Oxidative Desymmetrization Enables the Concise Synthesis of a trans-Cyclooctene Linker for Bioorthogonal Bond Cleavage.

Modified trans-cyclooctenes (TCO) are capable of highly efficient molecular manipulations in biological environments, driven by the bioorthogonal reaction with tetrazines (Tz). The development of click-cleavable TCO has fueled the field of in vivo chemistry and enabled the design of therapeutic strategies that have already started to enter the clinic. A key element for most of these approaches is the implementation of a cleavable TCO linker. So far, only one member of this class has been developed, a compound that requires a high synthetic effort, mainly to fulfill the multilayered demands on its chemical structure. To tackle this limitation, we developed a dioxolane-fused cleavable TCO linker (dcTCO) that can be prepared in only five steps by applying an oxidative desymmetrization to achieve diastereoselective introduction of the required functionalities. Based on investigation of the structure, reaction kinetics, stability, and hydrophilicity of dcTCO, we demonstrate its bioorthogonal application in the design of a caged prodrug that can be activated by in-situ Tz-triggered cleavage to achieve a remarkable >1000-fold increase in cytotoxicity.

Network pharmacology, molecular docking technology integrated with pharmacodynamic study to reveal the potential targets of Schisandrol A in drug-induced liver injury by acetaminophen.

Schisandrae Chinensis Fructus (SCF) was a Traditional Chinese Medicine for protecting liver. However, underlying therapeutic mechanisms of these bioactive lignans from SCF similar hepatoprotective effects against drug-induced liver injury (DILI) by acetaminophen (APAP) are still unclear. This study aims to discover the potential regulation mechanisms of Schisandrol A in the treatment of DILI by APAP. The integrated UPLC-Q-TOF/MS, pharmacodynamic study, histopathological combination with network pharmacology and molecular docking technology were used to explore the potential mechanisms. The results showed that Schisandrol A reduced the level of AST, ALT, MDA, PNP, TNF-α and IL-1ß, increased the levels of the GSH against acute liver failure. Additionally, Schisandrol A could improve the morphological characteristics of DILI by APAP in mice with liver tissue. Molecular docking results had showed that Schisandrol A with high scores when docking with COX-2, ALOX5, CYP2E1, CYP2C9, CYP2C19, EGFR SRC, Nrf2, MAPK14 and MAPK8. The study demonstrated that Schisandrol A could play critical roles in DILI by APAP via regulating TNF signaling pathway, inhibiting oxidative stress, inflammation and inhibiting the activities of cytochrome P450 enzymes, which contributed to searching for leading compounds and the development of new drugs for DILI by APAP.

Regulation of cell signaling pathways by Schisandrin in different cancers: Opting for "Swiss Army Knife" instead of "Blunderbuss".

There has been an exponential growth in the field of molecular oncology and cutting-edge research has enabled us to develop a better understanding of therapeutically challenging nature of cancer. Based on the mechanistic insights garnered from decades of research, puzzling mysteries of multifaceted nature of cancer have been solved to a greater extent. Our rapidly evolving knowledge about deregulated oncogenic cell signaling pathways has allowed us to dissect different oncogenic transduction cascades which play critical role in cancer onset, progression and metastasis. Pharmacological targeting of deregulated pathways has attracted greater than ever attention in the recent years. Henceforth, discovery and identification of high-quality biologically active chemicals and products is gaining considerable momentum. There has been an explosion in the dimension of natural product research because of tremendous potential of chemopreventive and pharmaceutical significance of natural products. Schisandrin is mainly obtained from Schisandra chinensis. Schisandrin has been shown to be effective against different cancers because of its ability to inhibit/prevent cancer via modulation of different cell signaling pathways. Importantly, regulation of non-coding RNAs by schisandrin is an exciting area of research that still needs detailed and comprehensive research.   However, we still have unresolved questions about pharmacological properties of schisandrin mainly in context of its regulatory role in TGF/SMAD, SHH/GLI, NOTCH and Hippo pathways.

Schisandrol A Attenuates Myocardial Ischemia/Reperfusion-Induced Myocardial Apoptosis through Upregulation of 14-3-3θ.

