Schisandrin B protects PC12 cells against oxidative stress of neurodegenerative diseases

Schisandrin B protect inner hair cells from cisplatin by inhibiting celluar oxidative stress and apoptosis

Cisplatin is an effective chemotherapeutic agent; however, ototoxicity is one of its negative effects that greatly limits the use of cisplatin in clinical settings. Previous research has shown that the most important process cisplatin damage to inner ear cells, such as hair cells (HCs), is the excessive production and accumulation of ROS. Schisandrin B (SchB), is a low-toxicity, inexpensive, naturally occurring antioxidant with a variety of pharmacological effects. Therefore, the potential antioxidant effects of SchB may be useful for cisplatin ototoxicity treatment. In this study, the effects of SchB on cochlear hair cell viability, ROS levels, and expression of apoptosis-related molecules were evaluated by CCK-8, immunofluorescence, flow cytometry, and qRT-PCR, as well as auditory brainstem response (ABR) and dysmorphic product otoacoustic emission (DPOAE) tests to assess the effects on inner ear function. The results showed that SchB treatment increased cell survival, prevented apoptosis, and reduced cisplatin-induced ROS formation. SchB treatment reduced the loss of cochlear HCs caused by cisplatin in exosome culture. In addition, SchB treatment attenuated cisplatin-induced hearing loss and HC loss in mice. This study demonstrates the ability of SchB to inhibit cochlear hair cell apoptosis and ROS generation and shows its potential therapeutic effect on cisplatin ototoxicity.

Schisandrin B Protects against Ischemic Brain Damage by Regulating PI3K/AKT Signaling in Rats

OBJECTIVE

To explore the effect and mechanism of schisandrin B (Sch B) in the treatment of cerebral ischemia in rats.

METHODS

The cerebral ischemia models were induced by middle cerebral artery occlusion (MCAO) and reperfusion. Sprague-Dawley rats were divided into 6 groups using a random number table, including sham, MCAO, MCAO+Sch B (50 mg/kg), MCAO+Sch B (100 mg/kg), MCAO+Sch B (100 mg/kg)+LY294002, and MCAO+Sch B (100 mg/kg)+wortmannin groups. The effects of Sch B on pathological indicators, including neurological deficit scores, cerebral infarct volume, and brain edema, were subsequently studied. Tissue apoptosis was identified by terminal transferase-mediated dUTP nick end-labeling (TUNEL) staining. The protein expressions involved in apoptosis, inflammation response and oxidative stress were examined by immunofluorescent staining, biochemical analysis and Western blot analysis, respectively. The effect of Sch B on phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling was also explored.

RESULTS

Sch B treatment decreased neurological deficit scores, cerebral water content, and infarct volume in MCAO rats (P<0.05 or P<0.01). Neuronal nuclei and TUNEL staining indicated that Sch B also reduced apoptosis in brain tissues, as well as the Bax/Bcl-2 ratio and caspase-3 expression (P<0.01). Sch B regulated the production of myeloperoxidase, malondialdehyde, nitric oxide and superoxide dismutase, as well as the release of cytokine interleukin (IL)-1 β and IL-18, in MCAO rats (P<0.05 or P<0.01). Sch B promoted the phosphorylation of PI3K and AKT. Blocking the PI3K/AKT signaling pathway with LY294002 or wortmannin reduced the protective effect of Sch B against cerebral ischemia (P<0.05 or P<0.01).

CONCLUSIONS

Sch B reduced apoptosis, inflammatory response, and oxidative stress of MCAO rats by modulating the PI3K/AKT pathway. Sch B had a potential for treating cerebral ischemia.

Schisandrin B Improves the Hypothermic Preservation of Celsior Solution in Human Umbilical Cord Mesenchymal Stem Cells

BACKGROUND

Human umbilical cord mesenchymal stem cells (hUCMSCs) have emerged as promising therapy for immune and inflammatory diseases. However, how to maintain the activity and unique properties during cold storage and transportation is one of the key factors affecting the therapeutic efficiency of hUCMSCs. Schisandrin B (SchB) has many functions in cell protection as a natural medicine. In this study, we investigated the protective effects of SchB on the hypothermic preservation of hUCMSCs.

METHODS

hUCMSCs were isolated from Wharton's jelly. Subsequently, hUCMSCs were exposed to cold storage (4 °C) and 24-h re-warming. After that, cells viability, surface markers, immunomodulatory effects, reactive oxygen species (ROS), mitochondrial integrity, apoptosis-related and antioxidant proteins expression level were evaluated.

