Carbon Tetrachloride-induced Acute Liver Injury Research Articles

Involvement of TGF-β1/Smad3 Signaling in Carbon Tetrachloride-Induced Acute Liver Injury in Mice.

Transforming growth factor-beta1 (TGF-β1) is a major factor in pathogenesis of chronic hepatic injury. Carbon tetrachloride (CCl4) is a liver toxicant, and CCl4-induced liver injury in mouse is a classical animal model of chemical liver injury. However, it is still unclear whether TGF-β1 is involved in the process of CCl4-induced acute chemical liver injury. The present study aimed to evaluate the role of TGF-β1 and its signaling molecule Smad3 in the acute liver injury induce by CCl4. The results showed that CCl4 induced acute liver injury in mice effectively confirmed by H&E staining of liver tissues, and levels of not only liver injury markers serum ALT and AST, but also serum TGF-β1 were elevated significantly in CCl4-treated mice, compared with the control mice treated with olive oil. Our data further revealed that TGF-β1 levels in hepatic tissue homogenate increased significantly, and type II receptor of TGF-β (TβRII) and signaling molecules Smad2, 3, mRNA expressions and Smad3 and phospho-Smad3 protein levels also increased obviously in livers of CCl4-treated mice. To clarify the effect of the elevated TGF-β1/Smad3 signaling on CCl4-induced acute liver injury, Smad3 in mouse liver was overexpressed in vivo by tail vein injection of Smad3-expressing plasmids. Upon CCl4 treatment, Smad3-overexpressing mice showed more severe liver injury identified by H&E staining of liver tissues and higher serum ALT and AST levels. Simultaneously, we found that Smad3-overexpressing mice treated with CCl4 showed more macrophages and neutrophils infiltration in liver and inflammatory cytokines IL-1β and IL-6 levels increment in serum when compared with those in control mice treated with CCl4. Moreover, the results showed that the apoptosis of hepatocytes increased significantly, and apoptosis-associated proteins Bax, cytochrome C and the cleaved caspase 3 expressions were up-regulated in CCl4-treated Smad3-overexpressing mice as well. These results suggested that TGF-β1/Smad3 signaling was activated during CCl4-induced acute liver injury in mice, and Smad3 overexpression aggravated acute liver injury by promoting inflammatory cells infiltration, inflammatory cytokines release and hepatocytes apoptosis. In conclusion, the activation of TGF-β signaling contributes to the CCl4-induced acute liver injury. Thus, TGF-β1/Smad3 may serve as a potential target for acute liver injury therapy.

Gold nanoflowers modified ITO glass as SERS substrate for carbon tetrachloride-induced acute liver injury in vitro detection

For the sensitive and convenient detection of acute liver injury, several methods and materials have been developed.

Chemokine Receptor Ccr6 Deficiency Alters Hepatic Inflammatory Cell Recruitment and Promotes Liver Inflammation and Fibrosis.

Chronic liver diseases are characterized by a sustained inflammatory response in which chemokines and chemokine-receptors orchestrate inflammatory cell recruitment. In this study we investigated the role of the chemokine receptor CCR6 in acute and chronic liver injury. In the absence of liver injury Ccr6 -/- mice presented a higher number of hepatic macrophages and increased expression of pro-inflammatory cytokines and M1 markers Tnf-α, Il6 and Mcp1. Inflammation and cell recruitment were increased after carbon tetrachloride-induced acute liver injury in Ccr6 -/- mice. Moreover, chronic liver injury by carbon tetrachloride in Ccr6 -/- mice was associated with enhanced inflammation and fibrosis, altered macrophage recruitment, enhanced CD4+ cells and a reduction in Th17 (CD4+IL17+) and mature dendritic (MHCII+CD11c+) cells recruitment. Clodronate depletion of macrophages in Ccr6 -/- mice resulted in a reduction of hepatic pro-inflammatory and pro-fibrogenic markers in the absence and after liver injury. Finally, increased CCR6 hepatic expression in patients with alcoholic hepatitis was found to correlate with liver expression of CCL20 and severity of liver disease. In conclusion, CCR6 deficiency affects hepatic inflammatory cell recruitment resulting in the promotion of hepatic inflammation and fibrosis.

