Sinomenine, a natural dextrorotatory morphinan analog, is anti-inflammatory and neuroprotective through inhibition of microglial NADPH oxidase

Mas-related G protein-coupled receptors in gastrointestinal dysfunction and inflammatory bowel disease: A review

Inflammatory bowel disease (IBD) is a chronic debilitating condition, hallmarked by persistent inflammation of the gastrointestinal tract. Despite recent advances in clinical treatments, the aetiology of IBD is unknown, and a large proportion of patients are refractory to pharmacotherapy. Understanding IBD immunopathogenesis is crucial to discern the cause of IBD and optimise treatments. Mas-related G protein-coupled receptors (Mrgprs) are a family of approximately 50 G protein-coupled receptors that were first identified over 20 years ago. Originally known for their expression in skin nociceptors and their role in transmitting the sensation of itch in the periphery, new reports have described the presence of Mrgprs in the gastrointestinal tract. In this review, we consider the impact of these findings and assess the evidence that suggests that Mrgprs may be involved in the disrupted homeostatic processes that contribute to gastrointestinal disorders and IBD. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.

A high-throughput behavioral screening platform for measuring chemotaxis by C. elegans

Throughout history, humans have relied on plants as a source of medication, flavoring, and food. Plants synthesize large chemical libraries and release many of these compounds into the rhizosphere and atmosphere where they affect animal and microbe behavior. To survive, nematodes must have evolved the sensory capacity to distinguish plant-made small molecules (SMs) that are harmful and must be avoided from those that are beneficial and should be sought. This ability to classify chemical cues as a function of their value is fundamental to olfaction and represents a capacity shared by many animals, including humans. Here, we present an efficient platform based on multiwell plates, liquid handling instrumentation, inexpensive optical scanners, and bespoke software that can efficiently determine the valence (attraction or repulsion) of single SMs in the model nematode, Caenorhabditis elegans. Using this integrated hardware-wetware-software platform, we screened 90 plant SMs and identified 37 that attracted or repelled wild-type animals but had no effect on mutants defective in chemosensory transduction. Genetic dissection indicates that for at least 10 of these SMs, response valence emerges from the integration of opposing signals, arguing that olfactory valence is often determined by integrating chemosensory signals over multiple lines of information. This study establishes that C. elegans is an effective discovery engine for determining chemotaxis valence and for identifying natural products detected by the chemosensory nervous system.

Sinomenine exerts a neuroprotective effect on PD mouse model through inhibiting PI3K/AKT/mTOR pathway to enhance autophagy

BACKGROUND

Parkinson's disease (PD), as a chronic and progressive neurodegenerative disease, is associated with autophagy. This study focused on the regulation of sinomenine (SN) on autophagy in PD and its related mechanism.

METHODS

The PD mouse model was constructed by MPTP inducement, and the mouse motor function after modeling and SN treatment was examined by rotarod, grip strength, and foot printing tests. Tyrosine hydroxylase (TH)/LC3B-positive neurons in the substantia nigra pars compacta of mouse brains were detected by immunofluorescence. The expressions of proteins related to autophagy (Beclin1, p62, LC3-I and LC3-II) and phosphorylated phosphoinositide 3-kinase (PI3K)/AKT/mechanistic target of rapamycin kinase (mTOR) signaling pathway were measured by western blot. Rescue experiments were performed to determine the effects of MHY1485 (mTOR activator) on SN-treated PD mice.

RESULTS

SN potentiated the motor ability in PD mice, promoted the survival of dopaminergic neurons, increased the protein expression level of Beclin1, LC3-II/LC3-I ratio and LC3B-positive neurons, lowered the protein expression level of p62 and inactivated PI3K/AKT/mTOR pathway in the substantia nigra tissue of mouse brains. Moreover, MHY1485 reversed the above effects of SN on PD mice via reactivating PI3K/AKT/mTOR pathway.

CONCLUSION

SN augments the autophagy of dopaminergic neurons via inhibiting the PI3K/AKT/mTOR pathway and exerts a neuroprotective effect on PD mice.

A systematic review: Sinomenine

Sinomenine (SIN), an alkaloid derived from the traditional Chinese medicine, Caulis Sinomenii, has been used as an anti-inflammatory drug in China for over 30 years. With the continuous increase in research on the pharmacological mechanism of SIN, it has been found that, in addition to the typical rheumatoid arthritis (RA) treatment, SIN can be used as a potentially effective therapeutic drug for anti-tumour, anti-renal, and anti-nervous system diseases. By reviewing a large amount of literature and conducting a summary analysis of the literature pertaining to the pharmacological mechanism of SIN, we completed a review that focused on SIN, found that the current research is insufficient, and offered an outlook for future SIN development. We hope that this review will increase the public understanding of the pharmacological mechanisms of SIN, discover SIN research trial shortcomings, and promote the effective treatment of immune diseases, inflammation, and other related diseases.

Sustainable strategies for using natural extracts in smart food packaging

The growing demand for sustainable and eco-friendly food packaging has prompted research on innovative solutions to environmental and consumer health issues. To enhance the properties of smart packaging, the incorporation of bioactive compounds derived from various natural sources has attracted considerable interest because of their functional properties, including antioxidant and antimicrobial effects. However, extracting these compounds from natural sources poses challenges because of their complex chemical structures and low concentrations. Traditional extraction methods are often environmentally harmful, expensive and time-consuming. Thus, green extraction techniques have emerged as promising alternatives, offering sustainable and eco-friendly approaches that minimise the use of hazardous solvents and reduce environmental impact. This review explores cutting-edge research on the green extraction of bioactive compounds and their incorporation into smart packaging systems in the last 10 years. Then, an overview of bioactive compounds, green extraction techniques, integrated techniques, green extraction solvents and their application in smart packaging was provided, and the impact of bioactive compounds incorporated in smart packaging on the shelf lives of food products was explored. Furthermore, it highlights the challenges and opportunities within this field and presents recommendations for future research, aiming to contribute to the advancement of sustainable and efficient smart packaging solutions.

An efficient behavioral screening platform classifies natural products and other chemical cues according to their chemosensory valence in C. elegans

Throughout history, humans have relied on plants as a source of medication, flavoring, and food. Plants synthesize large chemical libraries and release many of these compounds into the rhizosphere and atmosphere where they affect animal and microbe behavior. To survive, nematodes must have evolved the sensory capacity to distinguish plant-made small molecules (SMs) that are harmful and must be avoided from those that are beneficial and should be sought. This ability to classify chemical cues as a function of their value is fundamental to olfaction, and represents a capacity shared by many animals, including humans. Here, we present an efficient platform based on multi-well plates, liquid handling instrumentation, inexpensive optical scanners, and bespoke software that can efficiently determine the valence (attraction or repulsion) of single SMs in the model nematode, Caenorhabditis elegans. Using this integrated hardware-wetware-software platform, we screened 90 plant SMs and identified 37 that attracted or repelled wild-type animals, but had no effect on mutants defective in chemosensory transduction. Genetic dissection indicates that for at least 10 of these SMs, response valence emerges from the integration of opposing signals, arguing that olfactory valence is often determined by integrating chemosensory signals over multiple lines of information. This study establishes that C. elegans is an effective discovery engine for determining chemotaxis valence and for identifying natural products detected by the chemosensory nervous system.

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.

