Synthesis and biological evaluation of novel sinomenine derivatives as anti-inflammatory agents

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.

Network pharmacology-based approach to explore the underlying mechanism of sinomenine on sepsis-induced myocardial injury in rats

Background: Sepsis, a systemic disease, usually induces myocardial injury (MI), and sepsis-induced MI has become a significant contributor to sepsis-related deaths in the intensive care unit. The objective of this study is to investigate the role of sinomenine (SIN) on sepsis-induced MI and clarify the underlying mechanism based on the techniques of network pharmacology. Methods: Cecum ligation and puncture (CLP) was adopted to induce sepsis in male Sprague-Dawley (SD) rats. Serum indicators, echocardiographic cardiac parameters, and hematoxylin and eosin (H&E) staining were conducted to gauge the severity of cardiac damage. The candidate targets and potential mechanism of SIN against sepsis-induced MI were analyzed via network pharmacology. Enzyme-linked immunosorbent assay was performed for detecting the serum concentration of inflammatory cytokines. Western blot was applied for evaluating the levels of protein expression. Terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling assay was applied to assess cardiomyocyte apoptosis. Results: SIN significantly improved the cardiac functions, and attenuated myocardial structural damage of rats as compared with the CLP group. In total, 178 targets of SIN and 945 sepsis-related genes were identified, and 33 overlapped targets were considered as candidate targets of SIN against sepsis. Enrichment analysis results demonstrated that these putative targets were significantly associated with the Interleukin 17 (IL-17) signal pathway, inflammatory response, cytokines-mediated signal pathway, and Janus Kinase-Signal Transducers and Activators of Transcription (JAK-STAT) pathway. Molecular docking suggested that SIN had favorable binding affinities with Mitogen-Activated Protein Kinase 8 (MAPK8), Janus Kinase 1 (JAK1), Janus Kinase 2 (JAK2), Signal Transducer and Activator of Transcription 3 (STAT3), and nuclear factor kappa-B (NF-κB). SIN significantly reduced the serum concentration of Tumor Necrosis Factor-α (TNF-α), Interleukin 1 Beta (IL-1β), Interleukin 6 (IL-6), Interferon gamma (IFN-γ), and C-X-C Motif Chemokine Ligand 8 (CXCL8), lowered the protein expression of phosphorylated c-Jun N-terminal kinase 1 (JNK1), JAK1, JAK2, STAT3, NF-κB, and decreased the proportion of cleaved-caspase3/caspase3. In addition, SIN also significantly inhibited the apoptosis of cardiomyocytes as compared with the CLP group. Conclusion: Based on network pharmacology analysis and corresponding experiments, it was concluded that SIN could mediate related targets and pathways to protect against sepsis-induced MI.

Towards Better Sinomenine-Type Drugs to Treat Rheumatoid Arthritis: Molecular Mechanisms and Structural Modification

Sinomenine is the main component of the vine Sinomenium acutum. It was first isolated in the early 1920s and has since attracted special interest as a potential anti-rheumatoid arthritis (RA) agent, owing to its successful application in traditional Chinese medicine for the treatment of neuralgia and rheumatoid diseases. In the past few decades, significant advances have broadened our understanding of the molecular mechanisms through which sinomenine treats RA, as well as the structural modifications necessary for improved pharmacological activity. In this review, we summarize up-to-date reports on the pharmacological properties of sinomenine in RA treatment, document their underlying mechanisms, and provide an overview of promising sinomenine derivatives as potential RA drug therapies.

Protective effect of sinomenine on isoproterenol-induced cardiac hypertrophy in mice

