Bacterial testicular inflammation is one of the important causes of male infertility. Using plant-derived compounds to overcome the side effects of antibiotics is an alternative treatment strategy for many diseases. Schizandrin B (SchB) is a bioactive compound of herbal medicine Schisandra chinensis which has multiple pharmacological effects. However its effect and the mechanism against testicular inflammation are unknown. Here we tackled these questions using models of lipopolysaccharide (LPS)-induced mice and -Sertoli cells (SCs). Histologically, SchB ameliorated the LPS-induced damages of the seminiferous epithelium and blood-testicular barrier, and reduced the production of pro-inflammatory mediators in mouse testes. Furthermore, SchB decreased the levels of pro-inflammatory mediators and inhibited the nuclear factor kB (NF-κB) and MAPK (especially JNK) signaling pathway phosphorylation in LPS-induced mSCs. The bioinformatics analysis based on receptor prediction and the molecular docking was further conducted. We targeted androgen receptor (AR) and illustrated that AR might bind with SchB in its function. Further experiments indicate that the AR expression was upregulated by LPS stimulation, while SchB treatment reversed this phenomenon; similarly, the expression of the JNK-related proteins and apoptotic-related protein were also reversed after AR activator treatment. Together, SchB mitigates LPS-induced inflammation and apoptosis by inhibiting the AR-JNK pathway.

Schisandra chinensis fruit (Omiza in Korean), used for the production tea or liquor, and is known to enhance skeletal muscle function. However, the effect of Omiza extract (OM) on obesity-induced skeletal muscle atrophy remains unclear. This study investigated the effect of OM on skeletal muscle mass and performance in obese mice. OM increased skeletal muscle weight, size and improved skeletal muscle performance. Further, it also suppressed obesity-induced increases in proinflammatory cytokines, MuRF1, and Atrogin1 in mouse skeletal muscle and enhanced the expression of MHC and the phosphorylation of AKT/mTOR signaling molecules, thereby suppressing myostatin expression and regulating Smad-FOXO signaling. Schizandrin B, a major component of OM inhibited palmitic acid induced atrophy in C2C12 cells via Smad-FOXO regulation, suggesting that it partially contributed to the effects of OM against obesity-induced muscle atrophy. Taken together, OM may have the potential to prevent and treat obesity-induced muscle atrophy.

Drug-induced liver injury (DILI) occurs frequently worldwide. Acetaminophen (APAP) is a common drug causing DILI. Current treatment methods are difficult to achieve satisfactory results. Therefore, there is an urgent need to provide safe and effective treatment for patients. Schizandrin B (Sch B), the main component of Schisandra, has a protective effect on liver. However, the potential mechanism of Sch B in the treatment of APAP induced liver injury has not been elucidated to date. In our research, we studied the effect of Sch B on protecting damaged liver cells and explored the potential mechanism underlying its ability to reduce APAP liver injury. We found that Sch B could reduce hepatocyte apoptosis, oxidative stress injury and inflammatory response. These effects were positively correlated with the dose of Sch B. Sch B regulated glucose 6-phosphate dehydrogenase expression by upregulating the expression of p21-activated kinase 4 and polo-like kinase 1. Sch B could inhibit the mitogen-activated protein kinase (MAPK)-c-Jun N-terminal kinase (JNK)-extracellular signal-regulated kinase (ERK) signaling pathway and regulate the expression of apoptosis-related proteins to reduce the incidence of cell apoptosis. In addition, Sch B reduced the expression levels of reactive oxygen species and inflammatory cytokines in hepatocyte. Consequently, we described for the first time that Sch B could not only activate the pentose phosphate pathway but also inhibit the MAPK-JNK-ERK signaling pathway, thereby achieving antioxidative and anti-inflammatory effects and inhibiting hepatocyte apoptosis. These findings indicated the potential use of Sch B in curing liver damage induced by APAP.

Ulcerative colitis (UC) is a chronic inflammatory disease with increasing incidence and prevalence in many countries. The purpose of this study is to explore the function of Schisandrin B and its underlying molecular mechanisms in colitis. In this study, mice with colitis were induced by giving 2.0% dextran sulfate sodium (DSS, MP) in the drinking water for seven days. Furthermore, TCMSP server and GEO DataSets were used to analyze the mechanism of Schisandrin B in colitis. It was found that Schisandrin B presented colitis in mice model. At the same time, Schisandrin B not only reduced inflammation in vivo and vitro model of colitis, but also suppressed the nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome in vivo and vitro model of colitis. In addition, Schisandrin B induced AMP-activated protein kinase (AMPK) / Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway in model of colitis, and regulated AMPK protein at 316 sites. The inhibition of AMPK reduced the anti-inflammation effects of Schisandrin B on NLRP3 inflammasome. Apart from that, Schisandrin B decreased reactive oxygen species (ROS)-induced mitochondrial damage and reduced epithelial cells damage of colitis through regulating pyroptosis. Collectively, our novel findings for first time showed that, Schisandrin B suppressed NLRP3 inflammasome activation-mediated interleukin-1beta (IL-1β) level and pyroptosis in intestinal epithelial cells of colitis model through the activation of AMPK/Nrf2 dependent signaling-ROS-induced mitochondrial damage, which may be a significant therapeutic approach in the treatment of acute colitis.

