Bile Duct Ligation Rat Model Research Articles

Impact of Liver Sympathetic Nervous System on Liver Fibrosis and Regeneration After Bile Duct Ligation in Rats.

The sympathetic nervous system (SNS) affects many functions of the body. SNS fibers regulate many aspects of liver function, repair, and regeneration. However, in the model of bile duct ligation (BDL) in rats, the kind of impact caused by the regulation of liver SNS on liver fibrosis and liver regeneration is unclear. The main research objective of this experiment is to examine the effect of SNS on liver fibrosis and liver regeneration. Twenty-four male Sprague-Dawley (SD) rats were assigned randomly to four groups. These groups included the sham surgery group (sham), model group (BDL), 6-hydroxydopamine group (BDL+6-OHDA), and spinal cord injury group (BDL+SCI). In the sham group, only exploratory laparotomy was performed without BDL. In the 6-OHDA group, 6-OHDA was used to remove sympathetic nerves after BDL. In the spinal cord injury group, rats underwent simultaneous BDL and spinal cord injury. After 3weeks of feeding, four groups of rats were euthanized using high-dose anesthesia without pain. Moreover, liver tissue and blood were taken to detect liver fibrosis and regeneration indicators. After intraperitoneal injection of 6-OHDA into BDL rats, liver fibrosis indicators decreased. The administration of the injection effectively alleviated liver fibrosis and inhibited liver regeneration. However, after SCI surgery in BDL rats, liver fibrosis indicators increased. This resulted in exacerbating liver fibrosis and activating liver regeneration. The SNS plays a role in contributing to the liver injury process in the rat BDL model. Therefore, regulating the SNS may become a novel method for liver injury treatment.

Partial vasopressin 1a receptor agonism reduces portal hypertension and hyperaldosteronism and induces a powerful diuretic and natriuretic effect in rats with cirrhosis and ascites

The vasopressin system has emerged as a therapeutic focus for lowering portal hypertension and reducing splanchnic vasodilation in patients with refractory ascites. Clinically available vasopressin agonists are limited by preferential selectivity for V1 receptors that also have steep concentration–response curves with potential risks of excess vasoconstriction and/or complete antidiuretic effects. OCE-205 is a novel, selective, partial V1a receptor agonist with mixed agonist/antagonist activity and no V2 receptor activation at therapeutic doses. We carried out two studies assessing the in vivo effects of OCE-205 in different rat models of cirrhosis and ascites. In a carbon tetrachloride rat cirrhosis model, OCE-205 administration produced a marked reduction in portal hypertension and hyperaldosteronism, along with robust diuretic and natriuretic effects. These effects were accompanied by marked decreases in ascites volume, with three of five animals experiencing total mobilization of ascites. There was no evidence of fluid overload or sodium or water retention, confirming OCE-205′s lack of V2 receptor activity. In a second, corroborative study using a bile duct ligation rat model of ascites, OCE-205 produced significant decreases in ascites volume and body weight and a significant increase in urine volume versus vehicle. Urine sodium excretion increased significantly after the first administration of OCE-205 relative to vehicle; however, repeat administration over 5 days did not lead to hyponatremia. Thus, in separate in vivo models, the mixed agonist/antagonist OCE-205 demonstrated relevant and expected endpoint findings consistent with its known mechanism of action and in vitro pharmacology without apparent unwanted effects or nonspecific toxicities.