To study the effect of sinomenine (Sin) on isoproterenol (Iso, β-agonist)-induced cardiac hypertrophy (CH), we set up four mouse groups: control, Iso model, Iso+metoprolol (Met, β blocker) 60 mg/kg and Iso+Sin 120 mg/kg. CH was induced by Iso (s.c. for 28 days) in mice, and Sin or Met were orally administered by gavage for 28 days in total. Left ventricular diastolic anterior wall thickness (LVAWd), left ventricular diastolic posterior wall thickness (LVPWd), left ventricular ejection fraction (LVEF), and short axis shortening (FS) were measured by echocardiography. Malondialdehyde (MDA) and total superoxide dismutase (T-SOD) were measured by commercial kits. Lactate dehydrogenase (LDH), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) were measured by ELISA kits. Histological changes were observed using hematoxylin-eosin (HE) and Masson staining. Protein level of nuclear transcription factor-kappa B (NF-κB) was detected by immunohistochemistry. Compared with the control group, LVAWd, Left ventricular weight index (LVWI) and myocardial fibrosis of the Iso model group significantly increased, as well as NF-κB, LDH, MDA, TNF-α, and IL-1β levels. However, the activity of T-SOD decreased. Compared with the Iso model group, LVWI of Iso model+Sin or Iso model+Met group was improved, LVAWd, LVPWd and myocardial fibrosis decreased, and NF-κB, LDH, MDA, TNF-α and IL-1β levels decreased. T-SOD activity also increased. This study reveals that Sin inhibits the activation of NF-κB, lowers the levels of TNF-α and IL-1β, has anti-oxidative stress effect and inhibits myocardial inflammation in mouse heart, thereby demonstrating its efficacy in preventing Iso induced CH.

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.

C16, a novel sinomenine derivatives, promoted macrophage reprogramming toward M2-like phenotype and protected mice from endotoxemia

Macrophage plays a critical part in host defense, tissue repair, and anti-inflammation; Macrophage reprogramming is responsible for disease development or regression. We aimed to clarify the effect of sinomenine-4-hydroxy-palmitate (C16), on macrophage reprogramming and anti-inflammatory in endotoxemia model. According to a structure modification of SIN (Sinomenine), C16 was found. Then, based on the endotoxin model, the mice liver and kidney toxicity was evaluated and serum cytokines level of IL-6 (Interleukin-6), TNF-α (Tumor necrosis factor-α), and IL-1β (Interleukin-1β) were measured by ELISA (Enzyme linked immunosorbent assay). Then, we confirmed the effect of C16 on macrophages reprogramming, we used the flow cytometry to test the effect of C16 on macrophages apoptosis in vitro. Then, iNOS (Inducible nitric oxide synthase), M1-type related cytokines, such as IL-1β, TNF-α, and M2-type related cytokines, such as Arg-1 (Arginase-1), CD206, Fizz1, and Ym1 was detected, which expressed in ANA-1 and primary peritoneal macrophages. To further explore the molecular mechanism of C16 in reprogramming of macrophages from M1 toward M2 phenotype, the expression of STAT1 (signal transducer and activator of Transcription 1), STAT3, ERK1/2 (extracellular signal regulated kinase1/2), AKT, p38, and its corresponding phosphorylation were determined by western blot. Our results demonstrated that C16 improved the survival rate of LPS- (lipopolysaccharide) challenged mice and decreased the inflammatory cytokines expression; After C16 treatment, the expression of M1 phenotype correlation factors decreased significantly, while the expression of M2 phenotype correlation factors increased significantly at different levels compared with normal group. It indicated that C16 reprogram macrophages phenotype from M1 toward M2 following LPS stimulus. Furthermore, the results also showed that C16 showed anti-inflammatory effect by inhibiting LPS-induced p38, AKT and STAT1 phosphorylation and contributing ERK1/2 activation. C16 promoted macrophage reprogramming toward M2-like phenotype via p-p38/p-AKT or STAT1 signals pathway and C16 might be a valid candidate for inflammatory disease.

Chemoproteomics-based target profiling of sinomenine reveals multiple protein regulators of inflammation

Although sinomenine (SIN) has been used to treat several inflammation-related diseases in the clinic for decades, the detailed anti-inflammatory mechanism remains elusive. Here, we present a chemoproteomic study that supports a polypharmacological mode of action for SIN to inhibit inflammation. Notably, functional validation revealed multiple new protein regulators whose knockdown could significantly affect inflammation.

Design and synthesis of C-ring quinoxaline-substituted sinomenine 1,2,3-triazole derivatives via click reactions

The synthesis of C-ring quinoxaline-substituted sinomenine 1,2,3-triazole derivatives at the 4-OH via click reactions is accomplished, and a total of 16 novel sinomenine double N-heterocyclic derivatives are obtained in 74%–95% yields. The C-ring is first transformed into a 1,2-diketone structure under the action of hydrochloric acid, and then reacted with o-phenylenediamine to obtain a C-ring quinoxaline-substituted structure. The 4-OH of sinomenine reacts with chloropropyne to give an alkynyl sinomenine, and then reacts with sodium azide and various benzyl chlorides to give the target compounds. All the synthesized derivatives are characterized by Fourier-transform infrared spectrometry, high resolution mass spectrometry, 1H NMR, and 13C NMR spectroscopy.

