Anti-fibrotic effects of tetrandrine on bile-duct ligated rats

Targeting HSP47 and HSP70: promising therapeutic approaches in liver fibrosis management

Liver fibrosis is a liver disease in which there is an excessive buildup of extracellular matrix proteins, including collagen. By regulating cytokine production and the inflammatory response, heat shock proteins (HSPs) contribute significantly to a wider spectrum of fibrotic illnesses, such as lung, liver, and idiopathic pulmonary fibrosis by aiding in the folding and assembly of freshly synthesized proteins, HSPs serve as chaperones. HSP70 is one of the key HSPs in avoiding protein aggregation which induces its action by sending unfolded and/or misfolded proteins to the ubiquitin–proteasome degradation pathway and antagonizing influence on epithelial-mesenchymal transition. HSP47, on the other hand, is crucial for boosting collagen synthesis, and deposition, and fostering the emergence of fibrotic disorders. The current review aims to provide light on how HSP70 and HSP47 affect hepatic fibrogenesis. Additionally, our review looks into new therapeutic approaches that target HSP70 and HSP47 and could potentially be used as drug candidates to treat liver fibrosis, especially in cases of comorbidities.

Inhibitors and Activators of the p38 Mitogen- Activated MAP Kinase (MAPK) Family as Drugs to Treat Cancer and Inflammation

The p38 MAP kinases are a sub-family of the broad group of mitogen-activated serine-threonine protein kinases. The best-characterised, most widely expressed, and most targeted by drugs is p38α MAP kinase. This review briefly summarises the place of p38α MAP kinase in cellular signalling and discusses the structures and activity profiles of representative examples of the major classes of inhibitors and activators (both synthetic compounds and natural products) of this enzyme. Primary screening was primarily direct in vitro inhibition of isolated p38α enzyme.

A comprehensive review of natural products to fight liver fibrosis: Alkaloids, terpenoids, glycosides, coumarins and other compounds

The discovery of drugs to treat liver fibrosis has long been a challenge over the past decades due to its complicated pathogenesis. As a primary approach for drug development, natural products account for 30% of clinical drugs used for disease treatment. Therefore, natural products are increasingly important for their medicinal value in liver fibrosis therapy. In this part of the review, special focus is placed on the effect and mechanism of natural compounds, including alkaloids, terpenoids, glycosides, coumarins and others. A total of 36 kinds of natural compounds demonstrate significant antifibrotic effects in various liver fibrosis models in vivo and in hepatic stellate cells (HSCs) in vitro. Revealing the mechanism will provide further basis for clinical conversion, as well as accelerate drug discovery. The mechanism was further summarized with the finding of network regulation by several natural products, such as oxymatrine, paeoniflorin, ginsenoside Rg1 and taurine. Moreover, there are still improvements needed in investigating clinical efficacy, determining mechanisms, and combining applications, as well as semisynthesis and modification. Therefore, natural products area promising resource for agents that protect against liver fibrosis.

Natural products for the prevention and treatment of cholestasis: A review

Cholestasis is a common manifestation of decreased bile flow in various liver diseases. It results in fibrosis and even cirrhosis without proper treatment. It is believed that a wide range of factors, including transporter dysfunction, oxidative stress, inflammatory damage, and immune disruption, can cause cholestasis. In recent years, natural products have drawn much attention for specific multiple-target activities in diseases. Many attempts have been made to investigate the anticholestatic effects of natural products with advanced technology. This review summarizes recent studies on the biological activities and mechanisms of recognized compounds for cholestasis treatment. Natural products, including various flavonoids, phenols, acids, quinones, saponins, alkaloids, glycosides, and so on, function as comprehensive regulators via ameliorating oxidative stress, inflammation, and apoptosis, restoring bile acid balance with hepatic transporters, and adjusting immune disruption. Moreover, in this progress, nuclear factor erythroid 2-related factor 2, reactive oxygen species production, heme oxygenase-1, NF-κB, cholesterol 7 alpha-hydroxylase, and farnesoid X receptors are thought as main targets for the activity of natural products. Therefore, this review presents the detailed mechanisms that include multiple targets and diverse signalling pathways. Natural products are the valuable when seeking novel therapeutic agents to treat cholestatic liver diseases.