Asthma is a chronic inflammatory disorder of the airways. Schisandrin B (SB) is the main effective component. This study investigated the effects of SB on airway inflammation and airway remodeling in asthma. The rat model of asthma was established. The rats were treated with SB to evaluate the effects of SB on airway inflammation, airway remodeling, NLRP3 inflammasome activation, and pyroptosis. Alveolar macrophages of rats were isolated, and the macrophage inflammatory model was established by lipopolysaccharide (LPS) induction. The LPS-induced macrophages were treated with SB. The binding relationship between miR-135a-5p and TPRC1 was analyzed. LPS + SB-treated macrophages were transfected with miR-135a-5p inhibitor. The expressions of key factors of the STAT3/NF-κB pathway were detected. SB reduced airway inflammation and airway remodeling in asthmatic rats. SB inhibited NLRP3 inflammasome activation and reduced pyroptosis in asthmatic rats and LPS-induced macrophages. SB reversely regulated the miR-135a-5p/TRPC1 axis. Downregulation of miR-135a-5p attenuated the inhibitory effect of SB on NLRP3 inflammasome activation. SB inhibited the STAT3/NF-κB pathway via the miR-135a-5p/TRPC1 axis. In conclusion, SB inhibited NLRP3 inflammasome activation and reduced pyroptosis via the miR-135a-5p/TRPC1/STAT3/NF-κB axis, thus alleviating airway inflammation and airway remodeling in asthma. This study may confer novel insights for the management of asthma.

Schizandrin B exhibits prominent antioxidant and anti-inflammatory effects, and plays an important role in ameliorating myocardial ischemia/reperfusion injury. However, the underlying protective mechanisms remain to be elucidated. The aim of the present study was to explore the cardioprotective effects of schizandrin B against hypoxia/reoxygenation (H/R)-induced H9c2 cell injury, focusing on the role of the adenosine monophosphate-activated protein kinase (AMPK)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in this process. The results showed that schizandrin B attenuated the H/R-induced decrease in cell viability and the increase in lactate dehydrogenase release, as well as the apoptosis rate in H9c2 cells. Schizandrin B also mitigated H/R-induced oxidative stress, as illustrated by the decrease in intracellular reactive oxygen species generation, malondialdehyde content and NADPH oxidase 2 expression, and the increase in antioxidant enzyme superoxide dismutase and glutathione peroxidase activities. In addition, schizandrin B reversed the H/R-induced upregulation of pro-inflammatory cytokines [interleukin (IL)-1β (IL-1β) tumor necrosis factor-α, IL-6 and IL-8] and the downregulation of anti-inflammatory cytokines (transforming growth factor-β and IL-10) in the culture supernatant. Notably, schizandrin B increased the expression of Nrf2, NAD(P)H: Quinone oxidoreductase (NQO-1) and heme oxygenase-1 (HO-1) in H/R-treated H9c2 cells, activating the Nrf2 signaling pathway. The cardioprotection of schizandrin B against H/R injury was inhibited by Nrf2 knockdown induced byNrf-2-specific small interfering RNA (siRNA; si-Nrf2) transfection. Furthermore, schizandrin B enhanced phosphorylated (p)-AMPK expression, while AMPK knockdown induced by AMPK-specific siRNA(si-AMPK) transfection remarkably eliminated schizandrin B-induced cardioprotection and reduced Nrf2 expression in H/R-treated H9c2 cells. Taken together, these results suggested that schizandrin B exerts cardioprotection on H/R injury in H9c2 cells due to its antioxidant and anti-inflammatory activities via activation of the AMPK/Nrf2 pathway.