Schisandrol A (SA), one of the most abundant bioactive lignans extracted from the Schisandra chinensis (Turcz.) Baill., has multiple pharmacological properties. However, the underlying mechanisms of SA in protection against myocardial ischemia/reperfusion (MI/R) injury remain obscure. The present experiment was performed to explore the cardioprotective effects of SA in MI/R injury and hypoxia/reoxygenation- (H/R-) induced cardiomyocyte injury and clarify the potential underlying mechanisms. SA treatment significantly improved MI/R injury as reflected by reduced myocardium infarct size, attenuated histological features, and ameliorated biochemical indicators. In the meantime, SA could profoundly ameliorate oxidative stress damage as evidenced by the higher glutathione peroxidase (GSH-Px) as well as lower malondialdehyde (MDA) and reactive oxygen species (ROS). Additionally, SA alleviated myocardial apoptosis as evidenced by a striking reduction of cleaved caspase-3 expression and increase of Bcl-2/Bax ratio. Further experiments demonstrated that SA had certain binding capability to the key functional protein 14-3-3θ. Mechanistically, SA prevented myocardial apoptosis through upregulating 14-3-3θ expression. Interestingly, siRNA against 14-3-3θ could promote apoptosis of cardiomyocytes, and H/R injury after knockdown of 14-3-3θ could further aggravate apoptosis, while overexpression of 14-3-3θ could significantly reduce apoptosis induced by H/R injury. Further, 14-3-3θ siRNA markedly weakened the antiapoptotic role of SA. Our results demonstrated that SA could exert apparent cardioprotection against MI/R injury and H/R injury, and potential mechanisms might be associated with inhibition of cardiomyocyte apoptosis at least partially through upregulation of 14-3-3θ.

Schisandrin B Attenuates Airway Inflammation by Regulating the NF-κB/Nrf2 Signaling Pathway in Mouse Models of Asthma.

BACKGROUND: Asthma is a complex inflammatory disorder that plagues a large number of people. Schisandrin B is an active ingredient of the traditional Chinese herbal medicine Schisandra with various proven physiological activities such as anti-inflammatory and antioxidant activities. In this study, we explored the anti-inflammatory and antioxidant effects and provided the mechanistic insights into the activity of schisandrin B in a mouse model of ovalbumin- (OVA-) induced allergic asthma. METHODS: Male BALB/c mice were sensitized and challenged with OVA to induce asthma and treated with various doses (15 mg/kg, 30 mg/kg, and 60 mg/kg) of SCH to alleviate the features of allergic asthma, airway hyperresponsiveness, inflammatory response, OVA-specific immunoglobulin (Ig)E level, and pathological injury. RESULTS: Schisandrin B significantly attenuated the airway hyperresponsiveness induced by OVA. Moreover, schisandrin B administration suppressed inflammatory responses, reduced the level of IgE, and attenuated pathological injury. Mechanistically, schisandrin B treatment promoted the activation of nuclear erythroid 2-related factor 2 (Nrf2), but suppressed the stimulation of the NF-κB pathway caused by OVA. CONCLUSION: Taken together, our study suggests that schisandrin B attenuates the features of asthmatic lungs by inhibiting the NF-κB pathway and activating the Nrf2 signaling pathway.

Identification and molecular study on the interaction of Schisandrin C with human 5-HT3A receptor.

Schisandrin C (Sch C) is one of the main components of Schisandra chinensis (Schisandra). Since the olden times, Schisandra has been used as a traditional herbal medicine in Asia. Recent studies have shown that Schisandra is effective against irritable bowel syndrome (IBS) in an animal model and affects IBS through the 5-HT3A pathway in the IBS rat model. However, there lacks fundamental research on the interaction of specific components of Schisandra with the 5-HT3A receptor for the treatment of IBS. We hypothesized that a component of Schisandra binds to the 5-HT3A receptor and identified Sch C via a screening work using two electrode-voltage clamps (TEVC). Thus, we aimed to elucidate the neuropharmacological actions between Sch C and the 5-HT3A receptor at molecular and cellular levels. Co-treatment of Sch C with 5-HT inhibited I5-HT in a reversible, concentrate-dependent, like-competition, and voltage-independent manner, and IC50 values of Sch C. Besides, the main binding positions of Sch C were identified through 3D modeling and point mutation were V225A and V288Y on 5-HT3A receptor. Thus, we suggest the potential of Sch C in treating IBS in a manner that suppresses excessive neuronal serotonin signaling in the synapse of sensory neurons and enterochromaffin (EC) cells. In conclusion, the results demonstrate the mechanism of interaction between Sch C and 5-HT3A receptor and reveal Sch C as a novel antagonist.

