Schisandrol B and schisandrin B inhibit TGFβ1-mediated NF-κB activation via a Smad-independent mechanism

Cyclosporin A inhibits prostate cancer growth through suppression of E2F8 transcription factor in a MELK‑dependent manner

The treatment of advanced prostate cancer remains a formidable challenge due to the limited availability of effective treatment options. Therefore, it is imperative to identify promising druggable targets that provide substantial clinical benefits and to develop effective treatment strategies to overcome therapeutic resistance. Cyclosporin A (CsA) showed an anticancer effect on prostate cancer in cultured cell and xenograft models. E2F8 was identified as a master transcription factor that regulated a clinically significant CsA specific gene signature. The expression of E2F8 increased during prostate cancer progression and high levels of E2F8 expression are associated with a poor prognosis in patients with prostate cancer. MELK was identified as a crucial upstream regulator of E2F8 expression through the transcriptional regulatory network and Bayesian network analyses. Knockdown of E2F8 or MELK inhibited cell growth and colony formation in prostate cancer cells. High expression levels of E2F8 and androgen receptor (AR) are associated with a worse prognosis in patients with prostate cancer compared with low levels of both genes. The inhibition of E2F8 improved the response to AR blockade therapy. These results suggested that CsA has potential as an effective anticancer treatment for prostate cancer, while also revealing the oncogenic role of E2F8 and its association with clinical outcomes in prostate cancer. These results provided valuable insight into the development of therapeutic and diagnostic approaches for prostate cancer.

Metabolic profiling on the analysis of different parts of Schisandra chinensis based on UPLC-QTOF-MS with comparative bioactivity assays

The Schisandra chinensis is an important edible plant, and previous phytochemical research focused on the S. chinensis fruit (SF) due to its long history as traditional Chinese medicine. Schisandra chinensis fruit was used as an astringent tonic to astringe the lungs and the kidneys, replenish energy, promote the production of body fluids, tonify the kidney, and induce sedation. The components of S. chinensis, such as its stems (SS), leaves (SL), and roots (SR), have drawn little attention regarding their metabolites and bioactivities. In this study, a strategy of combining a chemical database with the Progenesis QI informatics platform was applied to characterize the metabolites. A total of 332 compounds were tentatively identified, including lignans, triterpenoids, flavonoids, tannins, and other compound classes. Heatmap and principal component analysis (PCA) showed remarkable differences in different parts of the plants. By multiple orthogonal partial least-squares discriminant analyses (OPLS-DA), 76 compounds were identified as potential marker compounds that differentiate these different plant parts. Based on the variable influence on the projection score from OPLS-DA, the active substances including gomisin D, schisandrol B, schisantherin C, kadsuranin, and kadlongilactone F supported the fact that the biological activity of the roots was higher than that of the fruit. These substances can be used as marker compounds in the plant roots, which likely contribute to their antioxidant and anti-inflammatory activities. The plant roots could be a new medicinal source that exhibits better activity than that of traditional medicinal parts, which makes them worth exploring.

Nuciferine attenuates lipopolysaccharide-stimulated inflammatory responses by inhibiting p38 MAPK/ATF2 signaling pathways

Nuciferine, isolated from Nelumbo nucifera (commonly known as lotus) leaves, has been shown to have beneficial effects, including antioxidant, anti-obesity, anti-diabetic, and anti-inflammatory properties. However, little is known about the mechanism of nuciferine action on the inflammatory response. This study aimed to investigate the anti-inflammatory effects of nuciferine and its underlying molecular mechanisms in lipopolysaccharide (LPS)-stimulated murine macrophages. In this study, nuciferine reduced LPS-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production and mRNA expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. Nuciferine also decreased the production of pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. Furthermore, nuciferine inhibited the LPS-mediated transcriptional activity of nuclear factor (NF)-κB and activator protein (AP)-1, and the nuclear translocation of NF-κB p65 and activating transcription factor 2 (ATF2), an AP-1 subunit. Nuciferine also decreased the phosphorylation of IκB kinase (IKK), inhibitor of NF-κB (IκB), NF-κB, mitogen-activated protein kinase 3 (MKK3), MKK6, p38 mitogen-activated protein kinase (MAPK), and ATF2. Overall, our findings suggest that nuciferine may exert anti-inflammatory effects in LPS-induced macrophages by inhibiting the NF-κB and p38 MAPK/ATF2 signaling pathways.