Exogenous putrescine affects polyamine and arginine metabolism in rat liver following bile ductus ligation

Rat bile duct ligation (BDL) represents a useful method that mimics obstructive extrahepatic cholestasis, which is known to be a frequent disorder in humans. Polyamines (putrescine, spermidine, and spermine) are one of the key molecules regulating cell proliferation and differentiation. This work aimed to evaluate the potential beneficial properties of putrescine in rat BDL model by studying several biochemical parameters reflecting liver function and polyamine metabolism. Rats that were subjected to BDL were injected with putrescine (150 mg/kg) for 9 days, while in parallel another group with BDL remained untreated. Two control groups were included as well, sham-opened and putrescine-treated group. The following plasma parameters: ALT, AST, γ-GT, ALP, bilirubin, bile acids, as well as liver malondialdehyde and polyamine concentration and the activity of enzymes involved in polyamine metabolism were studied. After BDL, significant alterations in plasma biochemical parameters occurred, where a 9-day putrescine treatment significantly alleviated liver function deterioration. Putrescine also increased liver polyamines’ concentrations and polyamine and diamine oxidase activities in rats submitted to BDL. Our results demonstrated, for the first time, that putrescine plays an important role in preserving liver tissue function in rats with experimentally induced cholestasis.

Therapeutic Effect of Glycyrrhizin Arginine Salt on Rat Cholestatic Cirrhosis and its Mechanism

To investigate the therapeutic effect of glycyrrhizin arginine salt on rat cholestatic cirrhosis, we subjected male Sprague Dawley rats to common bile duct ligation for 14 days and treated them with distilled water (model group), arginine, or a low or high dose of glycyrrhizin arginine salt by gavage. A sham-operated group was used as a control group. Treatment with glycyrrhizin arginine salt substantially improved animal growth rates, reduced the ratio of liver weight to body weight and decreased total bilirubin, aspartate aminotransferase, 8-isoprostane and malondialdehyde compared with the values measured in the model group. The progress of liver fibrosis, as detected by hematoxylin and eosin and Masson’s trichrome staining, was slower in the glycyrrhizin arginine salt groups than in the model group or the arginine group. Reductions of bile salt pool size, hepatic hydroxyproline content and fibrosis score were also seen in the glycyrrhizin arginine salt groups compared with the model group. Furthermore, glycyrrhizin arginine salt significantly reduced the expression of transforming growth factor [Formula: see text]1 (TGF-[Formula: see text]1), [Formula: see text]-smooth muscle actin, tumor necrosis factor-[Formula: see text] and matrix metalloproteinases 2 and 9. Glycyrrhizin arginine salt also inhibited the expression of [Formula: see text]-SMA and matrix metalloproteinases 2 and 9 in response to TGF-[Formula: see text]1 in LX-2 cells and primary rat hepatic stellate cells and mitigated the cytotoxicity induced by rat bile in HepG2 cells and primary rat hepatocytes.

Rosmarinic acid attenuates hepatic fibrogenesis via suppression of hepatic stellate cell activation/proliferation and induction of apoptosis

OBJECTIVE

To investigate the antifibrotic role of rosmarinic acid (RA), a natural polyphenolic compound, on HSCs activation/proliferation and apoptosis in vitro and in vivo.

METHODS

The impact of RA on stellate cell line (HSC-T6) proliferation, activation and apoptosis was assessed along with its safety on primary hepatocytes. In vivo, rats were divided into: (i) normal; (ii) thioacetamide (TAA)-intoxicated rats for 12 weeks; (iii) TAA + silymarin or (iv) TAA + RA. At the end of experiment, liver functions, oxidative stress, inflammatory and profibrogenic markers, tissue inhibitor metalloproteinases type-1 (TIMP-1) and hydroxyproline (HP) levels were evaluated. Additionally, liver histopathology and immunohistochemical examinations of alpha-smooth muscle actin (α-SMA), caspase-3 and proliferation cellular nuclear antigen (PCNA) were determined.