In-vitro activity of cefiderocol, cefepime/zidebactam, cefepime/enmetazobactam, omadacycline, eravacycline and other comparative agents against carbapenem-nonsusceptible Enterobacterales: results from the Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART) in 2017-2020.

This study examined the susceptibility of carbapenem-nonsusceptible Enterobacterales (CNSE) to cefiderocol, cefepime/zidebactam, cefepime/enmetazobactam, omadacycline, eravacycline and other comparative agents. Non-duplicate Enterobacterales isolates from 16 Taiwanese hospitals were evaluated. Minimum inhibitory concentrations (MICs) were determined using the broth microdilution method, and susceptibility results were interpreted based on relevant guidelines. In total, 201 CNSE isolates were investigated, including 26 Escherichia coli isolates and 175 Klebsiella pneumoniae isolates. Carbapenemase genes were detected in 15.4% (n=4) of E. coli isolates and 47.4% (n=83) of K. pneumoniae isolates, with the most common being blaKPC (79.3%, 69/87), followed by blaOXA-48-like (13.8%, 12/87). Cefiderocol was the most active agent against CNSE; only 3.8% (n=1) of E. coli isolates and 4.6% (n=8) of K. pneumoniae isolates were not susceptible to cefiderocol. Among the carbapenem-resistant E. coli and K. pneumoniae isolates, 88.5% (n=23) and 93.7% (n=164), respectively, were susceptible to ceftazidime/avibactam. For cefepime/zidebactam, 23 (88.5%) E. coli isolates and 155 (88.6%) K. pneumoniae isolates had MICs ≤2/2 mg/L. For cefepime/enmetazobactam, 22 (84.6%) E. coli isolates and 85 (48.6%) K. pneumoniae isolates had MICs ≤2/8 mg/L. The higher MICs of K. pneumoniae against cefepime/enmetazobactam were due to only one (1.5%) of the 67 blaKPC-carrying isolates being susceptible. MICs of omadacycline were significantly higher than those of eravacycline and tigecycline. In summary, cefiderocol, ceftazidime/avibactam and cefepime/zidebactam were more effective against carbapenem-nonsusceptible E. coli and K. pneumoniae than other drugs, highlighting their potential as valuable therapeutics.

Schisandrin B inhibits epithelial­mesenchymal transition and stemness of large­cell lung cancer cells and tumorigenesis in xenografts via inhibiting the NF­κB and p38 MAPK signaling pathways.

Lung cancer is one of the most common types of cancer in the world, resulting in numerous cancer­associated deaths. The properties of cancer stem cells (CSCs) are important for the initiation and deterioration of lung cancer. Schisandrin B (SchB), an active compound extracted from Schisandra chinensis, exerts anticancer effects in various malignancies, including lung cancer. Nevertheless, the potential of SchB in epithelial­mesenchymal transition (EMT) and CSC features of large­cell lung cancer remains unclear. The present study established cancer stem­like cells derived from large­cell lung cancer cells, NCI­H460 and H661, and revealed that SchB inhibited the viability of cancer stem­like cells at concentrations of ≥40 µmol/l. Moreover, SchB prominently inhibited cell migration, invasion and EMT. Sphere­forming assays and western blotting demonstrated that the stemness of cancer stem­like cells was alleviated by SchB treatment. Mechanistically, the current findings revealed that SchB contributed to the suppression of the NF­κB and p38 MAPK signaling pathways. Notably, further results revealed that the malignant behaviors of NCI­H460­CSCs induced by the activation of the NF­κB and p38 MAPK signaling pathways were suppressed by SchB treatment. Consistently, the inhibitory role of SchB in EMT and CSC activities, as well as in the activation of the NF­κB and p38 MAPK signaling pathways, was confirmed in vivo. In conclusion, the present study demonstrated that SchB exerted inhibitory effects on large­cell lung cancer cells via targeting the NF­κB and p38 MAPK signaling pathways, suggesting that SchB may act as a potential therapeutic drug for large­cell lung cancer.