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 sensitizes human gastric cancer cells to cisplatin through negative regulation of PI3K/AKT/Wnt signaling pathway

Sinomenine (SIN) has been reported its antitumor effects on various types of human cancers, but there is no available information regarding the antitumor effects of SIN and cisplatin on gastric cancer. Here, we examined the antitumor effects of SIN combined with cisplatin on gastric cancer cells as well as the underlying biological mechanisms. CCK-8 assay and Calcusyn 2.0 software analysis, Hoechst 33258 staining and flow cytometry, transwell assay showed that SIN and cisplatin synergistically inhibited growth, induced apoptosis, and suppressed invasion than did either drug alone in gastric cancer cells. Interestingly, no change in the AKT level was found, whereas SIN and cisplatin led to a dramatic decrease in p-AKT level compared with either alone treatment. SIN and cisplatin further decreased the Bcl-2, procaspase-3, and β-catenin, but increased Bax, cleaved dcaspase 3, MMP9, and MMP2 in combined group than in either alone group. Immunofluorescence staining showed again a significant decrease in nucleus β-catenin was found in combined group. These data suggested that SIN sensitizes human gastric cancer cells to cisplatin through negative regulation of PI3K/AKT/Wnt signaling pathway. In conclusion, SIN and cisplatin exerted synergistic antitumor effects in gastric cancer cells and might constitute a promising therapeutic approach for gastric cancer.

Sinomenine Inhibits Migration and Invasion of Human Lung Cancer Cell through Downregulating Expression of miR-21 and MMPs

Sinomenine is an alkaloid derived from Sinomenium acutum. Recent studies have found that sinomenine can inhibit various cancers by inhibiting the proliferation, migration and invasion of tumors and inducing apoptosis. This study aims to investigate the effect and mechanism of sinomenine on inhibiting the migration and invasion of human lung adenocarcinoma cells in vitro. The results demonstrate that viabilities of A549 and H1299 cells were inhibited by sinomenine in a dose-dependent manner. When treated with sub-toxic doses of sinomenine, cell migration and invasion are markedly suppressed. Sinomenine decreases the mRNA level of matrix metalloproteinase-2 (MMP-2), MMP-9, and the extracellular inducer of matrix metalloproteinase (EMMPRIN/CD147), but elevates the expression of reversion-inducing cysteine-rich proteins with kazal motifs (RECK) and the tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2. In addition, sinomenine significantly increases the expression of the epithelial marker E-cadherin but concomitantly decreases the expression of the mesenchymal marker vimentin, suggesting that it suppresses epithelial–mesenchymal transition (EMT). Moreover, sinomenine downregulates oncogenic microRNA-21 (miR-21), which has been known to target RECK. The downregulation of miR-21 decreases cell invasion, while the upregulation of miR-21 increases cell invasion. Furthermore, the downregulation of miR-21 stimulates the expression of RECK, TIMP-1/-2, and E-cadherin, but reduces the expression of MMP-2/-9, EMMPRIN/CD147, and vimentin. Taken together, the results reveal that the inhibition of A549 cell invasion by sinomenine may, at least in part, be through the downregulating expression of MMPs and miR-21. These findings demonstrate an attractive therapeutic potential for sinomenine in lung cancer anti-metastatic therapy.

Synthesis, characterization and anti-inflammatory activity evaluation of 1,2,4-triazole and its derivatives as a potential scaffold for the synthesis of drugs against prostaglandin-endoperoxide synthase

Substituted 1,2,4-triazole nucleus is common in several drugs used in a variety of clinical conditions including infections, hypoglycemia, hypertension and cancer. In this study, we synthesized 1,2,4-triazole and its 16 hydrazone derivatives (B1-B16), characterized them by IR, NMR and Mass spectroscopy, and evaluated their radical scavenging and anti-inflammatory activities in vitro and in vivo. Out of 16 derivatives, five (B1, B5, B6, B9, and B13) demonstrated a significant radical scavenging and anti-inflammatory activity in vitro. B6, which possessed two electron-donating hydroxyl groups, was most active among all. Molecular docking and MD simulation of the complex of B6 with prostaglandin-endoperoxide synthase (PTGS) or cyclooxygenase (COX) showed that B6 occupied celecoxib binding site in COX with high affinity (the binding free energy of the complex with COX-1 was -10.5, and -11.2 kcal/mol with COX-2). Maximum anti-inflammatory activity was also shown by the B6 derivative in vivo, in the rat model of carrageenan-induced inflammation. B6, along with four other derivatives (B1, B5, B9 and B13) exhibited 80-90% free radical scavenging activity. The IC₅₀ values of these compounds were ≥40 µM. Griess nitrite and dichloro-dihydro-fluorescein-diacetate assays suggested a significant inhibition of nitric oxide and reactive oxygen species, especially by B6 and B9. Taken together, out of 16 derivatives, B6 is reported to have highest anti-inflammatory and antioxidant activity at a low dose level, which may be attributed to its two electron-donating hydroxyls. B6 is proposed to be an important scaffold for the synthesis of new drugs against PTGS for use in a myriad of inflammatory and infectious diseases.Communicated by Ramaswamy H. Sarma.