RESULTS

RA exhibited anti-proliferative effects on cultured HSCs in a time and concentration dependent manner showing an IC₅₀ of 276 μg/mL and 171 μg/mL for 24 h and 48 h, respectively, with morphological reversion of activated stellate cell morphology to quiescent form. It significantly improved ALT, AST, oxidative stress markers and reduced TIMP-1, HP levels, inflammatory markers and fibrosis score (S1 vs S4). Furthermore, reduction in α-SMA plus elevation in caspase-3 expressions of HSCs in vitro and in vivo associated with an inhibition in proliferation of damaged hepatocytes were recorded.

CONCLUSIONS

RA impeded the progression of liver fibrosis through inhibition of HSCs activation/proliferation and induction of apoptosis with preservation of hepatic architecture.

Beneficial effect of tetrandrine on refractory epilepsy via suppressing P-glycoprotein

Patients with refractory epilepsy are resistance to antiepileptic drugs (AEDs). The mechanisms of drug resistance are varied, but one of them is the overexpression of multidrug transporters, such as P-glycoprotein (P-gp), in the brain. Tetrandrine (TTD) is a bis-benzylisoquinoline alkaloid isolated from the root of Stephania tetrandra (S, Moore) and is found to have a favorable effect against multidrug resistance (MDR) in chemotherapy. However, whether TTD affects AEDs in refractory epilepsy is unknown. In this study, we investigated the change in AED treatment efficacy in doxorubicin-induced drug resistant cells after TTD administration. We also examined the effect of TTD on seizure behaviors in the refractory epileptic rats, specifically the expression of MDR1 mRNA and P-gp protein in the cortex and hippocampus of the refractory epileptic rats. Our results demonstrated that TTD decreased cell resistance to phenytoin and valproate. TTD decreased seizure rate and increased the treatment efficacy of AEDs by reducing the expression of P-gp at mRNA and protein levels in vivo. These data support the use of TTD as an adjuvant drug for treating refractory epilepsy.

The effect of antifibrotic drugs in rat precision-cut fibrotic liver slices

Two important signaling pathways in liver fibrosis are the PDGF- and TGFβ pathway and compounds inhibiting these pathways are currently developed as antifibrotic drugs. Testing antifibrotic drugs requires large numbers of animal experiments with high discomfort. Therefore, a method to study these drugs ex vivo was developed using precision-cut liver slices from fibrotic rat livers (fPCLS), representing an ex vivo model with a multicellular fibrotic environment. We characterized the fibrotic process in fPCLS from rat livers after 3 weeks of bile duct ligation (BDL) during incubation and tested compounds predominantly inhibiting the TGFβ pathway (perindopril, valproic acid, rosmarinic acid, tetrandrine and pirfenidone) and PDGF pathway (imatinib, sorafenib and sunitinib). Gene expression of heat shock protein 47 (Hsp47), α smooth muscle actin (αSma) and pro-collagen 1A1 (Pcol1A1) and protein expression of collagens were determined. During 48 hours of incubation, the fibrosis process continued in control fPCLS as judged by the increased gene expression of the three fibrosis markers, and the protein expression of collagen 1, mature fibrillar collagen and total collagen. Most PDGF-inhibitors and TGFβ-inhibitors significantly inhibited the increase in gene expression of Hsp47, αSma and Pcol1A1. Protein expression of collagen 1 was significantly reduced by all PDGF-inhibitors and TGFβ-inhibitors, while total collagen was decreased by rosmarinic acid and tetrandrine only. However, fibrillar collagen expression was not changed by any of the drugs. In conclusion, rat fPCLS can be used as a functional ex vivo model of established liver fibrosis to test antifibrotic compounds inhibiting the PDGF- and TGFβ signalling pathway.

