Macrophage potentiates the recovery of liver zonation and metabolic function after acute liver injury.

The liver is an exclusive organ with tremendous regenerative capacity. Liver metabolic functions exhibit spatial heterogeneity, reflecting liver zonation. The mechanisms controlling the proliferation of hepatocytes and the accompanying matrix reconstruction during regeneration have been well explored, but the recovery potential of differentiated metabolic functions and zonation after liver injury remains unclear. We employed a mouse model of carbon tetrachloride (CCl4) induced-acute liver injury with clodronate-induced macrophage depletion to clarify the impact of liver injury on liver metabolism and recovery dynamics of metabolic function and liver zonation during regeneration. Depleting macrophages suppressed tissue remodelling and partially delayed cell proliferation during regeneration after liver injury. In addition, recovery of metabolic functions was delayed by suppressing the tissue remodelling caused by the depleted macrophages. The model revealed that drug metabolic function was resilient against the dysfunction caused by liver injury, but glutamine synthesis was not. Metabolomic analysis revealed that liver branched-chain amino acid (BCAA) and carbohydrate metabolism were suppressed by injury. The plasma BCAA concentration reflected recovery of hepatic function during regeneration. Our study reveals one aspect of the regenerative machinery for hepatic metabolism following acute liver injury.

Nootkatone confers hepatoprotective and anti-fibrotic actions in a murine model of liver fibrosis by suppressing oxidative stress, inflammation, and apoptosis.

In this study, the hepatoprotective and anti-fibrotic actions of nootkatone (NTK) were investigated using carbon tetrachloride (CCl4 )-induced liver fibrosis in mice. CCl4 administration elevated serum aspartate and alanine transaminases levels, respectively. In addition, CCl4 produced hepatic oxidative and nitrative stress, characterized by diminished hemeoxygenase-1 expression, antioxidant defenses, and accumulation of 4-hydroxynonenal and 3-nitrotyrosine. Furthermore, CCl4 administration evoked profound expression of pro-inflammatory cytokine expressions such as tumor necrosis factor-α, monocyte chemoattractant protein-1, and interleukin-1ß in hepatic tissues, which corroborated with nuclear factor κB activation. Additionally, CCl4 -treated animals exhibited higher apoptosis, characterized by increased caspase 3 activity, DNA fragmentation, and poly (ADP-ribose) polymerase activation. Moreover, histological and biochemical investigations revealed marked fibrosis in the livers of CCl4 -administered animals. However, NTK treatment mitigated CCl4 -induced phenotypic changes. In conclusion, our findings suggest that NTK exerts hepatoprotective and anti-fibrotic actions by suppressing oxidative stress, inflammation, and apoptosis.

Hepatoprotective activities of Antrodia camphorata and its triterpenoid compounds against CCl4-induced liver injury in mice.

ETHNOPHARMACOLOGY RELEVANCE: Antrodia camphorata (AC) is a rare and precious fungus indigenous to Taiwan used as a traditional medicine for the treatment of liver injury. Triterpenoids are the major bioactive constituents of A. camphorata and have been reported to possess hepatoprotective activities. To meet the increasing demand, artificial cultivation techniques have been developed. AIM OF THE STUDY: This study aims to evaluate the hepatoprotective activities of AC samples derived from different cultivation techniques and to dissect the main active triterpenoid compounds. MATERIALS AND METHODS: The ethanol extracts of five batches of AC samples, including wild growing fruiting bodies, cutting wood culture fruiting bodies, dish cultures, cutting wood culture mycelia, and submerged fermentation mycelia were orally administered (50mg/kg or 200mg/kg) to ICR mice for 7 days. On the last day, CCl4 (0.2%, 7mL/kg, i.p.) was used to induce liver injury, and the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined 24h after the injection. Moreover, a HepG2 cell model treated with CCl4 (0.35%) was used to screen the protective activities of 29 AC triterpenoids. After incubation for 6h, viabilities of the cells were tested using MTS assay. The in vivo hepatoprotective activities of antcin B and antcin K were further studied on the mice model by ALT and AST tests and histopathologic examinations. To elucidate the mechanisms, the mRNA levels of iNOS, COX2, TNF-α and IL-1ß, and the protein levels of NF-κB (p65/p-p65), iNOS and COX2 in liver tissues were determined. RESULTS: The wild growing or cutting wood culture fruiting bodies, and the dish cultures of AC showed more potent activities than the mycelia (P<0.001). At 20µM, 16 of 29 triterpenoids showed significant protective activities, increasing HepG2 cell viability from 46% of the CCl4 group to >90%. Antcin B and antcin K could dose-dependently (10 or 50mg/kg, 7 days, i.g.) decrease the serum levels of ALT and AST, and decrease the incidence of liver necrosis. The effects of 50mg/kg of antcin K or antcin B were almost identical to those of 100mg/kg silymarin. Furthermore, qRT-PCR and Western blotting analyses revealed they could down-regulate IL-1ß, TNF-α, iNOS, COX-2 and NF-κB in liver tissues at both transcriptional and translational levels. CONCLUSION: The results indicate that cultivation techniques remarkably affect the hepatoprotective activities of AC. Antcin K and antcin B are the major hepatoprotective compounds of A. camphorata, and the mechanism is related with anti-inflammation. Given its high natural abundance and good oral absorption, antcin K could be a promising drug candidate for liver injury.