Effects of pharmaceutical formulations containing thyme on carbon tetrachloride-induced liver injury in rats.

BackgroundHerbal supplements are widely used in the treatment of various liver disases, but some of them may also induce liver injuries. Regarding the infuence of thyme and its constituents on the liver, conflicting results have been reported in the literature. The objective of this study was to examine the influence of two commonly used pharmaceutical formulations containing thyme (Thymus vulgaris L.), tincture and syrup, on carbon tetrachloride-induced acute liver injury in rats.MethodsChemical composition of investigated formulations of thyme was determined by gas chromatography and mass spectrometry. Activities of enzyme markers of hepatocellular damage in serum and antioxidant enzymes in the liver homogenates were measured using the kinetic spectrophotometric methods. Liver morphology was characterized by light microscopy using routine hematoxylin and eosin staining.ResultsThymol was found to be predominant active constituent in both tincture and syrup. Investigated thyme preparations exerted antioxidant effects in liver by preventing carbon tetrachloride-induced increase of lipid peroxidation. Furthermore, co-treatment with thyme preparations reversed the activities of oxidative stress-related enzymes xanthine oxidase, catalase, peroxidase, glutathione peroxidase and glutathione reductase, towards normal values in the liver. Hepatotoxicity induced by carbon tetrachloride was reflected by a marked elevation of AST and ALT activities, and histopathologic alterations. Co-administration of thyme tincture resulted in unexpected exacerbation of AST and ALT values in serum, while thyme syrup managed to reduce activites of aminotransferases, in comparison to carbon tetrachloride-treated animals.ConclusionsDespite demonstrated antioxidant activity, mediated through both direct free radical scavenging and activation of antioxidant defense mechanisms, thyme preparations could not ameliorate liver injury in rats. Molecular mechanisms of diverse effects of thyme preparations on chemical-induced hepatotoxicity should be more in-depth investigated.

Geniposide alleviates inflammation by suppressing MeCP2 in mice with carbon tetrachloride-induced acute liver injury and LPS-treated THP-1 cells

Geniposide (GP), an iridoid glucoside extracted from Gardenia jasminoides Ellis fruits, has been used as a herbal medicine to treat liver and gall bladder disorders for many years. However the mechanism of anti-inflammatory is largely unknown. In this study, GP significantly attenuated inflammation in acute liver injury (ALI) mice model and in lipopolysaccharide (LPS)-induced THP-1 cells. It was demonstrated that GP obviously decreased the expression of Methyl-CpG binding protein 2 (MeCP2) in vivo and in vitro. Knockdown of MeCP2 with siRNA suppressed the expressions of IL-6 and TNF-α, while over-expression of MeCP2 had a proinflammatory effect on the expression of IL-6 and TNF-α in LPS-induced THP-1 cells. Mechanistically, it was indicated that GP had anti-inflammatory effects at least in part, through suppressing MeCP2. Interestingly, GP could attenuate expressions of Sonic hedgehog (Shh) and GLIS family zinc finger 1 (GLIS1) but increase Ptched1 (PTCH1) expression. Similar findings were also demonstrated at the protein level by siRNA MeCP2. Furthermore, over-expression of MeCP2 obviously increased Shh and GLIS1 expressions but reduced PTCH1 expression. Taken together, GP may serve as an effective modulator of MeCP2-hedgehog pathway (Hh)-axis during the pathogenesis of inflammation. Our findings shed light on the potential therapeutic feature of GP in recovering inflammatory diseases.

Secreted IL-1α promotes T-cell activation and expansion of CD11b(+) Gr1(+) cells in carbon tetrachloride-induced liver injury in mice.

