The effect of taurine treatment on oxidative stress in experimental liver fibrosis

Testosterone enhances taurine synthesis by upregulating androgen receptor and cysteine sulfinic acid decarboxylase expressions in male mouse liver

Taurine is an end-product of cysteine metabolism, whereas cysteine dioxygenase (CDO) and cysteine sulfinate decarboxylase (CSAD) are key enzymes regulating taurine synthesis. Sex steroids, including estrogens and androgens, are associated with liver physiopathological processes; however, we still do not know whether taurine and sex steroids interact in regulating liver physiology and hepatic diseases, and whether there are sex differences, although our recent study shows that the estrogen is involved in regulating taurine synthesis in mouse liver. The present study was thus proposed to identify whether 17-β-estradiol and testosterone (T) play their roles by regulating CDO and CSAD expression and taurine synthesis in male mouse liver. Our results demonstrated that testosterone did not have a significant influence on CDO expression but significantly enhanced CSAD, androgen receptor (AR) expressions, and taurine levels in mouse liver, cultured hepatocytes, and HepG2 cells, whereas these effects were abrogated by AR antagonist flutamide. Furthermore, our results showed that testosterone increased CSAD-promoter-luciferase activity through the direct interaction of the AR DNA binding domain with the CSAD promoter. These findings first demonstrate that testosterone acts as an important factor to regulate sulfur amino acid metabolism and taurine synthesis through AR/CSAD signaling pathway. In addition, the in vivo and in vitro experiments showed that 17-β-estradiol has no significant effects on liver CSAD expression and taurine synthesis in male mice and suggest that the effects of sex steroids on the taurine synthesis in mouse liver have sex differences. These results are crucial for understanding the physiological functions of taurine/androgen and their interacting mechanisms in the liver.NEW & NOTEWORTHY This study demonstrates that testosterone functions to enhance taurine synthesis by interacting with androgen receptor and binding to cysteine sulfinate decarboxylase (CSAD) promoter zone. Whereas estrogen has no significant effects either on liver CSAD expression or taurine synthesis in male mice and suggests that the effects of sex steroids on taurine synthesis in the liver have gender differences. These new findings are the potential for establishing effective protective and therapeutic strategies for liver diseases.

CCl4 inhibits the expressions of hepatic taurine biosynthetic enzymes and taurine synthesis in the progression of mouse liver fibrosis

Carbon tetrachloride (CCl4) is a widely used hepatotoxin for the studies of liver fibrosis and cirrhosis, and taurine has function to abate liver fibrosis induced by CCl4. But the interacting mechanisms between taurine and CCl4 in liver are still largely unknown. These made us to hypothesize that CCl4 may induce liver fibrosis by affecting the expressions of taurine biosynthetic enzymes and taurine synthesis. We thus assayed the expressions of hepatic cysteine dioxygenase (CDO), cysteine sulfonate acid decarboxylase (CSAD) and taurine transporter (TauT) in the progression of mouse liver fibrosis induced by CCl4. The results demonstrated that CCl4 treatment markedly decreased hepatic CSAD, CDO expressions, and taurine levels in hepatic tissue, although TauT expression did not exhibit significant decline. It was contrasting that hepatic α-SMA, serum AST, ALT, ALP kept increasing, which were accompanied by the pathological characters of liver, whereas taurine supplement attenuated the progression of liver fibrosis induced by CCl4. These results demonstrate that CCl4 may induce liver fibrosis by inhibiting hepatic CSAD and CDO expressions and taurine synthesis, which are crucial for our understanding the mechanisms of liver fibrosis induced by CCl4, and also potential for establishing therapeutic strategies of liver fibrosis and related diseases.

Taurine Upregulates miRNA-122-5p Expression and Suppresses the Metabolizing Enzymes of Glycolytic Pathway in Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a complicated disease with a poor prognosis and high mortality rates. The prevention, control, diagnosis, and treatment of liver cancer have become vital focuses in healthcare research.