Hepatoprotective Effect of Low Doses of Caffeine on CCl4-Induced Liver Damage in Rats.

Several studies have shown the hepatoprotective effect of the consumption of coffee and tea, which is mainly attributed to caffeine. Many experimental studies have demonstrated this effect; however, these studies used high caffeine doses that are not related to human consumption. The aim of this study was to evaluate the hepatoprotective effect of low doses of caffeine on carbon tetrachloride (CCl4)-treated rats. Low doses of caffeine (CAFF) 5 and 10 mg/kg (CAFF5 and CAFF10) were evaluated in chronic liver damage induced by CCl4 (0.75 mL/kg) in rats. CAFF treatment was administered once a day and CCl4 administration was twice weekly for 10 weeks. Liver function tests (biochemical markers) and functional (sleeping time) and histological (hematoxylin-eosin and Masson trichrome stains) parameters were carried out at the end of damage treatment. Daily treatments of CAFF5 and CAFF10 exhibited a hepatoprotective effect supported by a decrease of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (AP) serum activities and bilirubin serum levels compared with control and also restored serum albumin levels and liver glutathione (GSH). Moreover, CAFF prevented CCl4-induced prolongation in pentobarbital sleeping time and a decrease of liver fibrosis and cell death. Our results demonstrated that low doses of CAFF exert a hepatoprotective effect against CCl4 -induced liver damage in rats.

[THE RHYTHMIC ORGANIZATION OF THE ANNUAL DYNAMICS OF FUNCTIONAL INDICATORS OF RAT LIVER UNDER TOXIC LOAD].

Purpose: The purpose of this study was to investigate the annual dynamics of the functional state of the liver of rats with experimental hepatitis on early period of intoxication. Materials and methods: This research was conducted for three years on 172 adult male rats Wistar. The toxic hepatitis was caused by subcutaneous injection three times a 50% oil solution of carbon tetrachloride. The studies were conducted in the winter (January), summer (June-July), spring (April) and autumn (October) on the 4th day after the last administration of the toxin. Activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the level of total lipids (TL), total bilirubin (TB), malondialdehyde (MDA) and thymol (T) using standard sets of Biotest «Lachema¼ were determined in the blood serum. Statistic processing of primary chronograms of investigated parameters was performed with the program "сosinor analysis." Results: It was found that in the control animals was dominated by annual and circannual rhythms of the liver functions and in the spectra of the studied parameters were observed several subdominant harmonic. The maxima of liver function detected to the different time intervals on an annual scale, that is, they were not coordinated with each other. On day 4 experimental hepatitis was increased the average annual of study functions (with the exception of ТL) and in their rhythmic organization was observed the inner synchronization by period and acrophase. In the spectra of the rhythms of the studied parameters mainly was determined by only the annual harmonic with acrophase in the autumn months. It can together indicate the development of a powerful pathological process in the liver.

Inhibition of TGFß type I receptor activity facilitates liver regeneration upon acute CCl4 intoxication in mice.

