Sinomenine Research Articles

Sinomenine reduces neuronal cell apoptosis in mice after traumatic brain injury via its effect on mitochondrial pathway.

BackgroundSinomenine (SIN) has been shown to have protective effects against brain damage following traumatic brain injury (TBI). However, the mechanisms and its role in these effects remain unclear. This study was conducted to investigate the potential mechanisms of the protective effects of SIN.MethodsThe weight-drop model of TBI in Institute of Cancer Research (ICR) mice were treated with SIN or a vehicle via intraperitoneal administration 30 min after TBI. All mice were euthanized 24 h after TBI and after neurological scoring, a series of tests were performed, including brain water content and neuronal cell death in the cerebral cortex.ResultsThe level of cytochrome c (Cyt c), malondialdehyde (MDA), glutathione peroxidase (GPx) and superoxide dismutase 1 (SOD) were restored to some degree following the SIN treatment. The SIN treatment significantly decreased caspase-3 expression and reduced the number of positive cells by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and improved the survival of neuronal cells. Additionally, the pretreatment levels of MDA were restored, while Bax translocation to mitochondria and Cyt c release into the cytosol were reduced by the SIN treatment.ConclusionSIN protected neuronal cells by protecting them against apoptosis via mechanisms that involve the mitochondria following TBI.

Sinomenine inhibits the growth of glioma cells through STAT3 signal pathway

The present study was designed to examine effects of Sinomenine (SM) on glioma cells growth in vivo and in vitro. Cells growth and apoptosis were detected by MTT assay, TUNEL assay and flow cytometric analysis. In the study, SM treatment led to growth inhibition on a series of glioma cell lines, including U87, U373, U251, Hs683 and T98G. SM prevented U87 growth in the nude mice as well. Inhibitory effects of SM on U87 cells proliferation in vitro and in vivo were more effective than that of temozolomide (TMZ), and SM has synergistic effects with TMZ in the glioma therapy. SM induced apoptotic death in U87 cells via activation of caspase-3, caspase-8 and caspase-9, and down-regulation of HIAP, Bcl-2 and survivin. Moreover, we observed SM decreased the expression of phosphorylated STAT3 (p-STAT3) both in vivo and in vitro. Interestingly, using a specific activator of STAT3, we demonstrated overexpression of p-STAT3 impaired, SM mediated growth inhibition and apoptosis induction in the U87 cells. In summary, our results indicate SM induced growth suppression of human glioma cells through inhibiting phosphorylation of STAT3.

Sinomenine, an Alkaloid Derived from Sinomenium acutum Potentiates Pentobarbital-Induced Sleep Behaviors and Non-Rapid Eye Movement (NREM) Sleep in Rodents.

Sinomenium acutum has been long used in the preparations of traditional medicine in Japan, China and Korea for the treatment of various disorders including rheumatism, fever, pulmonary diseases and mood disorders. Recently, it was reported that Sinomenium acutum, has sedative and anxiolytic effects mediated by GABA-ergic systems. These experiments were performed to investigate whether sinomenine (SIN), an alkaloid derived from Sinomenium acutum enhances pentobarbital-induced sleep via γ-aminobutyric acid (GABA)-ergic systems, and modulates sleep architecture in mice. Oral administration of SIN (40 mg/kg) markedly reduced spontaneous locomotor activity, similar to diazepam (a benzodiazepine agonist) in mice. SIN shortened sleep latency, and increased total sleep time in a dose-dependent manner when co-administrated with pentobarbital (42 mg/kg, i.p.). SIN also increased the number of sleeping mice and total sleep time by concomitant administration with the sub-hypnotic dosage of pentobarbital (28 mg/kg, i.p.). SIN reduced the number of sleep-wake cycles, and increased total sleep time and non-rapid eye movement (NREM) sleep. In addition, SIN also increased chloride influx in the primary cultured hypothalamic neuronal cells. Furthermore, protein overexpression of glutamic acid decarboxylase (GAD65/67) and GABAA receptor subunits by western blot were found, being activated by SIN. In conclusion, SIN augments pentobarbital-induced sleeping behaviors through GABAA-ergic systems, and increased NREM sleep. It could be a candidate for the treatment of insomnia.