Increased PRL-1 in BM-derived MSCs triggers anaerobic metabolism via mitochondria in a cholestatic rat model

Mesenchymal stem cell (MSC) therapy in chronic liver disease is associated with mitochondrial anaerobic metabolism. Phosphatase of regenerating liver-1 (PRL-1), known as protein tyrosine phosphatase type 4A, member 1 (PTP4A1), plays a critical role in liver regeneration. However, its therapeutic mechanism remains obscure. The aim of this study was to establish genetically modified bone marrow (BM)-MSCs overexpressing PRL-1 (BM-MSCsPRL-1) and to investigate their therapeutic effects on mitochondrial anaerobic metabolism in a bile duct ligation (BDL)-injured cholestatic rat model. BM-MSCsPRL-1 were generated with lentiviral and nonviral gene delivery systems and characterized. Compared with naive cells, BM-MSCsPRL-1 showed an improved antioxidant capacity and mitochondrial dynamics and decreased cellular senescence. In particular, mitochondrial respiration in BM-MSCsPRL-1 generated using the nonviral system was significantly increased as well as mtDNA copy number and total ATP production. Moreover, transplantation of BM-MSCsPRL-1 generated using the nonviral system had predominantly antifibrotic effects and restored hepatic function in a BDL rat model. Decreased cytoplasmic lactate and increased mitochondrial lactate upon the administration of BM-MSCsPRL-1 indicated significant alterations in mtDNA copy number and ATP production, activating anaerobic metabolism. In conclusion, BM-MSCsPRL-1 generated by a nonviral gene delivery system enhanced anaerobic mitochondrial metabolism in a cholestatic rat model, improving hepatic function.

Effect of Artichoke Extract on Hypercholesterolemic Status of Bile Duct Ligation Rat Model

Objective: Dietary plants have gained great attention, because they can play important role in enhancement of health and wellbeing. The purpose of our study was to look into the effect of artichoke extract on hypercholesterolemic status of bile duct ligation rat model. Materials and Methods: In this study we used 21 Wistar albino rats. They randomly assigned into three groups; Group 1 (control group) underwent laparotomy alone and the common bile duct was only exposed and no drug was applied. Group 2 (BDL group) was subjected only to bile duct ligation (BDL) and no drug was applied. Group 3 (BDL +Ac) received a daily dose of 1.5 g/kg/per os of artichoke extract starting 24 hours after BDL. After 7 days of treatment, the animals were sacrificed, the blood samples were taken and total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels were analysed. Results: TC decreased in BDL+ Ac group compared to BDL group (44.42±21.19, 61.2±11.3). The LDL-C decreased in BDL+ Ac group compared to BDL group (28,5±10,05, 38,4±3,91) with a statistical significance (p<0,05). HDL decreased in BDL group and in BDL+ Ac group compared to the control group; however, it indicated no statistically significant difference (p>0,05). Conclusion: In this research, artichoke extract application may improve hypercholesterolemic status of bile duct ligation. Further studies with larger volume are required to support our promising results.

Central nervous system and systemic oxidative stress interplay with inflammation in a bile duct ligation rat model of type C hepatic encephalopathy

The role and coexistence of oxidative stress (OS) and inflammation in type C hepatic encephalopathy (C HE) is a subject of intense debate. Under normal conditions the physiological levels of intracellular reactive oxygen species are controlled by the counteracting antioxidant response to maintain redox homeostasis. Our previous in-vivo1H-MRS studies revealed the longitudinal impairment of the antioxidant system (ascorbate) in a bile-duct ligation (BDL) rat model of type C HE.Therefore, the aim of this work was to examine the course of central nervous system (CNS) OS and systemic OS, as well as to check for their co-existence with inflammation in the BDL rat model of type C HE. To this end, we implemented a multidisciplinary approach, including ex-vivo and in-vitro electron paramagnetic resonance spectroscopy (EPR) spin-trapping, which was combined with UV–Vis spectroscopy, and histological assessments. We hypothesized that OS and inflammation act synergistically in the pathophysiology of type C HE.Our findings point to an increased CNS- and systemic-OS and inflammation over the course of type C HE progression. In particular, an increase in the CNS OS was observed as early as 2-weeks post-BDL, while the systemic OS became significant at week 6 post-BDL. The CNS EPR measurements were further validated by a substantial accumulation of 8-Oxo-2′-deoxyguanosine (Oxo-8-dG), a marker of oxidative DNA/RNA modifications on immunohistochemistry (IHC). Using IHC, we also detected increased synthesis of antioxidants, glutathione peroxidase 1 (GPX-1) and superoxide dismutases (i.e.Cu/ZnSOD (SOD1) and MnSOD (SOD2)), along with proinflammatory cytokine interleukin-6 (IL-6) in the brains of BDL rats. The presence of systemic inflammation was observed already at 2-weeks post-surgery. Thus, these results suggest that CNS OS is an early event in type C HE rat model, which seems to precede systemic OS. Finally, our results suggest that the increase in CNS OS is due to enhanced formation of intra- and extra-cellular ROS rather than due to reduced antioxidant capacity, and that OS in parallel with inflammation plays a significant role in type C HE.