Schisandra chinensis is widely used and effective in protecting liver. There are many mechanisms of drug-induced hepatocyte injury, among which endoplasmic reticulum (ER) stress-induced cell injury plays an important role. However, little is known about whether schisandra chinensis can inhibit rifampicin (RFP)-induced hepatocyte injury by affecting ER stress. In our study, firstly, L02 cells were treated with different concentrations of RFP for different time intervals, and the apoptosis, survival rate and endoplasmic reticulum stress gene and protein expressions of glucose-regulated protein 78 (GRP 78), PKR-like ER kinase (PERK), activating transcription factor (ATF)4, C/EBP-homologus protein (CHOP), ATF6, arginine-rich, mutated in early stage tumors (ARMET), p-inositol-requiring enzyme 1 (IRE1) and X-box binding protein 1 (XBP-1) were measured. We found that RFP increased apoptosis of L02 cells, decreased cell survival, and increased the gene and protein expression levels of GRP78, PERK, ATF4, CHOP, ATF6, ARMET, p-IRE1 and XBP-1, suggesting that RFP could induce hepatocyte injury, and the degree of injury was positively correlated with the dose and time of RFP. Next, we treated RFP-damaged hepatocytes with schizandrin B. We found that schizandrin B increased cell survival rate in dose-dependent and time-dependent manner, decreased cell apoptosis rate, and reduced protein and gene expression levels of GRP78, PERK, ATF4, CHOP, ATF6, ARMET and XBP-1. These results indicate that schizandrin B alleviates RFP-induced injury in L02 cells by inhibiting ER stress.

Schizandrin B (Sch B) is the main component isolated from Schizandra fruit (Schisandra chinensis). While Sch B is established as having antioxidant, anti-proliferation and anti-inflammatory properties, but its activity in sepsis remains unclear. In the present study, we investigated the anti-inflammatory effects of Sch B in sepsis. Our experimental results demonstrated that Sch B inhibited production of IL-1β, TNF-α, IL-6 and HMGB1 by LPS-activated RAW264.7 cells. Moreover, Sch B suppressed expression of iNOS, reduced production of PGE2, blocked expression of MyD88 and TLR4, suppressed the activity of NF-κB and decreased phosphorylation of MAPKs in LPS-activated RAW264.7 cells. Administration of Sch B also reduced production of IL-1β and TNF-α, attenuated infiltration of inflammatory cells and tissue damage in lung, liver and kidney, and enhanced survival rate of LPS-challenged mice. Taken together, our data suggest that Sch B has anti-inflammatory properties against LPS-induced inflammation and sepsis. Sch B could protect against LPS-induced sepsis via the TLR4/NF-κB/MyD88 signaling pathway, and potentially be a novel anti-inflammatory and immunosuppressive drug candidate for treating sepsis.

1. Deoxyschizandrin and schizandrin B have diverse pharmacological effects, including hepatoprotective activity. We aim to study their hepatic uptake and their effects on the hepatic uptake of other clinical drugs mediated by OATP1B1 and OATP1B3. 2. Deoxyschizandrin exhibited a high affinity for OATP1B1 with Km of 17.61 ± 0.43 μM but a low affinity for OATP1B3. Similarly, schizandrin B also showed a strong affinity for OATP1B1 with Km of 18.45 ± 1.23 μM but a weak affinity for OATP1B3. 3. Atorvastatin and rifampicin could inhibit the uptake of deoxyschizandrin and schizandrin B mediated by OATP1B1. 4. Intriguingly, both deoxyschizandrin and schizandrin B significantly promoted the uptake of atorvastatin (with EC50 of 50.58 ± 8.08 and 24.70 ± 5.82 µM, respectively) and rosuvastatin (with EC50 of 13.46 ± 2.70 and 8.99 ± 4.73 µM, respectively) mediated by OATP1B1. Deoxyschizandrin could markedly promote the uptake of fluvastatin but inhibit the uptake of sodium taurocholate (TCNa) mediated by OATP1B1. 5. The promotion on hepatic uptake of statins mediated by OATP1B1 might lead to enhanced efficacy of cholesterol lowering and reduced risk of myopathy for hyperlipidemia patients when given statins together with deoxyschizandrin or schizandrin B.

The effectiveness of traditional Chinese medicine (TCM) against various diseases urges more low cost, speed and sensitive analytical methods for investigating the phamacology of TCM and providing a theoretical basis for clinical use. The potential of second-order calibration method was validated for the quantification of two effective ingredients of Schisandra chinensis in human plasma using spectrofluorimetry. The results obtained in the present study demonstrate the advantages of this strategy for multi-target determination in complex matrices. Although the spectra of the analytes are similar and a large number of interferences also exist, second-order calibration method could predict the accurate concentrations together with reasonable resolution of spectral profiles for analytes of interest owing to its \'second-order advantage\'. Moreover, the method presented in this work allows one to simply experimental procedure as well as reduces the use of harmful chemical solvents.