Liver Collagen Content Research Articles

Trypanosoma cruzi infection and benznidazole therapy independently stimulate oxidative status and structural pathological remodeling of the liver tissue in mice.

This study used a murine model of Chagas disease to investigate the isolated and combined impact of Trypanosoma cruzi infection and benznidazole (BZ) therapy on liver structure and function. Male C57BL/6 mice were challenged with T. cruzi and BZ for 15 days. Serum levels of cytokines and hepatic enzymes, liver oxidative stress, morphology, collagen, and glycogen content were monitored. Separately, T. cruzi infection and BZ treatment resulted in a pro-oxidant status and hepatic reactive damage. Concurrently, both T. cruzi infection and BZ treatment induced upregulation of antioxidant enzymes and pathological reorganization of the liver parenchyma and stroma. T. cruzi infection increased serum levels of Th1 cytokines, which were reduced by BZ in both infected and non-infected animals. BZ also induced functional organ damage, increasing serum levels of liver enzymes. When combined, T. cruzi infection and BZ therapy elicited intense hepatic reactive damage that was not compensated by antioxidant enzymatic reaction, subsequently culminating in more severe morphofunctional hepatic injury. Taken together, these findings indicate that during specific treatment of Chagas disease, hepatic pathology may be a result of an interaction between BZ metabolism and specific mechanisms activated during the natural course of T. cruzi infection, rather than an isolated toxic effect of BZ on liver structure and function.

Effect of quercetin on cadmium fluoride-induced alterations in hydroxyproline/collagen content in mice liver

Purpose/aim of the study: To study the effect of quercetin, a flavanoid on cadmium fluoride-induced alterations in hydroxyproline and collagen content in mice liver.Materials and methods: Following experimental groups were studied: Group 1, normal mice; Group 2, CdF2-treated mice administered single intraperitoneal (i.p.) injections of CdF2 1 mg/kg bw (body weight); Group 3, CdF2-treated mice administered single i.p. injections of CdF2 2 mg/kg bw; Group 4, mice-injected i.p. with 100 mg quercetin/kg bw; and Group 5, mice-injected i.p. with 100 mg quercetin/kg bw followed by 2 mg CdF2/kg bw after 2 h. Mice were sacrificed 24 h after CdF injection by asphyxiation with carbon dioxide.Results: 1 mg/kg and 2 mg/kg body weight (bw) of CdF2 caused a significant increase in hepatic total Hyp and collagen when compared with the liver of control mice. This was associated with significant changes in free, peptide bound, and protein bound Hyp fraction in the livers of treated mice. Quercetin treatment alone and with CdF2 also caused a significant increase in total Hyp and total collagen in mice liver.Conclusion: We conclude that quercetin has a synergestic effect with CdF2 on the total Hyp and collagen content in mice liver.

Epigenetic histone methylation regulates transforming growth factor β-1 expression following bile duct ligation in rats

Multiple mechanisms contribute to the liver fibrosis following cholestasis. Recent research has focused on the role of transforming growth factor β-1 (TGF-β1) in the progression of fibrosis. The aim of our study is to examine the role of epigenetic chromatin marks, such as histone H3 lysine methylation (H3Kme), in bile duct ligation (BDL)-induced TGF-β1 gene expression in rat liver. Time course of methylated-histone H3 and SET7/9 recruitment were determined by chromatin immunoprecipitation in livers from BDL rats on days 1, 4, 9 and 14. Levels of TGF-β1 and SET7/9 were determined by western blots. The effect of SET7/9 knockdown on BDL-induced expression of TGF-β1, serum enzymes and liver collagen content was studied in vivo. Results showed that BDL increased the expression of the TGF β-1. Increased levels of active chromatin marks (H3K4me1, H3K4me2, and H3K4me3) and decreased levels of repressive marks (H3K9me2 and H3K9me3) in TGF-β1 promoter accompanied the changes in expression of the TGF β-1. BDL also increased expression of the H3K4 methyltransferase SET7/9 and recruitment to the promoter. SET7/9 gene knockdown with siRNAs significantly attenuated BDL-induced TGF-β1 gene expression, serum enzymes and liver collagen content. Taken together, these results show the functional role of epigenetic chromatin histone H3Kme in BDL-induced TGF-β1 expression. Pharmacologic and other therapies that reverse these modifications could have potential hepatoprotective effects for BDL-induced cirrhosis.