Sinomenine-induced histamine release-like anaphylactoid reactions are blocked by tranilast via inhibiting NF-κB signaling

Zhengqing Fengtongning (ZQFTN), the pharmaceutical preparation of sinomenine (SIN) derived from the medicinal plant Sinmenium acutum, is well-known in China as an effective treatment for rheumatoid arthritis (RA). However, its histamine-release anaphylactoid reactions (HRARs) occur often in some patients. Therefore, it is desirable to establish effective clinical protocols to manage such HRARs. In the study, rat models with systemic HRARs and local HRARs of the skin were established. The level of vascular permeability and mast cell numbers was determined by quantitative analysis using Evans blue dye and histological assays. The levels of histamine, leukotriene B4 (LTB4) and IL-33 in plasma were detected by UHPLC–SPE–MS, ELISA and immunohistochemistry assays, respectively. The results demonstrated that SIN significantly induced both systemic and local HRARs in rats, showing significant decrease of body temperature, increases in vascular permeability in skin, injury of lung tissues and mast cell infiltration and IL-33 expression in skin and lung tissues. Mechanistic study showed that tranilast could prevent SIN-triggered HRARs via inhibition of H1 receptor gene expression and NF-κB signaling. Our findings provide evidence that mast cell membrane stabilizers and H1 receptor blockers effectively prevent SIN-induced HRARs, and cromolyn, cetirizine and tranilast can be used in the clinic for the management of HRARs induced by ZQFTN.

Suppressing mPGES-1 expression by sinomenine ameliorates inflammation and arthritis

Recently, microsomal prostaglandin E synthase 1 (mPGES-1) has attracted much attention from pharmacologists as a promising strategy and an attractive target for treating various types of diseases including rheumatoid arthritis (RA), which could preserve the anti-inflammatory effect while reducing the adverse effects often occur during administration of non-steroidal anti-inflammatory drugs (NSAIDs). Here, we report that sinomenine (SIN) decreased prostaglandin (PG)E2 levels without affecting prostacyclin (PG)I2 and thromboxane (TX)A2 synthesis via selective inhibiting mPGES-1 expression, a possible reason of low risk of cardiovascular event compared with NSAIDs. In addition, mPGES-1 protein expression was down-regulated by SIN treatment in the inflamed paw tissues both in carrageenan-induced edema model in rats and the collagen-II induced arthritis (CIA) model in DBA mice. More interestingly, SIN suppressed the last step of mPGES-1 gene expression by decreasing the DNA binding ability of NF-κB, paving a new way for drug discovery.

Sinomenine inhibits the inflammatory responses of human fibroblast-like synoviocytes via the TLR4/MyD88/NF-κB signaling pathway in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a systemic autoimmune disorder mainly characterized by inflammation of the synovial tissue that can lead to destruction of bone and cartilage. Sinomenine is an alkaloid extracted from the stem of the Chinese medicinal plant Sinomenium acutum. It has been reported that sinomenine has immunosuppressive and anti-inflammatory properties. However, the molecular mechanism underlying the effect of sinominine on IL-1β-induced human RA fibroblast-like synoviocytes (RAFLS) is poorly understood. Therefore, in this study, we investigated the effect of sinomenine on the expression of inflammatory cytokines in IL-1β-treated human RAFLS in vitro and the underlying mechanism. RAFLS viability was evaluated using the MTS assay after sinomenine treatment. The levels of inflammatory cytokines were measured with ELISA, RT-PCR and western blot, respectively. The levels of TLR4 and its downstream signaling targets were determined by western blot analysis. We found that sinomenine suppressed not only NO and PGE2 production but also iNOS and COX-2 expression in IL-1β-induced RAFLS. It also inhibited the expression of TNF-α and IL-6 in IL-1β-stimulated RAFLS. Furthermore, sinomenine prevented IL-1β-induced TLR4, MyD88 and p-NF-κB p65 expression. Taken together, these results demonstrated that sinomenine prevented IL-1β-induced inflammation in human RAFLS at least in part by inhibiting the TLR4/MyD88/NF-κB signaling pathway, suggesting that sinomenine could be a potential agent in the treatment of RA.