Insight into Bile Duct Reaction to Obstruction from a Three-dimensional Perspective Using ex Vivo Phase-Contrast CT.

Background Biliary obstruction leads to an increase in biliary pressure within the biliary system, which induces the morphologic adaptation of the biliary tree. Purpose To observe and to quantify the morphologic characteristics of the adaptation in a bile duct ligation rat model and verify it in patients with biliary atresia in a three-dimensional (3D) manner using x-ray phase-contrast CT. Materials and Methods A bile duct ligation model was induced in 40 male Sprague-Dawley rats, which were divided into five groups: the control group (no ligation) and groups 2, 4, 6, and 8 weeks after bile duct ligation (eight animals in each group). Liver tissue samples (approximately 1.8 cm in length and 1.3 cm in height) were imaged by using phase-contrast CT and compared with histologic analysis. With a combination of phase-contrast CT and 3D visualization technology, the entire biliary system and the intrahepatic vascular system were quantitatively analyzed according to downstream, midstream, and upstream domains based on bile duct volume, surface area, and other parameters. Additionally, liver explant tissues from 28 patients with biliary atresia were studied to determine the impact of biliary tract reconstruction. Results To offset the increased biliary pressure within the biliary system, the ductular reaction in the downstream, midstream, and upstream domains manifested as dilatation, spiderweb-like looping, and interconnected honeycomb-like patterns, respectively. The most severe ductular reaction occurred in the upstream domain, and the relative surface area (mean, 0.02 μm-1 ± 0.01, 0.04 μm-1 ± 0.01, 0.07 μm-1 ± 0.02, and 0.10 μm-1 ± 0.02 for the 2-8-week groups, respectively; P < .01 among the groups) and volume fraction of ductules (mean, 16.54% ± 4.62, 19.69% ± 6.41, 26.92% ± 5.82, and 38.34% ± 10.36 for the 2-8-week groups, respectively; P < .01 among the groups except between the 2- and 4-week groups [P = .062]) significantly increased over time. In patients with biliary atresia, it was observed that both fibrosis and proliferative ductules regressed after successful biliary tract reconstruction following Kasai portoenterostomy. Furthermore, ductular reaction was accompanied by a progressive increase in the arterial supply but a loss of portal blood supply. Conclusion X-ray phase-contrast CT with three-dimensional rendering of the biliary system in a bile duct ligation rat model provides key insights into ductular reaction or biliary self-adaptation triggered by increased biliary pressure. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Vannier and Wang in this issue.

The herbal medicines Inchinkoto and Saireito improved hepatic fibrosis via aquaporin 9 in the liver of a rat bile duct ligation model.

