CCl4-treated Rats Research Articles

Protective effects of Digera muricata (L.) Mart. on testis against oxidative stress of carbon tetrachloride in rat

Oxidative stress induced by carbon tetrachloride (2ml/kg body weight i.p.) in rat substantially decreases the increase in body weight and relative testis weight. It also markedly increases the level of TBARS and nitrites along with corresponding decrease in reduced glutathione and various antioxidant enzymes in testis, i.e., catalase, peroxidase, superoxide dismutase and glutathione peroxidase. Serum level of testosterone, luteinizing hormone and follicle stimulating hormone was significantly decreased while estradiol and prolactin were increased with carbon tetrachloride treatment. Histopathology of CCl4-treated rats indicated the partial degeneration of germ and Leydig cells along with deformities in spermatogenesis. Supplementation of Digera muricata (100, 150, 200mg/kg body weight orally) once a week for 16weeks results in decrease of TBARS and nitrite, while increase in antioxidant enzymes; catalase, peroxidase, superoxide dismutase, GSH-Px and GSH contents. Serum level of testosterone, luteinizing hormone, follicle stimulating hormone, estradiol, prolactin, histology, body weight and relative testis weight was also concomitantly restored to near normal level by D. muricata supplementation to carbon tetrachloride intoxicated rat. The results clearly demonstrate that D. muricata treatment augments the antioxidants defense mechanism against carbon tetrachloride induced toxicity and provides evidence that it may have a therapeutic role in free radical mediated diseases.

Suppressive Effect of Orthovanadate on Hepatic Stellate Cell Activation and Liver Fibrosis in Rats

Orthovanadate (OV), an inhibitor of protein tyrosine phosphatases, affects various biological processes in a cell-type-specific manner. In this study, we investigated the effect of OV on hepatic stellate cells (HSCs). When primary rat HSCs were cultured in the presence of 10% serum, they spontaneously lost characteristic stellate morphology, proliferated, and were transformed into an activated state with the formation of abundant stress fibers and increased expression of both alpha-smooth muscle actin and collagen type I mRNA. OV treatment inhibited proliferation and activation of HSCs and partially reversed the phenotype of activated HSCs. Among the signaling molecules investigated, phosphorylation of the Src protein at tyrosine 416 was the most striking in OV-treated HSCs. Treatment of cells with Src family inhibitors partially abrogated the effects of OV. Furthermore, transfection of v-Src into activated HSCs induced a stellate morphology similar to that in the quiescent state. We then examined whether OV could effectively suppress HSC activation in vivo after liver injury induced by either carbon tetrachloride or dimethylnitrosamine. OV significantly reduced the appearance of alpha-smooth muscle actin-positive cells and decreased collagen deposition, concomitant with an improvement in liver function. Our study showed for the first time that OV was able to suppress the activation of HSCs, possibly through the modulation of Src activity, and attenuated fibrosis after chronic liver injury.

Hepatoprotective Effects of Polysaccharides Isolated from Phellinus gilvus Against Carbon Tetrachloride-induced Liver Injury in Rats.

Phellinus gilvus (PG) is a widely used mushroom for health promotion. We studied the hepatoprotective effect of the polysaccharide aqueous extract of PG (PGP) against carbon tetrachloride (CCl4)-induced liver injury in rats. Sprague Dawley rats were divided into 5 groups: Normal control, CCl4 control, PGP 50, 100, and 200 mg/kg + CCl4. The levels of serum biochemical parameters, liver lipid peroxide and antioxidant enzymes, and histological appearances were evaluated. The CCl4-induced increments of alanine aminotransferase, asparate aminotransferase, and alkaline phosphatase levels in serum were significantly decreased by PGP-pretreatments. The PGP dose-dependently decreased hepatic malondialdehyde formations in CCl4-treatment groups. Hepatic antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) were elevated by PGP in CCl4-treatment groups. Histopathological evaluation of liver showed that the loss of hepatocytes, fatty changes, swelling and extensive necrosis of hepatocytes in centrilobular regions of the CCl4-treated rats were ameliorated by PGP pretreatment. The PGP has hepatoprotective and antioxidative effects in CCl4-induced liver injury of rat.