Protective effect of Tamarindus indica fruit pulp extract on collagen content and oxidative stress induced by sodium fluoride in the liver and kidney of rats

Fluorosis is a serious public health problem in many parts of the world. The generation of reactive oxygen species and lipid peroxidation has been considered to play an important role in the pathogenesis of chronic fluoride toxicity. The present study was undertaken to evaluate the protective effect of Tamarindus indica fruit pulp extract on the collagen content and oxidative stress in liver and kidney of fluoride-exposed rats. The first group served as control. The second group received 200 mg L−1 of sodium fluoride through drinking water. The third and fourth groups received T. indica fruit pulp extract (200 mg kg−1 body weight) alone and along with fluorinated drinking water respectively, daily by gavage for a period of 90 days. At the end of the experiment, blood samples were collected from all groups, and liver and kidney samples were taken concurrently. Levels of malondialdehyde and glutathione and the activities of superoxide dismutase and catalase were evaluated in the liver and kidney of experimental rats. Furthermore, level of hydroxyproline and histological examination of liver and kidney along with serum biochemical parameters were evaluated. In conclusion, fluoride was determined to cause adverse effects in rats, and the supplementation of tamarind to these animals alleviated the adverse effects of fluoride.

Failure of Fibrotic Liver Regeneration in Mice Is Linked to a Severe Fibrogenic Response Driven by Hepatic Progenitor Cell Activation

Failure of fibrotic liver to regenerate after resection limits therapeutic options and increases demand for liver transplantation, representing a significant clinical problem. The mechanism underlying regenerative failure in fibrosis is poorly understood. Seventy percent partial hepatectomy (PHx) was performed in C57Bl/6 mice with or without carbon tetrachloride (CCl4)-induced liver fibrosis. Liver function and regeneration was monitored at 1 to 14 days thereafter by assessing liver mass, alanine aminotransferase (ALT), mRNA expression, and histology. Progenitor (oval) cell mitogen tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and TWEAK-neutralizing antibody were used to manipulate progenitor cell proliferation in vivo. In fibrotic liver, hepatocytes failed to replicate efficiently after PHx. Fibrotic livers showed late (day 5) peak of serum ALT (3542 ± 355 IU/L compared to 93 ± 65 IU/L in nonfibrotic livers), which coincided with progenitor cell expansion, increase in profibrogenic gene expression and de novo collagen deposition. In fibrotic mice, inhibition of progenitor activation using TWEAK-neutralizing antibody after PHx resulted in strongly down-regulated profibrogenic mRNA, reduced serum ALT levels and improved regeneration. Failure of hepatocyte-mediated regeneration in fibrotic liver triggers activation of the progenitor (oval) cell compartment and a severe fibrogenic response. Inhibition of progenitor cell proliferation using anti-TWEAK antibody prevents fibrogenic response and augments fibrotic liver regeneration. Targeting the fibrogenic progenitor response represents a promising strategy to improve hepatectomy outcomes in patients with liver fibrosis.

Role of JNK Signalling and AHR in Fibrosis, Implications for New Therapeutics

In this study a role for signalling molecules in experimental fibrosis is established using a novel model of fibrosis. The yellow phosphorous treatment of AHR-/- knockout mice caused fibrosis within 7 days and provided a narrow window in which to characterize the regulation of signalling molecules. The mice used were AHR-/- mice (5 weeks) with and without Yellow Phosphorous (YP) treatment compared to C57BL/6 (5 weeks). YP (0.6 mg/kg) was administered to AHR-/- mice for 1 week. A subgroup of mice were also administered c-jun antisense. A group of AHR-/- mice (aged 10 to 24 week old) were also studied to verify the spontaneous development of liver fibrosis over time in these animals. As an index of fibrosis, the liver collagen content was determined by Sirius red/fast green staining in these animals, the levels of hepatic c-Jun and collagen were also assessed by Western analysis. Results indicate that without YP treatment, there was a significant spontaneous increase in the liver collagen content in the AHR-/- mice from weeks 5 to 24. Further, the results indicate that YP treatment increased the rate of fibrosis in AHR-/- mice and this increase in collagen content with only one week of YP treatment produced fibrosis ( i.e., elevated collagen levels) equivalent to that seen in spontaneously in untreated 24 week old AHR-/- mice. Using Western analysis both c-Jun and collagen were found to be elevated in livers of 5 weeks old AHR-/- mice treated with YP. We thus identified an up regulation of c-jun and collagen indicating an increased rate of fibrosis in this new model. The use of c-jun antisense technology effectively reduced target molecules. In conclusion, molecular targets were identified in an accelerated model of hepatic fibrosis and using antisense technology the targets were inhibited and fibrosis was blocked.