AIM

This study aimed to evaluate the in vitro effect of taurine (Tau) on the expression of miR-122-5p that targets some limiting glycolytic enzymes and affects the overall glycolytic pathway in HepG2 cells.

METHOD

IC₅₀ and the inhibitory effect of Tau on cell proliferation were measured after 48 h by MTT assay. Then, the mRNA expressions of some apoptosis-related genes P53, BAX, Caspase-3, and Bcl-2 were measured using quantitative real-time (qRT-PCR) and the protein levels were confirmed by enzyme-linked immunosorbent assay (ELISA). The activities of some antioxidant's biomarkers were assessed. The gene expression of miR-122-5p that targets some limiting glycolytic enzymes; Aldolase and Lactate dehydrogenase (LDH), were evaluated after treatment with Tau for 48 h.

RESULTS

A Significant inhibition in the proliferation of HepG2 was encountered after treatment with Tau in a dose-dependent manner. Moreover, the expression of apoptotic genes p53, Bax, and Caspase-3 exhibited a significant upregulation, while Bcl-2 showed a significant downregulation. These alterations in the expression levels were also confirmed on the protein level. The antioxidant activities of GPx, CAT, and NO were significantly elevated versus untreated control. Also, a significant increase in the expression level of miR-122-5p was observed after treatment with Tau affecting the metabolic activity of HCC cells. Concomitantly, a significant inhibition in ALDOA protein and the hallmark of glycolytic enzymes LDH and Aldolase were observed.

CONCLUSIONS

These observations showed that taurine inhibits HepG2 cell proliferation and restores the expression of miR-122-5p which inhibits the hallmark glycolytic enzymes and ultimately the metabolic activity of HCC cells. Tau is assumed to be a promising and effective antitumor therapy of HCC.

Hydrogen selenide, a vital metabolite of sodium selenite, uncouples the sulfilimine bond and promotes the reversal of liver fibrosis

Sodium selenite has alleviating effects on liver fibrosis; however, its therapeutic molecular mechanism remains unclear. Herein, hydrogen selenide, a major metabolite of Na₂SeO₃, was tested to uncouple the sulfilimine bond in collagen IV, the biomarker of liver fibrosis. A mouse model of liver fibrosis was constructed via a CCl₄-induced method, followed by the administration of 0.2 mg kg^-1 Na₂SeO₃ via gavage three times per week for 4 weeks. Changes in H₂Se, NADPH, and H₂O₂ levels were monitored in real time by using NIR-H₂Se, DCI-MQ-NADPH, and H₂O₂ probes in vivo, respectively. H₂Se continuously accumulated in the liver throughout the Na₂SeO₃ treatment period, but the levels of NADPH and H₂O₂ decreased. The expression of collagen IV was analyzed through Western blot and liquid chromatography-mass spectrometry. Results confirmed that the sulfilimine bond of collagen IV in the fibrotic mouse livers could be broken by H₂Se with the Na₂SeO₃ treatment. Therefore, the therapeutic effect of Na₂SeO₃ on liver fibrosis could be mainly attributed to H₂Se that uncoupled the sulfilimine bond to induce collagen IV degradation. This study provided a reasonable explanation for the molecular mechanism of the in vivo function of Na₂SeO₃ and the prevention of liver fibrosis by administering inorganic selenium.

A comprehensive review of natural products to fight liver fibrosis: Alkaloids, terpenoids, glycosides, coumarins and other compounds

The discovery of drugs to treat liver fibrosis has long been a challenge over the past decades due to its complicated pathogenesis. As a primary approach for drug development, natural products account for 30% of clinical drugs used for disease treatment. Therefore, natural products are increasingly important for their medicinal value in liver fibrosis therapy. In this part of the review, special focus is placed on the effect and mechanism of natural compounds, including alkaloids, terpenoids, glycosides, coumarins and others. A total of 36 kinds of natural compounds demonstrate significant antifibrotic effects in various liver fibrosis models in vivo and in hepatic stellate cells (HSCs) in vitro. Revealing the mechanism will provide further basis for clinical conversion, as well as accelerate drug discovery. The mechanism was further summarized with the finding of network regulation by several natural products, such as oxymatrine, paeoniflorin, ginsenoside Rg1 and taurine. Moreover, there are still improvements needed in investigating clinical efficacy, determining mechanisms, and combining applications, as well as semisynthesis and modification. Therefore, natural products area promising resource for agents that protect against liver fibrosis.