Liver exhibits a remarkable maintenance of functional homeostasis in the presence of a variety of damaging toxic factors. Tissue regeneration involves cell replenishment and extracellular matrix remodeling. Key regulator of homeostasis is the transforming growth factor-ß (TGFß) cytokine. To understand the role of TGFß during liver regeneration, we used the single-dose carbon tetrachloride (CCl4) treatment in mice as a model of acute liver damage. We combined this with in vivo inhibition of the TGFß pathway by a small molecule inhibitor, LY364947, which targets the TGFß type I receptor kinase [activin receptor-like kinase 5 (ALK5)] in hepatocytes but not in activated stellate cells. Co-administration of LY364947 inhibitor and CCl4 toxic agent resulted in enhanced liver regeneration; cell proliferation (measured by PCNA, phosphorylated histone 3, p21) levels were increased in CCl4 + LY364947 versus CCl4-treated mice. Recovery of CCl4-metabolizing enzyme CYP2E1 expression in hepatocytes is enhanced 7 days after CCl4 intoxication in the mice that received also the TGFß inhibitor. In summary, a small molecule inhibitor that blocks ALK5 downstream signaling and halts the cytostatic role of TGFß pathway results in increased cell regeneration and improved liver function during acute liver damage. Thus, in vivo ALK5 modulation offers insight into the role of TGFß, not only in matrix remodeling and fibrosis, but also in cell regeneration.

Enrichment and purification of total flavonoids from Cortex Juglandis Mandshuricae extracts and their suppressive effect on carbon tetrachloride-induced hepatic injury in Mice.

In the present work, a simple and efficient chromatographic separation method was developed for preparative separation and enrichment of total flavonoids (TFs) from Cortex Juglandis Mandshuricae (CJM) extracts and then the protective effect of TFs against CCl4-induced acute liver injury in mice was investigated. Enrichment and purification of TFs from CJM extracts were studied using six macroporous resins and HPD-750 resin was selected as the best resin according to its adsorption and desorption properties. The operating parameters of resin column chromatography were optimized. Under the optimal conditions, TFs from CJM with purity larger than 50% were produced and their antioxidant activity was further evaluated in vitro. The mice were orally administrated with the purified TFs for seven days and then given CCl4 (0.3%, 10mL/kg i.p.). The results showed that TFs of CJM significantly attenuated the activities of serum aspartate transaminase (AST) and alanine transaminase (ALT) compared with model group, as well as the relative liver weight. Histopathological observation also revealed that TFs reduced the incidence of liver lesions and improved hepatocyte abnormality. Moreover, oral administration of TFs significantly enhanced antioxidant enzyme activities (superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px)) and decreased the content of malondialdehyde (MDA). Histopathological and biochemical results elicited that TFs of CJM had significant hepatoprotective activity comparable to the standard silymarin. This is the first time to reveal the protective actions of the TFs from CJM against CCl4-induced liver damage in mice and this natural product should be developed as a new drug for treatment of live injury in future.

Liver Regeneration Induced By Extracorporeal Portal Vein Arterialization in a Swine Model of Carbon Tetrachloride Intoxication.

INTRODUCTION: This study aimed to determine whether a controlled portal blood arterialization by a liver extracorporeal device (L.E.O2 NARDO) is effective in treating acute hepatic failure (AHF) induced in swine by carbon tetrachloride (CCl4) administration. MATERIALS AND METHODS: Sixteen swine with AHF induced by intraperitoneal injection of CCl4 in oil solution were randomly divided into 2 groups: animals that received L.E.O2 NARDO treatment 48 hours after the intoxication (study group; n = 8); and animals that were sham operated 48 hours after the intoxication (control group; n = 8). Blood was withdrawn from the iliac artery and reversed in the portal venous system by an interposed extracorporeal device. Each treatment lasted 6 hours. The survival was assessed at 5 days after L.E.O2 NARDO treatment or sham operation. In both groups blood samples were collected for biochemical analysis at different study time and liver biopsies were performed 48 hours after intoxication and at humane killing. RESULTS: In the study group decreased transaminases levels and a more rapid international normalized ratio (INR) recover were detected as compared with the control group. Six animals of the study group (75%) versus 1 animal (12.5%) of the control group survived at 5 days after surgery with a statistically significant difference (P < .05). Liver biopsies performed at humane killing showed damaged areas of the livers reduced in the study group compared with biopsies of the control group. CONCLUSIONS: Arterial blood supply in the portal system through the L.E.O2 NARDO device is easily applicable, efficacious, and safe in a swine model of AHF induced by CCl4 intoxication.