Relationship between serum transforming growth factor ß1 and liver collagen content in rats treated with carbon tetrachloride

Transforming Growth Factor ß1 (TGFß1) plays a fundamental role in fibrogenesis, although its importance as a biomarker of liver disease is still matter of debate. Quantify serum TGFß1 and its association to liver collagen content in rats exposed to Carbon Tetrachloride (CCl4). Rats were submitted to a fibrosis model using CCl4 and sacrificed after 6, 10, 12 and 16 weeks of treatment. Serum levels of TGFß1 were measured by ELISA and collagen content was defined by morphometric analysis. Serum levels of TGFß1 increased between 6 and 10 weeks, whereas collagen density increased between 12 and 16 weeks. A negative correlation was observed between liver collagen deposition and serum levels of TGFß1 (r = -0. 48; P<0. 05). Serum levels of TGFß1 were inversely proportional to collagen intensity in cirrhotic livers of rats exposed to CCl4, thus suggesting a limited use as biomarker in advanced liver disease.

Anti-fibrotic effects of fresh and cryopreserved human amniotic membrane in a rat liver fibrosis model

The human amniotic membrane (hAM), thanks to its favorable properties, including anti-inflammatory, anti-fibrotic and pro-regenerative effects, is a well-known surgical material for many clinical applications, when used both freshly after isolation and after preservation. We have shown previously that hAM patching is a potential approach to counteract liver fibrosis. Indeed, when fresh hAM was used to cover the liver surface of rats with liver fibrosis induced by the bile duct ligation (BDL) procedure, the progression and severity of fibrosis were significantly reduced. Since cryopreservation enables safety and long-term storage of hAM but may influence its functional properties, here we compared the anti-fibrotic effects of fresh and cryopreserved hAM in rats with BDL-induced liver fibrosis. After BDL, the rat liver was covered with a piece of fresh or cryopreserved hAM, or left untreated. Six weeks later, the degree of liver fibrosis was assessed histologically using the Knodell and the METAVIR scoring systems. Digital image analysis was used to quantify the percentage of the areas of each liver section displaying ductular reaction, extracellular matrix (ECM) deposition, activated myofibroblasts and hepatic stellate cells (HSCs). Liver collagen content was also determined by spectrophotometric technique. The degree of liver fibrosis, ductular reaction, ECM deposition, and the number of activated myofibroblasts and HSCs were all significantly reduced in hAM-treated rats compared to control animals. Fresh and cryopreserved hAM produced the same anti-fibrotic effects. These findings indicate that cryopreservation maintains the anti-fibrotic properties of hAM when used as a patch to reduce the severity of liver fibrosis.

Assessment of liver steatosis and fibrosis in rats using integrated coherent anti-Stokes Raman scattering and multiphoton imaging technique

We report the implementation of a unique integrated coherent anti-Stokes Raman scattering (CARS), second-harmonic generation (SHG), and two-photon excitation fluorescence (TPEF) microscopy imaging technique developed for label-free monitoring of the progression of liver steatosis and fibrosis generated in a bile duct ligation (BDL) rat model. Among the 21 adult rats used in this study, 18 rats were performed with BDL surgery and sacrificed each week from weeks 1 to 6 (n = 3 per week), respectively; whereas 3 rats as control were sacrificed at week 0. Colocalized imaging of the aggregated hepatic fats, collagen fibrils, and hepatocyte morphologies in liver tissue is realized by using the integrated CARS, SHG, and TPEF technique. The results show that there are significant accumulations of hepatic lipid droplets and collagen fibrils associated with severe hepatocyte necrosis in BDL rat liver as compared to a normal liver tissue. The volume of normal hepatocytes keeps decreasing and the fiber collagen content in BDL rat liver follows a growing trend until week 6; whereas the hepatic fat content reaches a maximum in week 4 and then appears to stop growing in week 6, indicating that liver steatosis and fibrosis induced in a BDL rat liver model may develop at different rates. This work demonstrates that the integrated CARS and multiphoton microscopy imaging technique has the potential to provide an effective means for early diagnosis and detection of liver steatosis and fibrosis without labeling.