To determine if the administration of the Japanese herbal medicines Inchinkoto (ICKT) and Saireito (SRT) ameliorate hepatic fibrosis and derangement of hepatocyte aquaporins (AQPs) following bile duct ligation (BDL) in a rat model of obstructive cholestasis. Five groups of Wistar rats were used, and the groups included sham surgery (Sham group), BDL with no treatment (NT group), BDL plus ICKT (ICKT group), BDL plus SRT (SRT group), and BDL plus ICKT and SRT (SRT/ICKT group). Each herbal medicine was administered at 1g/kg/day on the first postoperative day. The serum levels and various clinical markers were measured with real-time polymerase chain reaction. Staining was used to evaluate the degree of fibrosis and the inflammatory responses. Serum aspartate aminotransferase and alanine aminotransferase in the ICKT and SRT/ICKT groups were significantly lower than those in the NT group. NF-κB mRNA expression was significantly decreased in the ICKT group and the SRT/ICKT group compared with the NT group. AQP9 mRNA expression was significantly increased in the ICKT group and the SRT/ICKT group compared with the NT group. The degree of Masson's trichrome staining in the SRT/ICKT group was significantly lower than that in the NT group. The degree of NF-κB staining in the SRT/ICKT group was significantly lower than that in the NT, ICKT, or SRT group. The postoperative administration of ICKT and SRT induced synergistic beneficial effects, resulting in the reduction of hepatic fibrosis via mechanisms involving the inhibition of NF-κB expression and the improvement of AQP9 downregulation.

Formyl Peptide Receptor 2 Alleviates Hepatic Fibrosis in Liver Cirrhosis by Vascular Remodeling.

Hexapeptide WKYMVm (Trp-Lys-Tyr-Met-Val-D-Met), a ligand of formyl peptide receptor 2, exhibits anti-inflammatory and angiogenic properties in disease models. However, the therapeutic effects of WKYMVm on hepatic fibrosis have not been evaluated to date. Therefore, we investigated whether WKYMVm exerts antifibrotic effects and induces vascular regeneration in a rat model of bile duct ligation (BDL). The antifibrotic and angiogenic effects of WKYMVm on liver regeneration in the BDL rat model were analyzed using biochemical assays, qRT-PCR, western blotting, immunofluorescence, and immunohistochemistry. To determine the effects of WKYMVm on hepatic fibrosis and angiogenesis in vitro, we measured the expression levels of fibrotic factors in hepatic stellate cells (HSCs) and angiogenic factors in human umbilical vein endothelial cells (HUVECs). WKYMVm attenuated the expression of collagen type I (Col I) and α-smooth muscle actin (α-SMA) and significantly increased the levels of angiogenetic factors in the BDL model (p < 0.05). WKYMVm reduced fibrotic marker expression in transforming growth factor (TGF)-β-induced HSCs and promoted angiogenic activity through tube formation in 5-Fluorouracil (FU)-treated HUVECs (p < 0.05). Also, WKYMVm administration enhanced hepatocyte proliferation in BDL rats (p < 0.05). The WKYMVm alleviates hepatic fibrosis by inhibiting HSC activation and promotes hepatic regeneration via vascular remodeling. These data suggest that the WKYMVm may be a new therapeutic agent for liver fibrosis.

Comparison of 18F-FDG, 18F-Fluoroacetate, and 18F-FEPPA for Imaging Liver Fibrosis in a Bile Duct-Ligated Rat Model.

Developing sensitive diagnostic methods for a longitudinal evaluation of the status of liver fibrosis is a priority. This study is aimed at assessing the significance of longitudinal positron emission tomography (PET) imaging with 18F-labeling tracers for assessing liver fibrosis in a rat model with bile duct ligation (BDL). Twenty-one 6-week-old Sprague-Dawley male rats were used in this study. Longitudinal PET images using [18F]N-2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([18F]FEPPA) (n = 3), [18F]fluoroacetate ([18F]FAc) (n = 3), and 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) (n = 3) were obtained at 0, 1, and 2 weeks after BDL. Biochemical assays, histological assays, immunohistochemical staining assays, and next generation sequencing analyses were also performed at 0 (n = 3), 1 (n = 3), 2 (n = 3), and 3 (n = 3) weeks after BDL, which demonstrated the severe damage in rat livers after BDL. Regarding [18F]FEPPA and [18F]FDG, there was a significantly higher uptake in the liver after BDL (both P < 0.05), which lasted until week 2. However, the uptake of [18F]FAc in the liver was not significantly different before and after BDL (P = 0.28). Collectively, both [18F]FEPPA and [18F]FDG can serve as sensitive probes for detecting the liver fibrosis. However, [18F]FAc is not recommended to diagnose liver fibrosis.