Interleukin-1α is mainly expressed on the cell membrane, but can also be secreted during inflammation. The roles of secreted and membrane IL-1α in acute liver inflammation are still not known. Here, we examined the functions of secreted and membrane IL-1α in a mouse model of carbon tetrachloride-induced acute liver injury. We show that secreted IL-1α aggravates liver damage and membrane IL-1α slightly protects mice from liver injury. Further studies showed that secreted IL-1α promotes T-cell activation. It also increased the expansion of CD11b(+) Gr1(+) myeloid cells, which may serve as a negative regulator of acute liver inflammation. Moreover, secreted IL-1α induced IL-6 production from hepatocytes. IL-6 neutralization reduced the proliferation of CD11b(+) Gr1(+) myeloid cells in vivo. CCL2 and CXCL5 expression was increased by secreted IL-1α in vitro and in vivo. Antagonists of the chemokine receptors for CCL2 and CXCL5 significantly reduced the migration of CD11b(+) Gr1(+) myeloid cells. These results demonstrate that secreted and membrane IL-1α play different roles in acute liver injury. Secreted IL-1α could promote T-cell activation and the recruitment and expansion of CD11b(+) Gr1(+) myeloid cells through induction of CCL2, CXCL5, and IL-6. The controlled release of IL-1α could be a critical regulator during acute liver inflammation.

Effects of 4-phenylbutyric acid on carbon tetrachloride-induced acute liver injury in mice

To explore the effects and the molecular mechanisms of 4-phenylbutyric acid (PBA) on carbon tetraehloride (CCl4)-induced acute liver injury in mice. Sixty adult, healthy, male ICR mice were divided equally into the control group, PBA group, CCl4 12 h group, CCl4 24 h group, CCl4 48 h group, CCl4 72 h group, PBA+CCl4 12 h group, PBA+CCl4 24 h group, PBA+CCl4 48 h group, and PBA+CCl4 72 h group. The CCl4 groups and the PBA+CCl4 groups were intraperitoneally (i.p.) injected with CCl4 (300 mL/kg). In the PBA+CCl4 groups, the mice were i.p. injected with PBA (400 mg/kg). All mice were sacrificed to collect blood and liver specimens at different time points after the CCl4 treatment. Serum alanine aminotransferase (ALT) was detected. Histological examination was performed using hematoxylin-eosin staining and light microscopy, and apoptosis was detected using terminal transferase dUTP nick end labeling. The hepatic distribution of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemistry. The hepatic protein expression of glucose-regulated protein (GRP78), C/EBP homologousprotein (CHOP), phosphorylated c-Jun N-terminal kinases (p-JNK), phosphorylated eukaryotic initiation factor 2a subunit (p-eIF2a), phosphorylated serine threonine kinase (p-akt), and nuclear factor-kappa B p65 (NF-kappa Bp65) were determined by western blot. The serum ALT level in the PBA+CCl4 groups was reduced as compared with that in the CCl4 groups at the various time points examined.The liver-to-body weight ratio of two groups showed a significant difference only at the 48 h time point (P<0.01). PBA reduced the degree of hepatic necrosis and apoptosis caused by CCl4, and reduced the expression of hepatic GRP78 and other endoplasmic reticulum stress-related proteins (P<0.01). The protein levels of p-akt, NF-kappa Bp65 and PCNA was significantly decreased in the PBA+CCl4 groups (P<0.01). The endoplasmic reticulum stress inhibitor PBA alleviated acute hepatic necrosis and apoptosis but restrained hepatic proliferation.

Dihydromyricetin alleviates carbon tetrachloride-induced acute liver injury via JNK-dependent mechanism in mice.