Isolation of a novel lutein-protein complex from Chlorella vulgaris and its functional properties.

A novel kind of lutein-protein complex (LPC) was extracted from heterotrophic Chlorella vulgaris through aqueous extraction. The purification procedure contained solubilization of thylakoid proteins by a zwitterionic detergent CHAPS, anion exchange chromatography and gel filtration chromatography. Both wavelength scanning and HPLC analysis confirmed that lutein was the major pigment of the protein-based complex, and the mass ratio of lutein and protein was determined to be 9.72 : 100. Besides showing lipid peroxidation inhibition activity in vitro, LPC exerted significant antioxidant effects against ABTS and DPPH radicals with IC50 of 2.90 and 97. 23 µg mL(-1), respectively. Meanwhile, in vivo antioxidant activity of the complex was evaluated using the mice hepatotoxicity model; LPC significantly suppressed the carbon tetrachloride-induced elevation of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, and decreased hepatic malondialdehyde (MDA) levels and the hepatosomatic index. Moreover, LPC could effectively restore the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the treated mice livers. Our findings further the progress in the research of natural protein-based lutein complexes, suggesting that LPC has the potential in hepatoprotection against chemical induced toxicity and in increasing the antioxidant capacity of the defense system in the human body.

Role of the sympathetic nervous system in carbon tetrachloride-induced hepatotoxicity and systemic inflammation.

Carbon tetrachloride (CCl4) is widely used as an animal model of hepatotoxicity and the mechanisms have been arduously studied, however, the contribution of the sympathetic nervous system (SNS) in CCl4-induced acute hepatotoxicity remains controversial. It is also known that either CCl4 or SNS can affect systemic inflammatory responses. The aim of this study was to establish the effect of chemical sympathectomy with 6-hydroxydopamine (6-OHDA) in a mouse model of CCl4-induced acute hepatotoxicity and systemic inflammatory response. Mice exposed to CCl4 or vehicle were pretreated with 6-OHDA or saline. The serum levels of aminotransferases and alkaline phosphatase in the CCl4-poisoning mice with sympathetic denervation were significantly lower than those without sympathetic denervation. With sympathetic denervation, hepatocellular necrosis and fat infiltration induced by CCl4 were greatly decreased. Sympathetic denervation significantly attenuated CCl4-induced lipid peroxidation in liver and serum. Acute CCl4 intoxication showed increased expression of inflammatory cytokines/chemokines [eotaxin-2/CCL24, Fas ligand, interleukin (IL)-1α, IL-6, IL-12p40p70, monocyte chemoattractant protein-1 (MCP-1/CCL2), and tumor necrosis factor-α (TNF-α)], as well as decreased expression of granulocyte colony-stimulating factor and keratinocyte-derived chemokine. The overexpressed levels of IL-1α, IL-6, IL-12p40p70, MCP-1/CCL2, and TNF-α were attenuated by sympathetic denervation. Pretreatment with dexamethasone significantly reduced CCl4-induced hepatic injury. Collectively, this study demonstrates that the SNS plays an important role in CCl4-induced acute hepatotoxicity and systemic inflammation and the effect may be connected with chemical- or drug-induced hepatotoxicity and circulating immune response.

Cardioprotective role of leaves extracts of Carissa opaca against CCl4 induced toxicity in rats.