Protective Effects of Spermidine Against Cirrhotic Cardiomyopathy in Bile Duct-Ligated Rats

Cirrhotic cardiomyopathy is a critical factor that causes morbidity and mortality in crucial conditions such as liver transplantation. In animal model, the common pathophysiologic mechanisms of cirrhotic cardiomyopathy are similar to those associated with bile duct ligation (BDL). Overproduction of inflammatory and oxidant markers plays a crucial role in cirrhotic cardiomyopathy. Spermidine, a multifunctional polyamine, is known for its antioxidant and anti-inflammatory effects. In this study, we investigated the effects of spermidine on development of cirrhotic cardiomyopathy in BDL rats. Rats were randomly housed in 6 groups. Except the normal and sham groups, BDL was performed for all the control and spermidine groups. Seven days after operation, 3 different doses of spermidine (5, 10 and 50 mg/kg) were administrated until day 28, in spermidine groups. At the end of the fourth week, the electrocardiography (ECG) and papillary muscle isolation were performed. The serum level of tumor necrosis factor-a (TNF-α), interleukin-1β (IL-1β), and IL-10 and cardiac level of superoxide dismutase, glutathione (GSH). and malondialdehyde (MDA) were assessed. Furthermore, the nuclear factor-κB (NF-κB) expression was assessed by western blot. Cardiac histopathological changes were monitored. The serum levels of magnesium (Mg) and potassium (K) were investigated. Control group, exhibited exaggerated signs of cirrhotic cardiomyopathy in comparison with the sham group. Co-administration of spermidine at the dose of 10 mg/kg in BDL rats significantly improved the cardiac condition, reduced the inflammatory mediators, and increased antioxidant enzymes. In addition, the histopathologic findings were in accordance with the other results of the study. Besides, there was no significant alteration in serum levels of Mg and K. This study demonstrates that spermidine at the dose of 10 mg/kg significantly improved the cirrhotic cardiomyopathy in BDL model in rats.

Quercetin improves platelet function and ultrastructure in cholestatic liver injury in rats: Role of ORAI1 gene expression

Platelet dysfunction in liver diseases and especially in cholestatic liver diseases is not fully understood. The aim of the present work is to investigate the functional changes of platelets in bile duct ligated (BDL) rat model of cholestasis. The work was conducted on 30 male rats divided into 3 groups: Sham, BDL and quercetin-treated BDL (BDL-Q). Results: Rats from the BDL group showed prolonged bleeding time and diminished platelet aggregation in response to ADP (50 μmol/L), however, changes in platelet count were insignificant. Electron microscopic (EM) photos of platelets from BDL group showed signs of activation. vWF levels were decreased in the plasma of BDL group. ORAI1 gene expression was significantly reduced in their platelets after being exposed to ADP. In BDL-Q rats, bleeding time and platelet aggregation defects were improved. EM demonstrated a picture that is midway between sham and BDL platelets. vWF levels and ORAI1 gene expression increased significantly. ORAI1 expression in platelets was positively correlated to vWF levels. The study concluded that defective platelet function in BDL rat model of cholestasis is due to decrease ORAI1 gene expression and that quercetin administration enhances its expression and improves platelet function.

Gene Therapy for Treatment of Chronic Hyperammonemia in a Rat Model of Hepatic Encephalopathy