Role of taurine, its haloamines and its lncRNA TUG1 in both inflammation and cancer progression. On the road to therapeutics? (Review)

For one century, taurine is considered as an end product of sulfur metabolism. In this review, we discuss the beneficial effect of taurine, its haloamines and taurine upregulated gene 1 (TUG1) long non‑coding RNA (lncRNA) in both cancer and inflammation. We outline how taurine or its haloamines (N‑Bromotaurine or N‑Chlorotaurine) can induce robust and efficient responses against inflammatory diseases, providing insight into their molecular mechanisms. We also provide information about the use of taurine as a therapeutic approach to cancer. Taurine can be combined with other chemotherapeutic drugs, not only mediating durable responses in various malignancies, but also circumventing the limitations met from chemotherapeutic drugs, thus improving the therapeutic outcome. Interestingly, the lncRNA TUG1 is regarded as a promising therapeutic approach, which can overcome acquired resistance of cancer cells to selected strategies. In this regard, we can translate basic knowledge about taurine and its TUG1 lncRNA into potential therapeutic options directed against specific oncogenic signaling targets, thereby bridging the gap between bench and bedside.

Serum metabolites detect the presence of advanced fibrosis in derivation and validation cohorts of patients with non-alcoholic fatty liver disease

OBJECTIVE

Non-invasive and accurate diagnostic tests for the screening of disease severity in non-alcoholic fatty liver disease (NAFLD) remain a major unmet need. Therefore, we aimed to examine if a combination of serum metabolites can accurately predict the presence of advanced fibrosis.

DESIGN

This is a cross-sectional analysis of a prospective derivation cohort including 156 well-characterised patients with biopsy-proven NAFLD and two validation cohorts, including (1) 142 patients assessed using MRI elastography (MRE) and(2) 59 patients with biopsy-proven NAFLD with untargeted serum metabolome profiling.

RESULTS

In the derivation cohort, 23 participants (15%) had advanced fibrosis and 32 of 652 analysed metabolites were significantly associated with advanced fibrosis after false-discovery rate adjustment. Among the top 10 metabolites, 8 lipids (5alpha-androstan-3beta monosulfate, pregnanediol-3-glucuronide, androsterone sulfate, epiandrosterone sulfate, palmitoleate, dehydroisoandrosterone sulfate, 5alpha-androstan-3beta disulfate, glycocholate), one amino acid (taurine) and one carbohydrate (fucose) were identified. The combined area under the receiver operating characteristic curve (AUROC) of the top 10 metabolite panel was higher than FIB--4 and NAFLD Fibrosis Score (NFS) for the detection of advanced fibrosis: 0.94 (95% CI 0.897 to 0.982) versus 0.78 (95% CI0.674 to 0.891), p=0.002 and versus 0.84 (95% CI 0.724 to 0.929), p=0.017, respectively. The AUROC of the top 10 metabolite panel remained excellent in the independent validation cohorts assessed by MRE or liver biopsy: c-statistic of 0.94 and 0.84, respectively.

CONCLUSION

A combination of 10 serum metabolites demonstrated excellent discriminatory ability for the detection of advanced fibrosis in an derivation and two independent validation cohorts with greater diagnostic accuracy than the FIB-4-index and NFS. This proof-of-concept study demonstrates that a non-invasive blood-based diagnostic test can provide excellent performance characteristics for the detection of advanced fibrosis.