Ultrasonic-assisted extraction of sinomenine from Sinomenium acutum using magnetic ionic liquids coupled with further purification by reversed micellar extraction

Magnetic ionic liquids (MILs) have the same features as conventional ionic liquids (ILs), moreover they possess the potentiality of being recovered under the action of permanent magnetic field. Thus, MILs based on imidazolium cations and iron(III) anions were used for the ultrasonic-assisted extraction (UAE) of sinomenine (SIN) from Sinomenium acutum for the first time in this study. The extraction conditions were investigated in the single factor experiments, then the major factors of MIL concentration, liquid/solid ratio, and ultrasonic irradiation time were optimized by response surface methodology (RSM). The extraction yield reached 10.57 mg/g under the optimized conditions. The crude MIL extract of SIN was further purified by reversed micellar extraction (RME) using AOT/isooctane system. The recovery and the purity of SIN reached 81.3% and 82.6%, respectively after purification by RME. This hybrid method of MIL-UAE and RME used for the extraction and purification of SIN was effective, rapid, and potential for scale-up.

Influence of sinomenine upon mesenchymal stem cells in osteoclastogenesis

With the advent of aging, the morbidity rates of such diseases as osteoarthritis, rheumatoid arthritis, and osteoporosis has witnessed a significant increase. As a common rattan drug, sinomenine (SIN) has been widely applied for the treatment of various arthritic diseases in traditional Chinese medicine (TCM) clinics. Given that SIN has been reported to inhibit the expression of Prostaglandin E2 (PGE2) in several types of cells, in this study, the influence of SIN treatment on PGE2 expression in mesenchymal stem cells (MSCs), thereby changing the osteoprotegerin (OPG) receptor/activator for the nuclear factor-κ B ligand (RANKL) ratio, was investigated. Our results showed that, when compared with the untreated cells, treatment with 0.25mM SIN can down-regulate the mRNA and protein expression levels of the Prostaglandin E synthase 3 (PTGES3) or PGE2 and RANKL, while the OPG was up-regulated. After being cultured with SIN treated MSC-conditioned medium (stMSC-CM), the amount of TRAP-positive multinucleated osteoclasts differentiated from RAW264.7 cells was reduced. Also, the expression levels of specific markers for active osteoclasts were decreased when incubated with stMSC-CM. Moreover, these changes were able to be recovered when the exogenous RANKL was added to the MSC-CM culture. This indicates that the increased OPG/RANKL ratio can reduce the osteoclastogenesis of RAW264.7 cells. Our results demonstrated that SIN has an inhibitory effect on osteoclast differentiation through mechanisms involving the inhibition of the PGE2-induced OPG/RANKL ratio. SIN can also serve as a proinflammatory mediator to regulate the MSC immunosuppressive effects. Our findings suggest that SIN can be useful for the treatment of bone diseases associated with over-activity of osteoclasts.

Immunosuppressive effect of sinomenine in an allergic rhinitis mouse model.

Allergic rhinitis (AR) is a chronic allergic airway disease that has become a significant global public health issue. Sinomenine (SN), a natural phytochemical found in Sinomenium acutum, showed anti-inflammatory and immunosuppressive effect in previous studies. In order to explore the role of SN in the treatment of AR, mice were sensitized and challenged by ovalbumin (OVA) to establish an AR mouse model. SN was administered to AR mice orally, and compared with dexamethasone treatment as a positive control. Nasal symptoms and histopathological changes were used to evaluate the effect of SN treatment in the AR mice model. In addition, the levels of anti-OVA specific IgE and various cytokines in the serum were measured by enzyme-linked immunosorbent assay, while the levels of transforming growth factor-β (TGF-β) in the mucosa were also detected by western blot analysis and reverse transcription-quantitative polymerase chain reaction. AR mice that received SN treatment had reduced symptom scores and milder eosinophil infiltration. The serum levels of anti-OVA specific IgE and interleukin-4 significantly decreased following SN treatment. Furthermore, TGF-β expression levels in the serum and nasal mucosa tissue in AR mice increased when compared with those in AR mice without treatment. In conclusion, SN treatment alleviated the symptoms of AR in mice and had an immunosuppressive effect on AR, which may result from the upregulation of TGF-β.

Sinomenine Protects PC12 Neuronal Cells against H2O2-induced Cytotoxicity and Oxidative Stress via a ROS-dependent Up-regulation of Endogenous Antioxidant System.