Schisandrol A, the main active ingredient of Schisandrae Chinensis Fructus, inhibits pulmonary fibrosis through suppression of the TGF-β signaling pathway as revealed by UPLC-Q-TOF/MS, network pharmacology and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra chinensis decoction derived from the book of Waitai Miyao (Tao Wang, Tang dynasty) is often used in the treatment of idiopathic pulmonary fibrosis (IPF), which is included in the Grand Ceremony of Chinese formulae (Huairen Peng, 1994). Schisandrae Chinensis Fructus (Sch) is one of the most important herbs in this formula. According to the "Shennong's Herbal Classicherbal" of the Han Dynasty, Sch has sour taste, warm nature, which has the effect of tonifying qi and curing cough. In addition, according to the "Compendium of Materia Medica" of the Ming Dynasty, Sch is used to treat cough and asthma, which has the effect of moistening the lung and tonifying the kidney. However, the active ingredients of Sch absorption into the plasma and its pharmacological mechanism of treatment for IPF still remained unclear.

AIM OF THE STUDY

Our research aimed at identifying the absorbed active ingredients and metabolized of Sch in rat plasma and the mechanism of anti-IPF based on serum pharmacochemistry.

MATERIALS AND METHODS

First, the rats were divided into control group and Sch group. Sch sample was orally administrated to the rats for seven days. The blood samples were drawn into an Eppendorf tube after the last dosing. The ultrahigh performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS) was applied to identify the absorption components and metabolites of Sch in rat plasma. Second, the network pharmacology combined with molecular docking analysis was further investigated to illuminate its potential mechanism of treatment for IPF by the biological targets regulating related pathways. Finally, the mechanism of action was verified by experimental in vitro and in vivo.

RESULTS

A total of 78 compounds, consist of 13 prototype lignans and 65 metabolites (including isomers) were identified. Network pharmacology study and molecular docking analysis indicated that schisandrol A (L1) play an anti-fibrosis role by regulating the TGF-β signaling pathway. Experimental in vitro and in vivo verified that the schisandrol A could inhibiting pulmonary fibrosis through TGF-β signaling pathway. The effect and mechanism of schisandrol A inhibiting pulmonary fibrosis were reported for the first time.

CONCLUSIONS

In this study, the absorption active ingredients of Sch in rat plasma were combined with the network pharmacology investigation and experimental in vitro and in vivo to elucidate its biological mechanism of treatment for IPF. The results provided a theoretical support for understanding the bioactive compounds and the pharmacological mechanism of Sch.

UGT1A1 dysfunction increases liver burden and aggravates hepatocyte damage caused by long-term bilirubin metabolism disorder