Protective effects of silymarin on fumonisin B₁-induced hepatotoxicity in mice

The present study was conducted to investigate the effect of silymarin on experimental liver toxication induced by Fumonisin B₁ (FB₁) in BALB/c mice. The mice were divided into six groups (n = 15). Group 1 served as the control. Group 2 was the silymarin control (100 mg/kg by gavage). Groups 3 and 4 were treated with FB₁ (Group 3, 1.5 mg/kg FB₁, intraperitoneally; and Group 4, 4.5 mg/kg FB₁). Group 5 received FB₁ (1.5 mg/kg) and silymarin (100 mg/kg), and Group 6 was given a higher dose of FB₁ (4.5 mg/kg FB₁) with silymarin (100 mg/kg). Silymarin treatment significantly decreased (p < 0.0001) the apoptotic rate. FB₁ administration significantly increased (p < 0.0001) proliferating cell nuclear antigen and Ki-67 expression. Furthermore, FB₁ elevated the levels of caspase-8 and tumor necrosis factor-alpha mediators while silymarin significantly reduced (p < 0.0001) the expression of these factors. Vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) expressions were significantly elevated in Group 4 (p < 0.0001). Silymarin administration alleviated increased VEGF and FGF-2 expression levels (p < 0.0001). In conclusion, silymarin ameliorated toxic liver damage caused by FB₁ in BALB/c mice.

Review of experimental models for inducing hepatic cirrhosis by bile duct ligation and carbon tetrachloride injection

PURPOSE

To present a review about a comparative study of bile duct ligation versus carbon tetrachloride Injection for inducing experimental liver cirrhosis.

METHODS

This research was made through Medline/PubMed and SciELO web sites looking for papers on the content "induction of liver cirrhosis in rats". We have found 107 articles but only 30 were selected from 2004 to 2011.

RESULTS

The most common methods used for inducing liver cirrhosis in the rat were administration of carbon tetrachloride (CCl4) and bile duct ligation (BDL). CCl4 has induced cirrhosis from 36 hours to 18 weeks after injection and BDL from seven days to four weeks after surgery.

CONCLUSION

For a safer inducing cirrhosis method BDL is better than CCl4 because of the absence of toxicity for researches and shorter time for achieving it.

Antifibrotic effects of triptolide on hepatic stellate cells and dimethylnitrosamine-intoxicated rats

Triptolide (C₃₈H₄₂O₆N₂, TP, a diterpene triepoxide derived from Tripterygium wilfordii Hook F.), is a potent immunosuppresive and antiinflammatory agent. The present study investigated whether TP exerted antihepatofibrotic effects in vitro and in vivo. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with tumor necrosis factor-α (TNF-α) or transforming growth factor (TGF)-β1. The inhibitory effects of TP on the nuclear factor-κB (NFκB) signaling cascade and fibrosis markers, including α-smooth muscle actin (α-SMA) and collagen, were assessed. An in vivo therapeutic study was conducted in dimethylnitrosamine (DMN)-treated rats. The rats were randomly assigned to one of three groups: control rats, DMN rats receiving vehicle only and DMN rats receiving TP (20 μg/kg). Treatment was given by gavage twice daily for 3 weeks starting 1 week after the start of DMN administration. TP (5-100 nM) concentration-dependently inhibited the NFκB transcriptional activity induced by TNF-α, lipopolysaccharide and phorbol 12-myristate 13-acetate in HSC-T6 cells. In addition, TP also suppressed TNF-α and TGF-β1-induced collagen deposition and α-SMA secretion in HSC-T6 cells. In vivo, TP treatment significantly reduced hepatic fibrosis scores, collagen contents, IL-6 and TNF-α levels, and the number of α-SMA and NFκB-positive cells in DMN rats. The results showed that TP exerted antifibrotic effects in both HSC-T6 cells and DMN rats.