Sinomenine (SN), a purified alkaloid from Chinese herb Sinomenium acutum that was used preferentially in the treatment of rheumatoid diseases, has exerted neuroprotective effects and anti-inflammatory properties in many previous studies. Some studies have revealed that the antioxidant property of SN, acting mainly through inhibiting NADPH oxidase activation, was involved in the beneficial effects of SN. However, SN belongs to the family of dextrorotatory morphinan analogues, which may initiate elevation of reactive oxygen species (ROS) levels. Thus in the present report, we conducted studies to examine its impact and mechanism on the resistance of PC12 neuronal cells to oxidative stress. Precondition with SN (0.1-5μM) for 12h significantly decreased H2O2-induced cytotoxicity and remarkably alleviated oxidative injury. However, SN exhibited little direct free radical scavenging property in vitro and induced "appropriate" production of ROS in PC12 cell. Interestingly, the SN-triggering ROS production served as a signal to activate the Nrf2 antioxidant system including Nrf2, HO-1, and NQO-1, which was inhibited by the antioxidant trolox. Furthermore, Nrf2 knockdown largely attenuated the beneficial effects of SN precondition on oxidative stress. In conclusion, our findings suggested that SN increased the resistance to oxidative stress in neuronal cells via a ROS-dependent up-regulation of endogenous antioxidant system, and this mechanism may be involved in the neuroprotection of SN.

Sinomenine inhibits ovarian cancer cell growth and metastasis by mediating the Wnt/β-catenin pathway via targeting MCM2

Sinomenine (SIN), an isoquinoline isolated from the Chinese medicinal plantSinomenium acutum, is well known for its curative effect on rheumatic and arthritic diseases.

Sinomenine Provides Neuroprotection in Model of Traumatic Brain Injury via the Nrf2-ARE Pathway.

The neuroprotective effect of sinomenine (SIN) has been demonstrated in several brain injury models. However, its role and molecular mechanism in traumatic brain injury (TBI) remain unknown. In this study, we investigated the neuroprotective effects of SIN in the weight-drop model of TBI in male ICR mice. Mice were randomly divided into the sham and TBI groups, SIN (10 mg/kg, 30 mg/kg and 50 mg/kg, administered intraperitoneally) or equal volume of vehicle was given at 30 min after TBI. Treatment with 30 mg/kg SIN significantly improved motor performance and alleviated cerebral edema. However, treatment with 10 mg/kg or 50 mg/kg SIN did not exhibit a better outcome. Therefore, we chose 30 mg/kg SIN for our subsequent experiments. SIN significantly increased the expression of Bcl-2 and decreased that of cleaved caspase-3, indicating that SIN is anti-apoptotic. This was confirmed by the observation that SIN-treated animals had fewer apoptotic neurons. Cortical malondialdehyde content, glutathione peroxidase (GPx) activity and superoxide dismutase (SOD) activity were restored in the group that received SIN. Furthermore, Western blot and immunofluorescence experiments showed that SIN enhanced the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) to the nucleus. SIN administration also significantly upregulated the expression of the downstream factors heme oxygenase 1 and NAD(P)H:quinone oxidoreductase 1 at pre- and post-transcriptional levels. Together, these data demonstrate that SIN exerts a neuroprotective effect in a model of TBI, possibly by activating the Nrf2–antioxidant response element (ARE) pathway.

The neuroprotection of Sinomenine against ischemic stroke in mice by suppressing NLRP3 inflammasome via AMPK signaling

Neuroinflammation remains the primary cause of morbidity and mortality in stroke-induced secondary brain injury. The NOD-like receptor pyrin 3 (NLRP3) inflammasome is involved in diverse inflammatory diseases, including cerebral ischemia, and is thus considered an effective therapeutic target. In the present study, we investigated the neuroprotection of Sinomenine (SINO), a potent natural anti-apoptotic and anti-inflammatory molecule, against cerebral ischemia in a mouse model of middle cerebral artery occlusion (MCAO) in vivo and in an oxygen glucose deprivation (OGD)-treated astrocytes/microglia model in vitro. SINO administration intraperitoneally alleviated the cerebral infarction, brain edema, neuronal apoptosis, and neurological deficiency after MCAO induction. SINO also attenuated astrocytic and microglial activation in the ischemic hemisphere. NLRP3 inflammasome activation after MCAO and OGD induction, with the up-regulation of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cleaved caspase-1 and pro-inflammatory cytokines, was significantly inhibited by SINO treatment both in vivo and in vitro. In addition, SINO reversed the OGD-induced inhibition of AMPK phosphorylation in vitro. Further, the suppressive effect of SINO on NLRP3 inflammasomes was blocked by an AMPK inhibitor, Compound C. Our findings demonstrate that SINO exerts a neuroprotective effect in ischemic stroke by inhibiting NLRP3 inflammasomes via the AMPK pathway, which also provides evidence of a novel treatment for clinical stroke therapy.