Hepatoprotective Effect ofShidagonglaoon Acute Liver Injury Induced by Carbon Tetrachloride

This study investigates the hepatoprotective activity of ethanol extract from Shidagonglao roots (SDGL(EtOH)). The hepatoprotective effect of SDGL(EtOH) (20, 100 and 500 mg/kg) was analyzed on carbon tetrachloride (CCl(4))-induced acute liver injury. Rats pretreated orally with SDGL(EtOH) (100 and 500 mg/kg) and silymarin (200 mg/kg) for 3 consecutive days prior to the administration of a single dose of 50% CCl(4) (0.10 ml/100 g of bw, ip) significantly prevented the increases in the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in CCl(4)-treated rats. Histological analysis also showed that SDGL(EtOH) (100 and 500 mg/kg) and silymarin reduced the incidence of liver lesions including vacuole formation, neutrophil infiltration and necrosis of hepatocytes induced by CCl(4) in rats. Moreover, the SDGL(EtOH) (100 and 500 mg/kg) increased the activities of anti-oxidative enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRd) and decreased malondialdehyde (MDA) level in liver, as compared to those in the CCl(4)-treated group. Furthermore, SDGL(EtOH) (100 and 500 mg/kg) and silymarin attenuated the increased levels of tumor necrosis factor-alpha (TNF-alpha) in serum and nitric oxide (NO) in liver as compared to the CCl(4)-treated group. The hepatoprotective mechanisms of SDGL(EtOH) are likely related to inhibition of TNF-alpha, MDA and NO productions via increasing the activities of antioxidant enzymes (SOD, GPx and GRd). These experimental results suggest that SDGL(EtOH) can attenuate CCl(4)-induced acute liver injury in rats.

Carbon tetrachloride-induced hepatotoxicity in pregnant and lactating rats

Carbon tetrachloride (CCl4) is well known to induce hepatotoxicity after being metabolized to trichloromethyl free radical ((.)CCl3) by CYP2E1. In the present study, the hepatotoxicity induced by a single oral dose (2,000 mg/kg) of CCl4 was compared between pregnant (gestation days (GD) 13 and 19) or postpartum (postpartum days (PPD) 1, 13 and 27) and non-pregnant rats. Hepatotoxicity in CCl4-treated pregnant rats evaluated by blood chemistry (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) activities) and histopathological finding (area of damaged hepatocytes) was minimal on GD19, being weaker than that in non-pregnant rats. CYP2E1 expression in non-treated pregnant rats decreased as pregnancy progressed and reached minimum level on GD19. Thus, the degree of CCl4-induced hepatotoxicity roughly corresponded to CYP2E1 levels during pregnancy. After delivery, hepatotoxicity in CCl4-treated lactating rats was maximal on PPD13, being stronger than that in non-pregnant rats, and then it decreased slightly on PPD27. The CYP2E1 level in the non-treated lactating rats tended to increase but remained at lower levels until PPD13 compared with that in non-pregnant rats. Thus, the degree of CCl4-induced hepatotoxicity did not correspond to CYP2E1 levels during lactation. This suggests that during lactation, there may be certain factors other than CYP2E1 expression responsible for the degree of CCl4-induced hepatotoxicity.

Methoxy VO-salen complex: In vitro antioxidant activity, cytotoxicity evaluation and protective effect on CCl 4-induced oxidative stress in rats

Reactive oxygen species (ROS) play crucial roles in normal physiological processes. However, the overproduction of ROS is involved in the onset of many degenerative diseases. Regarding this fact, discovery of new antioxidants is interesting for many research groups. In this study, we evaluated the antioxidant properties of a methoxy VO-salen (MetVO-salen) complex employing various in vitro systems. In addition, the cytotoxic effect of MetVO-salen was assessed based on MTT in treated K562 cells. In an in vivo approach, the protective effect of MetVO-salen against CCl 4-induced oxidative stress in rats was also investigated in terms of superoxide dismutase (SOD) and catalase (CAT) activities, as well as in terms of the levels of malondialdehyde (MDA) and glutathione (GSH). Our results indicated that MetVO-salen has an effective capability in scavenging superoxide ( O 2 − ) and hydrogen peroxide (H 2O 2) radicals in a dose-dependent manner. In vivo results also showed that the administration of MetVO-salen to the CCl 4-treated rats caused a significant (222%) increase in SOD activity, a 59% enhancement in GSH content and a 31% decrease in the level of MDA compared to the CCl 4-treated control rats. Overall, MetVO-salen appears to be an effective antioxidant and is quite suitable for further biological evaluation.