Zingiber officinale acts as a nutraceutical agent against liver fibrosis

Background/objectiveZingiber officinale Roscoe (ginger) (Zingiberaceae) has been cultivated for thousands of years both as a spice and for medicinal purposes. Ginger rhizomes successive extracts (petroleum ether, chloroform and ethanol) were examined against liver fibrosis induced by carbon tetrachloride in rats.ResultsThe evaluation was done through measuring antioxidant parameters; glutathione (GSH), total superoxide dismutase (SOD) and malondialdehyde (MDA). Liver marker enzymes; succinate and lactate dehydrogenases (SDH and LDH), glucose-6-phosphatase (G-6-Pase), acid phosphatase (AP), 5'- nucleotidase (5'NT) and liver function enzymes; aspartate and alanine aminotransferases (AST and ALT) as well as cholestatic markers; alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), total bilirubin were estimated. Liver histopathological analysis and collagen content were also evaluated. Treatments with the selected extracts significantly increased GSH, SOD, SDH, LDH, G-6-Pase, AP and 5'NT. However, MDA, AST, ALT ALP, GGT and total bilirubin were significantly decreased.ConclusionsExtracts of ginger, particularly the ethanol one resulted in an attractive candidate for the treatment of liver fibrosis induced by CCl4. Further studies are required in order to identify the molecules responsible of the pharmacological activity.

F-25 Garlic extract reduces rat liver fibrosis and collagen content via TGFβ and tissue transglutaminase inactivation

F-25 Garlic extract reduces rat liver fibrosis and collagen content via TGFβ and tissue transglutaminase inactivation

Coffee prevents CCl4-induced liver cirrhosis in the rat

Previous clinical observations suggested that coffee may have beneficial effects on the liver. In fact, an inverse relationship between coffee consumption and liver cirrhosis has been reported in humans. However, the causative role of coffee has not been established; therefore, the aim of this work was to study the effect of coffee in an experimental model of liver damage. In this work, cirrhosis was induced by chronic CCl(4) administration and soluble or grain coffee (SC, GC, respectively) were co-administered for 8weeks. CCl(4) administration elevated serum alkaline phosphatase and alanine aminotranspherase, liver lipid peroxidation, collagen content (fourfold) and TGF-β mRNA, and protein levels; depleted liver glycogen and reduced glutathione (GSH) content. Coffee prevented most of the changes produced by CCl(4). Histopathological analysis was in agreement with biochemical and molecular data. The best effect was produced by GC. It is worth noting that GC preserved the normal collagen content as well as the normal TGF-β mRNA and protein levels. Our results suggest (1) that coffee plays a causative role in preventing cirrhosis (at least experimental cirrhosis); (2) that action mechanisms are probably associated with down regulation of the profibrogenic cytokine TGF-β and to its antioxidant properties and, (3) that GC is more potent than SC. These findings suggest a beneficial effect of coffee on the liver. However, more clinical and basic studies must be performed before reaching a final recommendation.

Effectiveness of the PPARγ agonist, GW570, in liver fibrosis

The peroxisome proliferator-activated receptors (PPARs) are well established to be important in modulating the fibrogenic response to liver injury. PPARγ plays a role in hepatic fibrosis, presumably by virtue of its expression in hepatic stellate cells, which are key effectors of fibrosis. In this study, we evaluated whether the potent nonthiozolidinedione PPARγ agonist, GW570, had effects on isolated stellate cells and hepatic fibrosis in vivo. Liver fibrosis and stellate cell activation were induced in vivo by either bile duct ligation (BDL) or administration of carbon tetrachloride (CCl(4)). Primary cultures of stellate cells isolated from normal rats were exposed to GW570. The PPARγ agonist was also given to male Sprague-Dawley rats before or during injury to test its ability to ameliorate fibrosis. Fibrosis biomarkers including total collagen, hydroxyproline, collagen I α1 and smooth muscle α actin were measured. GW570 had potent effects on isolated stellate cells, both simulating PPARγ mediated gene transcription, as well as inhibiting collagen I α1 mRNA and protein expression and smooth muscle α actin protein abundance, consistent with suppression of stellate cell activation. In BDL liver injury, a daily dose of 10 mg/kg per day of GW570 inhibited collagen I α1 mRNA, while concentrations of 1 also inhibited fibrosis as measured by hydroxyproline and total collagen content. Lower doses of GW570 (0.1-1.0 mg/kg per day) did not significantly abrogate whole liver collagen or hydroxyproline content in this model. In a CCl(4) model, 0.1-1.0 mg/kg per day GW570 reduced expression of smooth muscle α actin, but did not affect whole liver collagen or hydroxyproline content. Finally, we found that GW570 had anti-inflammatory effects on Kupffer cells as well as in vivo during CCl(4) injury. PPARγ receptor agonism with the nonthiozolidinedione, GW570, inhibited stellate cell activation in vitro and in vivo, and abrogated the fibrogenic response to injury in a dose responsive fashion.