RESULTS

SchB significantly alleviated the cells injury and maintained unique properties such as differentiation potential, level of surface markers and immunomodulatory effects of hUCMSCs. The protective effects of SchB on hUCMSCs after hypothermic storage seemed associated with its inhibition of apoptosis and the anti-oxidative stress effect mediated by nuclear factor erythroid 2-related factor 2 signaling.

CONCLUSION

These results demonstrate SchB could be used as an agent for hypothermic preservation of hUCMSCs.

Schisandrin B protects boar spermatozoa against oxidative damage and increases their fertilization ability during in vitro storage

Oxidative stress due to low temperatures during in vitro preservation reduces boar spermatozoa quality. It has been proven that Schisandrin B (Sch-B) can act against oxidative stress in cells. Therefore, the purpose of this study was to investigate whether the treatment with Sch-B could improve the quality of boar sperm during storage at 17 °C. Semen samples were randomly divided into four groups and added to the Beltsville Thawing Solution containing different concentrations of Sch-B (0, 0.1, 0.5, and 1 mg/L) after collection. Each group was then preserved at 17 °C and the sperm motility, membrane integrity, and acrosome integrity were detected to determine the maximum available concentration of Sch-B for sperm. The optimal concentration was set at 0.1 mg/L and was used in subsequent experiments. Sperms treated with 0 and 0.1 mg/L Sch-B were evaluated for lipid peroxidation (MDA) and fertilization ability through in vitro fertilization. Finally, the quality of blastocysts which were formed by 0 and 0.1 mg/L Sch-B-treated sperm was determined. The results showed that compared with the control, the addition of 0.1 mg/L Sch-B improved boar sperm motility, and the addition of 0.1 and 0.5 mg/L Sch-B improved sperm membrane integrity and acrosome integrity. Treatment with 0.1 mg/L Sch-B reduced the level of MDA and increased the cleavage rate, blastocyst rate, and total cell number of blastocysts compared to the rate and number in the control group. However, no significant difference was observed in the ROS levels of blastocysts between the treatment and the control groups. The expression levels of CAT, SOD2, and Bcl-2 in IVF-blastocysts formed using sperm stored for one day at 17 °C were significantly higher than those in the control blastocysts. On day 4 of storage, CAT and Bcl-2 expression were significantly higher in IVF-blastocysts formed from sperm treated with 0.1 mg/L Sch-B than that in the control blastocysts. The ratio of Bax/Bcl-2 was also significantly higher in IVF-blastocysts formed using Sch-B-treated sperm. Our findings demonstrate that treatment with Sch-B can protect boar sperm from oxidative stress during liquid preservation and can increase the fertilization ability of the sperm.

Supplementation of Schisandrin B in Semen Extender Improves Quality and Oxidation Resistance of Boar Spermatozoa Stored at 4 °C

During cold storage, boar spermatozoa undergo oxidative stress, which can impair sperm function and fertilizing capacity. The objective of the present study was to assess the effects of Schisandrin B (Sch B) in semen extenders on the quality of boar semen stored at hypothermia. Semen was collected from twelve Duroc boars and diluted in extenders supplemented with different concentrations of Sch B (0 μmol/L, 2.5 μmol/L, 5 μmol/L, 10 μmol/L, 20 μmol/L, and 40 μmol/L). Here, we demonstrated that 10 μmol/L Sch B provided the best effects on motility, plasma membrane integrity, acrosome integrity, sperm normality rate, average movement velocity, wobbility, mitochondrial membrane potential (MMP), and DNA integrity of sperm. The results of Sch B effects on antioxidant factors in boar sperm showed that Sch B significantly elevated the total antioxidant capacity (T-AOC) and markedly decreased the reactive oxygen species (ROS) and malondialdehyde (MDA) content of sperm. The expression of catalase (CAT) and superoxide dismutase (SOD) mRNA was increased, while the expression of glutathione peroxidase (GPx) mRNA demonstrated no change compared to non-treated boar sperm. Compared to the non-treated group, Sch B triggered a decrease in Ca²⁺/protein kinase A (PKA) and lactic acid content in boar sperm. Similarly, Sch B led to a statistically higher quantitative expression of AWN mRNA and a lower quantitative expression of porcine seminal protein I (PSP-I) and porcine seminal protein II (PSP-II) mRNA. In a further reverse validation test, no significant difference was observed in any of the parameters, including adhesion protein mRNA, calcium content, lactic acid content, PKA, and protein kinase G (PKG) activity after sperm capacitation. In conclusion, the current study indicates the efficient use of Sch B with a 10 μmol/L concentration in the treatment of boar sperm through its anti-apoptosis, antioxidative, and decapacitative mechanisms, suggesting that Sch B is a novel candidate for improving antioxidation and decapacitation factors in sperm in liquid at 4 °C.