Calcium staining by the glyoxal-bis-(2-hydroxyanil)-method in the livers of rats treated with CCl4, diltiazem, and with both agents together

We studied the histochemistry of Ca in livers treated with CCl4, diltiazem (one of the Ca antagonists), and both agents together to determine whether hepatocytes or other parts of the liver lesions show Ca staining and whether the grade or location of Ca in these injuries varies. For Ca staining, cryostat sections were treated by the glyoxal-bis-(2-hydroxyanil) (GBHA)-method using O.C.T. imbedding compound instead of paraffin. Diltiazem-treated rats showed Ca granules in the bile canaliculi around the terminal hepatic veins and Kupffer cells 6 h after intragastric injection. Rats treated with CCl4 showed fine red granules in the cytoplasm of the hepatocytes around the terminal hepatic veins as soon as 5 min mildly and 2 h moderately after intraperitoneal injection. Hepatocytes around the terminal hepatic veins showed positive Ca granules 6 to 30 h after intragastric injection of CCl4. Hepatocytes stained by Ca showed acidophilic degeneration and coagulative necrosis. The hepatocytes of rats treated with both diltiazem and CCl4 revealed fewer Ca granules than those treated with CCl4 alone. In summary, Ca was stained by the GBHA method from the early stage of liver injury by CCl4 and was closely involved in acidophilic degeneration and coagulative necrosis of hepatocytes. The Ca staining in liver cells in CCl4-treated rats was decreased by diltiazem.

Aquilegia vulgaris extract attenuates carbon tetrachloride-induced liver fibrosis in rats

Six groups of male Wistar rats were treated as follows: in groups II, III and V liver damage was induced by CCl 4 ( per os, 1590 mg/kg b.w. day) given 2 days a week for 6 weeks; group III was treated simultaneously with ethanol extract of A quilegia vulgaris (100 mg/kg b.w. day) for 6 weeks; group V with silymarin, positive control, at a dose of 100mg/kg b.w. day for 6 weeks; and groups IV and VI received only the extract or silymarin, respectively. Microsomal lipid peroxidation in the liver increased following CCl 4 treatment by 61–213% and was not changed significantly by the extract. The effect of silymarin was more pronounced, 19–52% decrease in the lipid peroxidation level. Hepatic glutathione was depleted by 22% in CCl 4-treated rats. The extract tested did not change this parameter. The activity of antioxidant enzymes was significantly reduced after CCl 4 administration, by 42–63%. Co-administration of the extract or silymarin resulted in significant increase in these enzymes activity; however, the basal level was not reached. Hepatic hydroxyproline concentration was elevated over 5-fold in comparison with controls. Co-administration of the extract or silymarin decreased the level of hydroxyproline by 66% and 55%, respectively. Activity of serum hepatic enzymes was elevated in rats treated with CCl 4 by 47–8700%. Both the extract and silymarin reduced significantly these enzymes’ activity. The extract caused a fall in bilirubin and cholesterol level in rats treated with CCl 4 by 42% and 17%, respectively. Histopathological examination revealed less-severe fibrosis in rats co-administered the extract or silymarin when compared to animals treated with CCl 4 alone.

Potential therapeutic effects of a traditional Chinese formulation, BJ-JN, on liver fibrosis induced by carbon tetrachloride in rats