To assess the effects of dihydromyricetin (DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride (CCl4) treatment. C57 BL/6 mice were used in this study. Mice were orally administered with DHM (150 mg/kg) for 4 d after CCl4 treatment. Serum and liver tissue samples were collected on days 1, 2, 3, 5 and 7 after CCl4 treatment. The anti-inflammatory effect of DHM was assessed directly by hepatic histology detection and indirectly by serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, and superoxide dismutase (SOD). Inflammatory cytokines, such as interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), were detected using ELISA kits. Proliferating cell nuclear antigen (PCNA) staining was used to evaluate the role of DHM in promoting hepatocyte proliferation. Hepatocyte apoptosis was measured by TUNEL assay. Furthermore, apoptosis proteins Caspases-3, 6, 8, and 9 were detected by Western blot. SP600125 were used to confirm whether DHM regulated liver regeneration through JNK/TNF-α pathways. DHM showed a strong anti-inflammatory effect on CCl4-induced liver injury in mice. DHM could significantly decrease serum ALT, AST, IL-1β, IL-6 and TNF-α and increase serum albumin, SOD and liver SOD compared to the control group after CCl4 treatment (P < 0.05). PCNA results indicated that DHM could significantly increase the number of PCNA positive cells compared to the control (348.9 ± 56.0 vs 107.1 ± 31.4, P < 0.01). TUNEL assay showed that DHM dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control (365.4 ± 99.4 vs 90.5 ± 13.8, P < 0.01). Caspase activity detection showed that DHM could reduce the activities of Caspases- 8, 3, 6 and 9 compared to the control (P < 0.05). The results of Western blot showed that DHM increased the expression of JNK and decreased TNF-α expression. However, DHM could not affect TNF-α expression after SP600125 treatment. Furthermore, DHM could significantly improve the survival rate of acute liver failure (ALF) mice (73.3% vs 20.0%, P < 0.0001), and SP600125 could inhibit the effect of DHM. These findings demonstrate that DHM alleviates CCl4-induced liver injury, suggesting that DHM is a promising candidate for reversing liver injury and ALF.

Naringin prevents carbon tetrachloride-induced acute liver injury in mice

The protective effects and mechanisms of action of naringin (Nar) against carbon tetrachloride (CCl4)-induced hepatic injury in mice were investigated. The results showed that oral administration of Nar significantly decreased the levels of alanine transaminase and alanine transaminase in serum, nitric oxide, inducible nitric oxide synthase and thiobarbituric acid reactive substances in hepatic tissue, and markedly increased the levels of superoxide dismutase, catalase, glutathione peroxidase and glutathione/oxidized glutathione ratio compared with the model group. Transmission electron microscopy and histopathology assay also showed the hepatoprotective effect of Nar against the damage. In addition, Nar markedly decreased cytochrome P4502E1 expression, suppressed oxidative stress, inflammation and apoptosis, and decreased phosphorylation levels of mitogen-activated protein kinases caused by CCl4. These results imply that Nar has perfect effect against CCl4-induced liver injury in mice, which should be developed as an effective food and healthcare product for the treatment of liver injury in the future.

Therapeutic detoxification of quercetin against carbon tetrachloride-induced acute liver injury in mice and its mechanism.

This study observes the therapeutic detoxification of quercetin, a well-known flavonoid, against carbon tetrachloride (CCl4) induced acute liver injury in vivo and explores its mechanism. Quercetin decreased CCl4-increased serum activities of alanine and aspartate aminotransferases (ALT/AST) when orally taken 30 min after CCl4 intoxication. The results of a histological evaluation further evidenced the ability of quercetin to protect against CCl4-induced liver injury. Quercetin decreased the CCl4-increased malondialdehyde (MDA) and reduced the glutathione (GSH) amounts in the liver. It also reduced the enhanced immunohistochemical staining of the 4-hydroxynonenal (4-HNE) in the liver induced by CCl4. Peroxiredoxin (Prx) 1, 2, 3, 5, 6, thioredoxin reductase 1 and 2 (TrxR1/2), thioredoxin 1 and 2 (Trx1/2), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) all play critical roles in maintaining cellular redox homeostasis. Real-time polymerase chain reaction (PCR) results demonstrated that quercetin reversed the decreased mRNA expression of all those genes induced by CCl4. In conclusion, our results demonstrate that quercetin ameliorates CCl4-induced acute liver injury in vivo via alleviating oxidative stress injuries when orally taken after CCl4 intoxication. This protection may be caused by the elevation of the antioxidant capacity induced by quercetin.