Effects of Taurine and Vitamin D on Antioxidant Enzyme Activity and Lipids Profiles in Rats Fed Diet Deficient Calcium

Calcium deficiency is a worldwide problem affecting both developed and developing countries. The deficiency in calcium leads to a marked decrease of superoxide dismutase. It is known that vitamin D protects cells against oxidative damages while taurine plays an anti-inflammatory and antioxidant role. In this study, we examined whether vitamin D and taurine supplementation had a protective effect on oxidative stress in rats fed calcium deficient diet. Female SD rats (mean weight 60 ∼ 70 g) were divided into four groups; control, taurine, vitamin D, taurine + vitamin D for 6 weeks (taurine: 2 g/100 g diet, vitamin D: 0.5 mg/100 g diet). We then analyzed the level of triglyceride (TG), total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C) in serum and level of TC, TG in liver. We investigated antioxidative enzyme activities such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). We observed that weight gain was not significantly different in the experimental groups. Food efficiency ratio (FER) was significantly higher in the normal control group than the taurine and vitamin D groups (p < 0.05). The level of liver TC was significantly lower in taurine, vitamin D, taurine + vitamin D groups than control group (p < 0.05). The concentration of malondialdehyde (MDA) was significantly lower in the taurine group than the control group. The activity of SOD was higher in taurine group than other experimental groups (p < 0.05), but GSH-Px and CAT were not significantly different. In conclusion, taurine has a positive effect on SOD activity but not on vitamin D. Also taurine and vitamin D have a protective effect as observed in liver TC in rats fed with a diet which lacks calcium.

Deficiency of DJ-1 Ameliorates Liver Fibrosis through Inhibition of Hepatic ROS Production and Inflammation

Liver fibrosis is a global health problem and previous studies have demonstrated that reactive oxygen species (ROS) play important roles in fibrogenesis. Parkinson disease (autosomal recessive, early onset) 7 (Park7) also called DJ-1 has an essential role in modulating cellular ROS levels. DJ-1 therefore may play functions in liver fibrogenesis and modulation of DJ-1 may be a promising therapeutic approach. Here, wild-type (WT) and DJ-1 knockout (DJ-1 KO) mice were administrated with carbon tetrachloride (CCl4) to induce liver fibrosis or acute liver injury. Results showed that DJ-1 depletion significantly blunted liver fibrosis, accompanied by marked reductions in liver injury and ROS production. In the acute CCl4 model, deficiency of DJ-1 showed hepatic protective functions as evidenced by decreased hepatic damage, reduced ROS levels, diminished hepatic inflammation and hepatocyte proliferation compared to WT mice. In vitro hepatic stellate cells (HSCs) activation assays indicated that DJ-1 has no direct effect on the activation of HSCs in the context of with or without TGFβ treatment. Thus our present study demonstrates that in CCl4-induced liver fibrosis, DJ-1 deficiency attenuates mice fibrosis by inhibiting ROS production and liver injury, and further indirectly affecting the activation of HSCs. These results are in line with previous studies that ROS promote HSC activation and fibrosis development, and suggest the therapeutic value of DJ-1 in treatment of liver fibrosis.

Effect of taurine on chronic and acute liver injury: Focus on blood and brain ammonia

Hyperammonemia is associated with chronic and acute liver injury. There is no promising therapeutic agent against ammonia-induced complications. Hence, finding therapeutic molecules with safe profile of administration has clinical value. The present study was conducted to evaluate the role of taurine (TA) administration on plasma and brain ammonia and its consequent events in different models of chronic and acute liver injury and hyperammonemia. Bile duct ligated (BDL) rats were used as a model of chronic liver injury. Thioacetamide and acetaminophen-induced acute liver failure were used as acute liver injury models. A high level of ammonia was detected in blood and brain of experimental groups. An increase in brain ammonia level coincided with a decreased total locomotor activity of animals and significant changes in the biochemistry of blood and also liver tissue. TA administration (500 and 1000 mg/kg, i.p), effectively alleviated liver injury and its consequent events including rise in plasma and brain ammonia and brain edema. The data suggested that TA is not only a useful and safe agent to preserve liver function, but also prevented hyperammonemia as a deleterious consequence of acute and chronic liver injury.