Lignans as Pharmacological Agents in Disorders Related to Oxidative Stress and Inflammation: Chemical Synthesis Approaches and Biological Activities

Plant lignans exhibit a wide range of biological activities, which makes them the research objects of potential use as therapeutic agents. They provide diverse naturally-occurring pharmacophores and are available for production by chemical synthesis. A large amount of accumulated data indicates that lignans of different structural groups are apt to demonstrate both anti-inflammatory and antioxidant effects, in many cases, simultaneously. In this review, we summarize the comprehensive knowledge about lignan use as a bioactive agent in disorders associated with oxidative stress and inflammation, pharmacological effects in vitro and in vivo, molecular mechanisms underlying these effects, and chemical synthesis approaches. This article provides an up-to-date overview of the current data in this area, available in PubMed, Scopus, and Web of Science databases, screened from 2000 to 2022.

Dietary Plant Polyphenols as the Potential Drugs in Neurodegenerative Diseases: Current Evidence, Advances, and Opportunities

Neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD), are characterized by the progressive degeneration of neurons. Although the etiology and pathogenesis of neurodegenerative diseases have been studied intensively, the mechanism is still in its infancy. In general, most neurodegenerative diseases share common molecular mechanisms, and multiple risks interact and promote the pathologic process of neurogenerative diseases. At present, most of the approved drugs only alleviate the clinical symptoms but fail to cure neurodegenerative diseases. Numerous studies indicate that dietary plant polyphenols are safe and exhibit potent neuroprotective effects in various neurodegenerative diseases. However, low bioavailability is the biggest obstacle for polyphenol that largely limits its adoption from evidence into clinical practice. In this review, we summarized the widely recognized mechanisms associated with neurodegenerative diseases, such as misfolded proteins, mitochondrial dysfunction, oxidative damage, and neuroinflammatory responses. In addition, we summarized the research advances about the neuroprotective effect of the most widely reported dietary plant polyphenols. Moreover, we discussed the current clinical study and application of polyphenols and the factors that result in low bioavailability, such as poor stability and low permeability across the blood-brain barrier (BBB). In the future, the improvement of absorption and stability, modification of structure and formulation, and the combination therapy will provide more opportunities from the laboratory into the clinic for polyphenols. Lastly, we hope that the present review will encourage further researches on natural dietary polyphenols in the treatment of neurodegenerative diseases.

Reducing oxidative stress may be important for treating pirarubicin-induced cardiotoxicity with schisandrin B

The cardiotoxicity of pirarubicin (THP) seriously affects its clinical application, which cannot be ignored. The antioxidant effect of schisandrin B (SchB) has been extensively reported in the context of dietotherapy. However, whether this antioxidant effect can protect the heart from THP damage remains unknown. The aim of the present study was to investigate whether the antioxidant effect of SchB can antagonize the cardiotoxicity of THP. Changes in electrocardiogram (ECG), echocardiography and serum lactate dehydrogenase, brain natriuretic peptide, creatine kinase MB and cardiac troponin T levels were used to detect the degree of cardiac damage. The levels of superoxide dismutase (SOD), malondialdehyde, catalase and total antioxidant capacity in the serum and heart were measured to observe the oxidative stress state of rats. Primary cardiomyocytes were cultured, and cell viability and reactive oxygen species (ROS) production were detected. Western blotting was used to detect the expression levels of SOD2, NOX2, pro/cleaved-caspase3 and Bcl-2/Bax in heart tissue and primary cardiomyocytes to verify the related signaling pathways. THP-treated rats showed a range of cardiac damage, including an abnormal ECG, echocardiography and myocardial enzymes. In the cellular experiments, cell viability decreased and ROS increased. However, this damage was alleviated after SchB treatment. Further studies demonstrated that SchB antagonized THP cardiotoxicity via its antioxidant effect. In conclusion, SchB protects the heart from THP damage in rats, and the mechanism may be closely associated with its antioxidant effect.

