Schisantherin E (Schizantherin-E)

Schisantherin A ameliorates liver fibrosis through TGF-β1mediated activation of TAK1/MAPK and NF-κB pathways in vitro and in vivo

Backgroud: Schisandra chinensis, a traditional Chinese medicine for liver protection, can significantly improve liver fibrosis. However, it is still unclear which active components in Schisandra chinensis play an anti-fibrosis role. Purpose: The purpose of present study was to observe the anti-fibrosis effect of schisantherin A (SCA) on liver fibrosis and explore its underlying mechanism. Methods: The liver fibrosis model of mice was constructed by the progressive intraperitoneal injection of thioacetamide (TAA), and SCA (1, 2, and 4 mg/kg) was administered by gavage for 5 weeks. The biochemical indicators and inflammatory cytokines were measured, changes in the pathology of the mice liver were observed by hematoxylin & eosin (H&E) and Masson stainings for studying the anti-fibrosis effect of SCA. A hepatic stellate cell (HSCs) activation model induced by transforming growth factor-β1 (TGF-β1) was established, and the effect of SCA on the HSCs proliferation was observed by MTT assay. The expressions of target proteins related to transforming growth factor-β-activated kinase 1 (TAK1)/mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways were evaluated by western blotting, immunohistochemistry or immunofluorescence analysis, to explore the potential mechanism of SCA. Results: SCA could significantly ameliorate the pathological changes of liver tissue induced by TAA, and reduce the serum transaminase level, the hydroxyproline level and the expression of α-smooth muscle actin (α-SMA) and collagen 1A1 (COL1A1) proteins in the liver tissue. SCA could significantly lower the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in the serum and liver tissue, and down-regulate the expression of target proteins related to TAK1/MAPK and NF-κB pathways in the liver tissue. The in vitro studies demonstrated that SCA significantly inhibited the proliferation and activation of HCS-T6 cells induced by TGF-β1, decreased TNF-α and IL-6 levels, and inhibited the TAK1 activation induced by TGF-β1 and then the expression of MAPK and NF-κB signaling pathway-related proteins. Conclusion: Together, SCA can ameliorate the liver fibrosis induced by TAA and the HSC-T6 cell activation induced by TGF-β1 in mice, and its mechanism may be to inhibit the HSCs activation and inflammatory response by inhibiting TGF-β1 mediated TAK1/MAPK and signal pathways.

Computational insights into the different catalytic activities of CYP3A4 and CYP3A5 toward schisantherin E

The cytochromes CYP3A4 and CYP3A5 share 84% sequence identity, but they exhibit different catalytic activities toward some substrates. Schisantherin E (SE) was recently identified as a selective substrate of CYP3A5, which exhibited catalytic efficiency that was more than 23 times higher than CYP3A4. At present, however, the structural determinants responsible for the different catalytic activities of the two enzymes toward SE have not been fully understood. In this study, a combination of molecular docking, molecular dynamic simulations, and binding free energy calculation was performed on the CYP3A4/CYP3A5-SE systems to investigate the issue. The results demonstrate that Ser119 in CYP3A4 and Glu374 in CYP3A5 formed direct hydrogen bonding with SE, respectively. Additionally, one water molecule located between the B-C loop and the I helix mediated different hydrogen-bonding networks between CYP3A4/3A5 and SE. The residue differences (Phe/Leu108 and Leu/Phe210) triggered the distinct conformational changes of the Phe-cluster residues, especially Phe213 and Phe215, which formed stronger hydrophobic interactions with SE in CYP3A5. The calculated binding free energies were consistent with the experimental results.