Sinomenine induces the generation of intestinal Treg cells and attenuates arthritis via activation of aryl hydrocarbon receptor

Sinomenine (SIN), an anti-arthritis drug, has previously been proven to exert immunomodulatory activity in rats by inducing intestinal regulatory T-cells (Treg cells). Here, we assessed the effect of SIN on the generation and function of Treg cells in autoimmune arthritis, and the underlying mechanisms in view of aryl hydrocarbon receptor (AhR). The proportions of Treg cells and IL-17-producing T-cells (Th17 cells) differentiated from naive T-cells were analyzed by flow cytometric analysis. The AhR agonistic effect of SIN was tested by analyzing the activation of downstream signaling pathways and target genes. The dependence of intestinal Treg cell induction and arthritis alleviation by SIN on AhR activation was confirmed in a mouse collagen-induced arthritis (CIA) model. SIN promoted the differentiation and function of intestinal Treg cells in vitro. It induced the expression and activity of AhR target gene, promoted AhR/Hsp90 dissociation and AhR nuclear translocation, induced XRE reporter activity, and facilitated AhR/XRE binding in vitro, displaying the potential to be an agonist of AhR. In CIA mice, SIN induced the generation of intestinal Treg cells, and facilitated the immunosuppressive function of these Treg cells as shown by an adoptive transfer test. In addition, the induction of intestinal Treg cells and the anti-arthritic effect of SIN in CIA mice could be largely diminished by the AhR antagonist resveratrol. SIN attenuates arthritis by promoting the generation and function of Treg cells in an AhR-dependent manner.

Effects of sinomenine on hind limb ischemia-reperfusion injury and expression of Bcl-2 and Bax in skeletal muscle cells of rats

Objective To investigate the effects of sinomenine on hind limb ischemia-reperfusion (I/R) injury and expression of Bcl-2 and Bax in skeletal muscle cells of rats. Methods Fifty-four healthy adult male Wistar rats, aged 6-8 weeks, weighing 180-220 g, were divided into 3 groups (n=18 each) using a random number table: sham operation group (group S), group I/R and sinomenine group (group SIN). The rats were subjected to 4 h of ischemia on the proximal part of the right hind limb using elastic rubber bands followed by reperfusion in I/R and SIN groups.Sinomenine 60 mg/kg was injected intraperitoneally at 30 min before reperfusion in group SIN, and the equal volume of normal saline was given instead of sinomenine at 30 min before reperfusion in S and I/R groups.Immediately after onset of reperfusion and at 4 and 24 h of reperfusion, blood samples were collected from the cardiac apex to measure the concentrations of serum lactate dehydrogenase (LDH) and creatine kinase (CK). The animals were sacrificed immediately after blood sampling, and the gastrocnemius specimens of the hind limb were immediately removed for determination of the wet to dry weight ratio (W/D ratio) and expression of Bcl-2 and Bax in gastrocnemius cells (by immunohistochemistry) and for examination of the pathological changes after haematoxylin and eosin staining.The Bcl-2/Bax ratio was calculated. Results Compared with group S, the gastrocnemius W/D ratio and concentrations of serum LDH and CK were significantly increased, the expression of Bcl-2 was significantly down-regulated, the expression of Bax was significantly up-regulated, and the Bcl-2/Bax ratio was significantly decreased in I/R and SIN groups (P<0.05). Compared with group I/R, the gastrocnemius W/D ratio and concentrations of serum LDH and CK were significantly decreased, the expression of Bcl-2 was significantly up-regulated, the expression of Bax was significantly down-regulated, and the Bcl-2/Bax ratio was significantly increased in group SIN (P<0.05). The pathological changes of the gastrocnemius were significantly attenuated in group SIN as compared with group I/R. Conclusion Sinomenine can attenuate hind limb I/R injury, and the mechanism may be related to maintenance of the balance between Bcl-2 and Bax and to inhibition of apoptosis in skeletal muscle cells of rats. Key words: Sinomenium; Reperfusion injury; Extremities; Proto-oncogene proteins c-bcl-2; bcl-2-associated X protein