Liver protective effects of Xiaoyaosan in acute liver injury in mice

Objective To investigate the liver protective effects of Xiaoyaosan in carbon tetrachloride-induced acute liver injury in mice.Methods Thirty mice were randomly divided into a control group, a model group, and aXiaoyaosan group, with 10 mice in each group. The mice in theXiaoyaosan group were intragastrically administrated withXiaoyaosan, the mice in the remaining two groups were fed with an equal volume of distilled water. After 7 days, acute liver injury were inducedvia intraperitoneal injection of carbon tetrachloride peanut oil solution. The serum levels of alanine transaminase（ALT）, aspartate transaminase （AST）, malondialdehyde（MDA）and superoxide dismutase（SOD）were measured, and pathological changes of liver tissue was tested after 16 hours.Results The serum levels of ALT（136.46±15.75 U/Lvs. 22.96±6.23 U/L）, AST（145.37±16.39 U/Lvs. 31.89±7.26 U/L）, and MDA level in the liver tissue（17.48±3.45 nmol/mgvs. 4.22±1.08 nmol/mg）in the model group were significantly higher than those in the control group（allP〈0.01）, SOD level in the liver tissue significantly lower than that in the control group（261.60±20.29 U/mgvs. 336.73±25.34 U/mg,P〈0.01）. The serum levels of ALT（89.38±6.96 U/L,P〈0.01）, AST（119.04±20.44 U/L, P〈0.05）, MDA level（10.30±2.22 nmol/mg,P〈0.01） in the liver tissue in theXiaoyaosan group levels were significantly lower than those in the model group, and SOD level（304.77±31.71 U/mg,P〈0.01） in the liver tissue were significantly higher than that in the model group.ConclusionXiaoyaosan has liver protective effects in carbon tetrachloride-induced acute liver injury in mice. Key words: Xiaoyaosan; Drug-induced liver injury; Carbon tetrachloride

Icaritin ameliorates carbon tetrachloride-induced acute liver injury mainly because of the antioxidative function through estrogen-like effects.

To investigate the effects of icaritin, an active ingredient extracted from Epimedium Sagittatum (Sieb. et Zucc.), on CCl4-induced liver injury and its possible mechanisms. Hepatocytes isolated from Sprague-Dawley male rats were treated with 3 mmol/L CCl4 for 24 h to induce acute liver cell injury, then icaritin (0.1, 1, 10, 100 μmol/L, respectively) was administrated to the cells, and estrogen receptor antagonist ICI182,780 (1 μmol/L) was co-treated with 10 μmol/L icaritin. Biochemical parameters (alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), and superoxide dismutase (SOD)) and cell apoptosis were detected to evaluate the injury degree. Protein expressions of Bax, Bcl-2, liver fatty acid-binding protein (L-FABP), and peroxisome proliferator-activated receptor-α (PPAR-α) as well as reactive oxygen species (ROS) generation were determined by western blot. Icaritin alleviated CCl4-induced liver cell injury in a concentration-dependent manner and 10 μmol/L was the optimal concentration. Icaritin (10 μmol/L) significantly reduced activities of ALT, AST in cell culture medium and MDA level of the impaired liver cells, but increased the intercellular SOD activity. The apoptotic rate of the impaired liver cells was also decreased by icaritin (10 μmol/L) treatment. Icaritin might exert antioxidative and anti-apoptotic functions via estrogen-like effect, as the ratio of Bcl-2/Bax was significantly increased, while protein expressions of L-FABP and PPAR-α were markedly increased, and this function was blocked by the estrogen receptor antagonist ICI182,780 efficiently. Icaritin may be a promising drug candidate for acute liver injury benefiting from the antioxidative and anti-apoptotic functions via estrogen-like effect.