Aim of the study to evaluate the anti-fibrotic effects of BJ-JN (a traditional Chinese formulation) in CCl 4-induced liver fibrosis in rats. Materials and methods BJ-JN (0.5, 1.0, 2.0 g/kg) was administrated via gavage once a day starting from the fifth weeks after the CCl 4 treatment for subsequent 9 weeks. Evaluated with liver and spleen index, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), nitric oxide (NO), hepatic malondialdehyde (MDA) content and superoxide dismutase (SOD) activity, as well as with histopathologic changes of liver. The proliferation and collagen synthesis of primary hepatic stellate cells (HSCs) from normal, model and BJ-JN (2.0 g/kg) treatment rats were examined with 3H-TdR and 3H-Pro uptake assay, respectively. Results BJ-JN (0.5, 1.0, 2.0 g/kg) effectively reduced the elevated levels of liver and spleen index, serum ALT, AST, NO, HA, and hepatic MDA contents, enhance the reduced hepatic SOD activity in CCl 4-treated rats. The histopathological analysis suggested that BJ-JN obviously alleviated the degree of liver fibrosis induced by CCl 4. The proliferation and collagen synthesis of HSC isolated from BJ-JN (2.0 g/kg) treatment rats were remarkably inhibited. Conclusions Those results suggest BJ-JN has a protective and therapeutic effect on liver fibrosis induced by CCl 4, which might be associated with its anti-oxidative activity, inhibitory activity on HSC proliferation and collagen synthesis.

Platelet-derived growth factor isoform expression in carbon tetrachloride-induced chronic liver injury

Platelet-derived growth factor (PDGF) has an essential role in liver fibrogenesis, as PDGF-B and -D both act as potent mitogens on culture-activated hepatic stellate cells (HSCs). Induction of PDGF receptor type-β (PDGFRβ) in HSC is well documented in single-dose carbon tetrachloride (CCl4)-induced acute liver injury. Of the newly discovered isoforms PDGF-C and -D, only PDGF-D shows significant upregulation in bile duct ligation (BDL) models. We have now investigated the expression of PDGF isoforms and receptors in chronic liver injury in vivo after long-term CCl4 treatment and demonstrated that isolated hepatocytes have the requisite PDGF signaling pathways, both in the naive state and when isolated from CCl4-treated rats. In vivo, PDGF gene expression showed upregulation of all PDGF isoforms and receptors, with values peaking at 4 weeks and decreasing to near basal levels by 8 and 12 weeks. Interestingly, PDGF-C increased significantly when compared to BDL-models. PDGF-A, PDGF-C and PDGF receptor type-α (PDGFRα) correlated closely with inflammation and steatosis. Immunohistochemistry revealed expression of PDGF-B, -C and -D in areas corresponding to centrilobular necrosis, inflammation and fibrosis, whereas PDGF-A localized in regenerative hepatocytes. PDGFRβ was identified along the fibrotic septa, whereas PDGFRα showed positive staining in fibrotic septa and regenerative hepatocytes. Despite a significant decline of PDGF isoforms, hepatocyte regeneration peaked at 8 weeks. A marked difference in the degree of fibrosis was observed amongst the individual animals. In summary, PDGF expression in liver damage primarily parallels mesenchymal cell proliferation and extracellular matrix production, rather than hepatocyte regeneration. We conclude that PDGF levels in chronic liver injury peak at 4 weeks after onset of injury, and that the outcome of chronic toxic liver injury strongly depends on the individual capacity for tissue regeneration in the weeks following the peak of PDGF expression.

Quantitative rat liver function test by galactose single point method

The purpose of this study was to investigate the galactose single point (GSP) method, a residual liver function test recently recommended by the US Food and Drug Administration, which can be a useful tool for rat liver function measurement. Rats were treated either with carbon tetrachloride (CCl(4)) alone (1 mL/kg, intraperitoneally [i.p.]) for one day or with isoniazid (INH) alone (150 mg/kg, i.p.) or (in order to ameliorate the effects of INH) with a combination of INH and bis-p-nitrophenyl phosphate (BNPP) (25 mg/kg, i.p.) for 21 days. Hepatotoxicity was assayed by plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and scores of histological activity index-necroinflammation (HAI-NI) of the respective liver specimens. The GSP method in rats was defined by the galactose blood level after 60 min. Significant differences in GSP values were observed between controls and the CCl(4)-treated rats. After 21 days of treatment, no significant changes in AST and ALT values were observed among the control, INH and INH-BNPP groups. There were significant differences in average GSP values for controls (P < 0.001) and INH-BNPP (P < 0.001) compared with INH alone. Highly significant correlations (P < 0.001) were obtained between GSP and scores of HAI-NI for all the groups. GSP was concluded to be a more sensitive biomarker of INH-induced hepatotoxicity than AST or ALT in the rats. The GSP method has been proved to be a simple and useful tool for the quantitative determination of liver function in rats, which can possibly be extended to other animals.