Ellagic Acid and Schisandrins: Natural Biaryl Polyphenols with Therapeutic Potential to Overcome Multidrug Resistance in Cancer.

Multidrug resistance (MDR) is one of the major clinical challenges in cancer treatment and compromises the effectiveness of conventional anticancer chemotherapeutics. Among known mechanisms of drug resistance, drug efflux via ATP binding cassette (ABC) transporters, namely P-glycoprotein (P-gp) has been characterized as a major mechanism of MDR. The primary function of ABC transporters is to regulate the transport of endogenous and exogenous small molecules across the membrane barrier in various tissues. P-gp and similar efflux pumps are associated with MDR because of their overexpression in many cancer types. One of the intensively studied approaches to overcome this mode of MDR involves development of small molecules to modulate P-gp activity. This strategy improves the sensitivity of cancer cells to anticancer drugs that are otherwise ineffective. Although multiple generations of P-gp inhibitors have been identified to date, reported compounds have demonstrated low clinical efficacy and adverse effects. More recently, natural polyphenols have emerged as a promising class of compounds to address P-gp linked MDR. This review highlights the chemical structure and anticancer activities of selected members of a structurally unique class of 'biaryl' polyphenols. The discussion focuses on the anticancer properties of ellagic acid, ellagic acid derivatives, and schisandrins. Research reports regarding their inherent anticancer activities and their ability to sensitize MDR cell lines towards conventional anticancer drugs are highlighted here. Additionally, a brief discussion about the axial chirality (i.e., atropisomerism) that may be introduced into these natural products for medicinal chemistry studies is also provided.

Bioorthogonal Pretargeting Strategy for Anchoring Activatable Photosensitizers on Plasma Membranes for Effective Photodynamic Therapy.

Developing novel activatable photosensitizers with excellent plasma membrane targeting ability is urgently needed for smart photodynamic therapy (PDT). Herein, a tumor acidity-activatable photosensitizer combined with a two-step bioorthogonal pretargeting strategy to anchor photosensitizers on the plasma membrane for effective PDT is developed. Briefly, artificial receptors are first anchored on the cell plasma membrane using cell-labeling agents (Az-NPs) via the enhanced permeability and retention effect to achieve the tumor cell labeling. Then, pH-sensitive nanoparticles (S-NPs) modified with dibenzocyclooctyne (DBCO) and chlorin e6 (Ce6) accumulate in tumor tissue and disassemble upon protonation of their tertiary amines in response to the acidic tumor environment, exposing the contained DBCO and Ce6. The selective, highly specific click reactions between DBCO and azide groups enable Ce6 to be anchored on the tumor cell surface. Upon laser irradiation, the cell membrane is severely damaged by the cytotoxic reactive oxygen species, resulting in remarkable cellular apoptosis. Taken together, the membrane-localized PDT by our bioorthogonal pretargeting strategy to anchor activatable photosensitizers on the plasma membrane provides a simple but effective method for enhancing the therapeutic efficacy of photosensitizers in anticancer therapy.

Schisandrin B-mediated TH17 cell differentiation attenuates bowel inflammation.

Schisandrin B (Sch B) is the major active constituent of the traditional Chinese medicine Schisandra chinensis and has anti-inflammatory activity, but the target of Sch B remains unclear. T helper 17 (TH17) cells have been involved in the pathogenesis of many autoimmune and inflammatory diseases. Here, we showed that Sch B could decrease IL-17A production of CD4+ T cells by targeting STAT3 in vitro. Importantly, Sch B has therapeutic effects on DSS-induced acute and chronic colitis, CD4+CD45RBhigh T cell-induced colitis. Furthermore, we identified TH17 cells as the direct target of Sch B for mediating its anti-inflammatory activity. Sch B could serve as a lead for developing new therapeutics against TH17 cells or IL-17A cytokine-driven diseases.

Schizandrin ameliorates behavioral disorders in hepatic injury mice via regulation of oxidative stress and neuroinflammation.