Serum level of taurine would be associated with the amelioration of minimal hepatic encephalopathy in cirrhotic patients

AIM

A variety of treatment modalities including L-carnitine have been tried for cirrhotic patients with minimal hepatic encephalopathy (MHE), which improved MHE for some patients, but were not effective for the other patients. We aimed to identify pre-therapeutic independent factors to predict the amelioration of MHE after L-carnitine treatment.

METHODS

We performed a prospective cohort study on a total of 64 consecutive outpatients of cirrhotic patients who underwent blood biochemical examinations and neuropsychiatric (NP) test at Kobe University Hospital. MHE patients diagnosed by the NP test were p.o. administrated L-carnitine for 3 months. The patients with and without MHE amelioration were compared, and the independent factors were statistically examined. Predictive scoring systems of the amelioration of MHE were established using multivariate logistic regression.

RESULTS

The amelioration of MHE was found in 45.8% of MHE patients. Serum taurine before the treatment was the best predictive factor of the amelioration of MHE (P = 0.046). The predictive model using serum taurine discriminated well between patients with and without the amelioration of MHE (area under the receiver-operator curve, 0.748; 95% confidence interval, 0.531-0.901). The predictive scores of the amelioration of MHE enable the patient-specific probability to be easily looked up.

CONCLUSION

Serum taurine before L-carnitine treatment was shown to be an independent factor associated with the amelioration of MHE 3 months after the treatment. The easy pre-therapeutic prediction of MHE amelioration after L-carnitine treatment would help in improving awareness of the selection of MHE patients with good response to L-carnitine, thus being beneficial from a financial perspective.

Estradiol decreases taurine level by reducing cysteine sulfinic acid decarboxylase via the estrogen receptor-α in female mice liver

Cysteine sulfinic acid decarboxylase (CSAD) and cysteine dioxygenase (CDO) are two rate-limiting enzymes in taurine de novo synthesis, and their expressions are associated with estrogen concentration. The present study was designed to determine the relationship between 17β-estradiol (E₂) and taurine in female mice liver. We initially observed the mice had lower levels of CSAD, CDO, and taurine during estrus than diestrus. We then, respectively, treated the ovariectomized mice, the cultured hepatocytes, and Hep G2 cells with different doses of E₂, and the CSAD and CDO expressions and taurine levels were analyzed. The results showed that E₂ decreased taurine level in the serum and the cultured cells by inhibiting CSAD and CDO expressions. Furthermore, we identified the molecular receptor types through which E₂ plays its role in regulating taurine synthesis, and our results showed that estrogen receptor-α (ERα) expression was much higher than estrogen receptor-β (ERβ) in the liver and hepatocytes, and the inhibiting effects of E₂ on CSAD, CDO, and taurine level were partially abrogated in the ICI-182,780-pretreated liver and hepatocytes, and in ERα knockout mice. These results indicate that estradiol decreases taurine content by reducing taurine biosynthetic enzyme expression in mice liver.

Mass spectrometry-based metabolite profiling in the mouse liver following exposure to ultraviolet B radiation