Schisandrin A and B affect the proliferation and differentiation of neural stem cells

Schisandrin A and B (Sch A and B) are the important components of Asian dietary supplement and phytomedicine Schisandra chinensis (S. chinensis). They can enhance adult neurogenesis in vivo; however, these effects still need to be verified. Here NE-4 C neural stem cells (NSCs) were employed as the in vitro model and treated with Sch A and B at 0.1 μg/mL. EdU (5-Ethynyl-2'-deoxyuridine) labeling showed that both Sch A and B treatments enhanced NSC proliferation. Real-time PCR analysis showed the mRNA abundances of telomerase gene Tert and cell cycle gene Cyclin D1 were significantly up-regulated after the treatments. During the neurosphere induction, Sch B enhanced the neurosphere formation and neuronal differentiation, and increased the neurosphere semidiameters. Detection of the neuron differentiation marker Mapt indicates that both Sch A and B, especially Sch B, benefits the induced neuronal differentiation. Sch B treatment also enhanced mRNA expressions of the neurosphere-specific adhesion molecule Cdh2 and Wnt pathway-related genes including Mmp9, Cyclin D1 and β-catenin. Together, Sch A especially Sch B, promotes the proliferation, affects the survival, differentiation and neurogenesis of NSCs, which is consistent with their in vivo effects. This study provides further clue on the potential neuropharmacological effects of S. chinensis.

Schisandrin B Antagonizes Cardiotoxicity Induced by Pirarubicin by Inhibiting Mitochondrial Permeability Transition Pore (mPTP) Opening and Decreasing Cardiomyocyte Apoptosis

Objective: Pirarubicin (THP), one of the anthracycline anticancer drugs, is widely used in the treatment of various cancers, but its cardiotoxicity cannot be ignored. Schisandrin B (SchB) has the ability to upregulate cellular antioxidant defense mechanism and promote mitochondrial function and antioxidant status. However, it has not been reported whether it can resist THP-induced cardiotoxicity. The aim of this study was to investigate the effect of SchB on THP cardiotoxicity and its mechanism. Methods: The rat model of cardiotoxicity induced by THP was established, and SchB treatment was performed at the same time. The changes of ECG, cardiac coefficient, and echocardiogram were observed. The changes of myocardial tissue morphology were observed by H&E staining. Apoptosis was detected by TUNEL. The levels of LDH, BNP, CK-MB, cTnT, SOD, and MDA in serum were measured to observe the heart damage and oxidative stress state of rats. The expression of cleaved-caspase 9, pro/cleaved-caspase 3, Bcl-2/Bax, and cytosol and mitochondrial Cyt C and Bax was evaluated by western blot. H9c2 cardiomyocytes were cocultured with THP, SchB, and mPTP inhibitor CsA to detect the production of ROS and verify the above signaling pathways. The opening of mPTP and mitochondrial swelling were detected by mPTP kit and purified mitochondrial swelling kit. Results: After 8 weeks, a series of cardiotoxicity manifestations were observed in THP rats. These adverse effects can be effectively alleviated by SchB treatment. Further studies showed that SchB had strong antioxidant and antiapoptotic abilities in THP cardiotoxicity. Conclusion: SchB has an obvious protective effect on THP-induced cardiotoxicity. The mechanism may be closely related to the protection of mitochondrial function, inhibition of mPTP opening, and alleviation of oxidative stress and apoptosis of cardiomyocytes.

Epibrassinolide prevents tau hyperphosphorylation via GSK3β inhibition in vitro and improves Caenorhabditis elegans lifespan and motor deficits in combination with roscovitine

Glycogen synthase kinase 3β (GSK3β) is considered an important element of glycogen metabolism; however, it has many other regulatory roles. Changes in the GSK3β signaling mechanism have been associated with various disorders, such as Alzheimer's disease (AD), type II diabetes, and cancer. Although the effects of GSK3β inhibitors on reducing the pathological effects of AD have been described, an effective inhibitor has not yet been developed. Epibrassinolide (EBR), a brassinosteroid (BR), is structurally similar to mammalian steroid hormones. Our studies have shown that EBR has an inhibitory effect on GSK3β in different cell lines. Roscovitine (ROSC), a cyclin-dependent kinase (CDK) inhibitor, has also been identified as a potential GSK3 inhibitor. Within the scope of this study, we propose that EBR and/or ROSC might have mechanistic action in AD models. To test this hypothesis, we used in vitro models and Caenorhabditis elegans (C. elegans) AD strains. Finally, EBR treatment successfully protected cells from apoptosis and increased the inhibitory phosphorylation of GSK3β. In addition, EBR and/or ROSC treatment had a positive effect on the survival rates of C. elegans strains. More interestingly, the paralysis phenotype of the C. elegans AD model due to Aβ42 toxicity was prevented by EBR and/or ROSC. Our findings suggest that EBR and ROSC administration have neuroprotective effects on both in vitro and C. elegans models via inhibitory GSK3β phosphorylation at Ser9.