UGT1A1 is the only enzyme that can metabolize bilirubin, and its encoding gene is frequently mutated. UGT1A1*6 (G71R) is a common mutant in Asia which leads to the decrease of UGT1A1 activity and abnormal bilirubin metabolism. However, it is not clear whether low UGT1A1 activity-induced bilirubin metabolism disorder increases hepatocyte fragility. ugt1a^+/- mice were used to simulate the UGT1A1*6 (G71R) population. Under the same CCl₄ induction condition, ugt1a^+/- mice showed severer liver damage and fibrosis, indicating that ugt1a1 dysfunction increased liver burden and aggravated hepatocyte damage. In the animal experiment with a continuous intraperitoneal injection of bilirubin, the ugt1a^+/- mice livers had more serious unconjugated bilirubin accumulation. The accumulated bilirubin leads to hyperphosphorylation of IκB-α, Ikk-β, and p65 and a significant increase of inflammatory factor. The α-SMA and Collagen I proteins markedly up-regulated in the ugt1a^+/- mice livers. Immunofluorescence and confocal microscopy showed that hepatic stellate cells and Kupffer cells were activated in ugt1a^+/- mice. Comprehensive results show that there was a crosstalk relationship between low UGT1A1 activity-bilirubin-liver damage. Furthermore, cell experiments confirmed that unconjugated bilirubin activated the NF-κB pathway and induced DNA damage in hepatocytes, leading to the significant increase of inflammatory factors. UGT1A1 knockdown in hepatocytes aggravated the toxicity of unconjugated bilirubin. Conversely, overexpression of UGT1A1 had a protective effect on hepatocytes. Finally, Schisandrin B, an active ingredient with hepatoprotective effects, extracted from a traditional Chinese medicinal herb, which could protect the liver from bilirubin metabolism disorders caused by ugt1a1 deficiency by downregulating p65 phosphorylation, inhibiting Kupffer cells, reducing inflammation levels. Our data clarified the mechanism of liver vulnerability caused by cross-talk between low UGT1A1 activity bilirubin, and provided a reference for individualized prevention of liver fragility in Gilbert's syndrome.

HPLC-MS/MS-Mediated Analysis of the Pharmacokinetics, Bioavailability, and Tissue Distribution of Schisandrol B in Rats

Schisandrol B, a lignan isolated from dried Schisandra chinensis fruits, has been shown to exhibit hepatoprotective, cardioprotective, renoprotective, and memory-enhancing properties. This study sought to design a sensitive and efficient HPLC-MS/MS approach to measuring Schisandrol B levels in rat plasma and tissues in order to assess the pharmacokinetics, oral bioavailability, and tissue distributions of this compound in vivo. For this analysis, bifendate was chosen as an internal standard (IS). A liquid-liquid extraction (LLE) approach was employed for the preparation of samples that were subsequently separated with an Agilent ZORBAX Eclipse XDB-C₁₈ (4.6 × 150 mm, 5 μm) column with an isocratic mobile phase consisting of methanol and water containing 5 mM ammonium acetate and 0.1% formic acid (90 : 10, v/v). A linear calibration curve was obtained over the 5–2000 ng/mL and 1–1000 ng/mL ranges for plasma samples and tissue homogenates, respectively. This established method was then successfully applied to investigate the pharmacokinetics, oral bioavailability, and tissue distributions of Schisandrol B in Sprague-Dawley (SD) rats that were intravenously administered 2 mg/kg of Schisandrol B monomer, intragastrically administered Schisandrol B monomer (10 mg/kg), or intragastrically administered 6 mL/kg SCE (equivalent to 15 mg/kg Schisandrol B monomer). The oral absolute bioavailability of Schisandrol B following intragastric Schisandrol B monomer and SCE administration was approximately 18.73% and 68.12%, respectively. Tissue distribution studies revealed that Schisandrol B was distributed throughout several tested tissues, with particular accumulation in the liver and kidneys. Our data represent a valuable foundation for future studies of the pharmacologic and biological characteristics of Schisandrol B.

Transcriptome Analysis of the Anti-TGFβ Effect of Schisandra chinensis Fruit Extract and Schisandrin B in A7r5 Vascular Smooth Muscle Cells