BACKGROUND: Carissa opaca are used traditionally in Pakistan for the treatment of various human ailments. Therefore, the study is arranged out to assess the cardio protective potential of different fractions of Carissa opaca leaves on CCl4-induced oxidative trauma in kidney. METHODS: The parameters studied in this respect were the cardiac function test (CK (U/l), CKMB (U/l), genotoxicity (% DNA fragmentation), characteristic morphological findings and antioxidant enzymatic level of cardiac tissue homogenate. RESULT: The protective effects of various fractions of Carissa opaca (C. opaca) leaves extract against CCl4 administration was reviewed by rat cardiac functions alterations. Chronic toxicity caused by eight week treatment of CCl4 to the rats significantly changed the cardiac function test, decreased the activities of antioxidant enzymes and glutathione contents whereas significant increase was found in lipid peroxidation comparative to control group. Administration of various fractions of C. opaca leaves extract with CCl4 showed protective ability against CCl4 intoxication by restoring the cardiac functions alterations, activities of antioxidant enzymes and lipid peroxidation in rat. CCl4 induction in rats also caused DNA fragmentation and histopathalogical abnormalities which were restored by co-admistration of various fraction of C. opaca leaves extract. CONCLUSION: Results revealed that various fraction of C. opaca are helpful in cardiac dysfunctions.

Soya phospholipid complex of mangiferin enhances its hepatoprotectivity by improving its bioavailability and pharmacokinetics.

BACKGROUND: Mangiferin is a xanthonoid present in Mangifera indica. It has been reported for a variety of pharmacological activities, including hepatoprotection. However, the major disadvantage of mangiferin is its reduced biological activity due to poor absorption, low bioavailability and rapid elimination from the body after administration. The aim of this study was to prepare a phospholipid complex of mangiferin to overcome these limitations and to investigate the impact of the complex on hepatoprotective activity and bioavailability. RESULTS: The results showed that the complex has an enhanced hepatoprotective and in vivo antioxidant activity as compared to pure mangiferin at the same dose level (30 and 60 mg kg⁻¹). The complex restored the levels of serum hepatic marker enzymes and liver antioxidant enzymes with respect to carbon tetrachloride-treated animals. The complex also increased the bioavailability of mangiferin in rat serum by 9.75-fold compared to pure mangiferin at the same dose level and enhanced the elimination half-life (t(1/2 el)) from 1.71 ± 0.12 h⁻¹ to 3.52 ± 0.27 h⁻¹. CONCLUSION: The results suggested that the complexation of mangiferin with soya phospholipid enhanced the hepatoprotection and in vivo antioxidant activity, which may be due to the improved bioavailability and pharmacokinetics of mangiferin in rat serum.

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.

Hepatoprotection by chemical constituents of the marine brown alga Spatoglossum variabile: a relation to free radical scavenging potential.

CONTEXT: In the course of searching hepatoprotective agents from natural sources, the protective effect of chemical constituents of the marine brown alga Spatoglossum variabile Figaro et DE Notar (Dictyoaceae) against CCl4-induced liver damage in Wistar rats was investigated. The compounds were first investigated for in vitro radical scavenging potential and were also tested for ß-glucuronidase inhibition to further explore the relationship between hepatoprotection and antiradical potential. METHODS: The compounds cinnamic acid esters 1 and 2 and aurone derivatives 3 and 4 were first investigated for in vitro radical scavenging potential against 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH), and superoxide anion radicals. In vivo hepatoprotective studies were performed in seven groups (n = 6) of Wistar rats. The test groups were pretreated with compounds (10 mg/kg body weight, po) orally for 30 min before the intraperitoneal administration of a dose of 20% CCl4 diluted with dietary cooking oil. Moreover, compounds were also tested for ß-glucuronidase inhibition to explore the relationship between hepatoprotection and radical scavenging potential. RESULTS: The test compounds 1-4 were found to exhibit antiradical activity against 1,1-diphenyl-2-picrylhydrazyl radicals with IC50 values ranging between 54 and 138 µM, whereas aurone derivatives 3 and 4 additionally exhibited superoxide anion scavenging effects with IC50 values of 95 and 87 µM, respectively. In addition, these compounds were found to be weak inhibitors of xanthine oxidase (IC50 ≥1000 µM). In animal model, pretreatment with compounds 2-4 significantly blocked the CCl4-induced increase in the levels of the serum biochemical markers. CONCLUSION: It appears that the hepatoprotection afforded by these compounds was mainly due to their radical scavenging activity that protected the cells from the free radicals generated by CCl4-induced hepatotoxicity.

Reduced hepatic stellate cell expression of Kruppel-like factor 6 tumor suppressor isoforms amplifies fibrosis during acute and chronic rodent liver injury.