Pharmacodynamic effects and molecular mechanisms of lignans from Schisandra chinensis Turcz. (Baill.), a current review

Fruit of Schisandra chinensis Turcz. (Baill.) (S. chinensis) is a traditional herbal medicine widely used in China, Korea, and many other east Asian countries. At present, S. chinensis commonly forms Chinese medicinal formulae with other herbal medicines to treat liver disease and neurological disease in clinical. Modern researches indicated that lignans were the main active ingredients of S. chinensis with high content and novel dibenzocyclooctadiene skeletal structure, exhibited considerable antioxidant, anti-inflammatory, and neuroprotective properties. Additionally, some of these lignans also showed certain potentials in anti-cancer, anti-fibrosis, and other effects. In the current review, we summarize literature reported lignans from S. chinensis in the past five years, and highlight the molecular mechanisms of lignans in exerting their biological functions. Also, we point out some deficiencies of existing researches and discuss the future direction of lignans study.

Targeting apoptosis and autophagy following spinal cord injury: Therapeutic approaches to polyphenols and candidate phytochemicals

Spinal cord injury (SCI) is a neurological disorder associated with the loss of sensory and motor function. Understanding the precise dysregulated signaling pathways, especially apoptosis and autophagy following SCI, is of vital importance in developing innovative therapeutic targets and treatments. The present study lies in the fact that it reveals the precise dysregulated signaling mediators of apoptotic and autophagic pathways following SCI and also examines the effects of polyphenols and other candidate phytochemicals. It provides new insights to develop new treatments for post-SCI complications. Accordingly, a comprehensive review was conducted using electronic databases including, Scopus, Web of Science, PubMed, and Medline, along with the authors' expertise in apoptosis and autophagy as well as their knowledge about the effects of polyphenols and other phytochemicals on SCI pathogenesis. The primary mechanical injury to spinal cord is followed by a secondary cascade of apoptosis and autophagy that play critical roles during SCI. In terms of pharmacological mechanisms, caspases, Bax/Bcl-2, TNF-α, and JAK/STAT in apoptosis along with LC3 and Beclin-1 in autophagy have shown a close interconnection with the inflammatory pathways mainly glutamatergic, PI3K/Akt/mTOR, ERK/MAPK, and other cross-linked mediators. Besides, apoptotic pathways have been shown to regulate autophagy mediators and vice versa. Prevailing evidence has highlighted the importance of modulating these signaling mediators/pathways by polyphenols and other candidate phytochemicals post-SCI. The present review provides dysregulated signaling mediators and therapeutic targets of apoptotic and autophagic pathways following SCI, focusing on the modulatory effects of polyphenols and other potential phytochemical candidates.

A Comprehensive Review on Schisandrin B and Its Biological Properties

Nature is a vast source of bioactive molecules and has provided an active and efficient reservoir for drug discovery. Among natural compounds, one of the most promising is Schisandrin B (Sch B), isolated from Schisandra chinensis, which was documented to possess diversified pharmacokinetic propriety, among them antioxidant, anti-inflammation, cardioprotection, and neuroprotection. Due to its large biological properties, Sch B was recorded to be a potent cure for several diseases by targeting several signaling pathways. This review is aimed at emphasizing the recent data on the biological properties of Sch B among the molecular mechanism of this drug on tumoral, cardiac, and neural diseases. The data suggest that the antitumor activities of Sch B were mainly through apoptosis and cell cycle arrest at the diver's stage. It is reported that Sch B could be used as effective chemotherapy, neuroprotection, and cardioprotection since it possesses a spectrum of biological activities; however, further investigations on the mechanism of its action and preclinical trials are still mandatory to further validate the potential of this natural drug candidate.

Synthesis of novel caffeic acid derivatives and their protective effect against hydrogen peroxide induced oxidative stress via Nrf2 pathway

AIM

This study was aimed to synthesize novel caffeic acid derivatives and evaluate their potential applications for the treatment of oxidative stress associated disease.

MAIN METHODS

Caffeic acid sulfonamide derivatives were synthesized by coupling sulfonamides to the backbone of caffeic acid and fully characterized by melting point test, FT-IR, MS, NMR, UV-vis and n-octanol-water distribution assay. Their free radical scavenging ability was evaluated using DPPH assay and cytotoxicity against A549 cells were determined by MTT assay. The protective effect of these derivatives against hydrogen peroxide (H₂O₂) induced oxidative injury was assessed in A549 cells from cell viability, production of reactive oxygen species (ROS) and malondialdehyde (MDA), alternation of antioxidase activities, and expressions of Nrf2 and its target genes.

