Schizandrin C regulates lipid metabolism and inflammation in liver fibrosis by NF-κB and p38/ERK MAPK signaling pathways.

Liver fibrosis is considered a sustained wound healing response and metabolic syndrome, and its therapy is of great significance for chronic liver disease. Schizandrin C, as one lignan from hepatic protectant Schisandra chinensis, can depress the oxidative effect and lipid peroxidation, and protect against liver injury. In this study, C57BL/6J mice were used to estimate a liver fibrosis model by CCl4, and Schizandrin C exerted an anti-hepatic fibrosis effect, as evidenced by decreased alanine aminotransferase, aspartate aminotransferase and total bilirubin activities in serum, lower hydroxyproline content, recuperative structure and less collagen accumulation in the liver. In addition, Schizandrin C reduced the expressions of alpha-smooth muscle actin and type Ι collagen in the liver. In vitro experiments also revealed that Schizandrin C attenuated hepatic stellate cell activation in both LX-2 and HSC-T6 cells. Furthermore, lipidomics and quantitative real-time PCR analysis revealed that Schizandrin C regulated the lipid profile and related metabolic enzymes in the liver. In addition, the mRNA levels of inflammation factors were downregulated by Schizandrin C treatment, accompanied by lower protein levels of IκB-Kinase-ß, nuclear factor kappa-B p65, and phospho-nuclear factor kappa-B p65. Finally, Schizandrin C inhibited the phosphorylation of p38 MAP kinase and extracellular signal-regulated protein kinase, which were activated in the CCl4 fibrotic liver. Taken together, Schizandrin C can regulate lipid metabolism and inflammation to ameliorate liver fibrosis by nuclear factor kappa-B and p38/ERK MAPK signaling pathways. These findings supported Schizandrin C as a potential drug for liver fibrosis.

Schizandrin C exerts anti-neuroinflammatory effects by upregulating phase II detoxifying/antioxidant enzymes in microglia.

We investigated the anti-neuroinflammatory properties of schizandrin C by focusing on its roles in the induction of phase II detoxifying/antioxidant enzymes and in the modulation of upstream signaling pathways. Schizandrin C induced expression of phase II detoxifying/antioxidant enzymes including heme oxygenase-1 (HO-1) and NADPH dehydrogenase quinone-1 (NQO-1). Activation of upstream signaling pathways, such as the cAMP/protein kinase A/cAMP response element-binding protein (cAMP/PKA/CREB) and erythroid-specific nuclear factor-regulated factor 2 (Nrf-2) pathways, significantly increased following treatment with schizandrin C. In addition, expressions of schizandrin C-mediated phase II detoxifying/antioxidant enzymes were completely attenuated by adenylyl cyclase inhibitor (ddAdo) and protein kinase A (PKA) inhibitor (H-89). In microglia, schizandrin C significantly inhibited lipoteichoic acid (LTA)-stimulated pro-inflammatory cytokines and chemokines, prostaglandin E2 (PGE2), nitric oxide (NO), and reactive oxygen species (ROS) production, and inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and matrix metallopeptidase-9 (MMP-9) protein expressions. Moreover, schizandrin C suppressed LTA-induced nuclear factor-kappa B (NF-κB), activator protein-1 (AP-1), janus-kinase/signal transducer and activator of transcription (JAK-STATs), and mitogen-activated protein kinase (MAPK) activation. Schizandrin C also effectively suppressed ROS generation and NO production, as well as iNOS promoter activity in LTA-stimulated microglia. This suppressive effect was reversed by transfection with Nrf-2 and HO-1 siRNA and co-treatment with inhibitors ddAdo and H-89. Our results indicate that schizandrin C isolated from Schisandra chinensis could be used as a natural anti-neuroinflammatory agent, inducing phase II detoxifying/antioxidant enzymes via cAMP/PKA/CREB and Nrf-2 signaling.

Effects of Supplementation with a Schizandrin C Derivative DDB-mixed Preparation (DWP-04) on Antioxidant Activity in Cisplatin-induced Nephrotoxicity in Rats / 대한신장학회지

PURPOSE: This study investigated the effect of reducing cisplatin induced nephrotoxicity with DWP-04 that is the compound of Schizandrin C derivative biphenyldimethyl dicarboxylate (DDB), glutathione and selenium. For the purpose of observation is that how DWP-04 has influence on mechanism of reducing cisplatin induced nephrotoxicity with renal function test, free radical formation and detoxification enzyme system in renal tissue. METHODS: Five groups of rats were dosed with vehicle, cisplatin (2 mg/kg i.p.), cisplatin+DWP-04 (100, 200 mg/kg po), or cisplatin+sodium thiosulfate (200 mg/kg i.p.) daily for 4 weeks. RESULTS: Serum creatinine, lactate dehydrogenase and activity of hydroxy radical increased in the cisplatin group and suppressed in the cisplatin+DWP-04 group compared to the cisplatin group. The renal tissue concentration of lipid peroxidase and lipofuscin were increased in the cisplatin group compared to the other groups. The activity of aminopyrine N-demethylase, aniline hydroxylase, aldehyde oxidase and xanthine oxidase, of which free radical formation system in kidney was also decreased in the cisplatin+DWP-04 group compared to the cisplatin and cisplatin+sodium thiosulfate group. The activity of detoxification system of free radical, such as glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were markedly increased in the cisplatin+DWP-04 group than the cisplatin and the cisplatin+sodium thiosulfate group (p<0.05). CONCLUSION: It can be concluded that the mechanism of decreasing cisplatin-induced nephrotoxicity by DWP-04 is that the decreasing of the amount of lipid peroxide and lipofuscin in the renal tissue by increasing activity of the antioxidant defense system and the decreasing of reactive oxygen species by increasing detoxification enzyme activity.