Aim: The present study was aimed to evaluate the anxiolytic and antidepressant-like effects of schizandrin (from Schisandra chinensis (Turcz.) Baill. which is a functional food) against chronic liver injury in mice.Methods: Chronic liver injury was induced by the treatment of d-galactose (d-GaIN, 200 mg/kg, s.c.) for 8 weeks.Results: Administration of schizandrin (30 mg/kg, i.g.) significantly ameliorated d-GaIN-induced anxiety and depression-like behavior as evident from the results of open field test (OFT), sucrose preference test (SPT), tail suspension test (TST), forced swimming test (FST), novelty-suppressed feeding test (NSFT), and elevated plus maze (EPM) test. In addition, schizandrin remarkably reduced the oxidative stress due to its potential to enhance the levels of decreased CAT, GSH/GSSG, SOD, and increased MDA in peripheral and brain, the antioxidant activities might be related with the Nrf2/HO-1 pathway. Furthermore, schizandrin could dramatically inhibit the neuroinflammation in mice by reducing pro-inflammatory cytokines (TNF-α, IL-1ß, and IL-6) through regulating NF-κB/NLRP3/Iba-1 signaling. Besides, the elevated levels of ammonia, AST, and ALT were significantly reduced by schizandrin.Conclusion: The present data revealed that hyperammonemia produced due to liver injury-induced oxidative stress and neuroinflammation in the hippocampus and prefrontal cortex resulting in anxiety and depression were improved by schizandrin.

Schisandrin B Protects against Acute Ethanol-Induced Cardiac Injury by Downregulating Autophagy via the NOX4/ROS Pathway.

INTRODUCTION: Although oxidative stress has been demonstrated to mediate acute ethanol-induced changes in autophagy in the heart, the precise mechanism behind redox regulation in acute ethanol heart disease remains largely unknown. METHODS: Wild-type C57BL/6 mice were intraperitoneally injected with ethanol (3 g/kg/day) for 3 consecutive days. The effects of ethanol on cultured primary cardiomyocytes and H9c2 myoblasts were also studied in vitro. Levels of autophagic flux, cardiac apoptosis and function, reactive oxygen species (ROS) accumulation, NOX4, and NOX2 were examined. The NOX4 gene was knocked down with NOX4 siRNA. RESULTS: In this study, we demonstrated that schisandrin B inhibited acute ethanol-induced autophagy and sequent apoptosis. In addition, schisandrin B treatment improved cardiac function in ethanol-treated mice. Furthermore, NOX4 protein expression was increased during acute ethanol exposure, and the upregulation of NOX4 was significantly inhibited by schisandrin B treatment. The knockdown of NOX4 prevented ROS accumulation, cell autophagy, and apoptosis. CONCLUSION: These results highlight that NOX4 is a critical mediator of ROS and elaborate the role of the NOX4/ROS axis in the effect of schisandrin B on autophagy and autophagy-mediated apoptosis in acute ethanol exposure, which suggests a therapeutic strategy for acute alcoholic cardiomyopathy.

Treatment of extended-spectrum ß-lactamases infections: what is the current role of new ß-lactams/ß-lactamase inhibitors?

PURPOSE OF REVIEW: The widespread diffusion of extended-spectrum ß-lactamases (ESBLs)-producing Enterobacteriales currently represents a major threat for public health worldwide. Carbapenems are currently considered the first-line choice for serious ESBL infections. However, the dramatic global increase in ESBL prevalence has led to a significant overuse of carbapenems that has promoted the selection and spread of carbapenemases, which might further prejudicated our ability to treat infections due to multidrug-resistant pathogens. Therefore, strategies to limit the use of carbapenems should be implemented. RECENT FINDINGS: Although piperacillin-tazobactam should no longer be considered an alternative to carbapenems for definitive treatment of bloodstream infections due to ESBL-producing strains, it might still represent an alternative for step-down therapy or for low-to-moderate severity infection originating from urinary or biliary sources and when piperacillin-tazobactam minimum inhibitory concentration of 4 mg/l or less. Ceftazidime-avibactam and ceftolozane-tazobactam are both carbapenem sparing agents that appear interesting alternatives for treatment of serious ESBL infections. New ß-lactams/ß-lactamase inhibitors (BL/BLI), including cefepime-enmetazobactam, ceftaroline fosamil-avibactam, aztreonam-avibactam and cefepime-zidebactam, are also promising agents for treatment of ESBL infections, but further clinical data are needed to establish their efficacy relative to carbapenems. The role of carbapenems/ß-lactamase inhibitors remain to be clarified. SUMMARY: New BL/BLI have distinctive specificities and limitations that require further investigations. Future randomized clinical trials are required to define the best strategy for their administering for ESBL infections.