D-Dopachrome tautomerase is a candidate for key proteins to protect the rat liver damaged by carbon tetrachloride

Carbon tetrachloride (CCl 4) is known to induce liver damage. Animal experiments with CCl 4 injections have revealed many findings, especially mechanisms of liver damage and liver regeneration. Recently, proteomic approaches have been introduced in various studies to evaluate the quantitative and qualitative changes in the comprehensive proteome level. The aim of this research is to elucidate the key protein for liver damage, liver protection and liver regeneration by using proteomic techniques. 50 % (v/v) CCl 4 in corn oil was administered intraperitoneally to adult male rats at a dose of 4 ml/kg body weight. Approximately 24 h after the injection, the liver was removed and extracted proteins were analyzed with cleavable isotope coded affinity tag (cICAT) reagents, two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). A twelvefold increase in d-dopachrome tautomerase (DDT) was indicated. This enzyme has been reported to be involved in the biosynthesis of melanin, an antioxidant. According to the histological analysis, melanin levels were increased in un-damaged hepatocytes of CCl 4-treated rats. These results suggest that the increase in DDT is a response to liver damage, accelerates melanin biosynthesis and protects the liver from oxidative stress induced by CCl 4.

Pharmacological effects are model specific in animal models of portal hypertension

Pharmacological effects are model specific in animal models of portal hypertension

Effect of pretreatment with artichoke extract on carbon tetrachloride-induced liver injury and oxidative stress

Artichoke is a plant with antioxidant properties. In this study, we investigated the effect of artichoke extract pretreatment on carbon tetrachloride (CCl 4)-induced oxidative stress and hepatotoxicity. Rats were given artichoke leaf extract (1.5 g/kg/day) by gavage for 2 weeks and after then CCl 4 (1 ml/kg; i.p.) was applied. All rats were killed 24 h after the CCl 4 injection. CCl 4 administration resulted in hepatic necrosis and significant increases in plasma transaminase activities as well as hepatic malondialdehyde (MDA) and diene conjugate (DC) levels in the liver of rats. Glutathione (GSH) and vitamin C levels decreased, but vitamin E levels increased in the liver of CCl 4-treated rats. Hepatic superoxide dismutase (SOD) activities remained unchanged, but glutathione peroxidase (GSH-Px) and glutathione transferase (GST) activities decreased following CCl 4 treatment. In rats pretreated with artichoke extract, significant decreases in plasma transaminase activities and amelioration in histopathological changes in the liver were observed following CCl 4 treatment as compared to CCl 4-treated rats. In addition, hepatic MDA and DC levels decreased, but GSH levels and GSH-Px activities increased without any change in other antioxidant parameters following CCl 4 treatment in artichoke-pretreated rats. The present findings indicate that in vivo architoke extract administration may be useful for the prevention of oxidative stress-induced hepatotoxicity.

Identification of superoxide dismutase as a potential urinary marker of carbon tetrachloride-induced hepatic toxicity

The aim of this study was the identification of a novel protein marker of hepatotoxicity in rat urine. Rats were dosed by gavage with carbon tetrachloride (CCl 4) to induce acute liver injury. Surface enhanced laser desorption/ionisation (SELDI) ProteinChip technology revealed the appearance of a 15.7 kDa protein in the CCl 4-treated rat urine. One-dimensional sodium dodecyl sulphate polyacrylamide electrophoresis (SDS–PAGE) identified an 18.4 kDa protein in the CCl 4-treated rat urine. The appearance of either protein was coincident over a time course during which they first appeared at 12 h post-dosing, peaked at 36 h and had disappeared again within 3 days post-dosing. The protein was identified by in-gel digestion and nano-electrospray (nano-ES)-tandem mass spectrometry as Cu/Zn superoxide dismutase (SOD-1). SOD activity was found to be increased by 61.4-fold in CCl 4-treated rat urine. Western blots of tissue homogenates from the rats revealed a time-dependent loss of SOD-1 from the livers of CCl 4-treated rats matching the time course of SOD-1 appearance in urine. SOD-1 is not specifically located in liver; however, its appearance in urine in response to acute CCl 4-induced hepatotoxicity is a novel finding; this coupled with loss from the liver following injury suggests urinary SOD-1 may be a potential marker of hepatotoxicity.