Introduction and aim. Hepatic encephalopathy (HE), caused by hyperammonemia resulting from liver disease, is a spectrum of neuropsychiatric and motor disorders that can lead to death. Existing therapies are deficient and alternative treatments are needed. We have shown that gene therapy with a baculovirus vector containing the glutamine synthetase (Bac-GS) gene is efficient for reducing ammonia levels in an acute hyperammonemia rat model. However, the most common condition resulting from liver disease is chronic hyperammonemia. In this work, Bac-GS was evaluated in bile-duct ligated rats, a chronic liver disease model with hyperammonemia and some characteristics of Type C HE.Material and methods. Bac-GS was tested for mediating GS over-expression in HeLa cells and H9C2 myotubes. For determining the utility of Bac-GS for the reduction of ammonia levels in a chronic hyperammonemia animal model, four groups of rats were treated: control, sham, ligated with Bac-GS and ligated with Bac-GFP. Baculoviruses were injected i.m. 18 days post-surgery. Blood was drawn 2, 3 and 4 weeks post-surgery and plasma ammonia concentrations were quantified.Results. In protein lysates of cells and myotubes transduced with Bac-GS, a 44 kDa band corresponding to GS was detected. Significant results were obtained in the hyperammonemic bile-duct ligated rat model, as plasma ammonia was reduced to normal levels 3 days after treatment with Bac-GS. Furthermore, a transitory effect of Bac-GS was observed.Conclusion. Our results show that gene therapy by delivering GS is a promising alternative for treatment of hyperammonemia in acute-on-chronic liver failure patients with HE.

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.

PBI-4050 Reduces Stellate Cell Activation and Liver Fibrosis through Modulation of Intracellular ATP Levels and the Liver Kinase B1/AMP-Activated Protein Kinase/Mammalian Target of Rapamycin Pathway.

Hepatic fibrosis is a major cause of morbidity and mortality for which there is currently no effective therapy. We previously showed that 2-(3-pentylphenyl)acetic acid (PBI-4050) is a dual G protein-coupled receptor GPR40 agonist/GPR84 antagonist that exerts antifibrotic, anti-inflammatory, and antiproliferative action. We evaluated PBI-4050 for the treatment of liver fibrosis in vivo and elucidated its mechanism of action on human hepatic stellate cells (HSCs). The antifibrotic effect of PBI-4050 was evaluated in carbon tetrachloride (CCl4)- and bile duct ligation-induced liver fibrosis rodent models. Treatment with PBI-4050 suppressed CCl4-induced serum aspartate aminotransferase levels, inflammatory marker nitric oxide synthase, epithelial to mesenchymal transition transcription factor Snail, and multiple profibrotic factors. PBI-4050 also decreased GPR84 mRNA expression in CCl4-induced injury, while restoring peroxisome proliferator-activated receptor γ (PPARγ) to the control level. Collagen deposition and α-smooth muscle actin (α-SMA) protein levels were also attenuated by PBI-4050 treatment in the bile duct ligation rat model. Transforming growth factor-β-activated primary HSCs were used to examine the effect of PBI-4050 and its mechanism of action in vitro. PBI-4050 inhibited HSC proliferation by arresting cells in the G0/G1 cycle phase. Subsequent analysis demonstrated that PBI-4050 signals through a reduction of intracellular ATP levels, activation of liver kinase B1 (LKB1) and AMP-activated protein kinase (AMPK), and blockade of mammalian target of rapamycin (mTOR), resulting in reduced protein and mRNA levels of α-SMA and connective tissue growth factor and restored PPARγ mRNA expression. Our findings suggest that PBI-4050 may exert antifibrotic activity in the liver through a novel mechanism of action involving modulation of intracellular ATP levels and the LKB1/AMPK/mTOR pathway in stellate cells, and PBI-4050 may be a promising agent for treating liver fibrosis.

Hepatoprotective effect of boldine in a bile duct ligated rat model of cholestasis/cirrhosis

Liver fibrosis is a debilitating disease associated with chronic liver injury. Oxidative stress is known as a pivotal mechanism in the initiation and propagation of liver fibrosis. Boldine is a potent antioxidant molecule with several pharmacological effects. The current investigation aimed to evaluate the effect of boldine in bile duct ligated (BDL) rats as a model of cholestasis and cirrhosis. BDL animals received boldine (5, 10, and 20mg/kg/day, oral) for 14days (Cholestatic rats) and 28days (Cirrhotic rats). The serum biomarkers of liver injury were drastically increased in the BDL group. Moreover, the level of oxidative stress markers was significantly increased in BDL animals. Severe bridging fibrosis, tissue necrosis, and inflammation were also detected in BDL rats. It was found that boldine (5, 10, and 20mg/kg/day, oral) restored the BDL-induced depletion of glutathione content and tissue antioxidant capacity. Moreover, histopathological changes and collagen deposition were markedly attenuated by the boldine treatment. The beneficial effects of boldine administration in cholestasis/cirrhosis might be associated with anti-fibrotic properties via antioxidant activities.