Schisantherin A attenuates sepsis-induced acute kidney injury by suppressing inflammation via regulating the NRF2 pathway.

AIMS: Tubulointerstitial inflammation is recognized as a key determinant of progressive sepsis-induced acute kidney injury (AKI). Schisantherin A (SchA) has been shown to be capable of regulating inflammatory processes. In the present study, we explored the possibility of SchA in preventing lipopolysaccharide (LPS)-induced kidney inflammation and injury. MATERIALS AND METHODS: AKI was induced by a single intraperitoneal injection of LPS in CD1 mice, administration of SchA was used for treatment. The protective effect of SchA on renal function and inflammation were analyzed respectively; the NRK-52E cell line was employed for the in vitro study and relative molecular mechanism was explored. KEY FINDINGS: Administration with SchA markedly attenuated LPS-induced damage on renal function and histopathological changes of the kidney. Additionally, pretreatment with SchA could inhibit the expression of inflammatory factors in the kidneys. In NRK-52E cells, SchA treatment significantly inhibited LPS-induced NF-κB activation and pro-inflammatory cytokine expression. Moreover, SchA could promote NRF2 pathway activation, and further blockade of NRF2 activation reversed the SchA-induced inhibition of NF-κB activation. SIGNIFICANCE: These presented results indicated that SchA may have great potential for protecting against sepsis-induced AKI.

Preventive Effects of Schisandrin A, A Bioactive Component of Schisandra chinensis, on Dexamethasone-Induced Muscle Atrophy.

Muscle wasting is caused by various factors, such as aging, cancer, diabetes, and chronic kidney disease, and significantly decreases the quality of life. However, therapeutic interventions for muscle atrophy have not yet been well-developed. In this study, we investigated the effects of schisandrin A (SNA), a component extracted from the fruits of Schisandra chinensis, on dexamethasone (DEX)-induced muscle atrophy in mice and studied the underlying mechanisms. DEX+SNA-treated mice had significantly increased grip strength, muscle weight, and muscle fiber size compared with DEX+vehicle-treated mice. In addition, SNA treatment significantly reduced the expression of muscle degradation factors such as myostatin, MAFbx (atrogin1), and muscle RING-finger protein-1 (MuRF1) and enhanced the expression of myosin heavy chain (MyHC) compared to the vehicle. In vitro studies using differentiated C2C12 myotubes also showed that SNA treatment decreased the expression of muscle degradation factors induced by dexamethasone and increased protein synthesis and expression of MyHCs by regulation of Akt/FoxO and Akt/70S6K pathways, respectively. These results suggest that SNA reduces protein degradation and increases protein synthesis in the muscle, contributing to the amelioration of dexamethasone-induced muscle atrophy and may be a potential candidate for the prevention and treatment of muscle atrophy.

Schisandrin ameliorates cognitive deficits, endoplasmic reticulum stress and neuroinflammation in streptozotocin (STZ)-induced Alzheimer's disease rats.