Although many studies have been performed on the effects of ultraviolet (UV) radiation on the skin, only a limited number of reports have investigated these effects on non-skin tissue. This study aimed to describe the metabolite changes in the liver of hairless mice following chronic exposure to UVB radiation. We did not observe significant macroscopic changes or alterations in hepatic cholesterol and triglyceride levels in the liver of UVB-irradiated mice, compared with those for normal mice. In this study, we detected hepatic metabolite changes by UVB exposure and identified several amino acids, fatty acids, nucleosides, carbohydrates, phospholipids, lysophospholipids, and taurine-conjugated cholic acids as candidate biomarkers in response to UVB radiation in the mouse liver by using various mass spectrometry (MS)-based metabolite profiling including ultra-performance liquid chromatography-quadrupole time-of-flight (TOF)-MS, gas chromatography-TOF-MS and nanomate LTQ-MS. Glutamine exhibited the most dramatic change with a 5-fold increase in quantity. The results from altering several types of metabolites suggest that chronic UVB irradiation may impact significantly on major hepatic metabolism processes, despite the fact that the liver is not directly exposed to UVB radiation. MS-based metabolomic approach for determining regulatory hepatic metabolites following UV irradiation will provide a better understanding of the relationship between internal organs and UV light.

Pathogenesis of liver cirrhosis

Liver cirrhosis is the final pathological result of various chronic liver diseases, and fibrosis is the precursor of cirrhosis. Many types of cells, cytokines and miRNAs are involved in the initiation and progression of liver fibrosis and cirrhosis. Activation of hepatic stellate cells (HSCs) is a pivotal event in fibrosis. Defenestration and capillarization of liver sinusoidal endothelial cells are major contributing factors to hepatic dysfunction in liver cirrhosis. Activated Kupffer cells destroy hepatocytes and stimulate the activation of HSCs. Repeated cycles of apoptosis and regeneration of hepatocytes contribute to pathogenesis of cirrhosis. At the molecular level, many cytokines are involved in mediation of signaling pathways that regulate activation of HSCs and fibrogenesis. Recently, miRNAs as a post-transcriptional regulator have been found to play a key role in fibrosis and cirrhosis. Robust animal models of liver fibrosis and cirrhosis, as well as the recently identified critical cellular and molecular factors involved in the development of liver fibrosis and cirrhosis will facilitate the development of more effective therapeutic approaches for these conditions.

Effect of fishmeal replacement by soy protein concentrate with taurine supplementation on hepatic intermediary metabolism and antioxidant status of totoaba juveniles (Totoaba macdonaldi)

The effect of dietary incorporation of soy protein concentrate (SPC) and the concomitant supplementation with taurine on hepatic intermediary metabolism and antioxidant status of totoaba (Totoaba macdonaldi) juveniles was assessed. Four isoproteic and isolipidic diets were formulated containing either 30 or 60% of SPC (diets SP30 and SP60), supplemented or not with 1% of taurine (diets SP30T and SP60T). A fish meal (FM) based diet, without SPC and taurine supplementation, was used as a control. Triplicate groups of 32 totoaba juveniles (average body mass=7.5g) were fed these diets over 45days. Results revealed that dietary FM replacement by SPC depressed the overall intermediary metabolism. Activity of key enzymes of amino acid catabolism and gluconeogenesis was significantly reduced and a trend to reduce glycolysis and glucose-6-phosphate dehydrogenase activity was observed. The incorporation of the highest level of SPC also significantly increased hepatic lipid peroxidation and the activity of superoxide dismutase. Concomitant taurine supplementation restored the activity of amino acid catabolic and gluconeogenic enzymes and hexokinase to levels similar of those of the control diet. Taurine supplementation also led to a significant increase of glucose-6-phosphate dehydrogenase and catalase activity, as well as to a significant reduction of liver lipid peroxidation. These results suggest that taurine may play an important metabolic modulation action on totoaba fed SPC based diets, contributing to the enhancement of the overall metabolism and to the reduction of liver oxidative damage.