Schisandra chinensis fruit extract (SCE) has been used as a traditional medicine for treating vascular diseases. However, little is known about how SCE and schisandrin B (SchB) affect transcriptional output-a crucial factor for shaping the fibrotic responses of the transforming growth factor β (TGFβ) signaling pathways in in vascular smooth muscle cells (VSMC). In this study, to assess the pharmacological effect of SCE and SchB on TGFβ-induced transcriptional output, we performed DNA microarray experiments in A7r5 VSMCs. We found that TGFβ induced distinctive changes in the gene expression profile and that these changes were considerably reversed by SCE and SchB. Gene Set Enrichment Analysis (GSEA) with Hallmark signature suggested that SCE or SchB inhibits a range of fibrosis-associated biological processes, including inflammation, cell proliferation and migration. With our VSMC-specific transcriptional interactome network, master regulator analysis identified crucial transcription factors that regulate the expression of SCE- and SchB-effective genes (i.e., TGFβ-reactive genes whose expression are reversed by SCE and SchB). Our results provide novel perspective and insight into understanding the pharmacological action of SCE and SchB at the transcriptome level and will support further investigations to develop multitargeted strategies for the treatment of vascular fibrosis.

Polydatin prevents bleomycin-induced pulmonary fibrosis by inhibiting the TGF-β/Smad/ERK signaling pathway

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, irreversible interstitial lung disease, with no effective cure. Polydatin is a resveratrol glucoside with strong antioxidant, anti-inflammatory and anti-apoptotic properties, which is used for treating health-related disorders such as cardiac disabilities, various types of carcinoma, hepatitis and hepatic fibrosis. The present study aimed to investigate the protective effect of polydatin against bleomycin-induced IPF and the possible underlying mechanism. A549 cells were treated with transforming growth factor-β1 (TGF-β1) and polydatin to observe phenotypic transformation and the related gene expression was detected. Sprague-Dawley rats were divided into seven groups and intratracheally infused with bleomycin to establish a pulmonary fibrosis model (the sham control group received saline). The rats were given pirfenidone (50 mg/kg), resveratrol (40 mg/kg) and polydatin (10, 40 and 160 mg/kg) for 28 days. The results demonstrated that polydatin had low toxicity to A549 cells and inhibited TGF-β1-induced phenotypic transformation as determined by MTS assay or observed using a light microscope. It also decreased the gene expression levels of α-smooth muscle actin and collagen I and increased the gene expression levels of epithelial cell cadherin in vitro and in vivo by reverse transcription-quantitative PCR. Furthermore, polydatin ameliorated the pathological damage and fiber production in lung tissues found by hematoxylin and eosin staining and Masson trichrome staining. Polydatin administration markedly reduced the levels of hydroxyproline, tumor necrosis factor-α, interleukin (IL)-6, IL-13, myeloperoxidase and malondialdehyde and promoted total superoxide dismutase activity in lung tissues as determined using ELISA kits or biochemical reagent kits. It inhibited TGF-β1 expression and phosphorylation of Smad 2 and 3 and ERK-1 and -2 in vivo as determined by western blot assays. These results suggest that polydatin protects against IPF via its anti-inflammatory, antioxidant and antifibrotic activities, and the mechanism may be associated with its regulatory effect on the TGF-β pathway.

Immunomodulatory effects of fermented Platycodon grandiflorum extract through NF-κB signaling in RAW 264.7 cells

BACKGROUND/OBJECTIVES

Platycodon grandiflorum (PG), an oriental herbal medicine, has been known to improve liver function, and has both anti-inflammatory and antimicrobial properties. However, little is known about the immune-enhancing effects of PG and its mechanism. In this study, we aimed to investigate whether fermented PG extract (FPGE), which has increased platycodin D content, activates the immune response in a murine macrophage cell line, RAW 264.7.

MATERIALS/METHODS

Cell viability was determined by Cell Counting Kit-8 assay and the nitric oxide (NO) levels were measured using Griess reagent. Cytokine messenger RNA levels of were monitored by quantitative reverse transcription polymerase chain reaction. To investigate the molecular mechanisms underlying immunomodulatory actions of FPGE in RAW 264.7 cells, we have conducted luciferase reporter gene assay and western blotting.

RESULTS

We found that FPGE treatment induced macrophage cell proliferation in a dose-dependent manner. FPGE also modulated the expression of NO and pro-inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. The activation and phosphorylation levels of nuclear factor kappa B (NF-κB) were increased by FPGE treatment. Moreover, 5-aminoimidazole-4-carboxamide ribonucleotide, an activator of AMP-activated kinase (AMPK), significantly reduced both lipopolysaccharides- and FPGE-induced NF-κB reporter gene activity.