Antioxidant activity in vitro and hepatoprotective effect of Phlomis maximowiczii in vivo.

A number of medicinal plants and there compounds played a major role in the treatment of hepatic disorders. They were widely used for the treatment of these disorders, and oxidant stress injury was one of the liver injury mechanisms. The present study evaluated the antioxidant activity and the hepatoprotective effect of each extracts of Phlomis maximowiczii. The antioxidant activity was assayed by the methods of ABTS, FRAP and DPPH in vitro. Hepatoprotective effect of P. maximowiczii extracts was examined using carbon tetrachloride-induced acute liver injury in mice. P. maximowiczii n-butanol (PMBU) extract, ABTS (IC50=18.96 µg/mL), DPPH (IC50=25.15 µg/mL), and FRAP (RACT50=2775.6±144.18 µmol/g), showed higher scavenging capacity than that of P. maximowiczii ethyl acetate (PMEA). The n-butanol extract could significantly reduce the level of GPT, GOT and MDA (P<0.05, P<0.001 and P<0.001, respectively) and increase the level of SOD (P<0.001), respectively. The antioxidant activity of n-butanol extract in vitro was related with the level of MDA and SOD in vivo, and hepatoprotective effect of n-butanol extract also had relationship with its antioxidant activity in vivo.

Induction of hepatic Bach1 mRNA expression by carbon tetrachloride-induced acute liver injury in rats.

Hepatic oxidative stress is a major contributor to the pathogenesis of several acute liver diseases. Diagnostic markers of hepatic oxidative stress may facilitate early detection and intervention. Bach1 is an oxidative stress-responsive transcription factor that represses heme oxygenase 1 (HO-1), the rate-limiting enzyme in the catabolism of heme, a potent pro-oxidant. We previously demonstrated that carbon tetrachloride (CCl4) causes oxidative hepatic injury in rats, exacerbated by free heme, suggesting that CCl4 may affect Bach1 gene expression. In the present study, we used northern blot analysis to measure Bach1, HO-1 and δ-aminolevulinate synthase (ALAS1; a heme biosynthesis enzyme) mRNA expression levels during acute hepatic injury induced by CCl4 (at doses of 0.1, 1.0 and 2.0 ml/kg body weight). Oxidative injury was assessed by measuring serum alanine aminotransferase (ALT), hepatic malondialdehyde (MDA) and glutathione (GSH) content. Treatment with CCl4 induced a significant dose-dependent increase in Bach1 mRNA 1–3 h after administration. Bach1 mRNA peaked at 6 h after CCl4 treatment (1 ml/kg), followed by a rapid decrease and gradual return to baseline by 12 h after treatment. The timecourse of transient Bach1 mRNA induction roughly mirrored that of HO-1 mRNA, while ALAS1 mRNA was inversely downregulated. Serum ALT levels and hepatic MDA concentration were significantly increased at 24 h after CCl4 treatment, while the hepatic GSH content was significantly reduced within 3 h of treatment. Serum ALT levels were positively correlated with Bach1 mRNA levels. These findings indicate that Bach1 mRNA is transiently induced in rat liver by CCl4, possibly as a regulatory mechanism to restore HO-1 to baseline following free heme catabolism. Our findings also suggest that Bach1 mRNA expression may be a novel indicator of the extent of oxidative hepatic injury caused by free heme.