Evaluation of the Reparative Effect of Sinomenine in an Acetaminophen-Induced Liver Injury Model

Due to its rising global prevalence, liver failure treatments are urgently needed. Sinomenine (SIN), an alkaloid from sinomenium acutum, is being studied for its liver-repair properties due to Acetaminophen (APAP) overdose. SIN's effect on APAP-induced hepatotoxicity in rats was examined histologically and biochemically. Three groups of 30 adult male Wistar rats were created: control, APAP-only, and APAP + SIN. Histopathological and biochemical analyses were performed on liver samples after euthanasia. SIN is significantly protected against APAP damage. Compared to APAP-only, SIN reduced cellular injury and preserved hepatocellular architecture. The APAP + SIN Group had significantly lower ALT, MDA, and GSH levels, protecting against hepatocellular damage and oxidative stress. SIN also had dose-dependent antioxidant properties. When examining critical regulatory proteins, SIN partially restored Sirtuin 1 (SIRT1) levels. While BMP-7 levels were unaffected, histopathological evidence and hepatocyte damage percentages supported SIN's liver-restorative effect. SIN protected and repaired rats' livers from APAP-induced liver injury. This study suggests that SIN may treat acute liver damage, warranting further research into its long-term effects, optimal dosage, and clinical applications. These findings aid liver-related emergency department interventions and life-saving treatments.

Discovery of sinomenine/8-Bis(benzylthio)octanoic acid hybrids as potential anti-leukemia drug candidate via mitochondrial pathway

Traditional Chinese medicine Qingfengteng primarily acquired from the dried canes of Sinomenium acutum (Thunb.) Rehd. et Wils. var. cinereum Rehd. et Wils. and S. acutum (Thunb.) Rehd. et Wils. For the therapeutic treatment of rheumatism, acute arthritis, and rheumatoid arthritis based on Qingfengteng, sinomenine hydrochloride was recently made the principal active ingredient in various dosage forms. 8-Bis(benzylthio)octanoic acid (CPI-613) was an orphan medicine that the FDA and EMA approved orphan for the treatment of certain resistant malignancies. Its unique mode of action and minimal toxicity toward normal tissues made for an apt pharmacophore. In order to expand the field of sinomenine anticancer structures, sinomenine/8-Bis(benzylthio)octanoic acid derivatives were designed and synthesized. Among them, target hybrids e4 stood out for having notable cytotoxic effects against cancer cell lines, especially for K562 cells, with IC50 values of 2.45 μM and high safety. In-depth investigations demonstrated that e4 caused apoptosis by stopping the cell cycle at G1 phase, and doing so by altering the morphology of the nucleus and causing membrane potential of the in mitochondria to collapse. These results indicated e4 exerted an antiproliferative effect through apoptosis induction via mitochondrial pathway.

Therapeutic potential of natural products in inflammation: underlying molecular mechanisms, clinical outcomes, technological advances, and future perspectives

Chronic inflammation is a common underlying factor in many major diseases, including heart disease, diabetes, cancer, and autoimmune disorders, and is responsible for up to 60% of all deaths worldwide. Metformin, statins, and corticosteroids, and NSAIDs (non-steroidal anti-inflammatory drugs) are often given as anti-inflammatory pharmaceuticals, however, often have even more debilitating side effects than the illness itself. The natural product-based therapy of inflammation-related diseases has no adverse effects and good beneficial results compared to substitute conventional anti-inflammatory medications. In this review article, we provide a concise overview of present pharmacological treatments, the pathophysiology of inflammation, and the signaling pathways that underlie it. In addition, we focus on the most promising natural products identified as potential anti-inflammatory therapeutic agents. Moreover, preclinical studies and clinical trials evaluating the efficacy of natural products as anti-inflammatory therapeutic agents and their pragmatic applications with promising outcomes are reviewed. In addition, the safety, side effects and technical barriers of natural products are discussed. Furthermore, we also summarized the latest technological advances in the discovery and scientific development of natural products-based medicine.

Analysis of non-volatile metabolites and quantitation of the anti-arthritic alkaloid sinomenine from blood fruit (Haematocarpus validus (Miers) Bakh.f. ex Forman)

Haematocarpus validus (Miers) Bakh. f. ex Forman, a lesser-known fruit and medicinal plant of high nutraceutical and medicinal value, is used as anti-arthritic, hepatoprotective, and anti-inflammatory agents in ethnomedicine. Metabolome studies in H. validus are a virgin area of research and here we report the spectra of non-volatiles present in the methanolic leaf and fruit extract, using high-resolution liquid chromatography-mass spectrometry. Furthermore, the alkaloid sinomenine was quantified using high-performance thin layer chromatography spectrodensitometric analysis owing to its pharmacological importance as anti-arthritic and anti-inflammatory drug. Electrospray ionization with protonation in positive mode was selected for the analysis and the spectral data was interrogated using MassHunter software. A total of 40 compounds were identified from leaf and fruit samples and the major classes of compounds identified were alkaloids, terpenoids, steroids, tripeptides, vitamins, and related compounds. For separation and quantitation of sinomenine, chloroform:methanol:water (60:30:6.5, v/v) was used as the mobile phase and sinomenine hydrochloride as reference compound. The analysis confirmed the presence of sinomenine in both non-defatted and defatted methanolic leaf extract with quantities 45.73 and 26.02 mg/100 g dry weight, respectively. H. validus is a non-conventional source of sinomenine, the anti-arthritic and anti-inflammatory alkaloid. Sinomenine detected in this study supports the ethnomedicinal uses of H. validus as an anti-arthritic agent. Further study is needed to elucidate the underlying molecular mechanism of its anti-arthritic attributes as well as the corresponding structure-activity relationships.

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.

Ergosterol Isolated from Antrodia camphorata Suppresses LPS-Induced Neuroinflammatory Responses in Microglia Cells and ICR Mice

Inflammation caused by microglial activation is important in neurodegenerative diseases. In this research, we tried to identify safe and effective anti-neuroinflammatory agents by screening a natural compounds library and found that Ergosterol can inhibit the nuclear factor kappa-light-chain enhancer of the activated B cells (NF-κB) pathway induced by lipopolysaccharide (LPS) in microglia cells. Ergosterol has been reported to be an effective anti-inflammatory agent. Nevertheless, the potential regulatory role of Ergosterol in neuroinflammatory responses has not been fully investigated. We further investigated the mechanism of Ergosterol that regulates LPS-induced microglial activation and neuroinflammatory reactions both in vitro and in vivo. The results showed that Ergosterol can significantly decrease the pro-inflammatory cytokines induced by LPS in BV2 and HMC3 microglial cells, possibly by inhibiting the NF-κB, protein kinase B (AKT), and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, we treated Institute of Cancer Research (ICR) mice with a safe concentration of Ergosterol following LPS injection. Ergosterol treatment significantly decreased microglial activation-associated ionized calcium-binding adapter molecule-1 (IBA-1), NF-κB phosphorylation, and pro-inflammatory cytokine levels. Moreover, Ergosterol pretreatment clearly reduced LPS-induced neuron damage by restoring the expression of synaptic proteins. Our data may provide insight into possible therapeutic strategies for neuroinflammatory disorders.

Comprehensive characterization of multiple components of Ziziphus jujuba Mill using UHPLC-Q-Exactive Orbitrap Mass Spectrometers

Ziziphus jujuba Mill is the dried ripe fruit of the Rhamnaceae family; it is widely distributed in Shandong, Henan, Liaoning, and other places in China. In folk medicine, it was used to restore vital energy, as a blood tonic, and for the treatment of spleen deficiency. To date, a complete investigation of the compounds of Z. jujuba has rarely been performed. Therefore, a reliable strategy based on UHPLC-Q-Exactive Orbitrap MS, combined with trace data acquisition mode (parallel reaction monitoring scanning, PRM) and multiple data processing methods, is necessary for the characterization of compounds in the Z. jujuba. Ultimately, 295 compounds, including 69 flavonoids, 60 alkaloids, 82 phenylpropanoids, 52 organic acids, and 32 other components, were identified in the Z. jujuba; of these, 270 have been reported in Z. jujuba for the first time. This study provides deep insights into the chemistry of Z. jujuba and could be useful for further studies aimed at identifying the factors contributing to the health benefits attributed to this fruit.