KEY FINDINGS

Six novel caffeic acid sulfonamide derivatives were obtained. The derivatives showed better liphophilicity than the parent caffeic acid. CASMZ, CAST and CASQ exhibited similar DPPH scavenging capability as caffeic acid, while the protection of hydroxyl groups on the benzene ring with acetyl groups caused decrease in radical scavenging activity. No inhibitory effect on the proliferation of A549 cells were observed up to a concentration of 50 μM. Pre-treatment of cells with these derivatives strongly inhibited H₂O₂ induced decrease of cell viability, reduced the production of ROS and MDA, promoted antioxidase activities, and further upregulated the expression of Nrf2 and its target genes.

SIGNIFICANCE

Caffeic acid sulfonamide derivatives were synthesized with simple reactions under mild conditions. They might protect cells from H₂O₂-induced oxidative injury via Nrf2 pathway.

Schisandrin A and B enhance the dentate gyrus neurogenesis in mouse hippocampus

Schisandrin A and B (Sch A and B) are the main effective components of Schisandra chinensis (S. chinensis), which is traditionally used to enhance mental and intellectual functions in eastern Asia. Previously, we reported Sch A and B remarkably affect adult neurogenesis in the subventricular zone of mouse lateral ventricle. Since the neurogenesis in the hippocampal dentate gyrus (DG) is more important to learning, memory and cognition, here we further examined their effects on the adult DG neurogenesis. Phosphohistone H3 (PHH3) immunostaining showed that Sch B significantly enhanced the cell proliferation in the DG. Glial fibrillary acidic protein (GFAP, mostly labels astrocytes and some stem cells) staining was used to further identify the proliferating cell type. Dramatically, increases of GFAP⁺ cells in both Sch A and B treated groups were observed. What's more, the total numbers of the mature neurons labeled by neuron-specific nuclear protein (NeuN) were also increased in both Sch A and B treated groups compared with the controls. Together, Sch A and B enhance the adult DG neurogenesis by increasing astrocytes/stem cells and improving the survival and maturation of DG neurons. Our study shed a new light on the neuropharmacological functions of the herbal medicine S. chinensis.

Traditional Chinese Medicine Jiuwei Zhenxin Granules in Treating Depression: An Overview

Depression is known as "Yu Zheng" in traditional Chinese medicine (TCM). Jiuwei Zhenxin granules (JZG) is a type of TCM. According to TCM theory, it nourishes the heart and spleen, tonifies Qi, and tranquilizes the spirit, and may also has effects in the treatment of depression. Here, we systematically reviewed recent basic and clinical experimental studies of JZG and depression, including studies of the pharmacological mechanisms, active ingredients, and clinical applications of JZG in depression treatment. This review will deepen our understanding of the pharmacological mechanisms, drug interactions, and clinical applications of TCM prescriptions and provide a basis for the development of new drugs in the treatment of depression.

Synthesis of caffeic acid sulfonamide derivatives and their protective effect against H2O2 induced oxidative damage in A549 cells

Exogenous antioxidants are considered as important therapeutic tools for oxidative stress associated disorders as they can regulate the redox state, which is associated with cell and organ function. Inspired by natural polyphenols, six new caffeic acid sulfonamide derivatives were synthesized by coupling sulfonamides to the backbone of caffeic acid with good yields. Their structure and lipophilicity were characterized by 1H nuclear magnetic resonance (NMR), ¹³C{¹H} NMR, infrared spectroscopy (IR) and oil–water partition coefficient assay. Their free radical scavenging activity and antioxidant activity were assessed by DPPH assay and hydrogen peroxide (H₂O₂) induced oxidative stress in human lung carcinoma A549 cells. The oil–water partition coefficient results indicate that the conjugation of sulfonamides increases the lipophilicity of caffeic acid. The CASMD, CASDZ and CASN results show higher free radical scavenging effects compared with vitamin C. The derivatives do not show any inhibitory effect on the proliferation of A549 cells up to a concentration of 200 μM, except CASDZ which significantly inhibits the growth of A549 cells at a concentration of 200 μM. In addition, the obtained derivatives markedly attenuate H₂O₂ induced decrease of cell viability, inhibit the production of ROS and MDA, and promote the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). Besides, treatment of H₂O₂ stimulated A549 cells with caffeic acid sulfonamide derivatives further increases mRNA expression of NF-E2-related factor 2 (Nrf2) and its target genes, including heme oxygenase-1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1) and thioredoxin reductase 1 (TXNRD1). These results suggest that these new caffeic acid sulfonamide derivatives have higher lipophilicity and better antioxidant activities than the parent caffeic acid, and they might be able to control the antioxidant response in cells via the Nrf2 pathway.

