(Pro)renin Receptor Knockdown Attenuates Liver Fibrosis Through Inactivation of ERK/TGF-ß1/SMAD3 Pathway.

BACKGROUND & AIMS: Activation of the (pro)renin receptor (PRR) up-regulates the expression of profibrotic genes in the kidney and heart. We aimed to investigate the role of PRR in hepatic fibrogenesis. METHODS: Human hepatic PRR levels were measured in patients with or without liver fibrosis. PRR expression was analyzed in primary mouse hepatic stellate cells (HSCs). Experimental fibrosis was studied in thioacetamide (TAA)-treated or methionine choline-deficient (MCD) diet-fed C57BL/6 mice. Lentivirus-mediated PRR short hairpin RNA was used to knockdown hepatic PRR expression. Lentiviral vectors expressing PRR short hairpin RNA or complementary DNA from the α-smooth muscle actin promoter were used for myofibroblast-specific gene knockdown or overexpression. RESULTS: PRR is up-regulated in human and mouse fibrotic livers, and in activated HSCs. Hepatic PRR knockdown reduced liver fibrosis by suppressing the activation of HSCs and expression of profibrotic genes in TAA or MCD diet-injured mice without significant changes in hepatic inflammation. Renin and prorenin increased the expression of PRR and production of TGF-ß1 in human activated HSC Lieming Xu-2 cells, and knockdown of PRR inactivated Lieming Xu-2 cells with decreased production of transforming growth factor (TGF)-ß1 and Mothers against decapentaplegic homolog 3 (Smad3) phosphorylation. Myofibroblast-specific PRR knockdown also attenuated liver fibrosis in TAA or MCD diet-injured mice. Mice with both myofibroblast-specific and whole-liver PRR knockdown showed down-regulation of the hepatic extracellular signal-regulated kinase (ERK)/TGF-ß1/Smad3 pathway. Myofibroblast-specific PRR overexpression worsened TAA-induced liver fibrosis by up-regulating the ERK/TGF-ß1/Smad3 pathway. CONCLUSIONS: PRR contributes to liver fibrosis and HSC activation, and its down-regulation attenuates liver fibrosis through inactivation of the ERK/TGF-ß1/Smad3 pathway. Therefore, PRR is a promising therapeutic target for liver fibrosis.

Antiviral effect of saikosaponin B2 in combination with daclatasvir on NS5A resistance-associated substitutions of hepatitis C virus.

BACKGROUND: Hepatitis C virus (HCV) is a major causative agent of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. The rapid progress in the development of direct-acting antivirals has greatly elevated the cure rate to ≥95% in recent years. However, the high cost of treatment is not affordable to patients in some countries, necessitating the development of less expensive treatment. METHODS: We adopted a cell culture-derived HCV system to screen a library of the pure compounds extracted from herbs deposited in the chemical bank of the National Research Institute of Chinese Medicine, Taiwan. RESULTS: We found that saikosaponin B2 inhibited viral entry, replication, and translation. Saikosaponin B2 is a plant glycoside and a component of xiao-chai-hu-tang, a traditional Chinese herbal medicine extracted from the roots of Bupleurum falcatum. It also inhibited daclatasvir-resistant mutant strains of HCV, especially in combination with daclatasvir. CONCLUSION: Our results may aid the development of a new combination therapy useful for patients with HCV who are intolerant or refractory to the currently available medications, including pegylated interferon and direct-acting antiviral agents.

Inhibitory Effects of Amentoflavone and Orobol on Daclatasvir-Induced Resistance-Associated Variants of Hepatitis C Virus.

Hepatitis C virus (HCV) is recognized as a major causative agent of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Despite rapid progress in the development of direct-acting antivirals (DAA) against HCV infection in recent years, cost-effective antiviral drugs with more affordable prices still need to be developed. In this study, we screened a library of natural compounds to identify natural HCV inhibitors. The library of the pure compounds extracted from Chinese herbs deposited in the chemical bank of National Research Institute of Chinese Medicine (NRICM), Taiwan was screened in the cell culture-derived HCV (HCVcc) system. We identified the flavone or flavan-based compounds amentoflavone, 7,4[Formula: see text]-dihydroxyflavanone, and orobol with the inhibition of viral entry, replication, and translation of the HCV life cycle. Amentoflavone and orobol also showed inhibitory effects on resistant-associated variants to the NS5A inhibitor daclatasvir. The results of this study have the potential to benefit patients who are intolerant to the adverse effect of pegylated interferon or who harbor resistant strains refractory to treatment by current direct-acting antiviral agents.