Molecular understanding of the translational models and the therapeutic potential natural products of Parkinson's disease

Parkinson's disease is the second most prevalent neurodegenerative disease after Alzheimer's disease, mostly happened in the elder population and the prevalence gradually increased with age. Parkinson's disease is a movement disorder that severely affects patients' daily life. The mechanism of Parkinson's disease still remains unknown, however, studies already proved that the damage or absence of dopaminergic neurons located in the substantia nigra and the decreased dopamine in the striatum are significantly related to Parkinson's disease. To date, the mainstream treatment of Parkinson's disease has been achieved by alleviating its associated morbid symptoms, such as the use of levodopa, carbidopa, dopamine receptor agonists, monoamine oxidase type B inhibitors, anticholinergic drugs, etc. However, strong side effects, even toxicity, have been reported after using these drugs, with reduced effectiveness over time. Plant compounds have shown good therapeutic effects in neurodegenerative diseases as a less toxic treatment. In this review, we have compiled several natural plant compounds and classified the currently reported compounds for therapeutic use based on their structural parent nuclei and constituent elements. We wish to inspire new ideas for the treatment of Parkinson's disease by summarizing their mechanisms.

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.

Astrocytic and microglial cells as the modulators of neuroinflammation in Alzheimer's disease

Neuroinflammation is instigated by the misfiring of immune cells in the central nervous system (CNS) involving microglia and astrocytes as key cell-types. Neuroinflammation is a consequence of CNS injury, infection, toxicity, or autoimmunity. It is favorable as well as a detrimental process for neurodevelopment and associated processes. Transient activation of inflammatory response involving release of cytokines and growth factors positively affects the development and post-injury tissue. However, chronic or uncontrolled inflammatory responses may lead to various neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis, and multiple sclerosis. These diseases have variable clinical and pathological features, but are underlaid by the aggregation of misfolded proteins with a cytotoxic effect. Notably, abnormal activation of glial cells could mediate neuroinflammation, leading to the neurodegenerative condition. Microglia, a type of glial cell, a resident immune cell, form the forefront defense of the CNS immune system. Dysfunctional microglia and astrocyte, a different kind of glial cell with homeostatic function, impairs the protein aggregate (amyloid-beta plaque) clearance in AD. Studies have shown that microglia and astrocytes undergo alterations in their genetic profile, cellular and molecular responses, and thus promote dysfunctional immune cross-talk in AD. Hence, targeting microglia and astrocytes-driven molecular pathways could resolve the particular layers of neuroinflammation and set a reliable therapeutic intervention in AD progression.

Sinomenine Confers Protection Against Myocardial Ischemia Reperfusion Injury by Preventing Oxidative Stress, Cellular Apoptosis, and Inflammation

Sinomenine (SIN), an alkaloid extracted from the root of S. acutum. sinomenine, has been shown to have antiarrhythmic, antioxidant, and anti-inflammatory effects in myocardial ischemia-reperfusion injury (MIRI) ex vivo. In this study, we investigated the cardioprotective effects of SIN in an in vivo mouse model of MIRI. Adult male C57BL/6J mice received SIN (80 mg/kg) for 5 days and underwent 30 min of percutaneous occlusion of the left anterior descending artery (LAD) followed by 24 h of reperfusion. Results showed that pretreatment with SIN significantly reduced myocardial infarct size and concentrations of markers of cardiac injury and improved left ventricular ejection fraction (EF) and shortening fraction (FS) in MIRI mice. The SIN pretreatment prevented the MIRI-induced decrease in the expression levels of Bcl-2, increase in the expression levels of caspase-3, caspase-9, and Bax, and increase in the number of TUNEL-positive cells in ischemic heart tissue. It was also found that pretreatment with SIN prevented the MIRI-induced oxidative stress imbalance in ischemic heart tissue, as shown by the increase in total antioxidant capacity (T-AOC) and glutathione (GSH) and the decrease in malondialdehyde (MDA), reactive oxygen species (ROS), and dihydroethidium (DHE) density. Further studies showed that the stimulus of cardiac ischemia/reperfusion caused a remarkable increase in the expression levels of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) mRNA in ischemic heart tissue, which was effectively prevented by pretreatment with SIN. These results demonstrate that SIN can attenuate MIRI-induced cardiac injury in vivo by preventing oxidative stress, inflammation, and apoptosis.

Analgesic Alkaloids Derived From Traditional Chinese Medicine in Pain Management

Chronic pain is one of the most prevalent health problems. The establishment of chronic pain is complex. Current medication for chronic pain mainly dependent on anticonvulsants, tricyclic antidepressants and opioidergic drugs. However, they have limited therapeutic efficacy, and some even with severe side effects. We turned our interest into alkaloids separated from traditional Chinese medicine (TCM), that usually act on multiple drug targets. In this article, we introduced the best-studied analgesic alkaloids derived from TCM, including tetrahydropalmatine, aloperine, oxysophocarpine, matrine, sinomenine, ligustrazine, evodiamine, brucine, tetrandrine, Stopholidine, and lappaconitine, focusing on their mechanisms and potential clinical applications. To better describe the mechanism of these alkaloids, we adopted the concept of drug-cloud (dCloud) theory. dCloud illustrated the full therapeutic spectrum of multitarget analgesics with two dimensions, which are “direct efficacy”, including inhibition of ion channels, activating γ-Aminobutyric Acid/opioid receptors, to suppress pain signal directly; and “background efficacy”, including reducing neuronal inflammation/oxidative stress, inhibition of glial cell activation, restoring the balance between excitatory and inhibitory neurotransmission, to cure the root causes of chronic pain. Empirical evidence showed drug combination is beneficial to 30–50% chronic pain patients. To promote the discovery of effective analgesic combinations, we introduced an ancient Chinese therapeutic regimen that combines herbal drugs with “Jun”, “Chen”, “Zuo”, and “Shi” properties. In dCloud, “Jun” drug acts directly on the major symptom of the disease; “Chen” drug generates major background effects; “Zuo” drug has salutary and supportive functions; and “Shi” drug facilitates drug delivery to the targeted tissue. Subsequently, using this concept, we interpreted the therapeutic effect of established analgesic compositions containing TCM derived analgesic alkaloids, which may contribute to the establishment of an alternative drug discovery model.

Advances in nanotechnology-based platforms for survivin-targeted drug discovery

INTRODUCTION

Due to its unique functional impact on multiple cancer cell circuits including proliferation, apoptosis, tumor dissemination, DNA damage repair and immune response, the inhibitor of apoptosis protein (IAP) survivin has gained high interest as a molecular target and a multitude of therapeutics were developed to interfere with survivin expression and functionality. First clinical evaluations of these therapeutics, however, were disappointing highlighting the need to develop advanced delivery systems of survivin-targeting molecules to increase stability, bioavailability as well as the selective guidance to tumor tissue.

AREAS COVERED

: This review focuses on advancements in nanocarriers to molecularly target survivin in human malignancies. A plethora of nanoparticle platforms, including liposomes, polymeric systems, dendrimers, inorganic nanocarriers, RNA/DNA nanotechnology and exosomes are discussed in the background of survivin-tailored RNA interference, small molecule inhibitors, dominant negative mutants or survivin vaccination or combined modality treatment with chemotherapeutic drugs and photo- dynamic/photothermal strategies.