UNLABELLED: Kruppel-like factor 6 (KLF6), a zinc finger transcription factor and tumor suppressor, is induced as an immediate-early gene during hepatic stellate cell (HSC) activation. The paradoxical induction of a tumor suppressor in HSCs during proliferation led us to explore the biology of wildtype KLF6 (KLF6(WT) ) and its antagonistic, alternatively spliced isoform KLF6(SV1) in cultured HSCs and animal models. The animal models generated include a global heterozygous KLF6 mouse (Klf6+/-), and transgenic mice expressing either hKLF6(WT) or hKLF6(SV1) under the control of the Collagen α2 (I) promoter to drive HSC-specific gene expression following injury. The rat Klf6 transcript has multiple splice forms that are homologous to those of the human KLF6 gene. Following a transient increase, all rat Klf6 isoforms decreased in response to acute carbon tetrachloride (CCl(4)) liver injury and culture-induced activation. After acute CCl(4), Klf6+/- mice developed significantly increased fibrosis and enhanced fibrogenic messenger RNA (mRNA) and protein expression. In contrast, HSC-specific transgenic mice overexpressing KLF6(WT) or KLF6(SV1) developed significantly diminished fibrosis with reduced expression of fibrogenic genes. Chromatin IP and quantitative reverse-transcription polymerase chain reaction in mouse HSCs overexpressing KLF6(WT) demonstrated KLF6(WT) binding to GC boxes in promoters of Colα1 (I), Colα2 (I), and beta-platelet-derived growth factor receptor (ß-Pdgfr) with reduced gene expression, consistent with transcriptional repression by KLF6. Stellate cells overexpressing either KLF6(WT) or KLF6(SV1) were more susceptible to apoptotic stress based on poly (ADP-ribose) polymerase (PARP) cleavage. CONCLUSION: KLF6 reduces fibrogenic activity of HSCs by way of two distinct mechanisms, direct transcriptional repression of target fibrogenic genes and increased apoptosis of activated HSCs. These results suggest that following its initial induction, sustained down-regulation of KLF6 in liver injury may allow de-repression of fibrogenic genes and decreased stellate cell clearance by inhibiting apoptosis.

Proteomics study on the hepatoprotective effects of traditional Chinese medicine formulae Yin-Chen-Hao-Tang by a combination of two-dimensional polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight mass spectrometry.

Proteomics can bring breakthroughs in the study of traditional Chinese medicine (TCM). Yin-Chen-Hao-Tang (YCHT), a famous TCM formulae, has been used to alleviate various types of liver injury. However, the underlying mechanisms and drug targets of YCHT associated with the hepatic injury are largely unknown. To identify the possible target proteins of YCHT, two-dimensional gel electrophoresis (2-DE)-based proteomics was performed and proteins altered after YCHT treatment were identified by MALDI-TOF/TOF-MS. Interestingly, 15 modulated proteins were identified, out of which 7 were found to be significantly altered by YCHT. YCHT treatment caused a statistically significant down-regulation of zinc finger protein 407, haptoglobin, macroglobulin, alpha-1-antitrypsin; significant up-regulation of transthyretin, vitamin D-binding protein, and prothrombin, appear to be involved in metabolism, energy generation, chaperone, antioxidation, signal transduction, protein folding and apoptosis. Finally, interaction network from 7 differentially expressed protein to the signal-related proteins was established using bioinformatic analysis. Of note, these signal-related proteins could be included in a network together with 7 proteins through direct interaction or only one intermediate partner. Functional pathway analysis suggested that these proteins were closely related in the protein-protein interaction network and the modulation of multiple vital physiological pathways. Thus, our data will help to understand the molecular mechanisms of hepatoprotective effects of YCHT.

Resveratrol nanoparticle system improves dissolution properties and enhances the hepatoprotective effect of resveratrol through antioxidant and anti-inflammatory pathways.