Schisandrin, an active component extracted from Schisandra chinensis (Turcz.) Baill has been reported to alleviate the cognitive impairment in neurodegenerative disorder like Alzheimer's disease (AD). However, the mechanism by which schisandrin regulates the cognitive decline is still unclear. In our study, intracerebroventricular injection of streptozotocin (STZ) was employed to establish AD model in male Wistar rats, and indicated dose of schisandrin was further administered. The Morris water maze test was performed to evaluate the ability of learning and memory in rats with schisandrin treatment. The results indicated that schisandrin improved the capacity of cognition in STZ-induced rats. The contents of pro-inflammatory cytokines in brain tissue were determined by ELISA, and the expressions of these cytokines were assessed by western-blot and immunohistochemistry. The results showed that treatment of schisandrin significantly reduced the production of inflammation mediators including tumor necrosis factor-α, interleukin-1ß and interleukin-6. Further study suggested a remarkable decrease in the expressions of ER stress maker proteins like C/EBP-homologous protein, glucose-regulated protein 78 and cleaved caspase-12 in the presence of schisandrin, meanwhile the up-regulation of sirtuin 1 (SIRT1) was also observed in the same group. Additionally, the results of western-blot and EMSA demonstrated that schisandrin inhibited NF-κB signaling in the brain of STZ-induced rats. In conclusion, schisandrin ameliorated STZ-induced cognitive dysfunction, ER stress and neuroinflammation which may be associated with up-regulation of SIRT1. Our study provides novel mechanisms for the neuroprotective effect of schisandrin in AD treatment.

Exploring the protective effects of schizandrol A in acute myocardial ischemia mice by comprehensive metabolomics profiling integrated with molecular mechanism studies.

Schizandrol A (SA) is an bioactive component isolated from the Schisandra chinensis (Turcz.) Baill., which has been used as a remedy to prevent oxidative injury. However, whether the cardioprotective effect of SA is associated with regulating endogenous metabolites remains unclear, thus we performed comprehensive metabolomics profiling in acute myocardial ischemia (AMI) mice following SA treatment. AMI was induced in ICR mice by coronary artery ligation, then SA (6 mg·kg-1·d-1, ip) was administered. SA treatment significantly decreased the infarct size, preserved the cardiac function, and improved the biochemical indicators and cardiac pathological alterations. Moreover, SA (10, 100 M) significantly decreased the apoptotic index in OGD-treated H8c2 cardiomycytes in vitro. By using HPLC-Q-TOF/MS, we conducted metabonomics analysis to screen the significantly changed endogenous metabolites and construct the network in both serum and urine. The results revealed that SA regulated the pathways of glycine, serine and threonine metabolism, lysine biosynthesis, pyrimidine metabolism, arginine and proline metabolism, cysteine and methionine metabolism, valine, leucine and isoleucine biosynthesis under the pathological conditions of AMI. Furthermore, we selected the regulatory enzymes related to heart disease, including ecto-5'-nucleotidase (NT5E), guanidinoacetate N-methyltransferase (GAMT), platelet-derived endothelial cell growth factor (PD-ECGF) and methionine synthase (MTR), for validation. In addition, SA was found to facilitate PI3K/Akt activation and inhibit the expression of NOX2 in AMI mice and OGD-treated H9c2 cells. In conclusion, we have elucidated SA-regulated endogenous metabolic pathways and constructed a regulatory metabolic network map. Furthermore, we have validated the new potential therapeutic targets and underlying molecular mechanisms of SA against AMI, which might provide a reference for its future application in cardiovascular diseases.

Schizandrin attenuates inflammation induced by avian pathogenic Escherichia coli in chicken type II pneumocytes.

Avian pathogenic Escherichia coli (APEC) is a kind of highly pathogenic parenteral bacteria, which adheres to chicken type II pneumocytes through pili, causing inflammatory damage of chicken type II pneumocytes. Without affecting the growth of bacteria, anti-adhesion to achieve anti-inflammatory effect is considered to be a new method for the treatment of multi-drug-resistant bacterial infections. In this study, the anti-APEC activity of schizandrin was studied in vitro. By establishing the model of chicken type II pneumocytes infected with APEC-O78, the adhesion number, the expression of virulence genes, the release of lactate dehydrogenase (LDH), levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, IL-8 and activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were detected. The results showed that schizandrin reduced the release of LDH and the adherence of APEC on chicken type II pneumocytes. Moreover, schizandrin markedly decreased the levels of IL-1ß, IL-8, IL-6, and TNF-α, the mechanism responsible for these effects was attributed to the inhibitory effect of schizandrin on NF-κB and MAPK signaling activation. In conclusion, our findings revealed that schizandrin could reduce the inflammatory injury of chicken type II pneumocytes by reducing the adhesion of APEC-O78 to chicken type II pneumocytes. The results indicate that schizandrin can be a potential agent to treat inflammation caused by avian colibacillosis.