average balance is still a struggle. Nutraceuticals are dietary supplements that promote joint health by balancing anabolic and catabolic signals. New therapeutic methods for OA treatment have been developed based on many research findings that show nutraceuticals have strong anti-inflammation, antioxidant, anti-bone resorption, and anabolic properties. For the treatment of osteoarthritis, we explore the possible involvement of nutraceuticals that target the Wnt/β-catenin and NF-κB pathways. PRACTICAL APPLICATIONS: In keeping with the aging population, osteoarthritis is becoming more widespread. In this extensive research, we studied the role of the Wnt/β-catenin and NF-κB pathway in OA formation and progression. Nutraceuticals that target these OA-related signaling pathways are a viable therapy option. Wnt/β-catenin and NF-κB signaling pathway are inhibited by polyphenols, flavonoids, alkaloids, and vitamins from the nutraceutical category, making them possible therapeutic drugs for OA therapy.

Sinomenine pretreatment alleviates hepatic ischemia/reperfusion injury through activating Nrf-2/HO-1 pathway

INTRODUCTION

Ischemia-reperfusion (IR) injury is induced by an interrupted blood flow and succeeding blood restoration, which is common in the operation of liver transplantation. Serious IR injury is a major reason leading to transplant failure. Hepatic IR is featured by excessive inflammatory response, oxidative stress, and apoptosis. Sinomenine (SIN) is derived from the herb Sinomeniumacutum and shows properties of anti-inflammation and antiapoptosis in multiple IR-induced organ injuries. However, the effect of SIN in hepatic IR has not been investigated.

METHODS

This study aims to investigate impacts of SIN on hepatic IR and the involved signaling pathway. An in vivo rat model of syngeneic orthotopic liver transplantation was constructed to induce the hepatic IR injury.

RESULTS

Results showed that SIN pretreatment provided a significant prevention against IR-induced hepatic injury as manifested by the downregulated activities of serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase, the alleviatedoxidative stress as shown by increased activities of serum superoxide dismutase and glutathione peroxidase, and decreased serum level of malondialdehyde, the suppressed inflammatory responses as shown by downregulated serum tumor necrosis factor-α, interleukin (IL)-6, IL-8 levels, and upregulated IL-10 level, as well as attenuated apoptosis as shown by decreased protein expression of cleaved caspase-3 and -9. In line with these results, SIN pretreatment also alleviatedthe hepatic histopathological changes in IR rats and induced Nrf-2/HO-1 activation. The use of brusatol, a selective inhibitor for Nrf-2, effectively reversed SIN-induced above effects.

CONCLUSIONS

Altogether, our results demonstrate that SIN might be a useful therapeutic drug for preventing hepatic IR-induced injury during clinical liver transplantation.

Clinical evidence construction of East Asian herbal medicine for inflammatory pain in rheumatoid arthritis based on integrative data mining approach

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory disease that leads to a significant social burden. East Asian herbal medicine (EAHM) has long been used to treat RA. Therefore, a systematic study of how EAHM treatments can be developed into new drugs using specific materials is needed.

METHODS

Eleven databases containing literature in English, Korean, Chinese, and Japanese were searched for randomized controlled trials comparing EAHM with conventional medicine (CM). A meta-analysis was performed on the variable data to assess their effects on inflammatory pain. Subsequently, we searched for core materials and combinations of core material-based data mining methods.

RESULTS

A total of 186 trials involving 19,716 patients with RA met the inclusion criteria. According to the meta-analysis, EAHM had a significantly superior effect on continuous pain intensity, tender joint count, and response rate. Patients treated with EAHM had a significantly reduced incidence of adverse events compared with those treated with CM. Based on additional analysis of the EAHM formula data included in this meta-analysis, 21 core materials and five core herbal combinations were identified.

CONCLUSION

EAHM remedies for RA have the adequate potential for use as candidate materials for treating inflammatory pain in RA. The candidate core herbs evaluated in this study act on multiple pathways and are expected to provide pain relief, sustained inflammation suppression, immune regulation, and prevention of joint destruction. It seems worthwhile to conduct follow-up research on drug development using the core materials derived from this review.

Potential therapeutic effects and pharmacological evidence of sinomenine in central nervous system disorders

Sinomenine is a natural compound extracted from the medicinal plant Sinomenium acutum. Its supplementation has been shown to present benefits in a variety of animal models of central nervous system (CNS) disorders, such as cerebral ischemia, intracerebral hemorrhage, traumatic brain injury (TBI), Alzheimer’s disease (AD), Parkinson’s disease (PD), epilepsy, depression, multiple sclerosis, morphine tolerance, and glioma. Therefore, sinomenine is now considered a potential agent for the prevention and/or treatment of CNS disorders. Mechanistic studies have shown that inhibition of oxidative stress, microglia- or astrocyte-mediated neuroinflammation, and neuronal apoptosis are common mechanisms for the neuroprotective effects of sinomenine. Other mechanisms, including activation of nuclear factor E2-related factor 2 (Nrf2), induction of autophagy in response to inhibition of protein kinase B (Akt)-mammalian target of rapamycin (mTOR), and activation of cyclic adenosine monophosphate-response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF), may also mediate the anti-glioma and neuroprotective effects of sinomenine. Sinomenine treatment has also been shown to enhance dopamine receptor D2 (DRD2)-mediated nuclear translocation of αB-crystallin (CRYAB) in astrocytes, thereby suppressing neuroinflammation via inhibition of Signal Transducer and Activator of Transcription 3 (STAT3). In addition, sinomenine supplementation can suppress N-methyl-D-aspartate (NMDA) receptor-mediated Ca²⁺ influx and induce γ-aminobutyric acid type A (GABA_A) receptor-mediated Cl⁻ influx, each of which contributes to the improvement of morphine dependence and sleep disturbance. In this review, we outline the pharmacological effects and possible mechanisms of sinomenine in CNS disorders to advance the development of sinomenine as a new drug for the treatment of CNS disorders.

The Nrf2 Pathway in Ischemic Stroke: A Review

Ischemic stroke, characterized by the sudden loss of blood flow in specific area(s) of the brain, is the leading cause of permanent disability and is among the leading causes of death worldwide. The only approved pharmacological treatment for acute ischemic stroke (intravenous thrombolysis with recombinant tissue plasminogen activator) has significant clinical limitations and does not consider the complex set of events taking place after the onset of ischemic stroke (ischemic cascade), which is characterized by significant pro-oxidative events. The transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2), which regulates the expression of a great number of antioxidant and/or defense proteins, has been pointed as a potential pharmacological target involved in the mitigation of deleterious oxidative events taking place at the ischemic cascade. This review summarizes studies concerning the protective role of Nrf2 in experimental models of ischemic stroke, emphasizing molecular events resulting from ischemic stroke that are, in parallel, modulated by Nrf2. Considering the acute nature of ischemic stroke, we discuss the challenges in using a putative pharmacological strategy (Nrf2 activator) that relies upon transcription, translation and metabolically active cells in treating ischemic stroke patients.