The present and future synthetic strategies of structural modifications of sinomenine

This review summarizes the modifications of sinomenine, a hot compound derived from herbal plants, which possesses diverse biological activities and low cytotoxicity.

Synthesis of C-ring hydrogenated sinomenine cinnamate derivatives via Heck reactions

The synthesis of C-ring hydrogenated sinomenine derivatives is accomplished from sinomenine by treatment with Zn-Hg/HCl, halogenation with NIS, and Heck reactions with various acrylates. A total of nine novel sinomenine cinnamate derivatives are obtained in 84%–93% yields. The structures of all the derivatives are characterized by 1H NMR, 13C NMR, and MS spectroscopy.

In situ hexagonal liquid crystal for intra-articular delivery of sinomenine hydrochloride

The aim of this study was to investigate the release behaviors of sinomenine hydrochloride loaded via in situ hexagonal liquid crystal (ISH), and its potential to improve the local bioavailability in knee joints of sinomenine hydrochloride (SMH) after intra-articular administration. The ISH was prepared by a liquid precursor mixture containing phytantriol (PT), Vitamin E acetate (VEA), ethanol (ET), and water. The in vitro release profiles revealed a sustained release of SMH from the optimized ISH formula (PT/VEA/ET/water, 60.8:3.2:16.0:20.0, w/w/w/w), which was selected for the in vivo pharmacokinetics and preliminary pharmacodynamics studies. In both healthy and adjuvant-induced arthritis (AA) rats, the SMH loaded ISH showed significantly smaller SMH AUC_0-∞ in plasma (P <  0.01), and higher SMH concentration in synoviums (2˜168 h) than that of SMH solution, indicating that the ISH significantly reduced the leakage of SMH into systemic circulation. The t_1/2α of SMH loaded ISH in the knee joints of AA rats, was longer (13.42 h) than that of healthy rats (1.34 h) (P < 0.05), most likely that in vivo drug release behavior of SMH loaded ISH was affected by the physiological environment of the joint. It was found that the SMH loaded ISH could benefit AA-rats by suppressing the level of IL-1β in comparison to SMH solutions. The results of the histopathology of knee joints in AA rats displayed that the SMH loaded ISH might be suitable for the development of treatment strategies for rheumatoid arthritis diseases.

Sinomenine hydrochloride sensitizes cervical cancer cells to ionizing radiation by impairing DNA damage response

The use of plant-based compounds derived from traditional medicine to improve human diseases has been gaining momentum, due to their high bioavailability and moderate adverse effects. Sinomenine is one such biomonomer alkali compound derived from Sinomenium acutum and is known for its anti-inflammatory and antitumor effects. However, the molecular mechanism(s) of its antitumor properties are not fully characterized. In the present study, we evaluated the radiosensitizing effects of the water-soluble sinomenine, sinomenine hydrochloride (SH) in human cervical cancer cell line (HeLa). SH sensitized HeLa cells to ionizing radiation (IR) by promoting accumulation of IR-induced DNA double-strand breaks (DSBs) and also by interfering with DNA damage checkpoint activation. We then investigated the molecular mechanisms underlying the SH-mediated cellular sensitization to IR and found that SH inhibited the expression of DNA damage response (DDR) factors Ku80 and Rad51 at the transcription level. Finally, the radiosensitizing activity of SH was confirmed in a cervical cancer mouse xenograft model. The combinatorial treatment of SH and IR significantly slowed the tumor growth rate compared with IR alone. Collectively, our study not only provides molecular insights into the novel role of SH in cellular response to IR, but also suggests a therapeutic potential of SH as a radiosensitizer in cervical cancer therapy.