CONCLUSIONS

Taken together, our findings suggest that FPGE may be a novel immune-enhancing agent acting via AMPK-NF-κB signaling pathway.

Immune-Enhancing Effects of Red Platycodon grandiflorus Root Extract via p38 MAPK-Mediated NF-κB Activation

Platycodongrandiflorus (PG) root extract has been widely used as an oriental herbal medicine. Red PG root extract (RPGE), which is made by steaming and drying PG several times, contains more saponin than raw (white) PG. Although RPGE has been known to have anti-inflammatory activity, the effects of RPGE on the immune-enhancing response remain unclear. In this study, we aimed to investigate the immune-enhancing effects of RPGE and its mechanism in macrophage cells and splenocytes. Our results revealed that cell proliferation of both macrophages and splenocytes correlate positively with the concentration of RPGE. Moreover, RPGE treatment increased the phagocytic activity of macrophage cells, as well as nitric oxide and cytokines production. Furthermore, RPGE induced phosphorylation of the p38 mitogen-activated protein kinase, which contributed to nuclear factor-kappa B activation. Thus, our findings suggest that RPGE may be a potential functional food for improving immune function.

Schizandrin B attenuates angiotensin II induced endothelial to mesenchymal transition in vascular endothelium by suppressing NF-κB activation

BACKGROUND

Angiotensin II (Ang II)-induced chronic inflammation and oxidative stress often leads to irreversible vascular injury, in which the endothelial to mesenchymal transition (EndMT) in the endothelial layers are involved. Schisandrin B (Sch B), a natural product isolated from traditional Schisandra chinensis, has been reported to exert vascular protective properties with unclear mechanism.

HYPOTHESIS/PURPOSE

This study investigated the protective effects and mechanism of Sch B against Ang II-induced vascular injury.

METHODS

C57BL/6 mice were subcutaneous injected of Ang II for 4 weeks to induce irreversible vascular injury. In vitro, Ang II-induced HUVECs injury was used to study the underlying mechanism. The markers of EndMT, inflammation and oxidative stress were studied both in vitro and in vivo.

RESULTS

Pre-administration of Sch B effectively attenuated phenotypes of vascular EndMT and fibrosis in Ang II-treated animals, accompanied with decreased inflammatory cytokine and ROS. The in vitro data from HUVECs suggest that Sch B directly targets NF-κB activation to suppress Ang II-induced EndMT and vascular injury. The activation of EndMT in the presence of Ang II is regulated by the NF-κB, a common player in inflammation and oxidative stress. Ang II-induced inflammation and oxidative stress also contributed to vascular EndMT development and Sch B inhibited inflammation/ROS-mediated EndMT by suppressing NF-κB.

CONCLUSION

EndMT contributes to vascular injury in Ang II-treated mice, and it can be prevented via suppressing NF-κB activation by Sch B treatment. These results also imply that NF-κB might be a promising target to attenuate vascular remodeling induced by inflammation and oxidative stress through an EndMT mechanism.

Protective effect of peptide DR8 on bleomycin-induced pulmonary fibrosis by regulating the TGF-β/MAPK signaling pathway and oxidative stress