Neutralization of ADAM8 ameliorates liver injury and accelerates liver repair in carbon tetrachloride-induced acute liver injury

Although some studies have described the function of ADAM8 (a disintegrin and metalloprotease 8) related with rheumatoid arthritis, cancer and asthma, etc., the concrete role of ADAM8 in acute liver injury is still unknown. So mice respectively received anti-ADAM8 monoclonal antibody (mAb) of 100 μg/100 μl, 200 μg/100 μl or 300 μg/100 μl in PBS or PBS pre-injection. Then acute liver injury was induced in the mice by intraperitoneal (i.p.) injection of carbon tetrachloride (CCl₄). Serum AST and ALT level, Haematoxylin-eosin (H&E) staining, the expression level of vascular endothelial growth factor (VEGF), cytochrome P450 1A2 (CYP1A2) and proliferating cell nuclear antigen (PCNA) were detected in the mice after CCl4 administration. Our results showed that anti-ADAM8 mAb pre-injection could effectively lower AST and ALT levels (P < 0.05 or P < 0.01) and reduce liver injury (P < 0.05 or P <0.01), induce the expression of VEGF, CYP1A2 and PCNA (P <0.05 or P < 0.01) in dose-dependent manner compared with the control mice which received PBS pre-injection. In summary, our study suggested that ADAM8 might promote liver injury by inhibiting the proliferation of hepatocytes, angiogenesis and affecting the metabolism function of liver during acute liver injury induced by CCl₄. Anti-ADAM8 mAb injection might be suitable as a potential method for acute liver injury therapy.

Protective effects of the total saponins from Rosa laevigata Michx fruit against carbon tetrachloride-induced acute liver injury in mice

Saponins are the major chemicals from Rosa laevigata Michx fruit. However, there have no papers to report the activities of the natural product against liver damage. In the present work, total saponins from R. laevigata Michx fruit (RLTS) with purity>70% was produced and then the protective effects of it against CCl4-induced acute liver injury in mice was tested. The results showed that RLTS decreased serum ALT and AST activities compared with model group, as well as the relative liver weight and histological findings. In addition, RLTS remarkably increased the levels of SOD, CAT, GSH-Px, GSH and decreased MDA, iNOS and NO levels in liver. Transmission electron microscopy and TUNEL assays showed that RLTS repaired fragmented DNA and mitochondrial change caused by CCl4. Further investigation demonstrated that RLTS pretreatment down-regulated the protein expression of CYP2E1, ATF6, GRP78, EIF2, COX-2, NF-κB, p53, Caspase-3, Caspase-9, Cytokeratin 18 and the levels of MAPKs phosphorylation, up-regulated Bcl-2 expression, and markedly decreased the gene expression of TNF-α, IL-6, Fas/FasL and Bax. This is the first time to reveal the hepatoprotective effect of total saponins from R. laevigata Michx fruit, which should be developed as a new drug for treatment of live injury in future.

Hepatoprotective effects of lycopene against carbon tetrachloride-induced acute liver injury in rats

Lycopene, the major carotenoid in tomatoes, is a known antioxidant that may lower oxidative stress biomarkers by a mechanism that is not fully elucidated. The intoxication of rats with carbon tetrachloride (CCl4) resulted in significant histological hepatic degradation accompanied by a marked increase in reactive oxygen species (ROS) and in the number of apoptotic cells. The induced oxidative stress in turn results in a significant elevation of lipid peroxidation and H2O2 generation, together with a decrease in the concentration of reduced glutathione (GSH) and a significant reduction in activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S transferase (GST). CCl4-intoxicated rats, pre-treated with lycopene, showed strongly reduced cell damage and ROS generation. The level of markers for hepatic integrity in lycopene pre-treated rats was close to the controls in the absence of CCl4 treatment, indicating the protective effect of lycopene pre-treatment. In the same way, lycopene pre-treated rats significantly increased SOD, CAT, GPx, GST activities and GSH level. In addition, we measured an increased lipoxygenase (LOX) activity in CCl4-intoxicated rats. This activity was reduced in lycopene pre-treated rats to values close to those observed in the controls, suggesting a potential pharmacological application of this dietary carotenoid.