Posttranslational Activation of Endothelial Nitric Oxide Synthase Attenuates Carbon Tetrachloride-Induced Hepatotoxicity in Newborn Rats

Nitric Oxide (NO) can be cytotoxic or cytoprotective depending on amount and location of its generation. eNOS is important in modulating blood flow and is allosterically regulated. Inducible NOS (iNOS) tends to produce large quantities of NO leading to cell injury. We studied the role and regulation of NOS in carbon tetrachloride (CCl(4))-induced hepatotoxicity in newborn rats. eNOS was expressed before birth, significantly increased on day of life (DOL) 2 reaching a maximum at DOL-20. iNOS was absent at all ages. CCl(4) treatment resulted in hepatic injury in newborn rats and damage was intensified by co-administration of a general NOS inhibitor. CCl(4) treatment increased eNOS activity without change in mRNA or protein levels. Administration of CCl(4) resulted in an increase in phosphorylation of threonine protein kinase (Akt) and eNOS, associated with an increase in eNOS activity. Administration of wortmannin (phosphatidylinositol 3-kinase, PI3 K, inhibitor) attenuated the phosphorylation of Akt and eNOS and reduced eNOS activity. Co-administration of CCl(4) and wortmannin potentiated the degree of hepatic injury. iNOS was not detectable in CCl(4)-treated rats. This data indicates a protective role for eNOS in CCl(4)-induced hepatotoxicity in newborn rats with protection accomplished by activation of eNOS via posttranslational modification of the PI3 K/Akt signaling pathway.

Multipotent cells from the human third molar: feasibility of cell-based therapy for liver disease

Adult stem cells have been reported to exist in various tissues. The isolation of high-quality human stem cells that can be used for regeneration of fatal deseases from accessible resources is an important advance in stem cell research. In the present study, we identified a novel stem cell, which we named tooth germ progenitor cells (TGPCs), from discarded third molar, commonly called as wisdom teeth. We demonstrated the characterization and distinctiveness of the TGPCs, and found that TGPCs showed high proliferation activity and capability to differentiate in vitro into cells of three germ layers including osteoblasts, neural cells, and hepatocytes. TGPCs were examined by the transplantation into a carbon tetrachloride (CCl 4)-treated liver injured rat to determine whether this novel cell source might be useful for cell-based therapy to treat liver diseases. The successful engraftment of the TGPCs was demonstrated by PKH26 fluorescence in the recipient's rat as to liver at 4 weeks after transplantation. The TGPCs prevented the progression of liver fibrosis in the liver of CCl 4-treated rats and contributed to the restoration of liver function, as assessed by the measurement of hepatic serum markers aspartate aminotransferase and alanine aminotransferase. Furthermore, the liver functions, observed by the levels of serum bilirubin and albumin, appeared to be improved following transplantation of TGPCs. These findings suggest that multipotent TGPCs are one of the candidates for cell-based therapy to treat liver diseases and offer unprecedented opportunities for developing therapies in treating tissue repair and regeneration.

Decrease of PECAM-1-gene-expression induced by proinflammatory cytokines IFN-γ and IFN-α is reversed by TGF-β in sinusoidal endothelial cells and hepatic mononuclear phagocytes

Background and aimThe mechanisms of transmigration of inflammatory cells through the sinusoids are still poorly understood. This study aims to identify in vitro conditions (cytokine treatment) which may allow a better understanding of the changes in PECAM (platelet endothelial cell adhesion molecule)-1-gene-expression observed in vivo.Methods and resultsIn this study we show by immunohistochemistry, that there is an accumulation of ICAM-1 (intercellular cell adhesion molecule-1) and ED1 positive cells in necrotic areas of livers of CCl4-treated rats, whereas there are few PECAM-1 positive cells observable. After the administration of CCl4, we could detect an early rise of levels of IFN-γ followed by an enhanced TGF-β protein level. As shown by Northern blot analysis and surface protein expression analysed by flow cytometry, IFN-γ-treatment decreased PECAM-1-gene-expression in isolated SECs (sinusoidal endothelial cells) and mononuclear phagocytes (MNPs) in parallel with an increase in ICAM-1-gene-expression in a dose and time dependent manner. In contrast, TGF-β-treatment increased PECAM-1-expression. Additional administration of IFN-γ to CCl4-treated rats and observations in IFN-γ-/- mice confirmed the effect of IFN-γ on PECAM-1 and ICAM-1-expression observed in vitro and increased the number of ED1-expressing cells 12 h after administration of the toxin.ConclusionThe early decrease of PECAM-1-expression and the parallel increase of ICAM-1-expression following CCl4-treatment is induced by elevated levels of IFN-γ in livers and may facilitate adhesion and transmigration of inflammatory cells. The up-regulation of PECAM-1-expression in SECs and MNPs after TGF-β-treatment suggests the involvement of PECAM-1 during the recovery after liver damage.