Liquid Chromatography Coupled with Linear Ion Trap Hybrid OrbitrapMass Spectrometry for Determination of Alkaloids in Sinomeniumacutum

The characterization of alkaloids is challenging because of the diversity of structures and the complicated fragmentation of collision induced structural dissociation in mass spectrometry. In this study, we analyzed the alkaloids in Sinomenium acutum (Thunb.) Rehderet Wil by high resolution mass spectrometry. Chromatographic separation was achieved on a Phenomenex Kinetex C18 (2.1 mm × 100 mm, 2.6 μm) column with a mobile phase consisting of acetonitrile and water (0.1% formic acid) under gradient elution. A total of 52 alkaloids were well separated and 45 of them were structurally characterized, including morphinans, aporphines, benzylisoquinolines, and protoberberines. Specially, mass spectrometric study of the morphinan alkaloids were explicitly investigated. Electrostatic potential plot from simulation was calculated for determination of protonation sites. Further fragmentation analysis suggested that the C₃H₇N, CH₄O, and H₂O elimination was displayed in MS² spectrum. These fragmentation pathways are universal for morphinan alkaloids having methoxy substituted cyclohexenone or cyclohexadienone moieties. Additionally, for nitrogen oxides, an ion-neutral complex intermediate is involved in the fragmentation process, generating additional oxygenated ions. All these results provided the universal rules of fragmentation used for detection of alkaloids, and will be expected to be highly useful for comprehensive study of multi-components in the herbal medicine analysis.

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.

A selective HPLC-MS/MS method for quantification of SND-117 in rat plasma and its application to a pharmacokinetic study

Rheumatoid arthritis (RA), a chronic systemic inflammatory disorder affects many adults. Sinomenine, a natural product, has been clinically available for the treatment of RA in China. SND-117, a sinomenine derivative with much more potent activity, might serve as a candidate for anti-arthritis. The aim of the present study was to develop a sensitive and rapid high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method for quantification of SND-117 in rat plasma and to understand its absolute bioavailability. The HPLC-MS/MS method was developed and fully validated for determination of SND-117 in rat plasma, and the pharmacokinetic differences were investigated after different administration routes. The pharmacokinetics parameters were calculated by non-compartment model with DAS 3.0 software. After the oral or intravenous administration of different doses of SND-117, the time to peak is 1.5h, half-life time is 8-10h. The absolute oral bioavailability of SND-117 in rats was 9.60%. The results showed that SND-117 in rats was quickly absorbed, slowly eliminate, and the kinetics were linear. This method was suitable for pharmacokinetic studies of SNA-117 in rats.

Biotransformation of (-)-(10E,15S)-10,11-Dehydrocurvularin

(-)-(10 E,15 S)-10,11-Dehydrocurvularin (1), produced from an associated-fungus of Scolopendra subspinipes mutilans on a gram scale, was microbiologically converted to curvularin (2) and 5-methoxycurvularin (3) by Antrodiella semisupina in 61% totally isolated yield. The structures of these compounds were elucidated on the basis of spectroscopic and mass spectrometric analysis. The undescribed assignments of 1H and 13C NMR spectral data for 5-methoxycurvularin (2) has now been explicitly provided. The cytotoxic activities of compounds 1-3 against four human cancer cell lines were evaluated. Dehydrocurvularin (1) showed moderate cytotoxicity against Caski and Hep-G2, and curvularin (2) was selectively cytotoxic against MDA-MB-231.

Sinomenine hydrochloride-loaded dissolving microneedles enhanced its absorption in rabbits

Sinomenine hydrochloride-loaded dissolving microneedles (SH-DM) were fabricated by maltose and poly-lactic-co-glycolic acid using a casting method. The mechanical strength of SH-DM was investigated by an insertion test. In vivo transdermal absorption experiment was performed to evaluate the percutaneous absorption of SH-DM, sinomenine hydrochloride gel (SH-G) was used as a control. The results demonstrated that prepared SH-DM was morphologically intact with sufficient mechanical strength after inserting into aluminum foil and rat skin. The value of area under curve obtained after administration of SH-DM through transdermal in rabbits showed a significantly rise and was 1.99 times higher than that of SH-G, and the relative bioavailability value was 199.21%. These results showed that SH-DM enhanced bioavailability and permeability of SH.