Hepatoprotective effect of methylsulfonylmethane against carbon tetrachloride-induced acute liver injury in rats

This study evaluated the effect of methylsulfonylmethane (MSM) on carbon tetrachloride (CCl₄)-induced acute liver injury in rats. A single injection of CCl₄ (2 ml/kg, i.p.) increased serum aminotransferases (ALT and AST) activities. In addition, CCl₄ treatment led to elevation of hepatic malondialdehyde (MDA) content as well as decrease in superoxide dismutase (SOD) and catalase (CAT) activities. Furthermore, cytochrome P450 2E1 (CYP2E1) content was suppressed while proinflammatory cytokines tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels increased in liver tissue after CCl4 administration. We showed that acute CCl₄-induced damage was accompanied by a rise in Bax/Bcl₂ ratio indicating apoptosis. Pre-treatment with MSM (400 mg/kg) inhibited the increases of serum ALT and AST activities, decreased hepatic MDA, TNF-α, IL-6 and Bax/Bcl₂ ratio compared to CCl₄ treated group. On the other hand, MSM raised SOD and CAT activities as well as CYP2E1 level in liver tissues. The present study shows that MSM possesses a hepatoprotective effect against CCl₄-induced liver injury in rats. This protective effect might be through its antioxidant, anti-inflammatory and antiapoptotic properties.

Proteomics Analysis of Hepatoprotective Effects for Scoparone Using MALDI-TOF/TOF Mass Spectrometry with Bioinformatics

Abstract Scoparone is an active ingredient of Yinchenhao (Artemisia annua L.), a well-known Chinese medicinal plant, and has been utilized in prevention and therapy of liver damage. However, the molecular drug targets associated with the pharmacological effects of scoparone are largely unknown. In the present article, we extend the previous research on Yinchenhao through a study of its active ingredient and thus the putative targets of scoparone. We employed two-dimensional gel electrophoresis, and all proteins expressed were identified by MALDI-TOF/TOF MS and database research. Protein-interacting networks and pathways were also mapped and evaluated. The possible protein network associated with scoparone was constructed, and contribution of these proteins to the protective effect of scoparone against the carbon tetrachloride-induced acute liver injury in rats are discussed herein. Hepatoprotective effects of scoparone on liver injury in rats were associated with regulated expression of six proteins which were closely related in our protein-protein interaction network, and appear to be involved in antioxidation and signal transduction, energy production, immunity, metabolism, and chaperoning. These observations collectively provide new insights on the molecular mechanisms of scoparone action against hepatic damage in rats.

Protection of a New Heptapeptide from &lt;i&gt;Carapax trionycis&lt;/i&gt; against Carbon Tetrachloride-Induced Acute Liver Injury in Mice

A new heptapeptide GAGPHGG (OC1) was isolated from Carapax trionycis which was a traditional Chinese medicine (TCM) used for treatment of hepatic diseases. The structure of OC1 was characterized by MS, NMR techniques, together with amino acid sequence analysis. The hepatoprotective activity of OC1 was evaluated in vivo using the CCl4-induced acute liver injury model. Combining the pathological examination and the biochemical assays, OC1 (0.34 mg/kg, hypodermic injection) displayed better hepatoprotective effect than bifendate (100 mg/kg, intragastric administration) against the acute liver injury induced by carbon tetrachloride (CCl4) in mice. Compared with the model group, OC1 could significantly suppress the increase of serum level of aminotransferase (alanine transaminase (ALT) and aspartate aminotransferase (AST)), decrease the formation of malondialdehyde (MDA) and elevate the activity of glutathione peroxidase (GSH-Px) in liver (p<0.01). And the acute toxic test showed that median lethal dose (LD50) of OC1 exceeded 6.8 mg/kg, via hypodermic injection in mice.