Induced Hepatic Fibrosis in Rats: Hepatic Steatosis, Macromolecule Content, Perfusion Parameters, and Their Correlations—Preliminary MR Imaging in Rats

To prospectively evaluate magnetic resonance (MR) imaging for the characterization of liver fibrosis by estimating fat and extracellular matrix content and hepatic perfusion parameters in CCl(4)-treated rats. The animal research protocol was approved by the Institutional Animal Care and Use Committee. Fifty-two rats (38 treated, 14 control) were included. A CCl(4) mixture was injected three times per week for 2-16 weeks. Fat-to-water ratios (FWRs) were calculated. Images were obtained with 12 saturation offset frequencies; magnetization transfer ratios (MTRs) were calculated. Distribution volume (DV), mean transit time (MTT), and portal fraction (PF) of blood inflow were calculated. For pairwise group comparisons, an unequal two-tailed Student t test was used. For pairwise correlations between variables, Pearson correlation coefficients were calculated. For multiple pairwise comparisons, Bonferroni correction was performed by adjusting the significance level (alpha). FWR and DV were correlated with CCl(4) treatment duration from 0 through 8 weeks (r = 0.658, P < .001 and r = -0.664, P < .001, respectively; alpha = .010). PF and MTT were correlated with CCl(4) treatment duration from 0 through 16 weeks (r = -0.483, P = .002 and r = 0.414, P = .008, respectively; alpha = .010). DV was inversely correlated with FWR over the same period (r = -0.581, P < .001; alpha = .007). Fibrotic rats without cirrhosis had a higher FWR and lower DV and PF (P < .001, P < .001, and P = .004, respectively; alpha = .017) than control rats, and lower MTR, DV, and MTT (P = .014, .001, and .010, respectively; alpha = .017) than cirrhotic rats. Cirrhotic rats had a higher FWR and a lower PF (P < .001, alpha = .017) than control rats. Magnetization transfer contrast is not a specific indicator of increased fibrosis in diseased liver; steatosis may influence some perfusion parameters.

Protective effects of total flavonoids of Bidens pilosa L. (TFB) on animal liver injury and liver fibrosis

The hepatoprotective effects of total flavonoids of Bidens pilosa L. (TFB), a traditional Chinese medicine were evaluated in carbon tetrachloride (CCl 4)-induced liver injury in mice and rats. Total flavonoids of Bidens pilosa L. (25, 50 and 100 mg/kg) were administered via gavage daily for 10 days to CCl 4-treated mice as well as TFB (30, 60 and 90 mg/kg) administered for 6 weeks to CCl 4-treated rats. Liver index (liver weight/body weight), serum levels of transaminases (alanine aminotransferase, ALT and aspartate aminotransferase, AST), hepatic malondialdehyde (MDA) content, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were evaluated following the 10 days treatment in mice. In addition histopathologic changes and nuclear factor-κB (NF-κB) expression of the liver were detected with hematoxylin–eosin (HE) and immunohistochemistry methods, respectively. The results showed that TFB (50 and 100 mg/kg) effectively reduced the CCl 4-induced elevated liver index, serum ALT, AST levels, hepatic MDA content, and restored hepatic SOD, GSH-Px activities in acute liver injury mice. TFB (60 and 90 mg/kg) treatment significantly inhibited NF-κB activation in liver fibrosis of rats. The histopathological analysis suggested that TFB reduced the degree of liver injury in mice and severity of liver fibrosis in rats. These results suggested that TFB had a protective and therapeutic effect on animal liver injury, which might be associated with its antioxidant properties and inhibition of NF-κB activation.