Sinomenine alleviates high glucose-induced renal glomerular endothelial hyperpermeability by inhibiting the activation of RhoA/ROCK signaling pathway

As an early sign of diabetic cardiovascular disease, endothelial dysfunction may contribute to progressive diabetic nephropathy (DN). Endothelial hyperpermeability induced by hyperglycemia (HG) is a central pathogenesis for DN. Sinomenine (SIN) has strong anti-inflammatory and renal protective effects, following an unknown protective mechanism against HG-induced hyperpermeability. We herein explored the role of SIN in vitro in an HG-induced barrier dysfunction model in human renal glomerular endothelial cells (HRGECs). The cells were exposed to SIN and/or HG for 24 h, the permeability of which was significantly increased by HG. Moreover, junction protein occludin in the cell-cell junction area and its total expression in HRGECs were significantly decreased by HG. However, the dysfunction of tight junction and hyperpermeability of HRGECs were significantly reversed by SIN. Furthermore, SIN prevented HG-increased reactive oxygen species (ROS) by activating nuclear factor-E2-related factor 2 (Nrf2). Interestingly, activation of RhoA/ROCK induced by HG was reversed by SIN or ROCK inhibitor. HG-induced hyperpermeability was prevented by SIN. High ROS level, tight junction dysfunction and RhoA/ROCK activation were significantly attenuated with knockdown of Nrf2. Mediated by activation of Nrf2, SIN managed to significantly prevent HG-disrupted renal endothelial barrier function by suppressing the RhoA/ROCK signaling pathway through reducing ROS. We successfully identified a novel pathway via which SIN exerted antioxidative and renal protective functions, and provided a molecular basis for potential SIN applications in treating DN vascular disorders.

Sinomenine attenuates renal fibrosis through Nrf2-mediated inhibition of oxidative stress and TGFβ signaling

Renal fibrosis is the common feature of chronic kidney disease and mainly mediated by TGFβ-associated pro-fibrogenic signaling, which causes excessive extracellular matrix accumulation and successive loss of kidney functions. Sinomenine (SIN), an alkaloid derived from medicinal herb extensively used in treatment of rheumatoid arthritis and various inflammatory disorders, displays renal protective properties in experimental animals; however its pharmacological potency against renal fibrosis is not explored. In this study we report that SIN possesses strong anti-renal fibrosis functions in kidney cell and in mouse fibrotic kidney. SIN beneficially modulated the pro-fibrogenic protein expression in TGFβ-treated kidney cells and attenuated the renal fibrotic pathogenesis incurred by unilateral ureteral obstruction (UUO), which correlated with its activation of Nrf2 signaling - the key defender against oxidative stress with anti-fibrotic potentials. Further investigation on its regulation of Nrf2 downstream events revealed that SIN significantly balanced oxidative stress via improving the expression and activity of anti-oxidant and detoxifying enzymes, and interrupted the pro-fibrogenic signaling of TGFβ/Smad and Wnt/β-catenin. Even more impressively SIN achieved its anti-fibrotic activities in an Nrf2-dependent manner, suggesting that SIN regulation of Nrf2-associated anti-fibrotic activities constitutes a critical component of SIN's renoprotective functions. Collectively our studies have demonstrated a novel anti-fibrotic property of SIN and its upstream events and provided a molecular basis for SIN's potential applications in treatment of renal fibrosis-associated kidney disorders.

Therapeutic Effect Analysis of Sinomenine on Rat Cerebral Ischemia–Reperfusion Injury

The objective of this study is to investigate the therapeutic effect of sinomenine (SIN) on rat cerebral ischemia-reperfusion (IR) injury and the molecular mechanism. One hundred thirty-five rats were equally randomized into sham-operated group, middle cerebral artery occlusion (MCAO) group, and SIN group, and reversible rat MCAO model was made according to the Longa method for the MCAO and SIN groups. Then, 15 rats from each group were decapitated at 6, 12, and 24 hours after reperfusion to obtain brain tissue samples. Rats in the SIN group were injected with sinomenine by tail vein (90 mg/kg) 1 hour before ischemia; rats in the MCAO and sham-operated groups were administrated with the same volume of saline. Neurological severity score (NSS), infarction volume, ischemic brain water content, and blood-brain barrier (BBB) permeability were determined at corresponding time points. Acid-sensing ion channel (ASIC) 1a mRNA level was determined by quantitative real-time polymerase chain reaction; ischemic brain contents of lactic acid (LD), lactic dehydrogenase (LDH), ATPase, and inflammatory factors were determined by spectrophotometric method. At 12 hours after reperfusion and since then, NSS in the SIN group decreased obviously; infarction volume, brain water content, and BBB permeability in the SIN group were lower than those in the MCAO group (P < .05). IR injury resulted in the upregulation of the contents of ASIC1a mRNA, LD, LDH, and inflammatory factors and the downregulation of the contents of ATPase, while SIN could reverse the upregulation/downregulation effect induced by IR injury (P < .05). Through its anti-inflammation effect, which alleviates acidosis, improves energy metabolism, and inhibits ASIC1a level, SIN protects ischemic rat brain against cerebral IR injury.