In vivo Quantification of Liver Stiffness in a Rat Model of Hepatic Fibrosis with Acoustic Radiation Force

Liver fibrosis is currently staged using needle biopsy, a highly invasive procedure with a number of disadvantages. Measurement of liver stiffness changes that accompany progression of the disease may provide a quantitative and noninvasive method to assess the health of the liver. The purpose of this study is to investigate the correlation between liver stiffness measured by radiation force induced shear waves and disease related changes in the liver. An additional aim is to present initial findings on the effects of liver viscosity on radiation force induced shear wave morphology. Liver fibrosis was induced in 10 rats using carbon tetrachloride (CCl 4), while five rats acted as controls. Liver stiffness was measured in vivo in all rats after a treatment period of 8 weeks using a modified Siemens SONOLINE Antares scanner (Siemens Medical Solutions USA, Ultrasound Division, Issaquah, WA, USA). The spatial coherence of radiation force induced shear waves propagating in the viscoelastic rat liver decreased significantly with propagation distance, compared with shear waves in an elastic phantom and a finite element model of a purely elastic medium. Animals were sacrificed after imaging and liver samples were taken for histopathologic analysis and collagen quantification using picrosirius red staining and hydroxyproline assay. At the end of the treatment period, five rats had healthy livers (stage F0), while six had severe fibrosis (F3) and the rest had light to moderate fibrosis (F1 and F2). The measured liver stiffness for the F0 group was 1.5 ± 0.1 kPa (mean ± 95% confidence interval) and for F3 livers was 1.8 ± 0.2kPa. In this study, liver stiffness was found to be linearly correlated with the amount of collagen in the liver measured by picrosirius red staining (r 2 = 0.43, p = 0.008). In addition, stiffness spatial heterogeneity was also linearly correlated with liver collagen content (r 2 = 0.58, p = 0.001) by picrosirius red staining. These results are consistent with those obtained by Salameh et al. (2007) and Yin et al. (2007b) using animal models of liver fibrosis and MR elastography. This suggests that stiffness measurement using acoustic radiation force can provide a quantitative assessment of the extent of fibrosis in the liver and can be potentially used for the diagnosis, management and study of liver fibrosis. (E-mail: michael.h.wang@duke.edu)

Compound Cordyceps TCM-700C exhibits potent hepatoprotective capability in animal model

A herbal preparation “Compound Codyceps-TCM-700C (CC-700C)” was tested for hepatoprotective effect against the carbon tetrachloride induced liver damages in Sprague-Dawley rat model for a period of 6-weeks. Two dosage levels of CC-700C, respectively 286.2 mg/kg-bw (L-TCM) and 2862 mg/kg-bw (H-TCM), and a positive control Silymarin (Sigma) were used to compare their therapeutic effect. Both CC-700C's and Silymarin showed nontoxic in nature, as evidenced by body weight gain, organ weights and appearance including liver, spleen, and kidney. The activities of aspartate aminotransferase (AST) and alanine-aminotransferase (ALT) were more effectively suppressed by CC-700C than Silymarin. In addition, all levels of serum bilirubin, serum albumin, triglyceride (TG), total cholesterol (TC), platelet count (PLT), and prothombin time (PT) except TG were shown effectively restored to normal values by CC-700C and Silymarin. Moreover, although levels of glutathione (GSH), glutathione reductase (GSH-Rd), and superoxide dismutase (SOD) were equally maintained by these three preparations, glutathione peroxidase (GSH-Px) was suppressed only by H-TCM, and SOD only by Silymarin. In contrast, the activity of catalase efficiently recovered to control level on administration of CC-700C, being far better than Silymarin. Finally the liver collagen content, an indication of fibrosis, was also significantly suppressed by CC-700C, better effect was by L-TCM, but both levels were superior to Silymarin. Conclusively, the herbal preparation “Compound Cordyceps TCM-700C” is a potent hepatoprotective preparation. For therapeutic use, a dosage of 286.2 mg/kg-bw would be sufficiently effective.