Synthesized caffeic acid derivatives exhibit protective effect on H₂O₂ induced oxidative injury in A549 cells via Nrf2 pathway.

Role of c-Myc/chloride intracellular channel 4 pathway in lipopolysaccharide-induced neurodegenerative diseases

LPS-induced neuronal apoptosis leads to neurodegenerative diseases (NDs). However, the mechanisms underlying NDs pathogenesis remains unclear. The apoptotic response to activation of the c-Myc/chloride intracellular channel (CLIC4) pathway is directed through a mitochondrial pathway. In this study, we aimed to explore the c-Myc/CLIC4 pathway in the progression of NDs induced by lipopolysaccharide (LPS). In an in vivo experiment, the results of HE staining, transmission electron microscopic, immunofluorescence microscopy of cleaved caspase-3 and Bax and the increasing expression of apoptotic pathway related proteins in mitochondria showed that LPS (10 mg/kg) administration damaged mitochondrial and induced hippocampal neuron apoptosis. The Western blot and RT-PCR indicated that LPS induced the activation of c-Myc/CLIC4 pathway. Furthermore, in an in vitro experiment, PC12 cells were exposed to LPS to induce cell injuries to mimic the model of NDs. To further confirm the role of the c-Myc/CLIC4 pathway in LPS-induced neuronal apoptosis, the gene knockout of c-Myc and CLIC4 were performed by CRISPR/Cas9. The results of the flow cytometry assay and Annexin V-FITC/PI showed that knocking out c-Myc and CLIC4 significantly reduced cell apoptosis. The results of Western blot and dual immunofluorescence with Cyt c and TOM20 showed that knocking out c-Myc and CLIC4 significantly reduced the expression of mitochondrial apoptosis-related proteins. Our data confirmed that LPS-induced apoptosis is regulated by the activation of c-Myc/CLIC4 pathway. These results support further research mechanisms underlying neurodegenerative diseases and can provide effective pharmacodynamic targets for the clinical development of therapeutic drugs for neurodegenerative diseases.

Low-molecular-weight chondroitin sulfate attenuated injury by inhibiting oxidative stress in amyloid β-treated SH-SY5Y cells

The neurotoxicity of aggregated amyloid β (Aβ) has been implicated as a critical cause in the pathogenesis of Alzheimer's disease. In a previous work, we have shown that low-molecular-weight chondroitin sulfate (LMWCS), a derivative of chondroitin sulfate, protected the SH-SY5Y neuroblastoma cells from Aβ25-35-induced neurotoxicity, decreased intracellular reactive oxygen species level and inhibited the cell apoptosis. However, the underlying mechanism of the antioxidative effect of LMWCS in the SH-SY5Y cells has not been well explored. In the present study, the SH-SY5Y cells were cultured and exposed to 30 μM Aβ25-35 in the absence or presence of LMWCS (50, 100 and 200 μg/ml). Results indicate that incubation of cells with LMWCS before Aβ25-35 exposure increased superoxide dismutase, glutathione peroxidase and Na/K-ATPase activities and decreased the malondialdehyde content. In addition, LMWCS inhibited the imbalance of Bcl-2 and Bax and decreased caspase-3 and caspase-9 expressions. LMWCS antagonizes Aβ25-35-induced neurotoxicity by attenuating oxidative stress, and our results suggest that LMWCS might be used as a potential compound for Alzheimer's disease prevention.

Schisandrin B alleviates acute oxidative stress via modulation of the Nrf2/Keap1-mediated antioxidant pathway

Schisandrin B (Sch B), one of the main effective components of the dried fruit of Schisandra chinensis, protects neurons from oxidative stress in the central nervous system. Here we investigated the neuroprotective effect of Sch B against damage caused by acute oxidative stress and attempted to define the possible mechanisms. Using the elevated plus maze and open field test, we found that forced swimming, an acute stressor, significantly induced anxiety-like behavior that was alleviated by oral Sch B treatment. In addition, the Sch B treatment reduced toxicity, malondialdehyde levels, and production of reactive oxygen species, an important factor for neuron damage. Antioxidants under the control of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, such as superoxide dismutase and glutathione, were significantly increased by Sch B treatment. Moreover, a higher percentage of intact cells in the amygdala of treated mice, revealed by Nissl staining, further verified the neuroprotective effect of Sch B. Several proteins, such as Nrf2 and its endogenous inhibitor Kelch-like ECH-associated protein 1 (Keap1), were abnormally expressed in mice subjected to forced swimming, but this abnormal expression was significantly reversed by Sch B treatment. Our results suggest that Sch B may be a potential therapeutic agent against anxiety associated with oxidative stress. The possible mechanism is neuroprotection through enhanced antioxidant activity.