EXPERT OPINION

Novel therapeutic approaches include the use of biocompatible nanoformulations carrying gene silencing or drug molecules to directly or indirectly target proteins, allow for a more precise and controlled delivery of survivin therapeutics. Moreover, surface modification of these nanocarriers may result in a tumor entity specific delivery. Therefore, nanomedicine exploiting survivin-tailored strategies in a multimodal background is considered the way forwaerd to enhance the development of future personalized medicine.

Sinomenine Attenuates Trimethyltin-Induced Cognitive Decline via Targeting Hippocampal Oxidative Stress and Neuroinflammation

Sinomenine is the main bioactive ingredient of the medicinal plant Sinomenium acutum with neuroprotective potential. This study was designed to assess beneficial effect of sinomenine in alleviation of trimethyltin (TMT)-induced cognitive dysfunction. TMT was administered i.p. (8 mg/kg, once) and sinomenine was daily given p.o. 1 h after TMT for 3 weeks at doses of 25 or 100 mg/kg. Cognitive performance was assessed in various behavioral tests. In addition, oxidative stress- and inflammation-associated factors were measured and histochemical evaluation of the hippocampus was conducted. Sinomenine at a dose of 100 mg/kg significantly and partially increased discrimination index in novel object recognition (NOR), improved alternation in short-term Y maze, increased step-through latency in passive avoidance paradigm, and also reduced probe trial errors and latency in the Barnes maze task. Moreover, sinomenine somewhat prevented inappropriate hippocampal changes of malondialdehyde (MDA), reactive oxygen species (ROS), protein carbonyl, nitrite, superoxide dismutase (SOD), tumor necrosis factor α (TNFα), interleukin 6 (IL 6), acetylcholinesterase (AChE) activity, beta secretase 1 (BACE 1) activity, and mitochondrial membrane potential (MMP) with no significant effect on glutathione (GSH), catalase, glutathione reductase, glutathione peroxidase, and myeloperoxidase (MPO). In addition, lower reactivity (IRA) for glial fibrillary acidic protein (GFAP) as an index of astrocyte activity was observed and loss of CA1 pyramidal neurons was attenuated following sinomenine treatment. This study demonstrated that sinomenine could lessen TMT-induced cognitive dysfunction which is partly due to its attenuation of hippocampal oxidative stress and neuroinflammation.

Design, synthesis, and pharmacological evaluation of sinomenine derivatives on rings A and C: Novel compounds screening for aplastic anemia targeting on cytotoxic T lymphocyte

Cytotoxic T lymphocyte (CTL), a key effector cell in aplastic anemia (AA) immune injury, is shown to be a potential target for AA drug therapy. However, there is no candidate for this target till now. Oriented by the inhibition activity of CTL and macrophage derived nitric oxide (NO), a series of novel sinomenine derivatives on rings A and C are designed, synthesized and screened. Among them, compound 3a demonstrates the best inhibitory activity on CTL with an IC₅₀ value of 2.3 μM, and a 97.1% inhibiton rate on macrophage NO production without significant cytotoxicity. Further, compound 3a exhibits substantial therapeutic efficacy on immune-mediated BM failure in AA model mice by improving the symptoms of anemia and the function of BM hematopoiesis, and shows more advantages in life quality improving than cyclosporine A (CsA). Its efficacy on AA at least partly comes from targeting on activated cluster of differentiation (CD)8⁺ T cell. Additionally, 3a also shows much less toxicity (LD₅₀ > 10.0 g/kg) than sinomenine (LD₅₀ = 1.1 g/kg) in preliminary acute toxicity assessment in mice, and has a low risk to inhibit hERG to cause cardiotoxicity. These results indicate that compound 3a merits further investigation for AA treatment by targeting on CTL.

Sinomenine Attenuated Capsaicin-Induced Increase in Cough Sensitivity in Guinea Pigs by Inhibiting SOX5/TRPV1 Axis and Inflammatory Response

Background

Chronic cough is a common complaint which affects a large number of patients worldwide. Increased cough sensitivity is a very important cause of chronic persistent cough. However, there are limited clinical diagnosis and treatment for increased cough sensitivity. Transient receptor potential vanilloid-1 (TRPVl) is a member of the transient receptor potential (TRP) family of channels which is very closely associated with respiratory diseases. However, the mechanism through which TRPV1 that influences downstream events is still poorly understood.

Results

Capsaicin induced increase in cough sensitivity by upregulating the protein level of TRPV1, leading to the secretions of Substance P and neurokinin A which stimulated neurogenic inflammation. However, sinomenine, a component of traditional Chinese medicine, significantly attenuated the capsaicin-induced cough by inhibiting the expression of TRPV1 in guinea pigs. In addition, capsaicin increased the expression of SOX5 which mediated the transcriptional upregulation of TRPV1. However, pretreatment with sinomenine reduced the expression of SOX5.

Conclusion

These results indicate that capsaicin induced increase in cough sensitivity by activating neurogenic inflammation, while sinomenine attenuated the increase in cough sensitivity by inhibiting the expressions of SOX5 and TRPV1 in guinea pigs. This finding may provide a novel target for the treatment of aggravated cough sensitivity.

Sinomenine Suppresses Development of Hepatocellular Carcinoma Cells via Inhibiting MARCH1 and AMPK/STAT3 Signaling Pathway

Promotion of apoptosis and suppression of proliferation in tumor cells are popular strategies for developing anticancer drugs. Sinomenine (SIN), a plant-derived alkaloid, displays antitumor activity. However, the mechanism of action of SIN against hepatocellular carcinoma (HCC) is unclear. Herein, several molecular technologies, such as Western Blotting, qRT-PCR, flow cytometry, and gene knockdown were applied to explore the role and mechanism of action of SIN in the treatment of HCC. It was found that SIN arrests HCC cell cycle at G0/G1 phase, induces apoptosis, and suppresses proliferation of HCC cells via down-regulating the expression of membrane-associated RING-CH finger protein 1 (MARCH1). Moreover, SIN induces cell death and growth inhibition through AMPK/STAT3 signaling pathway. MARCH1 expression was silenced by siRNA to explore its involvement in the regulation of AMPK/STAT3 signaling pathway. Silencing MARCH1 caused down-regulation of phosphorylation of AMPK, STAT3 and decreased cell viability and function. Our results suggested that SIN inhibits proliferation and promotes apoptosis of HCC cells by MARCH1-mediated AMPK/STAT3 signaling pathway. This study provides new support for SIN as a clinical anticancer drug and illustrates that targeting MARCH1 could be a novel treatment strategy in developing anticancer therapeutics.

Ligands and Signaling of Mas-Related G Protein-Coupled Receptor-X2 in Mast Cell Activation

Mas-related G protein-coupled receptor-X2 (MRGPRX2) is known as a novel receptor to activate mast cells (MCs). MRGPRX2 plays a dual role in promoting MC-dependent host defense and immunomodulation and contributing to the pathogenesis of pseudo-allergic drug reactions, pain, itching, and inflammatory diseases. In this article, we discuss the possible signaling pathways of MCs activation mediated by MRGPRX2 and summarize and classify agonists and inhibitors of MRGPRX2 in MCs activation. MRGPRX2 is a low-affinity and low-selectivity receptor, which allows it to interact with a diverse group of ligands. Diverse MRGPRX2 ligands utilize conserved residues in its transmembrane (TM) domains and carboxyl-terminus Ser/Thr residues to undergo ligand binding and G protein coupling. The coupling likely initiates phosphorylation cascades, induces Ca²⁺ mobilization, and causes degranulation and generation of cytokines and chemokines via MAPK and NF-κB pathways, resulting in MCs activation. Agonists of MRGPRX2 on MCs are divided into peptides (including antimicrobial peptides, neuropeptides, MC degranulating peptides, peptide hormones) and nonpeptides (including FDA-approved drugs). Inhibitors of MRGPRX2 include non-selective GPCR inhibitors, herbal extracts, small-molecule MRGPRX2 antagonists, and DNA aptamer drugs. Screening and classifying MRGPRX2 ligands and summarizing their signaling pathways would improve our understanding of MRGPRX2-mediated physiological and pathological effects on MCs.