Effects of armepavine against hepatic fibrosis induced by thioacetamide in rats

The aim of this study was to investigate if armepavine (Arm, C₁₉H₂₃O₃N) could exert inhibitory effects against hepatic fibrosis in rats. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with tumour necrosis factor-α (TNF-α) to evaluate the inhibitory effects of Arm. Rats were injected with thioacetamide (TAA; 300 mg/kg, intraperitoneally) thrice a week for 4 weeks to induce hepatic fibrosis, with Arm (3 or 10 mg/kg) given by gavage twice a day. Liver sections were taken for western blotting, fibrosis scoring and immunofluorescence staining. Arm (1-10 µm) concentration-dependently attenuated TNF-α-stimulated: (i) protein expressions of α-smooth muscle actin (α-SMA), collagen type I and angiopoietin-1; (ii) H₂O₂ production; and (iii) NF-κB, JunD and C/EBPß (cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding protein-ß (EBPß)) nuclear translocations in HSC-T6 cells. In vivo Arm treatment significantly reduced plasma aspartate transaminase and alanine transaminase levels, hepatic α-SMA expression and collagen contents, and fibrosis scores of TAA-injected rats. Moreover, Arm treatment decreased α-SMA- and NF-κB-positive cells in immunohistochemical staining, and mRNA expression levels of IL-6, TGF-ß1, TIMP-1, col1α2, iNOS and ICAM-1 genes, but up-regulated the metallothionein gene in the livers of TAA-injected rats. Our results indicated that Arm exerted both in vitro and in vivo antifibrotic effects in rats, with inhibition of NF-κB, JunD and C/EBPß pathways.

Tetrandrine blocks cardiac hypertrophy by disrupting reactive oxygen species-dependent ERK1/2 signalling

BACKGROUND AND PURPOSE

Tetrandrine, a well-known naturally occurring calcium antagonist with anti-inflammatory, antioxidant and anti-fibrogenetic activities, has long been used clinically for treatment of cardiovascular diseases such as hypertension and arrhythmia. However, little is known about the effect of tetrandrine on cardiac hypertrophy. The aims of the present study were to determine whether tetrandrine could attenuate cardiac hypertrophy and to clarify the underlying molecular mechanisms.

EXPERIMENTAL APPROACH

Tetrandrine (50 mg x kg(-1) x day(-1)) was administered by oral gavage three times a day for one week and then the mice were subjected to either chronic pressure overload generated by aortic banding (AB) or sham surgery (control group). Cardiac function was determined by echocardiography.

KEY RESULTS

Tetrandrine attenuated the cardiac hypertrophy induced by AB, as assessed by heart weight/body weight and lung weight/body weight ratios, cardiac dilatation and the expression of genes of hypertrophic markers. Tetrandrine also inhibited fibrosis and attenuated the inflammatory response. The cardioprotective effects of tetrandrine were mediated by blocking the increased production of reactive oxygen species and the activation of ERK1/2-dependent nuclear factor-kappaB and nuclear factor of activated T cells that occur in response to hypertrophic stimuli.

CONCLUSIONS AND IMPLICATIONS

Taken together, our results suggest that tetrandrine can improve cardiac function and prevent the development of cardiac hypertrophy by suppressing the reactive oxygen species-dependent ERK1/2 signalling pathway.

Neferine, a bisbenzylisoquinline alkaloid attenuates bleomycin-induced pulmonary fibrosis

In this study, we evaluated the potential anti-fibrotic property of neferine, a bisbenzylisoquinline alkaloid extracted from the seed embryo of Nelumbo mucifera Gaertn. Intratracheal bleomycin administration resulted in pulmonary fibrosis 14 and 21 days posttreatment, as evidenced by increased hydroxyproline content in bleomycin group (255.77+/-97.17 microg/lung and 269.74+/-40.92 microg/lung) compared to sham group (170.78+/-76.46 microg/lung and 191.24+/-60.45 microg/lung), and the hydroxyproline was significantly suppressed (193.07+/-39.55 microg/lung and 201.08+/-71.74 microg/lung) by neferine administration (20mg/kg, b.i.d). The attenuated-fibrosis condition was also validated by histological observations. Biochemical measurements revealed that bleomycin caused a significant decrease in lung superoxidae dismutase (SOD) activity, which was accompanied with a significant increase in malondialdehyde (MDA) levels and myeloperoxidase (MPO) activity on the 7th and 14th days. However, neferine reversed the decrease in SOD activity as well as the increase in MDA and MPO activity. Enzyme-linked immunosorbent assay and radio-immunity assay showed that treatment with neferine alleviated bleomycin-induced increase of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 and endothelin-1 in plasma or in tissue. Additionally, neferine blocked bleomycin-induced increases of NF-kappaB in nuclear extracts and TGF-beta(1) in total protein extracts of murine RAW264.7 macrophages. In summary, neferine attenuates bleomycin-induced pulmonary fibrosis in vitro and in vivo. The beneficial effect of neferine might be associated with its activities of anti-inflammation, antioxidation, cytokine and NF-kappaB inhibition.