Effects of Lignans from Schisandra chinensis Rattan Stems against Aβ1-42-Induced Memory Impairment in Rats and Neurotoxicity in Primary Neuronal Cells

Oxidative stress, which is caused by Amyloid-β deposition in brain, plays an important role in Alzheimer’s disease. In this study, we found that lignans from Schisandra chinensis rattan stems (rsSCH-L) could reduce the escape latency and the distance travelled by the Aβ_1–42 injected rats while the crossing platform time was enhanced in the Morris water maze test. Further research demonstrated that lignans from rsSCH-L attenuated Aβ_1-42-induced neuronal cell injury by increasing the content of SOD and GSH-Px and decreasing the levels of LDH, ROS, and MDA. Moreover, rsSCH-L also inhibited the apoptosis of primary neuronal cells. The mechanisms of the apoptosis were related with the downregulation of caspase-3, caspase-8, Bax, and upregulation of Bcl-2. Taken together, the results show that rsSCH-L can improve cognitive ability in vivo. Meanwhile rsSCH-L exhibit a neuroprotective environment against oxidative stress and apoptosis in vitro. Therefore, rsSCH-L may be a potential therapeutic agent for this neurodegenerative disease.

Schizandrin B inhibits the cis‑DDP‑induced apoptosis of HK‑2 cells by activating ERK/NF‑κB signaling to regulate the expression of survivin

The nephrotoxicity of cisplatin limits its clinical application. Schizandrin B (SchB) has been demonstrated to have a variety of potential cytoprotective activities. The present study explored the molecular mechanisms by which SchB inhibits the dichlorodiammine platinum (DDP)‑induced apoptosis of HK‑2 proximal tubule epithelial cells. In vitro assays demonstrated that SchB increased the viability of HK‑2 cells, alleviated the cis‑DDP‑induced activation of caspase‑3, reduced apoptosis and improved the nuclear morphology of HK‑2 cells. Additionally, the mechanism underlying the cis‑DDP‑induced apoptosis was indicated to involve the activation of p53, c‑Jun‑N‑terminal kinase (JNK) and p38 signaling. Furthermore, SchB was demonstrated to activate extracellular signal‑regulated kinase (ERK) and nuclear factor κB (NF‑κB) signaling, and induce the expression of survivin. The inhibition of ERK and NF‑κB signaling using U0126 and pyrollidine dithiocarbamate, respectively, inhibited the expression of survivin, whereas blocking the expression of survivin using small interfering RNA inhibited the alleviating effect of SchB on cis‑DDP‑induced apoptosis as indicated by a reduction in cleaved caspase‑3 expression. In conclusion, SchB regulates ERK/NF‑κB signaling to induce the expression of survivin, thereby alleviating cis‑DDP‑induced renal injury.

Schisandrin B inhibits the proliferation and invasion of glioma cells by regulating the HOTAIR-micoRNA-125a-mTOR pathway

Glioma is one of the most common malignant central nervous system tumors in humans. Schisandrin B (Sch B) has been confirmed to cause the proliferation and invasion of glioma cells. In the present study, the potential mechanism underlying the antitumor effect of Sch B on glioma cells was investigated. The glioma cell lines, U251 and U87, were exposed to Sch B, and the cell viability, apoptosis, migration, and invasion were determined using the MTT assay, flow cytometry, and transwell assay, respectively. Then, the effects of HOTAIR and miR-125a on tumor biology and the mammalian target of rapamycin (mTOR) protein expression in cell lines exposed to Sch B were investigated. The results showed that Sch B decreased HOTAIR expression and increased miR-125a-5p expression. HOTAIR overexpression decreased miR-125a expression and increased mTOR expression in cells with the treatment of Sch B. The miR-125a inhibitor reversed the effects of HOTAIR downregulation on cell proliferation and migration. On co-incubation with rapamycin, a specific mTOR inhibitor, the cell viability, migration, and invasion were decreased and cell apoptosis was increased in two cell lines exposed to Sch B after the treatment of pcDNA-HOTAIR. In conclusion, Sch B played an inhibitory role in the proliferation and invasion of glioma cells by regulating the HOTAIR-micoRNA-125a-mTOR pathway.