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

Sinomenine (SINO), which is used clinically to treat rheumatoid arthritis and neuralgia, is derived from the root and stems of Sinomenium acutum. SINO has been reported to exert analgesic, sedative and anti-inflammatory effects, and provides a protective role against shock and organ damage. Studies have suggested that SINO primarily exerts it anti-inflammatory function by inhibiting NF-κB signaling. There is also evidence to indicate that SINO may regulate inflammation Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling. The present study aimed to investigate whether the anti-inflammatory and cerebral protective effects of SINO were induced through Nrf2 both in vitro and in vivo. The results revealed that SINO significantly upregulated Nrf2 protein expression levels, increased Nrf2 nuclear translocation and the upregulated the protein expression levels of downstream factors. The treatment of a middle cerebral artery occlusion model mice with SINO effectively reduced cerebral damage and inflammation, and restored the balance in cerebral oxidative stress. In addition, SINO treatment also promoted Nrf2-dependent microglia M1/M2 polarization and inhibited the phosphorylation of IκBα as well as NF-κB nuclear translocation. This revealed an important upstream event that contributed to its anti-inflammatory and cerebral tissue protective effects. In conclusion, the findings of the present study identified a novel pathway through which SINO may exert its anti-inflammatory and cerebral protective functions, and provided a molecular basis for the potential applications of SINO in the treatment of cerebral inflammatory disorders.

Sinomenine alleviates dorsal root ganglia inflammation to inhibit neuropathic pain via the p38 MAPK/CREB signalling pathway

The objective of study was to investigate the inhibitory effect of sinomenine on neuropathic pain on dorsal root ganglia (DRG). The DRG cell line and spinal nerve ligation (SNL) model were used in this study. The effect of sinomenine on the cell viability was examined by MTT assay. The expression of p38 MAPK, NF-κB, c-fos, SP and TNF-α was detected by using immunofluorescence and immunohistochemistry assay. We also assessed the level of p-CaMKII, COX-2, p-CREB, IL-17A, TLR4 and IL-1β via western blotting and RT-qPCR. Compared to the controls, sinomenine showed a protective effect on TNF-α-induced apoptosis on DRG cells in a dose-dependent manner, with an increase of cell viability and a decrease of reactive oxygen species level as well as LDH release. Parallelly, sinomenine treatment significantly reduced the expression of various factors related to stress and inflammation, including p38 MAPK, NF-κB, c-fos, p-CAMKII, COX-2, p-CREB, TLR4 and IL-17A in DRG cells in vitro. Furthermore, we found that administration of sinomenine significantly reduced mechanical withdrawal threshold and thermal withdrawal latency and inhibited the inflammation and activation of p38 signaling in SNL rats. It is noting that combined therapy of sinomenine and pulsed radiofrequency exhibited higher efficacy of dorsal root ganglia inflammation than single treatment as well as the combination of oxycodone and pulsed radiofrequency. Sinomenine inhibited the apoptosis of DRG cell by regulating p38 MAPK/CREB signalling pathway, which provides evidence to alleviate neuropathic pain in clinic.

The Role of Chronic Inflammation in Various Diseases and Anti-inflammatory Therapies Containing Natural Products

Chronic inflammation represents a long-term reaction of the body's immune system to noxious stimuli. Such a sustained inflammatory response sometimes results in lasting damage to healthy tissues and organs. In fact, chronic inflammation is implicated in the development and progression of various diseases, including cardiovascular diseases, respiratory diseases, metabolic diseases, neurodegenerative diseases, and even cancers. Targeting nonresolving inflammation thus provides new opportunities for treating relevant diseases. In this review, we will go over several chronic inflammation-associated diseases first with emphasis on the role of inflammation in their pathogenesis. Then, we will summarize a number of natural products that exhibit therapeutic effects against those diseases by acting on different markers in the inflammatory response. We envision that natural products will remain a rich resource for the discovery of new drugs treating diseases associated with chronic inflammation.

Antinociceptive Effects of Sinomenine Combined With Ligustrazine or Paracetamol in Animal Models of Incisional and Inflammatory Pain

The management of postoperative and inflammatory pain has been a pressing challenge in clinical settings. Sinomenine (SN) is a morphinan derived alkaloid with remarkable analgesic properties in various kinds of pain models. The aim of the current study is to investigate if SN can enhance the effect of ligustrazine hydrochloride (LGZ) or paracetamol (PCM) in animal models of postoperative and inflammatory pain. And to determine if the combined therapeutic efficacies can be explained by pharmacokinetics changes. Pharmacological studies were performed using a rat model of incisional pain, and a mouse model of carrageenan induced inflammatory pain. Pharmacokinetic studies were performed using a microdialysis sampling and HPLC-MS/MS assay method to quantify SN, LGZ, and PCM levels in blood and extracellular fluid in brain. We found that SN plus LGZ or SN plus PCM produced marked synergistic analgesic effects. However, such synergy was subjected to pain modalities, and differed among pain models. Pharmacological discoveries could be partially linked to pharmacokinetic alterations in SN combinations. Though further evaluation is needed, our findings advocate the potential benefits of SN plus LGZ for postoperative pain management, and SN plus PCM for controlling inflammatory pain.

Sinomenine improve diabetic nephropathy by inhibiting fibrosis and regulating the JAK2/STAT3/SOCS1 pathway in streptozotocin-induced diabetic rats

AIMS

To investigate the therapeutic effects and potent mechanism of sinomenine (SIN) nanoliposomes on nephropathy in diabetic rats.

MAIN METHODS

The protective efficacies of SIN on the oxidative injury in renal HK-2 cell induced by hydrogen peroxide (H₂O₂) were investigated via the CCK-8 assay. Forty SD rats with streptozotocin (STZ)-induced diabetic kidney disease (DKD) were assigned to the saline group and three SIN groups (10, 20 and 40 mg/kg). During 6-week treatment, body weight, fasting glucose level and other metabolic parameters were recorded. H&E staining and changes in renal functions as well as expression levels of apoptosis and fibrosis-related factors in renal tissues were assessed. The qPCR and western blotting (WB) methods were used to detect relative expression levels of JAK/STAT/SOCS pathway-related factors in the renal tissues.

KEY FINDINGS

Cell viabilities of HK-2 cells with oxidative injury were obviously improved by incubating with SIN at 320 μg/mL for 92.9%. Significantly up-regulated GPX1, SOD2 and GSH contributed to the down-regulated ROS content in SIN-treated groups. Moreover, 6-week administration of SIN improved renal functions and worsening nephropathy morphology of DKD rats. SIN also ameliorated gradually increased renal cell apoptosis, suppressed expression levels of fibrosis-related proteins as well as IL-6 and ICAM-1, and regulated JAK2/STAT3/SOCS1 pathway, thereby exhibited protective effects on renal tissues of DKD rats.

CONCLUSION

SIN protects nephrocytes and decreases renal tissue injury via inhibiting oxidative stress, reducing renal cell apoptosis and fibrosis, regulating the JAK2/STAT3/SOCS1 pathway in DKD rats.

