Progress in research on the hepatoprotective effects of C-21 steroidal glycosides from Baishouwu.

The antitumour activity of C21 steroidal glycosides and their derivatives of Baishouwu: A review

Alpha-calcitonin gene-related peptide (alphaCGRP) is a 37-amino acid pleiotropic peptide that we previously showed to exert a hepatoprotective effect during concanavalin A (Con A)-induced acute hepatitis. In the present study, we used alphaCGRP(-/-) mice to further investigate the antifibrogenic and hepatoprotective effects of endogenous alphaCGRP in Con A-induced chronic hepatitis. Chronic hepatitis was induced in alphaCGRP(-/-) and wild-type mice by repeated administration of Con A. Serum transaminases were measured to assess hepatic injury. The severity of fibrosis and the activation of hepatic stellate cells (HSCs) were analysed by Masson trichrome staining and immunohistochemical staining of alpha-smooth muscle actin (alpha-SMA) respectively. Altered expression of fibrosis- and inflammation-related genes was evaluated using a quantitative real-time polymerase chain reaction. Activation and proliferation of HSCs were analysed using both primary cultured HSCs from the mice and the LI90 HSC cell line. alphaCGRP(-/-) mice showed more severe liver fibrosis than wild-type mice in a Con A-induced chronic hepatitis model. In histological and gene expression analyses, alphaCGRP(-/-) mice showed greater inflammatory and fibrotic changes, greater HSC activation and a higher incidence of apoptosis among nonparenchymal cells than wild-type mice. Endogenous alphaCGRP mitigates liver fibrosis in chronic hepatitis induced by repeated administration of Con A. alphaCGRP could be a useful therapeutic target for the treatment of chronic hepatitis.

BackgroundIn normal, homeostatic conditions, cholangiocytes are mitotically dormant, hepatic stellate cells (HSCs) are quiescent and mast cell (MC) numbers are relatively low. Upon injury resulting in hepatic fibrosis, there is an activation of HSCs and the release of pro‐inflammatory factors like TGF‐β1 from proliferating cholangiocytes. MCs infiltrate the liver following injury and promote biliary hyperplasia by releasing factors like histamine. In mice lacking the histidine decarboxylase gene (HDC−/− mice), MCs are morphologically altered and also low in number. We tested the hypothesis that MCs promote fibrosis in normal and HDC−/−mice by increasing HSC activation, cholangiocyte proliferation and TGF‐β1 release.MethodsNormal, wild‐type (WT) mice and HDC−/− mice were injected with 1xPBS or cultured MCs derived from fetal mouse liver (5 × 106) via tail vein delivery. After 6 days, mice were sacrificed and liver blocks, isolated cholangiocytes and serum was obtained. Biliary mass and proliferation was evaluated by immunohistochemistry for CK‐19 and PCNA, respectively, and hepatic fibrosis and collagen deposition was measured by Masson's Trichrome and Fast Green/Sirius Red staining. Real‐time PCR was performed in total liver and isolated cholangiocytes for fibrotic markers, α‐SMA, collagen‐type 1a and fibronectin. HSC activation was measured by immunofluorescence and real‐time PCR in total liver for synaptophysin‐9 (SYP‐9). TGF‐β1 secretion was measured by EIA in serum from all mice and by real‐time PCR in total liver and isolated cholangiocytes. In vitro, cultured HSCs and cholangiocytes were treated with cultured MCs and fibrosis markers and TGF‐β1 expression/secretion was measured.ResultsMC injection increased biliary mass, proliferation and hepatic fibrosis in both WT and HDC−/− mice compared to controls. HSC activation was also enhanced in mice injected with MC compared to controls. TGF‐β1 secretion in serum and gene expression was increased following MC injections in both WT and HDC−/− mice compared to controls. In vitro, co‐culture with MCs increased cholangiocyte and HSC proliferation, activation and fibrotic marker gene expression.ConclusionIn normal conditions, MCs are low in number, however; when the liver is damaged, MCs infiltrate, release profibrotic factors and induce further damage. Our results demonstrate that MCs promote biliary proliferation, HSC activation and hepatic fibrosis in normal and HDC−/−mice via increased TGF‐β1 signaling. MCs are a pro‐proliferative and pro‐fibrogenic component of hepatic fibrosis. Targeting MCs may be a key therapeutic in fibrotic‐related liver pathologies when MC numbers are increased.Support or Funding InformationVA Career Development Award

Anti-cancer activity of Marsdenialongise A, a new C21 steroidal glycoside isolated from Marsdenia longipes W.T. Wang (Apocynaceae)

Three new C21 steroidal glycosides from Tylophora atrofolliculata

C21 steroidal glycosides and oligosaccharides from the root bark of Periploca sepium

Three C21 steroidal glycosides, stephanoside E (compound 1) together with two new others (compound 2 and 3) were isolated from the metabolites of stemucronatoside K, an immunosuppressive C21 steroidal glycosides from Stephanotis mucronata. On the basis of chemical evidence and extensive spectroscopic methods including one-dimensional and two-dimensional nuclear magnetic resonance (NMR), structures of 2 and 3 were determined to be 12-O-acetyl- 20-O-(N-methyl) anthraniloylsarcostin 3-O-{b-D-6-deoxy-3-O-methyl-b-D- allopyranosyl-(1→4)- b-D- cymaropyranosyl-(1→4)- b-D-cymaropyranoside} (2) and 12-O-acetyl-20-O-(N-methyl) anthraniloylsarcostin 3-O-{6-deoxy-b-D- allopyranosyl-(1→4)- b-D-cymaropyranosyl-(1→4)- b-D-cymaropyranoside} (compound 3), respectively. Key words: Stemucronatoside K, metabolites, steroidal glycosides.