Sinomenine down-regulates TLR4/TRAF6 expression and attenuates lipopolysaccharide-induced osteoclastogenesis and osteolysis

Sinomenine (SIN) is an anti-inflammatory and anti-arthritic alkaloid derived from Sinomenioum acutum. Effects of SIN on lipopolysaccharide (LPS)-induced osteolysis have not been reported. Here, we found that SIN reduced LPS-induced erosion of skull bones in C57BL/6 mice significantly. LPS can induce bone-absorbing osteoclast formation independent of RANKL in pre-osteoclastic RAW264.7 cells in vitro. Here, SIN suppressed LPS-induced osteoclast formation and osteoclast survival in RAW264.7 cells. Expression of osteoclastic-specific marker genes was also inhibited by SIN during osteoclast differentiation and osteoclast survival stimulated with LPS. SIN showed much stronger inhibitory effects on expression of Fra-1 and MMP-9 mRNA in osteoclast differentiation rather than osteoclast survival. SIN dramatically inhibited LPS-induced TNF-α production in vitro and in vivo. Further signaling studies revealed that SIN suppressed the activation and relative gene expression of three notable nuclear factors (NF-κB, AP-1, NFAT), reduced intracellular levels of Ca2+, and down-regulated phosphorylation of MAPK p38 (but not JNK) in LPS-induced osteoclastogenesis. Focusing on upstream signals after LPS stimulation, SIN decreased expression of TLR4 and TRAF6 during osteoclast differentiation, and reduced expression of TLR4 (but not TRAF6) in osteoclast survival. These data suggest that SIN might be a potential agent for the treatment of osteolysis caused by Gram-negative bacteria infection or inflammation due to its inhibition of osteoclastogenesis through reduction of TLR4/TRAF6 expression and downstream signal transduction.

Sinomenine attenuates airway inflammation and remodeling in a mouse model of asthma.

Asthma is an inflammatory disease that involves airway inflammation and remodeling. Sinomenine (SIN) has been demonstrated to have immunosuppressive and anti-inflammatory properties. The aim of the present study was to investigate the inhibitory effects of SIN on airway inflammation and remodeling in an asthma mouse model and observe the effects of SIN on the transforming growth factor-β1 (TGF-β1)/connective tissue growth factor (CTGF) pathway and oxidative stress. Female BALB/c mice were sensitized by repetitive ovalbumin (OVA) challenge for 6 weeks in order to develop a mouse model of asthma. OVA-sensitized animals received SIN (25, 50 and 75 mg/kg) or dexamethasone (2 mg/kg). A blank control group received saline only. The area of smooth muscle and collagen, levels of mucus secretion and inflammatory cell infiltration were evaluated 24 h subsequent to the final OVA challenge. mRNA and protein levels of TGF-β1 and CTGF were determined by reverse transcription-quantitative polymerase chain reaction and immunohistology, respectively. The indicators of oxidative stress were detected by spectrophotometry. SIN significantly reduced allergen-induced increases in smooth muscle thickness, mucous gland hypertrophy, goblet cell hyperplasia, collagen deposition and eosinophilic inflammation. The levels of TGF-β1 and CTGF mRNA and protein were significantly reduced in the lungs of mice treated with SIN. Additionally, the total antioxidant capacity was increased in lungs following treatment with SIN. The malondialdehyde content and myeloperoxidase activities in the lungs from OVA-sensitized mice were significantly inhibited by SIN. In conclusion, SIN may inhibit airway inflammation and remodeling in asthma mouse models, and may have therapeutic efficacy in the treatment of asthma.