Pulmonary fibrosis (PF) is a fatal and irreversible lung disease that eventually causes respiratory failure, lung dysfunction and death. The peptide DHNNPQIR-NH₂ (DR8) has been reported to possess potent antioxidant activity, and an imbalance of oxidation/antioxidation is a crucial mechanism that causes PF. Here, we studied the ability of DR8 to improve PF and further explored the pathway in which DR8 plays a critical role. We found that after prophylactic or therapeutic treatment with DR8, fibrosis-associated indices, including marker proteins, proinflammatory cytokines and profibrogenic cytokines, were significantly downregulated. Importantly, DR8 could reduce bleomycin-induced pathological changes and collagen deposition, especially collagen I content. Furthermore, DR8 prominently upregulated nonenzymatic antioxidants and enzymatic antioxidants. Consistent with the in vivo results, we observed that DR8 significantly inhibited the proliferation and reactive oxygen species (ROS) generation of A549 cells and NIH3T3 cells stimulated with transforming growth factor-β1 (TGF-β1), as well as decreased NADPH oxidase 4 (NOX4) levels under the same conditions. Moreover, DR8 reversed the TGF-β1-induced upregulation of phosphorylated ERK1/2 and p38 MAPK in cells and the bleomycin-induced upregulation of these indices in mice. Our results indicate that DR8 could prevent and treat PF by reducing oxidative damage and suppressing the TGF-β/MAPK pathway. Because of the high efficiency and low toxicity of DR8, we consider that DR8 could be a candidate drug for PF, and our studies establish a foundation for the development of a lead compound to be used as a therapy for fibrosis-related diseases.

Schisandrin B inhibits TGF-β1-induced epithelial-mesenchymal transition in human A549 cells through epigenetic silencing of ZEB1

Purpose/Aim: More and more evidences suggest that airway remodeling of fibrotic lung diseases may be associated with epithelial-mesenchymal transition (EMT) of human A549 cells induced by transforming growth factor (TGF)-β1. Schisandrin B (Sch B) is the highest content of dibenzocyclooctadiene lignans in Schisandra chinensis. In this study, we assessed the inhibitory influences of Sch B on TGF-β1-stimulated EMT in human A549 cells. Materials and Methods: The influences of Sch B on cell viability, invasion and metastasis in TGF-β1-induced human A549 cells were detected by MTT, wound healing and transwell invasion assays. The expression levels of α-SMA, E-cadherin, ZEB1 and Twist1 were examined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot. The enrichment of H3K4me3 and H3K9me3 at the ZEB1 promoter was determined by ChIP analysis. Results: Experimental results showed that Sch B increased the expression of the epithelial phenotype marker E-cadherin and inhibited the expression of the mesenchymal phenotype marker α-SMA during EMT induced by TGF-β1. The enhancement in invasion and migration of TGF-β1-induced A549 cells was inhibited by Sch B. Sch B also repressed the expression of ZEB1 transcription factor in EMT, by increasing the enrichment of H3K9me3 at the ZEB1 promoter to repress its transcription while the expression of the Twist1 transcription factor was unaffected. Conclusions: Our data suggest that Sch B can prevent TGF-β1-stimulated EMT in A549 cells through epigenetic silencing of ZEB1, which may be clinically related to the efficient treatment of EMT-associated fibrotic diseases.

Bisdemethoxycurcumin protects against renal fibrosis via activation of fibroblast apoptosis

Renal fibrosis is the common final outcome of nearly all progressive chronic kidney diseases (CKD) that eventually develop into end-stage renal failure, which threatens the lives of patients. Currently, there are no effective drugs for the treatment of renal fibrosis. However, studies have shown that certain plant natural products have a fibrosis-alleviating effect. Thus, we have screened a large number of natural products for their ability to protect against renal fibrosis and found that bisdemethoxycurcumin has a good therapeutic effect in renal fibrosis according to the data obtained in a mouse model of unilateral ureteral obstruction (UUO). The results indicate that bisdemethoxycurcumin can efficiently attenuate renal fibrosis induced by UUO. Additional studies of the bisdemethoxycurcumin mechanism of action in the treatment of renal fibrosis demonstrated that the therapeutic effect of bisdemethoxycurcumin is mediated by the specific induction of fibroblast apoptosis at a concentration of 20 μM. bisdemethoxycurcumin can efficiently protect against renal fibrosis both in vitro and in vivo. This discovery will provide new ideas for renal fibrosis treatment in clinics and a new direction for the development of effective drug therapy of renal fibrosis.