Steroidal glycosides from the roots of Cynanchum stauntonii and their effects on the expression of iNOS and COX-2

New C21 steroidal glycosides from the roots of Cynanchum stauntonii and their protective effects on hypoxia/reoxygenation induced cardiomyocyte injury

Hepatoprotective and antifibrotic effect of a new silybin–phosphatidylcholine–Vitamin E complex in rats

Immunosuppressive C21 steroidal glycosides from the root of Cynanchum atratum

A chemical investigation on 80% ethanol extract from the whole plants of Tylophora ovata afforded two new C21 steroidal glycosides, ovatacosides A and B (1 and 2). Structural elucidation of both compounds were performed by spectral methods such as 1D and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy and high resolution mass spectrometry. The isolated components were evaluated in vitro for anti-inflammatory activities against COX-1 and COX-2 and radical scavenging potential using DPPH test. Consequently, 1 exhibited modest selective inhibition on COX-1 (61.9%) at the concentration of 100 μM and significant DPPH scavenging activity (IC50 = 42.9 μM) comparable with positive control Trolox (IC50 = 44.2 μM).

Three new C21 pregnane steroids, chonemorphols A-C (1, 3, and 4), 11 new C21 steroidal glycosides, chonemorphosides A-K (2 and 5-14), and 11 known compounds (15-25) were obtained from the vines and leaves of Chonemorpha megacalyx Pierre. Their structures were established using extensive spectroscopic data. The X-ray crystallographic data of 1 and 3 permitted definition of their absolute configurations. Notably, 1 and 2 possessed an uncommon 6/5/6/5/5-fused steroidal ring system. Compound 7 displayed significant cytotoxicity against several cancer cell lines with IC50 values of 2.0-3.6 μM.

Stress affects many organs in addition to the brain, including the liver. We assessed the effects on the liver of blocking N-methyl-d-aspartate (NMDA) glutamate receptors with memantine in acute and repeated restraint stress. Forty-two male albino rats were divided into 7 groups; control, acute restraint stress (ARS), ARS + memantine, repeated restraint stress, repeated restraint + memantine, and positive control groups. We measured serum iron, zinc, alanine transferase and aspartame transferase, hepatic malondialdehyde, tumor necrosis factor-α (TNF-α), glutathione peroxidase, superoxide dismutase, metallothionein content, zinc transporter ZRT/IRT-like protein 14 mRNA expression, and hepcidin expression. We conducted a histopathological evaluation via histological staining and immunostaining for glial fibrillary acidic protein and synaptophysin expression, both of which are markers of hepatic stellate cell (HSC) activation. Both ARS and repeated stress increased markers of hepatic cell injury, oxidative stress, and HSC activation. Blocking NMDA with memantine provided a hepatoprotective effect in acute and repeated restraint stress and decreased hepatic cell injury, oxidative stress, and HSC activation.

Liver fibrosis is a central feature of progressive liver diseases, including metabolic dysfunction-associated steatohepatitis (MASH). The profibrotic liver microenvironment drives hepatic stellate cell (HSC) activation and collagen deposition. However, the nature of HSC-mediated autocrine signaling during the fibrotic response has not been completely characterized. Here, we identify Netrin-1 as an autocrine factor that drives HSC activation and liver fibrosis in patients with MASH. Hepatic Netrin-1 expression was consistently elevated across multiple experimental models of liver fibrosis. Functional studies showed that adenovirus-associated virus (AAV)-mediated hepatic Netrin-1 overexpression exacerbated fibrosis, whereas HSC-specific conditional ablation of Netrin-1 markedly attenuated diet-induced MASH and CCl4-induced liver fibrosis. Notably, lipid nanoparticle-mediated siRNA knockdown of Netrin-1 ameliorated liver fibrosis in mice. Mechanistic investigations revealed that Netrin-1 promotes HSC activation through autocrine signaling mediated by the UNC5B receptor, which triggers rapid intracellular Ca2+ mobilization and downstream SMAD2 phosphorylation and fibrogenic gene expression. Collectively, our findings identify a novel autocrine signaling axis in which HSC-derived Netrin-1 establishes a positive feedback loop that sustains HSC activation and drives fibrotic progression. Blocking the Netrin-1-mediated fibrogenic response may offer a potential therapeutic strategy for anti-fibrotic interventions.