Corn peptides protect against thioacetamide-induced hepatic fibrosis in rats

Certain bioactive peptides are reported to be able to alleviate hepatic fibrosis. Our previous work has confirmed the hepatoprotective effect of corn peptides (CPs) that are prepared from a high protein by-product, corn gluten meal, on acute liver injury in an animal model. However, the antifibrotic activity of CPs remained to be elucidated. In this study, the hepatoprotective effect of CPs on thioacetamide (TAA)-induced liver fibrosis was tested. Results showed that CPs (100 mg/kg body weight) significantly decreased the levels of alanine transaminase/aspartate transaminase, laminin, type IV collagen, and type III collagen in serum and increased the serum albumin levels and total antioxidant capacity. Additionally, with CP treatment (100 mg/kg body weight), a significant decrease was observed in the levels of malondialdehyde, nitric oxide, hydroxyproline, transforming growth factor β1, and lactate dehydrogenase activity as well as the liver index, while the activity of superoxidedismutase was significantly increased in livers. The histological and morphological analysis showed that the hepatocyte structure in CP-treated rats was superior to that of TAA-injured rats, and inflammation and fibrosis were also ameliorated. Therefore, CPs can be used as an option for prevention and adjuvant therapy of liver fibrosis.

Transcriptomic and proteomic analysis of human hepatic stellate cells treated with natural taurine

The aim of this study was to investigate the differential expression of genes and proteins between natural taurine (NTau)‑treated hepatic stellate cells (HSCs) and control cells as well as the underlying mechanism of NTau in inhibiting hepatic fibrosis. A microculture tetrazolium (MTT) assay was used to analyze the proliferation of NTau‑treated HSCs. Flow cytometry was performed to compare the apoptosis rate between NTau-treated and non‑treated HSCs. Proteomic analysis using a combination of 2-dimensional gel electrophoresis (2DE) and mass spectrometry (MS) was conducted to identify the differentially expressed proteins. Microarray analysis was performed to investigate the differential expression of genes and real-time polymerase chain reaction (PCR) was used to validate the results. The experimental findings obtained demonstrated that NTau decreased HSC proliferation, resulting in an increased number of cells in the G0/G1 phase and a reduced number of cells in the S phase. Flow cytometric analysis showed that NTau-treated HSCs had a significantly increased rate of apoptosis when compared with the non‑treated control group. A total of 15 differentially expressed proteins and 658 differentially expressed genes were identified by 2DE and MS, and microarray analysis, respectively. Gene ontology (GO) functional analysis indicated that these genes and proteins were enriched in the function clusters and pathways related to cell proliferation, cellular apoptosis and oxidation. The transcriptome and proteome analyses of NTau-treated HSCs demonstrated that NTau is able to significantly inhibit cell proliferation and promote cell apoptosis, highlighting its potential therapeutic benefits in the treatment of hepatic fibrosis.

Taurine and liver diseases: a focus on the heterogeneous protective properties of taurine

Taurine (2-aminoethylsulfonic acid) has many physiological and pharmacological functions in most tissues. It is abundantly maintained in the liver by both endogenous biosynthesis and exogenous transport, but is decreased in liver diseases. In the hepatic lobule, there are heterogeneous differences in metabolism between the pericentral (PC) and periportal regions, and the distributions of the biosynthesis capacity and specific taurine transporter expression are predominantly in the PC region. In cases of depletion of hepatic taurine level, serious liver damages were observed in the PC region. Taurine has protective effects against xenobiotics-induced liver damages in the PC region, but not xenobiotics-induced PP region damages. The xenobiotics that injure the PC region are mainly catabolized by NADPH-dependent cytochrome P450 2E1 that is also predominantly expressed in the PC region. Taurine treatment seems to be a useful agent for CYP2E1-related liver diseases with predominant damages in the PC region.