Glechoma hederacea extracts attenuate cholestatic liver injury in a bile duct-ligated rat model

Ethnopharmacological relevanceIn traditional Chinese medicine, Glechoma hederacea is frequently prescribed to patients with cholelithiasis, dropsy, abscess, diabetes, inflammation, and jaundice. Polyphenolic compounds are main bioactive components of Glechoma hederacea. Aim of the studyThis study was aimed to investigate the hepatoprotective potential of hot water extract of Glechoma hederacea against cholestatic liver injury in rats. Materials and methodsCholestatic liver injury was produced by ligating common bile ducts in Sprague-Dawley rats. Saline and hot water extract of Glechoma hederacea were orally administrated using gastric gavages. Liver tissues and bloods were collected and subjected to evaluation using histological, molecular, and biochemical approaches. ResultsUsing a rat model of cholestasis caused by bile duct ligation (BDL), daily oral administration of Glechoma hederacea hot water extracts showed protective effects against cholestatic liver injury, as evidenced by the improvement of serum biochemicals, ductular reaction, oxidative stress, inflammation, and fibrosis. Glechoma hederacea extracts alleviated BDL-induced transforming growth factor beta-1 (TGF-β1), connective tissue growth factor, and collagen expression, and the anti-fibrotic effects were accompanied by reductions in α-smooth muscle actin-positive matrix-producing cells and Smad2/3 activity. Glechoma hederacea extracts attenuated BDL-induced inflammatory cell infiltration/accumulation, NF-κB and AP-1 activation, and inflammatory cytokine production. Further studies demonstrated an inhibitory effect of Glechoma hederacea extracts on the axis of high mobility group box-1 (HMGB1)/toll-like receptor-4 (TLR4) intracellular signaling pathways. ConclusionsThe hepatoprotective, anti-oxidative, anti-inflammatory, and anti-fibrotic effects of Glechoma hederacea extracts seem to be multifactorial. The beneficial effects of daily Glechoma hederacea extracts supplementation were associated with anti-oxidative, anti-inflammatory, and anti-fibrotic potential, as well as down-regulation of NF-κB, AP-1, and TGF-β/Smad signaling, probably via interference with the HMGB1/TLR4 axis.

The Possible Anti-fibrotic Effect of Artichoke on the Liver and Heart of Bile Duct Ligation Rat Model

The Possible Anti-fibrotic Effect of Artichoke on the Liver and Heart of Bile Duct Ligation Rat Model

Quercetin protects liver injury induced by bile duct ligation via attenuation of Rac1 and NADPH oxidase1 expression in rats

Bile duct ligation (BDL) and subsequent cholestasis are correlated with oxidative stress, hepatocellular injury and fibrosis. Quercetin is a flavonoid with antifibrotic, and hepatoprotective properties. However, the molecular mechanism underlying quercetin-mediated hepatoprotection is not fully understood. The current study was to evaluate mechanisms of hepatoprotective effect of quercetin in BDL rat model. We divided male Wistar rats into 4 groups (n=8 for each): sham, sham+quercetin (30 mg/kg per day), BDL, and BDL+quercetin (30 mg/kg per day). Four weeks later, the rats were sacrificed, the blood was collected for liver enzyme measurements and liver for the measurement of Rac1, Rac1-GTP and NOX1 mRNA and protein levels by quantitative PCR and Western blotting, respectively. Quercetin significantly alleviated liver injury in BDL rats as evidenced by histology and reduced liver enzymes. Furthermore, the mRNA and protein expression of Rac1, Rac1-GTP and NOX1 were significantly increased in BDL rats compared with those in the sham group (P<0.05); quercetin treatment reversed these variables back toward normal (P<0.05). Another interesting finding was that the antioxidant markers e.g. superoxide dismutase and catalase were elevated in quercetin-treated BDL rats compared to BDL rats (P<0.05). Quercetin demonstrated hepatoprotective activity against BDL-induced liver injury through increasing antioxidant capacity of the liver tissue, while preventing the production of Rac1, Rac1-GTP and NOX1 proteins.