Stephania tetrandra prevents and regresses liver fibrosis induced by carbon tetrachloride in rats

There is currently no safe and effective treatment for liver fibrosis. We have previously shown that Stephania tetrandra (ST) and Salvia miltiorrhiza (SM) suppress cell proliferation and enhance apoptosis of hepatic stellate cell (HSC) in vitro. In this study, we aimed to investigate the anti-fibrotic effect of these two herbs in vivo. Liver fibrosis was induced by carbon tetrachloride (CCl(4)) injection in rats for 5 weeks. SM, ST or SM + ST was gavaged on day 1 of CCl(4) administration to study the preventive effects of herbs on hepatic fibrosis. In a separate study designed to assess possible fibrosis regression, rats were randomly allocated to be treated with SM, ST or SM + ST when fibrosis was established. Liver injury and collagen content were assessed. HSC activation and apoptosis were determined. As compared with the CCL(4)-only rats, serum ALT was significantly lower in CCl(4)-treated rats that received either SM (P < 0.01) or ST (P < 0.01). Administration of ST significantly prevented (P < 0.01) or reversed the hepatic fibrosis (P < 0.01) induced by CCL(4). Moreover, rats treated with ST had reduced protein expression of alpha-SMA both in prevention (P < 0.05) and in regression (P < 0.01) experiments. The double-color staining of alpha-SMA and TUNEL showed that ST increased HSC apoptosis. However, co-treatment of SM + ST did not increase the antifibrotic effect of ST. Stephania tetrandra safely and effectively prevents and reverses hepatic fibrosis through activating HSC apoptosis in rats.

Hepatic fibrosis in mice lacking liver vitamin A stores

Loss of retinyl esters and lipid droplets from hepatic stellate cells (HSCs) is one of the first events in the development of hepatic fibrosis. Since lecithin:retinol acyltransferase‐deficient (Lrat−/−) mice lack HSC retinyl esters and lipid droplets, we investigated how this absence influences development of CCl4‐induced hepatic fibrosis. We also induced fibrosis in mice lacking diacylglycerol acyltransferase 1 (Dgat1−/−), an enzyme that can synthesize retinyl esters. Hepatic retinol and retinyl ester contents of CCl4‐treated wild type and Dgat1−/− mice were significantly lower than sham‐treated mice. Trichrome staining and qRT‐PCR indicated that, although liver collagen content increased in all the CCl4‐treated groups, more collagen was present in livers of Lrat−/− and Dgat1−/− mice compared to wild type. We measured mRNA levels by qRT‐PCR of a number of factors implicated in fibrosis development. TGFβ mRNA levels were similarly elevated in all CCl4‐treated groups but levels for Timp1, Cyp2S1 and Cyp26A1 were significantly more upregulated in Lrat−/− and Dgat1−/− mice than in wild type mice. Our data suggest that the absence of HSC vitamin A stores can influence the progression of hepatic fibrosis.

Immunomodulatory effects of curcumin treatment on murine schistosomiasis mansoni

Curcumin is a polyphenol derived from the dietary spice turmeric. It has been shown to regulate numerous transcription factors, cytokines, adhesion molecules, and enzymes that have been linked to inflammation. In addition to inhibiting the growth of a variety of pathogens, curcumin has been shown to have nematocidal activity. The present study was designed to evaluate the schistosomicidal activity of curcumin in vivo as well as immunomodulation of granulomatous inflammation and liver pathology in acute schistosomiasis mansoni. Mice were infected each with 80 Schistosoma ( S.) mansoni cercariae and injected intraperitoneally with curcumin at a total dose of 400 mg/kg body weight. Curcumin was effective in reducing worm and tissue-egg burdens, hepatic granuloma volume and liver collagen content by 44.4%, 30.9%, 79%, and 38.6%, respectively. Curcumin treatment restored hepatic enzymes activities to the normal levels and enhanced catalase activity in the liver tissue of infected mice. Moreover, hepato-spleenomegaly and eosinophilia induced by S. mansoni infection were largely improved with curcumin treatment. Infected mice treated with curcumin showed low serum level of both interleukin (IL)-12 and tumor necrosis factor alpha (TNF-α), but IL-10 level was not significantly altered. Specific IgG and IgG1 responses against both soluble worm antigen (SWAP) and soluble egg antigen (SEA) were augmented with curcumin treatment, but IgM and IgG2a responses were not significantly changed. In conclusion, curcumin treatment modulates cellular and humoral immune responses of infected mice and lead to a significant reduction of parasite burden and liver pathology in acute murine schistosomiasis mansoni.