Molecular insights of NADPH oxidases and its pathological consequences

Reactive oxygen species (ROS), formed by the partial reduction of oxygen, were for a long time considered to be a byproduct of cellular metabolism. Since, increase in cellular levels of ROS results in oxidative stress leading to damage of nucleic acids, proteins, and lipids resulting in numerous pathological conditions; ROS was considered a bane for aerobic species. Hence, the discovery of NADPH oxidases (NOX), an enzyme family that specifically generates ROS as its prime product came as a surprise to redox biologists. NOX family proteins participate in various cellular functions including cell proliferation and differentiation, regulation of genes and protein expression, apoptosis, and host defence immunological response. Balanced expression and activation of NOX with subsequent production of ROS are critically important to regulate various genes and proteins to maintain homeostasis of the cell. However, dysregulation of NOX activation leading to enhanced ROS levels is associated with various pathophysiologies including diabetes, cardiovascular diseases, neurodegenerative diseases, ageing, atherosclerosis, and cancer. Although our current knowledge on NOX signifies its importance in the normal functioning of various cellular pathways; yet the choice of ROS producing enzymes which can tip the scale from homeostasis toward damage, as mediators of biological functions remain an oddity. Though the role of NOX in maintaining normal cellular functions is now deemed essential, yet its dysregulation leading to catastrophic events cannot be denied. Hence, this review focuses on the involvement of NOX enzymes in various pathological conditions imploring them as possible targets for therapies. SIGNIFICANCE OF THE STUDY: The NOXs are multi-subunit enzymes that generate ROS as a prime product. NOX generated ROS are usually regulated by various molecular factors and play a vital role in different physiological processes. The dysregulation of NOX activity is associated with pathological consequences. Recently, the dynamic proximity of NOX enzymes with different molecular signatures of pathologies has been studied extensively. It is essential to identify the precise role of NOX machinery in its niche during the progression of pathology. Although inhibition of NOX could be a promising approach for therapeutic interventions, it is critical to expand the current understanding of NOX's dynamicity and shed light on their molecular partners and regulators.

Metabolic mechanism and anti-inflammation effects of sinomenine and its major metabolites N-demethylsinomenine and sinomenine-N-oxide

AIMS

Sinomenine (SIN) is clinically used as an anti-rheumatic drug. However, the metabolic and pharmacological mechanisms of SIN combined with its metabolites are unclear. This study aims to explore the cyclic metabolic mechanism of SIN, the anti-inflammation effects of SIN and its major metabolites (N-demethylsinomenine (DS) and sinomenine-N-oxide (SNO)), and the oxidation property of SNO.

MATERIALS AND METHODS

SIN was administrated to rats via gavage. Qishe pills (a SIN-containing drug) were orally administrated to humans. The bio-samples were collected to identify SIN's metabolites. Enzymatic and non-enzymatic incubations were used to reveal SIN's metabolic mechanism. Impacts of SIN, SNO and DS on the inflammation-related cytokine's levels and nuclear translocation of NF-κB were evaluated in LPS-induced Raw264.7 cells. ROS induced by SNO (10 μM) was also assessed.

KEY FINDINGS

CYP3A4 and ROS predominantly mediated the formation of SNO, and CYP3A4 and CYP2C19 primarily mediated the formation of DS. Noteworthily, SNO underwent N-oxide reduction both enzymatically, by xanthine oxidase (XOD), and non-enzymatically, by ferrous ion and heme moiety. The levels of IL-6 and TNF-α and nuclear translocation of NF-κB were ameliorated after pretreatment of SIN in LPS-induced Raw264.7 cells, while limited attenuations were observed after pretreatment of DS (SNO) even at 200 μM. In contrast, SNO induced ROS production.

SIGNIFICANCE

This study elucidated that SIN underwent both enzymatic and non-enzymatic cyclic metabolism and worked as the predominant anti-inflammation compound, while SNO induced ROS production, suggesting more studies of SIN combined with SNO and DS are necessary in case of DDI and potential toxicities.

Sinomenine Inhibited Interleukin-1β-Induced Matrix Metalloproteinases Levels via SOCS3 Up-Regulation in SW1353 Cells

Matrix metalloproteinases (MMPs) are required for collagen degradation which play a key pathological role in arthritis progression. Herein, the effect of sinomenine (SN) on Interleukin 1 beta (IL-1β)-induced MMPs production and its underlying mechanism were explored in SW1353 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that 200 and 400 µM SN significantly inhibited SW1353 cell proliferation, thus the lower dose of SN (25-100 µM) were used in the subsequent experiments. Notably, the increased mRNA and protein levels of suppressor of cytokine signaling (SOCS) 3 were dose-dependently induced by SN. SN significantly suppressed mRNA and protein levels of MMPs in IL-1β-induced SW1353 cells. Through Western blot analysis, SN showed inhibitory effect on IL-1β-induced TAK1 and p65 phosphorylation. Moreover, SN blocked the interaction of TRAF6 and TAK1 resulting in inactivation of IL-1β pathway. Mechanistically, the inhibitory effect of SN on MMPs levels alongside TRAF6 and TAK1 interactions was abrogated by silencing SOCS3. Moreover, SN did not inhibit TAK1 kinase activity. In TAK1 silencing cells, the levels of MMPs and p65 phosphorylation of SN-treatedcells were lower than dimethyl sulfoxide (DMSO)-treated cells, indicating that blocking interaction was not a unique way for SN to inhibit MMPs levels. Finally, SN significantly inhibited IL-6-induced Janus tyrosine kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) phosphorylation in SW1353 cells. The levels of JAK2 phosphorylation and MMPs did not show a significant difference between IL-6 + SOCS3-small interfering RNA (siRNA) + SN group and IL-6 + SOCS3-siRNA + DMSO group. These findings demonstrated that SOCS3 expression was increased by SN blocked IL-1β-induced interaction between TRAF6 and TAK1 as well as IL-6 pathway activation, thereby culminating in the inhibition of MMPs levels.

Nicotinamide Adenine Dinucleotide Phosphate Oxidase and Neurodegenerative Diseases: Mechanisms and Therapy

Significance: The growing incidence of neurodegenerative diseases significantly impacts the individuals who suffer from these disorders and is a major health concern globally. Although the specific mechanisms of neurodegenerative diseases are still far from being acknowledged, it is becoming clear that oxidative stress and neuroinflammation are critical contributing factors to the progression of neurodegeneration. Thus, it is conceivable that the inhibition of oxidative stress and neuroinflammation may represent promising therapeutic targets for the treatment of neurodegenerative diseases. Recent Advances: Recently, the strategy for neurodegenerative disease therapy has shifted from the use of antioxidants and conventional anti-inflammatory targets to upstream mediators due to the failure of most antioxidants and nonsteroidal anti-inflammatory drugs in clinical trials. Nicotinamide adenine dinucleotide phosphate oxidases (NOXs), a family of superoxide-producing enzyme complexes, have been identified as an upstream factor that controls both oxidative stress and neuroinflammation. Genetic inactivation or pharmacological inhibition of NOX enzymes displays potent neuroprotective effects in a broad spectrum of neurodegenerative disease models. Critical Issues: The detailed mechanisms of how NOX enzymes regulate oxidative stress and neuroinflammation still remain unclear. Moreover, the currently available inhibitors of NOX enzymes exhibit nonspecificity, off-target effects, unsuitable pharmacokinetic properties, and even high toxicity, markedly limiting their potential clinical applications. Future Directions: This review provides novel insights into the roles of NOXs in neurodegenerative pharmacology, and indicates the types of NOX enzyme inhibitors that should be identified and developed as candidates for future applications, which might reveal novel neurodegenerative disease therapies based on NOXs.