Schisantherin A exhibits anti-inflammatory properties by down-regulating NF-kappaB and MAPK signaling pathways in lipopolysaccharide-treated RAW 264.7 cells

Schisantherin A, a dibenzocyclooctadiene lignan isolated from the fruit of Schisandra sphenanthera, has been used as an antitussive, tonic, and sedative agent under the name of Wuweizi in Chinese traditional medicine. In the present study, we carry out a screening program to identify the anti-inflammatory potentials of schisantherin A. We found that schisantherin A reduced lipopolysaccharide (LPS (1 mg/L))-induced levels of TNF-alpha, IL-6, NO, and PGE2 (p<0.01 or p<0.05), and also reduced levels of iNOS and COX-2 in RAW 264.7 macrophages in a concentration-dependent manner. We further investigated signal transduction mechanisms to determine how schisantherin A affects. RAW264.7 cells were pretreated with 0.5, 2.5, or 25 mg/L of schisantherin A 1 h prior to treatment with 1 mg/L of LPS. Thirty minutes later, cells were harvested and mitogen activated protein kinases (MAPKs) activation and I kappaB alpha was measured by Western blot. Alternatively, cells were fixed and nuclear factor-kappaB (NF-kappaB) activation was measured using immunocytochemical analysis. Signal transduction studies showed that schisantherin A significantly inhibited extracellular signal-regulated kinase (ERK), p38, and c-jun NH2-terminal kinase (JNK) phosphorylation protein expression. Schisantherin A also inhibited p65-NF-kappaB translocation into the nucleus by I kappaB alpha degradation. By using specific inhibitors of ERK, JNK and p38, we found that schisantherin A may inhibit TNF-alpha mostly through ERK pathway. Therefore, schisantherin A may inhibit LPS-induced production of inflammatory cytokines by blocking NF-kappaB and MAPKs signaling in RAW264.7 cells.

Quality Evaluation of Wild and Cultivated Schisandrae Chinensis Fructus Based on Simultaneous Determination of Multiple Bioactive Constituents Combined with Multivariate Statistical Analysis

Schisandrae Chinensis Fructus, also called wuweizi in China, was a widely used folk medicine in China, Korea, and Russia. Due to the limited natural resources and huge demand of wuweizi, people tend to cultivate wuweizi to protect this species. However, the quality of wild and cultivated herbs of the same species may change. Little attention has been paid to comparing wild and cultivated wuweizi based on simultaneous determination of its active components, such as lignans and organic acids. An analytical method based on UFLC-QTRAP-MS/MS was used for the simultaneous determination of 15 components, including 11 lignans (schisandrin, gomisin D, gomisin J, schisandrol B, angeloylgomisin H, schizantherin B, schisanhenol, deoxyschizandrin, γ-schisandrin, schizandrin C, and schisantherin) and 4 organic acids (quinic acid, d(-)-tartaric acid, l-(-)-malic acid, and protocatechuic acid) in wuweizi under different ecological environments. Principal components analysis (PCA), partial least squares discrimination analysis (PLS-DA), independent sample t-test, and gray relational analysis (GRA) have been applied to classify and evaluate samples from different ecological environments according to the content of 15 components. The results showed that the differential compounds (i.e., quinic acid, l-(-)-malic acid, protocatechuic acid, schisandrol B) were significantly related to the classification of wild and cultivated wuweizi. GRA results demonstrated that the quality of cultivated wuweizi was not as good as wild wuweizi. The protocol not just provided a new method for the comprehensive evaluation and quality control of wild and cultivated wuweizi, but paved the way to differentiate them at the chemistry level.

Studies on the active principles of Schisandra sphenanthera Rehd. et Wils. The structures of schisantherin A, B, C, D, E, and the related compounds

Deoxyschisandrin (VIII) and five new lignans, named schisantherin A, B, C, D, and E, were isolated from the active fraction of the fruits of Schisandra sphenanthera Rehd. et Wils. Their configurations and conformations were established by exhaustive spectral analysis as well as chemical degradations as shown in Ia, Ib; IIa, IIb; IIIa, IIIb; IVa, IVb, and Va, Vb respectively, and their absolute configurations at biphenyl, at C6, C7, and C8 were all assigned to be S form. The position of the methylenedioxyl group in the structures of gamma-schisandrin and Wuweizisu C (as described in the literature), isolated from Schisandra chinensis, must be corrected as shown in VI and VII respectively. In pharmacologica studies and preliminary clinical trials, schisantherin A, B, C, and D showed good effect in lowering the serum glutamic-pyruvic transaminase level of the patients suffering from chronic virus hepatitis. Schisantherin E and deoxyschisandrin were not effective.