Partial Hepatectomy–Induced Regeneration Accelerates Reversion of Liver Fibrosis Involving Participation of Hepatic Stellate Cells

Hepatic fibrosis underlies most types of chronic liver diseases and is characterized by excessive deposition of extracellular matrix (ECM), altered liver architecture, and impaired hepatocyte proliferation; however, the fibrotic liver can still regenerate after partial hepatectomy (PH). Therefore, the present study was aimed at addressing whether a PH-induced regeneration normalizes ECM turnover and the possible involvement of hepatic stellate cells (HSC) during resolution of a pre-established fibrosis. Male Wistar rats were rendered fibrotic by intraperitoneal administration of swine serum for 9 weeks and subjected afterwards to 70% PH or sham-operation. Histological and morphometric analyses were performed, and parameters indicative of cell proliferation, collagen synthesis and degradation, and activation of HSC were determined. Liver collagen content was reduced to 75% after PH in cirrhotic rats when compared with sham-operated cirrhotic rats. The regenerating fibrotic liver oxidized actively free proline and had diminished transcripts for alpha-1 (I) collagen mRNA, resulting in decreased collagen synthesis. PH also increased collagenase activity, accounted for by higher amounts of pro-MMP-9, MMP-2, and MMP-13, which largely coincided with a lower expression of TIMP-1 and TIMP-2. Therefore, an early decreased collagen synthesis, mild ECM degradation, and active liver regeneration were followed by higher collagenolysis and limited deposition of ECM, probably associated with increased mitochondrial activity. Activated HSC readily increased during liver fibrosis and remained activated after liver regeneration, even during fibrosis resolution. In conclusion, stimulation of liver regeneration through PH restores the balance in ECM synthesis/degradation, leading to ECM remodeling and to an almost complete resolution of liver fibrosis. As a response to the regenerative stimulus, activated HSC seem to play a controlling role on ECM remodeling during experimental cirrhosis in rats. Therefore, pharmacological approaches for the resolution of liver fibrosis by blocking HSC activation should also evaluate possible effects on liver cell proliferation.

Elevated serum β-glucuronidase reflects hepatic lysosomal fragility following toxic liver injury in rats

The level of serum beta-glucuronidase increases in various pathological conditions, including liver disorders. The aim of this investigation was to study the changes in liver lysosomal membrane stability during experimentally induced hepatic fibrosis that may result in the elevation of serum beta-glucuronidase. Liver injury was induced by intraperitoneal injections of N-nitrosodimethylamine (NDMA) in adult male albino rats over 3 weeks. The progression of fibrosis was evaluated histopathologically as well as by monitoring liver collagen content. Lipid peroxides and beta-glucuronidase levels were measured in the liver homogenate and subcellular fractions on days 0, 7, 14, and 21 after the start of NDMA administration. Serum beta-glucuronidase levels were also determined. A significant increase was observed in beta-glucuronidase levels in the serum, liver homogenate, and subcellular fractions, but not in the nuclear fraction on days 7, 14, and 21 after the start of NDMA administration. Lipid peroxides also increased in the liver homogenate and the lysosomal fraction. The measurement of lysosomal membrane stability revealed a maximum lysosomal fragility on day 21 during NDMA-induced fibrosis. In vitro studies showed that NDMA has no significant effect on liver lysosomal membrane permeability. The results of this investigation demonstrated that lysosomal fragility increases during NDMA-induced hepatic fibrosis, which could be attributed to increased lipid peroxidation of lysosomal membrane. In this study, we also elucidated the mechanism of increased beta-glucuronidase and other lysosomal glycohydrolases in the serum during hepatic fibrosis.