Analgesic Mechanism of Sinomenine against Chronic Pain

Purified from the roots of the plant Sinomenium acutum, sinomenine is traditionally used in China and Japan for treating rheumatism and arthritis. Previously, we have demonstrated that sinomenine possessed a broad analgesic spectrum in various chronic pain animal models and repeated administration of sinomenine did not generate tolerance. In this review article, we discussed sinomenine's analgesic mechanism with focus on its role on immune regulation and neuroimmune interaction. Sinomenine has distinct immunoregulative properties, in which glutamate, adenosine triphosphate, nitric oxide, and proinflammatory cytokines are thought to be involved. Sinomenine may alter the unbalanced neuroimmune interaction and inhibit neuroinflammation, oxidative stress, and central sensitization in chronic pain states. In conclusion, sinomenine has promising potential for chronic pain management in different clinical settings.

Sinomenine inhibits amyloid beta-induced astrocyte activation and protects neurons against indirect toxicity

Amyloid beta is a major constituent of the plaques found in the brains of patients suffering from Alzheimer’s disease (AD). A growing body of research work suggests that neuroinflammation plays important roles in the development of AD. Thus, considerable efforts are directed towards identification of compounds that can reduce or inhibit neuroinflammation. Here, we show that sinomenine, a compound present in a Chinese medicinal plant, Sinomenium acutum, inhibits oligomeric amyloid beta-induced production of reactive oxygen species (ROS), nitric oxide (NO) and inflammation-related molecules from astrocytic cells. The conditioned medium from oligomeric amyloid beta-treated astrocytic cells induces cell death in the hippocampal neuronal cells. Importantly, sinomenine inhibits this cell death. In addition, this compound has inhibitory effects on the production of ROS, NO and inflammation-related factors from oligomeric amyloid-beta treated human astrocytes. Finally, the conditioned medium from oligomeric amyloid beta-treated human astrocytes induces cell death in the primary culture of human neurons, which is inhibited by sinomenine. Thus, sinomenine inhibits amyloid beta-induced production of toxic factors from astrocytes, and confers protection to hippocampal neuronal cells as well as human neurons against indirect toxicity. The results suggest that this compound could provide beneficial effects in AD and other neurodegenerative conditions by reducing inflammation and neuronal cell death.

Therapeutic Inducers of Apoptosis in Ovarian Cancer

Ovarian cancers remain one of the most common causes of gynecologic cancer-related death in women worldwide. The standard treatment comprises platinum-based chemotherapy, and most tumors develop resistance to therapeutic drugs. One mechanism of developing drug resistance is alterations of molecules involved in apoptosis, ultimately assisting in the cells' capability to evade death. Thus, there is a need to focus on identifying potential drugs that restore apoptosis in cancer cells. Here, we discuss the major inducers of apoptosis mediated through various mechanisms and their usefulness as potential future treatment options for ovarian cancer. Broadly, they can target the apoptotic pathways directly or affect apoptosis indirectly through major cancer-pathways in cells. The direct apoptotic targets include the Bcl-2 family of proteins and the inhibitor of apoptotic proteins (IAPs). However, indirect targets include processes related to homologous recombination DNA repair, micro-RNA, and p53 mutation. Besides, apoptosis inducers may also disturb major pathways converging into apoptotic signals including janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), wingless-related integration site (Wnt)/β-Catenin, mesenchymal-epithelial transition factor (MET)/hepatocyte growth factor (HGF), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK), and phosphatidylinositol 3-kinase (PI3K)/v-AKT murine thymoma viral oncogene homologue (AKT)/mammalian target of rapamycin (mTOR) pathways. Several drugs in our review are undergoing clinical trials, for example, birinapant, DEBIO-1143, Alisertib, and other small molecules are in preclinical investigations showing promising results in combination with chemotherapy. Molecules that exhibit better efficacy in the treatment of chemo-resistant cancer cells are of interest but require more extensive preclinical and clinical evaluation.

The antidepressant-like effects of sinomenine in mice: a behavioral and neurobiological characterization

Sinomenine is a bioactive alkaloid extracted from Sinomenium acutum. Here, we investigated the antidepressant effects of sinomenine in mice. The antidepressant actions of sinomenine were first examined in the forced-swim test and the tail-suspension test, and then assessed in the chronic social defeat stress (CSDS) model of depression. Changes in the brain-derived neurotrophic factor (BDNF) signaling pathway after CSDS and sinomenine treatment were also investigated. A tryptophan hydroxylase inhibitor and a BDNF signaling inhibitor were also used to determine the pharmacological mechanisms of sinomenine. It was found that sinomenine induced antidepressant-like effects in the forced-swim test and tail-suspension test without affecting the locomotor activity of mice. Sinomenine also prevented the CSDS-induced depressive-like symptoms. Moreover, sinomenine fully restored the CSDS-induced decrease in the hippocampal BDNF signaling pathway, whereas a BDNF signaling inhibitor, but not a tryptophan hydroxylase inhibitor, blocked the antidepressant effects of sinomenine. In conclusion, sinomenine exerts antidepressant effects in mice by promoting the hippocampal BDNF signaling pathway.

Lipopolysaccharides-mediated injury to chondrogenic ATDC5 cells can be relieved by Sinomenine via downregulating microRNA-192

Sinomenine (SIN) is an isoquinoline derived from Caulis Sinomenii that has been used to treat rheumatoid arthritis and osteoarthritis for several decades in China. This study aims to reveal the effects of SIN on mouse chondrogenic ATDC5 cells growth and inflammation. SIN was used to treat ATDC5 cells injured by lipopolysaccharides (LPS). The following parameters were determined for evaluating the treatment effects of SIN: cell viability, apoptosis, reactive oxygen species generation, and pro-inflammatory cytokines release. Besides, the expression of LPS-sensitive miRNA (miR-192) and the activation of NF-κB and MAPK signaling were studied to explain SIN's function. SIN with concentration of 30 μM significantly attenuated LPS-induced cell damage via increasing cell viability, inhibiting apoptosis and reactive oxygen species generation, and declining IL-6 and TNF-α release. miR-192 was downregulated by SIN treatment. Restoration of miR-192 expression by miRNA transfection could significantly impede SIN's protective action. Besides, the inhibitory effects of SIN on the activation of NF-κB and MAPK signaling were attenuated by miR-192 overexpression. Furthermore, GDF11 was found to be a target gene of miR-192. LPS-mediated injury to chondrogenic ATDC5 cells can be relieved by SIN via downregulating miR-192 and subsequently repressing the activation of NF-κB and MAPK signaling.

Sinomenine facilitates the efficacy of gabapentin or ligustrazine hydrochloride in animal models of neuropathic pain

Management of chronic pain is restricted by the lack of effective tools. This study evaluated the efficacies of sinomenine combined gabapentin or ligustrazine hydrochloride in treating peripheral and central chronic neuropathic pain. The study was conducted in mice with photochemically induced sciatic nerve injury, and in rats with photochemically induced spinal cord injury. For assessing the effectiveness of combined therapy, sinomenine, gabapentin or ligustrazine hydrochloride was injected intraperitoneally (i.p.), and pain behavioral tests were performed. At sub-effective dosages, pre-administration of sinomenine (for 60 min) plus gabapentin or ligustrazine hydrochloride, generated significant anti-allodynic effects in mice or rats with peripheral or central neuropathic pain. However, these effects were abolished when gabapentin or ligustrazine hydrochloride was pre-administered, and then sinomenine was given 60 min later. The combined efficacies of sinomenine and gabapentin or ligustrazine hydrochloride, cannot be blocked or reversed by the naloxone, suggesting the underlying mechanism is not mediated by opioid receptors. Moreover, following repeated treatments, sinomenine and gabapentin combination increased the baseline mechanical threshold, while generating prolonged analgesia, without introducing notable side effects. Sinomenine can enhance the efficacy of gabapentin or ligustrazine hydrochloride in rodent models of peripheral or central neuropathic pain, without introducing tolerance or other notable side effects. Findings of current study suggest that combing sinomenine and gabapentin or ligustrazine hydrochloride could be highly beneficial in neuropathic pain therapies.