Resveratrol (RES), a well-known antioxidant and anti-inflammatory compound, is abundant in red wine and exerts numerous pharmacological effects, including hepatoprotection and cadioprotection. Unfortunately, RES is restricted in clinical application due to poor dissolution property and adsorption. In addition, red wine as a supplement for preventing disease is not recommended for patients with alcohol-related disorders. To address these limitations, we successfully developed a novel RES nanoparticle system (RESN) and demonstrated that RESN could circumvent the physicochemical drawbacks of raw RES with respect to dissolution, such as the reduction of particle size, amorphous transformation, and hydrogen-bond formation. In addition, we employed an animal model of CCl4-induced hepatotoxicity to estimate the potential of the nanoparticle formulation to improve the hepatoprotective effect of orally administered RES. Our results demonstrated that RESN can diminish liver function markers (aspartate aminotransferase and alanine aminotransferase) by decreasing hepatocyte death due to CCl4-induced hepatotoxicity in rats, when compared with RES administration. The effect was achieved by reducing oxidative stress (decreased reactive oxygen species and lipid peroxidation) and lowering inflammatory cytokines (decreased tumor necrosis factor-α and interleukin 1ß) and protein expression (cyclooxygenase-2, inducible nitric oxide synthase, cytosolic phospholipase A2, and caspase-3). In conclusion, enhancement of the dissolution of RES through a nanoparticle engineering process can result in increased hepatoprotective effects mediated by antioxidant and anti-inflammatory activities. Consequently, we suggest that RESN deserves further study, perhaps in prophylaxis of chronic liver diseases.

Protective effects of salecan against carbon tetrachloride-induced acute liver injury in mice.

Carbon tetrachloride (CCl4) is a well-established model for screening hepato-protective drugs. The aim of the present study was to evaluate the potential protective effects of a novel soluble ß-glucan salecan on acute liver injury induced by CCl4 in mice and to further explore the underlying mechanisms. Mice were given salecan (40 mg kg⁻¹) or phosphate-buffered saline for 3 days prior to treatment with a single intraperitoneal dose of CCl4 (1 ml kg⁻¹ body weight). Animals were sacrificed at 0, 12, 24, 48, 72 and 96 h post-injection of CCl4. Serum liver enzyme levels, histology, lipid peroxidation, glutathione (GSH) content, expression of antioxidant enzymes and hepatocyte proliferation were subsequently evaluated. The serum levels of hepatic enzyme markers were markedly reduced in the salecan pretreatment group compared with the control group. Histopathological examination of the livers revealed that hepatocellular degeneration and necrosis were significantly attenuated at an early stage during CCl4 intoxication and liver recovery was markedly accelerated at a later stage in salecan pre-administered mice. Furthermore, salecan administration remarkably alleviated lipid peroxidation and restored GSH depletion. Meanwhile, the expression of antioxidant genes was significantly elevated in the salecan-treated group. Interestingly, the administration of salecan remarkably enhanced hepatocyte proliferation in the recovery phase after CCl4 injection. Taken together, these results demonstrated that salecan exhibits a protective action on acute hepatic injury induced by CCl4 through attenuating oxidative stress and accelerating hepatocyte regeneration.

Loss of histone acetyltransferase cofactor transformation/transcription domain-associated protein impairs liver regeneration after toxic injury.

Organ regeneration after toxin challenge or physical injury requires a prompt and balanced cell-proliferative response; a well-orchestrated cascade of gene expression is needed to regulate transcription factors and proteins involved in cell cycle progression and cell proliferation. After liver injury, cell cycle entry and progression of hepatocytes are believed to require concerted efforts of transcription factors and histone-modifying activities; however, the actual underlying mechanisms remain largely unknown. The purpose of our study was to investigate the role of the histone acetyltransferase (HAT) cofactor transformation/transcription domain-associated protein (TRRAP) and histone acetylation in the regulation of cell cycle and liver regeneration. To accomplish our purpose, we used a TRRAP conditional knockout mouse model combined with toxin-induced hepatic injury. After we treated the mice with a carbon tetrachloride toxin, conditional ablation of the TRRAP gene in those mice severely impaired liver regeneration and compromised cell cycle entry and progression of hepatocytes. Furthermore, loss of TRRAP impaired the induction of early and late cyclins in regenerating livers by compromising histone acetylation and transcription factor binding at the promoters of the cyclin genes. Our results demonstrate that TRRAP and TRRAP/HAT-mediated acetylation play an important role in liver regeneration after toxic injury and provide insight into the mechanism by which TRRAP/HATs orchestrate the expression of the cyclin genes during cell cycle entry and progression.