Inhibitory effects of armepavine against hepatic fibrosis in rats

Activation of hepatic stellate cells (HSCs) plays a crucial role in liver fibrogenesis. armepavine (Arm, C₁₉H₂₃O₃N), an active compound from Nelumbo nucifera, has been shown to exert immunosuppressive effects on T lymphocytes and on lupus nephritic mice. The aim of this study was to investigate whether Arm could exert anti-hepatic fibrogenic effects in vitro and in vivo. A cell line of rat HSCs (HSC-T6) was stimulated with tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS) to evaluate the inhibitory effects of Arm. An in vivo therapeutic study was conducted in bile duct-ligated (BDL) rats. BDL rats were given Arm (3 or 10 mg/kg) by gavage twice daily for 3 weeks starting from the onset of BDL. Liver sections were taken for fibrosis scoring, immuno-fluorescence staining and quantitative real-time mRNA measurements. In vitro, Arm (1-10 μM) concentration-dependently attenuated TNF-α- and LPS-stimulated α-SMA protein expression and AP-1 activation by HSC-T6 cells without adverse cytotoxicity. Arm also suppressed TNF-α-induced collagen collagen deposition, NFκB activation and MAPK (p38, ERK1/2, and JNK) phosphorylations. In vivo, Arm treatment significantly reduced plasma AST and ALT levels, hepatic α-SMA expression and collagen contents, and fibrosis scores of BDL rats as compared with vehicle treatment. Moreover, Arm attenuated the mRNA expression levels of col 1α2, TGF-β1, TIMP-1, ICAM-1, iNOS, and IL-6 genes, but up-regulated metallothionein genes. Our study results showed that Arm exerted both in vitro and in vivo antifibrotic effects in rats, possibly through anti-NF-κB activation pathways.

Chinese medicines as a resource for liver fibrosis treatment

Liver fibrosis is a condition of abnormal proliferation of connective tissue due to various types of chronic liver injury often caused by viral infection and chemicals. Effective therapies against liver fibrosis are still limited. In this review, we focus on research on Chinese medicines against liver fibrosis in three categories, namely pure compounds, composite formulae and combination treatment using single compounds with composite formulae or conventional medicines. Action mechanisms of the anti-fibrosis Chinese medicines, clinical application, herbal adverse events and quality control are also reviewed. Evidence indicates that some Chinese medicines are clinically effective on liver fibrosis. Strict quality control such as research to identify and monitor the manufacturing of Chinese medicines enables reliable pharmacological, clinical and in-depth mechanism studies. Further experiments and clinical trials should be carried out on the platforms that conform to international standards.

Tetrandrine ameliorates dextran-sulfate-sodium-induced colitis in mice through inhibition of nuclear factor -kappaB activation

BACKGROUND

Activation of nuclear factor (NF)-kappaB has been shown to play a critical role in the pathogenesis of ulcerative colitis (UC), and tetrandrine, a bisbenzylisoquinoline alkaloid isolated from the Chinese herb Radix Stephania tetrandra, has been demonstrated to be a potent inhibitor of NF-kappaB activation. The purpose of the study was to investigate effects of tetrandrine on experimental model of UC.

MATERIALS AND METHODS

Tetrandrine was administered in experimental colitis induced by dextran sulfate sodium (DSS). The disease activity index (DAI) and histological score were observed. NF-kappaB DNA binding activity was assessed by electrophoretic mobility shift assay. The expression of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta were measured by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay.

RESULTS

A significant improvement was observed in DAI and histological score in mice with tetrandrine, and the increase in NF-kappaB DNA binding activity, myeloperoxidase activity, IL-1beta, and TNF-alpha in mice with DSS-induced colitis was significantly reduced following administration of tetrandrine.

CONCLUSION

The administration of tetrandrine leads to an amelioration of DSS-induced colitis, suggesting administration of tetrandrine may provide a therapeutic approach for UC.