Clinical efficacy of Rong-Yang-Jyh-Gan-Tang on patients with chronic hepatitis C: A double-blinded randomized placebo-controlled crossover study.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Chinese medicine (TCM) has been widely used by the Chinese population for treatment of chronic hepatitis. However, the efficacy of TCM for patients with chronic hepatitis has not been confirmed, mostly due to the lack of available scientific parameters such as serum viral load to evaluate treatment response. AIM OF THE STUDY: We evaluated the efficacy of Rong-Yang-Jyh-Gan-Tang (RYJGT, composed of Long-Dan-Xie-Gan-Tang, Jia-Wei-Xia-Yao-San, Dan-Shen, and Hou-Po) on patients with chronic hepatitis C. MATERIALS AND METHODS: Thirty-six patients with chronic hepatitis C who had no response to or had contraindications to interferon-ribavirin therapy were randomly allocated to receive RYJGT 15g/day or placebo for 12 weeks. After a 2-week washout period, patients were crossed over to receive placebo or RYJGT for another 12 weeks. Evaluation parameters included liver biochemistries, serum HCVRNA, side effects of RYJGT/placebo, and TCM symptoms. RESULTS: Of the patients who had 12-week RYJGT treatment, 51.7% had decreased serum HCVRNA levels, whereas only 25.8% patients had decreased levels in the placebo group (p=0.036). TCM patterns of "Damp-Heat" and "Liver Qi Depression" had significantly improved after RYJGT treatment in comparison with the placebo. Logistic analyses showed that RYJGT treatment, and pre-treatment values of TCM symptoms of "Damp-Heat" and "Liver Qi Depression", were statistically significant factors in predicting the decrease in serum HCVRNA. CONCLUSION: Chronic hepatitis C patients who received a 12-week RYJGT treatment had significantly higher HCVRNA decrease ratio, and improved TCM symptoms of "Damp-Heat" and "Liver Qi Depression", than those who received the placebo. Our results require further larger scale clinical trials.

Honokiol thwarts gastric tumor growth and peritoneal dissemination by inhibiting Tpl2 in an orthotopic model.

Honokiol is known to suppress the growth of cancer cells; however, to date, its antiperitoneal dissemination effects have not been studied in an orthotopic mouse model. In the present study, we evaluated the antiperitoneal dissemination potential of Honokiol in an orthotopic mouse model and assessed associations with tumor growth factor-ß1 (TGFß1) and cells stimulated by a carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Our results demonstrate that tumor growth, peritoneal dissemination and peritoneum or organ metastasis of orthotopically implanted MKN45 cells were significantly decreased in Honokiol-treated mice and that endoplasmic reticulum (ER) stress was induced. Honokiol-treated tumors showed increased epithelial signatures such as E-cadherin, cytokeratin-18 and ER stress marker. In contrast, decreased expression of vimentin, Snail and tumor progression locus 2 (Tpl2) was also noted. TGFß1 and MNNG-induced downregulation of E-cadherin and upregulation of Tpl2 were abrogated by Honokiol treatment. The effect of Tpl2 inhibition in cancer cells or endothelial cells was associated with inactivation of CCAAT/enhancer binding protein B, nuclear factor kappa-light-chain-enhancer of activated B cell and activator protein-1 and suppression of vascular endothelial growth factor. Inhibition of Tpl2 in gastric cancer cells by small interfering RNA or pharmacological inhibitor was found to effectively reduce growth ability and vessel density in vivo. Honokiol-induced reversal of epithelial-to-mesenchymal transition (EMT) and ER stress-induced apoptosis via Tp12 may involve the paralleling processes. Taken together, our results suggest that the therapeutic inhibition of Tpl2 by Honokiol thwarts both gastric tumor growth and peritoneal dissemination by inducing ER stress and inhibiting EMT.

Multiple effects of Honokiol on the life cycle of hepatitis C virus.

BACKGROUND: Honokiol, a small active molecular compound extracted from magnolia, has recently been shown to inhibit hepatitis C virus (HCV) infection in vitro. AIMS: This study further characterized aspects of the HCV lifecycle affected by the antiviral functions of honokiol. METHODS: The influence of honokiol on HCV infection, entry, translation and replication was assessed in Huh-7.5.1 cells using cell culture-derived HCV (HCVcc), HCV pseudo-type (HCVpp) and sub-genomic replicons. RESULTS: Honokiol had strong antiviral effect against HCVcc infection at non-toxic concentrations. Combined with interferon-α, its inhibitory effect on HCVcc was more profound than that of ribavirin. Honokiol inhibited the cell entry of lentiviral particles pseudo-typed with glycoproteins from HCV genotypes 1a, 1b, and 2a, but not of the vesicular stomatitis virus. It had inefficient activity on HCV internal ribosome entry site (IRES)-translation at concentrations with significant anti-HCVcc effects. The expression levels of components of replication complex, NS3, NS5A and NS5B, were down-regulated by honokiol in a dose-dependent manner. It also inhibited HCV replication dose dependently in both genotypes 1b and 2a sub-genomic replicons. CONCLUSIONS: Honokiol inhibits HCV infection by targeting cell entry and replication and, only at a concentration >30 µM, IRES-mediated translation of HCV life cycle. Based on its high therapeutic index (LD(50) /EC(90)  = 5.4), honokiol may be a promising drug for the treatment of HCV infection.