The influence of alkaloids on oxidative stress and related signaling pathways

Alkaloids have always attracted scientific interest due to either their positive or negative effects on human beings. This review aims to summarize their antioxidant effects by both classical in vitro scavenging assay and at the cellular level. Since most in vitro studies used the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay, the results from those studies are summed up in the first part of the article. In the second part, available data on the effect of alkaloids on NADPH-oxidase, the key enzyme for reactive oxygen species production, at the cellular level, are summarized. More than 130 alkaloids were tested by DPPH assay. However, due to methodological differences, a direct comparison is hardly possible. It can be at least concluded that some of them were either similar to or even more active than standard antioxidants and the number of aromatic hydroxyl groups seems to be the major determinant for the activity. The data on inhibition of NADPH-oxidase activity by alkaloids demonstrated that there is little relationship to the DPPH assay. The mechanism seems to be based on inhibition of synthesis, activation or translocation of NADPH-oxidase subunits. In some alkaloids, activation of the nuclear factor Nrf2 pathway was documented to be the grounds for inhibition of NADPH-oxidase. Interestingly, many alkaloids can behave both as anti-oxidants and pro-oxidants depending on conditions and pro-oxidation might be the reason for activation of Nrf2. Available data on other "antioxidant" transcription factors FOXOs and PPARs are also mentioned.

Sinomenine inhibits proliferation, migration, and invasion of gastric cancer cells via MALAT1 to regulate miR-141: Clinical implications

BACKGROUND

Gastric cancer (GC), one of the common malignant tumors of the digestive system, has high morbidity and mortality. Sinomenine has been reported to exert anti-tumor activities in GC cells, but the action mechanism remains to be further investigated.

AIM

To explore the mechanism of Sinomenine to inhibit the proliferation, migration, and invasion of GC cells, the role of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and miR-141 in this process, and the clinical significance of these findings.

METHODS

Sinomenine at concentrations of 100 μmol/L, 200 μmol/L, and 400 μmol/L were applied to AGS cells cultured in vitro (L-SIN group, M-SIN group, and H-SIN group, respectively). Cell proliferation was detected by MTT assay after 24, 48, and 72 h of treatment. Transwell assay was employed to examine the migration and invasion of GES-1 and AGS cells after 24 h. RT-qPCR was employed to determine the expression levels of MALAT1 mRNA and miR-141 in GES-1 and AGS cells. AGS cells that had up-regulated miR-141 or down-regulated MALAT1 were constructed by cell transfection with Lipofectamine^TM2000, and RT-qPCR was used to detect transfection efficiency and the expression of miR-141. Then, the proliferation, migration, and invasion of AGS cells were examined. Binding sites of miR-141 were predicted, and luciferase reporter assay was conducted to confirm the relationship between miR-141 and MALAT1. The relative expression of miR-141 was determined. AGS cells with MALAT1 up-regulation only or with miR-141 up-regulation simultaneously were treated with 400 μmol/L Sinomenine, and the proliferation, migration, and invasion of the cells were determined.

RESULTS

Compared with GES-1 cells, the cell viability, migration, and invasion of control AGS in the control group were significantly higher (P < 0.05), the mRNA expression level of MALAT1 significantly increased (P < 0.05), and the mRNA expression level of miR-141 significantly decreased (P < 0.05). Compared with control AGS cells, the cell viability, migration, and invasion of AGS cells in the L-SIN group, M-SIN group, and H-SIN group were significantly reduced (P < 0.05), the expression of MALAT1 was significantly decreased, and the expression of miR-141 was significantly increased (P < 0.05), all of which were in a concentration-dependent manner. After transfection with si-MALAT1, the expression of MALAT1 was significantly decreased, the expression of miR-141 was significantly increased (P < 0.05), and the proliferation, migration, and invasion of AGS cells were significantly reduced (P < 0.05). Transfection with miR-141 mimic induced the same effects on AGS cells as those of transfection with si-MALAT1 (P < 0.05), with the expression of miR-141 up-regulated (P < 0.05). It was found that miR-141 has binding sites in the 3-'UTR of MALAT1, and the dual-luciferase reporter assay and RT-qPCR confirmed that MALAT1 is a target gene of miR-141. Up-regulation of MALAT1 could reverse the inhibitory effect of Sinomenine on the proliferation, invasion, and migration of GC cells, while up-regulation of miR-141 and MALAT1 simultaneously can partially alleviate such inhibitory effects (P < 0.05).

CONCLUSION

Sinomenine can inhibit the proliferation, migration, and invasion of AGS cells via mechanisms possibly related to targeting MALAT1 to regulate miR-141.

Anti-Depressant-Like Effect of Sinomenine on Chronic Unpredictable Mild Stress-Induced Depression in a Mouse Model

BACKGROUND Sinomenine (SIN) is an extract of the Chinese medicinal herb Sinomenium acutum; it has various pharmacological properties, including immunosuppression and anti-inflammation. The present study aimed to investigate whether SIN has an anti-depressant-like effect in a mouse model of depression induced by chronic unpredictable mild stress (CUMS), and to explore the underlying molecular mechanisms. MATERIAL AND METHODS A mouse model of depression was established and treated with different concentrations of SIN (30, 100, or 300 mg/kg). Then, behavioral tests, including sucrose preference test (SPT), forced swimming test (FST), and the tail suspension test (TST), were performed. The levels of norepinephrine (NE), 5-hydroxytryptamine (5-HT), and proinflammatory cytokines (interleukin-1β [IL-1β] interleukin-6 [IL-6], and tumor necrosis factor-α [TNF-α]) in the hippocampus of mice were detected by ELISA assay. The levels of p-p38, p-p65, NLRP3, ASC, and caspase-1 were measured by Western blot or/and qRT-PCR. RESULTS The results showed that SIN significantly relieved CUMSinduced depressive-like behaviors. Compared with the model mice, SIN treatment significantly increased the sucrose preference of the mice, and the immobility time in the forced swimming and the tail suspension test were shortened. In addition, SIN decreased CUMS-induced reduction in the concentrations of NE and 5-HT in the hippocampus of mice. SIN reduced CUMS-induced increases in the levels of IL-1β, IL-6, and TNF-α in the hippocampus of mice. Furthermore, activation of the p38MAPK-NF-κB pathway and the nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome induced by CUMS were inhibited by SIN treatment. CONCLUSIONS In conclusion, our results indicate the antidepressantlike effects of SIN on chronic unpredictable mild stress-induced depression in a mouse model.

Characterization and In Vitro Permeation Study of Cubic Liquid Crystal Containing Sinomenine Hydrochloride

This study developed a new transdermal delivery system for the improved delivery of sinomenine hydrochloride (SH). The delivery system utilized the advantages of lyotropic liquid crystals (LLC) creating an adaptable system that offers a variety of options for the field of transdermal delivery. The formulation was prepared, characterized, and evaluated for its skin penetration in vitro. In the study, the appearance of samples was characterized by visual observation, and these LLC gels were colorless and transparent. Polarizing light microscopy (PLM) and small-angle X-ray diffraction (SAXS) were used to analyze the internal structures of gels, and the gels displayed a cubic double-diamond (P_n3_m) internal structure with a dark field of vision. The Franze diffusion cell was used to evaluate its skin penetration. There were several factors which might influence the skin penetration of drugs, such as drug loading, water content, and the layer spacing of the LLC. In our case, drug concentration gradient played a more powerful role. The result of in vitro permeation studies demonstrated that the drug concentration was higher; the cumulative osmotic quantity of SH (Q) was greater. Therefore, the system was a promising formulation for successful percutaneous delivery of SH through the skin.