Suppressive effect of sinomenine combined with 5-fluorouracil on colon carcinoma cell growth

It is reported that sinomenine (SIN) and 5-fluorouracil (5-FU) both are effective for colon cancer, but their cooperative suppressive effects and toxicity remain to be clarified in detail. This study aimed to determine suppressive effects and toxicity of sinomenine (SIN) plus 5-fluorouracil (5-FU) on LoVo colon carcinoma cells in vitro and in vivo. CCK-8, Hoechst 33258 staining and an annexin V-FITC/PI apoptosis kit were used to detect suppressive effects. Western blotting was applied to investigate the essential mechanism underlying SIN and 5-FU-induced apoptosis. SIN or 5-FU or both were injected into nude mice, and then suppressive effects and side effects were observed. SIN plus 5-FU apparently inhibited the proliferation of LoVo cells and induced apoptosis. Moreover the united effects were stronger than individually (p<0.05). The results of annexin V-FITC /PI staining and Hoechst 33258 staining showed that the percentage of apoptotic cells induced by SIN and 5-FU combined or alone was significantly higher than the control group (p<0.05). Expression of Bax and Bcl-2 was up-regulated and down-regulated respectively. SIN or 5-FU significantly inhibited effects on the volume of tumour xenografts and their combined suppressive effects were stronger (p<0.05). No obvious side effects were observed. It was apparent that the united effects of SIN and 5-FU on the growth of colorectal carcinoma LoVo cells in vitro and in vivo were superior to those using them individually, and it did not markedly increase the side effects of chemotherapy.

Sinomenine hydrochloride protects against polymicrobial sepsis via autophagy

Sepsis, a systemic inflammatory response to infection, is the major cause of death in intensive care units (ICUs). The mortality rate of sepsis remains high even though the treatment and understanding of sepsis both continue to improve. Sinomenine (SIN) is a natural alkaloid extracted from Chinese medicinal plant Sinomenium acutum, and its hydrochloride salt (Sinomenine hydrochloride, SIN-HCl) is widely used to treat rheumatoid arthritis (RA). However, its role in sepsis remains unclear. In the present study, we investigated the role of SIN-HCl in sepsis induced by cecal ligation and puncture (CLP) in BALB/c mice and the corresponding mechanism. SIN-HCl treatment improved the survival of BALB/c mice that were subjected to CLP and reduced multiple organ dysfunction and the release of systemic inflammatory mediators. Autophagy activities were examined using Western blotting. The results showed that CLP-induced autophagy was elevated, and SIN-HCl treatment further strengthened the autophagy activity. Autophagy blocker 3-methyladenine (3-MA) was used to investigate the mechanism of SIN-HCl in vitro. Autophagy activities were determined by examining the autophagosome formation, which was shown as microtubule-associated protein light chain 3 (LC3) puncta with green immunofluorescence. SIN-HCl reduced lipopolysaccharide (LPS)-induced inflammatory cytokine release and increased autophagy in peritoneal macrophages (PM). 3-MA significantly decreased autophagosome formation induced by LPS and SIN-HCl. The decrease of inflammatory cytokines caused by SIN-HCl was partially aggravated by 3-MA treatment. Taken together, our results indicated that SIN-HCl could improve survival, reduce organ damage, and attenuate the release of inflammatory cytokines induced by CLP, at least in part through regulating autophagy activities.

Sinomenine inhibits microglia activation and attenuates brain injury in intracerebral hemorrhage

Intracerebral hemorrhage (ICH) causes morbidity and mortality and commonly follows the reperfusion after an ischemic event. Microglial activation mediated cytokine and protease secretion contributes to brain injury in ICH. Previous studies have shown that sinomenine possesses potent immunoregulatory properties. However, little is known about its exact role in ICH. In the present study, to investigate the effect of sinomenine on microglial cells inflammation, we treated ICH-challenged BV2 microglial cells with sinomenine in vitro, and explored its neuroprotection role in intracerebral hemorrhage in vivo. Changes in inflammatory cytokines, such as TNF-α, IL-1β and IL-6, reactive oxygen species (ROS) and NF-κB activation NF-κB were observed. In addition, the neurological deficit and cerebral water content of ICH mice were studied. The results demonstrated that sinomenine could inhibit the release of these cytokines and attenuate ROS production in a dose-dependent manner, and reduce NF-κB activation. Furthermore, sinomenine markedly inhibited cerebral water content and neurological deficit. In conclusion, our findings suggest that sinomenine played the protective effects through inhibition of microglial inflammation, and the findings also provided a novel therapy to treat ICH induced brain injury.