Effect of Rifaximin on Hepatic Fibrosis in Bile Duct-ligated Rat Model.

The translocation of bacteria and their lipopolysaccharides from the gut can promote fibrosis in cirrhotic patients. The aim of this study was to investigate the effects of rifaximin on hepatic fibrosis in a bile duct-ligated rat model. The bile duct ligation (BDL) was carried out for eight days (acute injury model: sham-operated rats [G1], BDL rats [G2], and BDL rats treated with rifaximin [G3]) or 22 days (chronic injury model: sham-operated rats [G4], BDL rats [G5], and BDL rats treated with rifaximin [G6]). Rifaximin (50 mg/kg/day) was administered daily via gavage after BDL. Liver function, serum tumor necrosis factor-alpha (TNF-α), and hepatic hydroxyproline levels were measured. Moreover, a histological analysis of fibrosis contents was performed using sirius red stain. In the acute injury model, the liver function and TNF-α level were not improved after the rifaximin treatment. The hydroxyproline levels (µg/g liver tissue) in G1, G2, and G3 were 236.4±103.1, 444.8±114.4, and 312.5±131.6, respectively; and fibrosis contents (%) were 0.22±0.04, 1.64±0.53, and 1.66±0.44, respectively. The rifaximin treatment did not ameliorate acute BDL-induced fibrosis. In the chronic injury model, the hydroxyproline levels in G4, G5, and G6 were 311.5±72.9, 1,110.3±357.9, and 944.3±209.3, respectively; and fibrosis contents (%) were 0.19±0.03, 5.04±0.18, and 4.42±0.68, respectively (G5 vs. G6, p=0.059). The rifaximin treatment marginally ameliorated chronic BDL-induced fibrosis. Rifaximin did not reduce inflammation and fibrosis in bile duct-ligated rat model.

Carvedilol Attenuates the Progression of Hepatic Fibrosis Induced by Bile Duct Ligation.

Background. The sympathetic nervous system (SNS) is responsible for hepatic stellate cells (HSCs) activation and the accumulation of collagen that occurs in hepatic fibrogenesis. Carvedilol has been widely used for the complication of hepatic cirrhosis in the clinic. Furthermore, it has powerful antioxidant properties. We assessed the potential antifibrotic effects of carvedilol and the underlying mechanisms that may further enhance its clinical benefits. Methods. Using a bile duct ligation rat model of hepatic fibrosis, we studied the effects of carvedilol on the fibrosis, collagen deposition, and oxidative stress based on histology, immunohistochemistry, western blot, and RT-PCR analyses. Results. Carvedilol attenuated liver fibrosis, as evidenced by reduced hydroxyproline content and the accumulation of collagen, downregulated TIMP-1 and TIMP-2, and upregulated MMP-13. MMP-2 was an exception, which was decreased after carvedilol treatment for 2 weeks and upregulated after carvedilol treatment for 4 weeks. Carvedilol reduced the activation of HSCs, decreased the induction of collagen, transforming growth factor-β1, and MDA content, and strengthened the SOD activity. The antifibrotic effects were augmented as dosages increased. Conclusions. The study indicates that carvedilol attenuated hepatic fibrosis in a dose-dependent manner. It can decrease collagen accumulation and HSCs activation by the amelioration of oxidative stress.