Regression of liver fibrosis by taurine in rats fed alcohol: effects on collagen accumulation, selected cytokines and stellate cell activation

The antifibrogenic effect of taurine in experimental liver fibrosis has been shown. The role of taurine to abate fibrogenic mediators and collagen deposition during liver fibrosis induced by simultaneous administration of iron carbonyl (0.5% w/w) and alcohol (6 g/kg/day) was investigated in this study. Liver histology, the levels of inflammatory cytokines, stellate cell activation, oxidative stress and collagen content were assessed. Liver fibrosis and a rise in collagen content in ethanol plus iron-fed rat were evident from van Gieson and Masson's trichrome staining respectively. Hepatic myeloperoxidase activity and plasma levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were markedly elevated. This was associated with an imbalance in the oxidant-antioxidant system, increased expression of transforming growth factor-β(1) (TGF-β(1)) and stellate cell activation suggested by α-smooth muscle actin (α-SMA) localization. This condition was protected in the presence of taurine. Taurine lowered the levels of IL-6, TNF-α and peroxidation products and the expression of α-SMA, desmin and TGF-β(1) and improved the antioxidant status. A positive relationship between hepatic collagen with iron and lipid peroxides and an inverse relationship between collagen and glutathione were noted. It is concluded that taurine reduces iron-potentiated alcoholic liver fibrosis by curtailing oxidative stress, production of inflammatory and fibrogenic mediators and activation of stellate cells.

Thiol redox systems and protein kinases in hepatic stellate cell regulatory processes

Hepatic stellate cells (HSC) are the major producers of collagen in the liver and their conversion from resting cells to a proliferating, contractile and fibrogenic phenotype ('activation') is a critical step, leading to liver fibrosis characterized by deposition of excessive extracellular matrix. Cytokines, growth factors, reactive oxygen and nitrogen species (ROS/RNS), lipid peroxides and their products deriving from hepatocytes, Kupffer cells and other cells converge on HSC and influence their activation. This review focuses on glutathione and thioredoxin pathways, with particular emphasis on their role in HSC. These two systems have been shown to act in the metabolism of hydrogen peroxide, control of thiol redox balance and regulation of signalling pathways. Particular attention is paid to mitochondria and NADPH oxidase. Detailed knowledge of specific signalling, redox conditions and apoptotic processes will be of help in devising proper pharmacological treatments for liver fibrosis.

Natural taurine promotes apoptosis of human hepatic stellate cells in proteomics analysis

AIM: To study the differential expression of proteins between natural taurine treated hepatic stellate cells and controls, and investigate the underlying regulatory mechanism of natural taurine in inhibiting hepatic fibrosis.

METHODS: A proteomic strategy combining two-dimensional gel electrophoresis and ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) was used to study the differential expression of proteins and Western blotting was used to validate the results. Gene ontology (GO) method was utilized to analyze the functional enrichment of differentially expressed proteins. Flow cytometry was performed to compare the apoptosis rate between taurine-treated and untreated hepatic stellate cells (HSCs).

RESULTS: Nineteen differentially expressed proteins (11 up-regulated and 8 down-regulated) were identified by 2D/MS, and the expression profiles of GLO1 and ANXA1 were validated by Western blotting. GO analysis found that these differentially expressed proteins were enriched within biological processes such as “cellular apoptosis”, “oxidation reaction” and “metabolic process” in clusters. Flow cytometric analysis showed that taurine-treated HSCs had a significantly increased apoptosis rate when compared with the control group.

CONCLUSION: Natural taurine can promote HSC apoptosis so as to inhibit hepatic fibrosis.

Effects of dietary taurine supplementation on growth performance and immune status in growing Japanese quail (Coturnix coturnix japonica)

The effect of dietary taurine was investigated on performance and immune responses in growing (1 to 42 d) Japanese quail. One-day-old quails of both sexes (300) were randomly allotted to 12 groups with 25 quails in each group (3 dietary treatments, 4 replicates). They were fed with maize-soybean meal-based diets containing 0, 0.01, or 0.05% taurine for 42 d. Dietary 0.01% taurine decreased food intake (P < 0.05) in the starter phase but did not affect BW gain and feed efficiency from d 1 to 42 of age. In the starter phase, dietary 0.05% taurine did not affect food intake but increased weight gain and improved feed efficiency (P < 0.05). In the grower phase, dietary 0.05% taurine did not affect weight gain but improved feed efficiency and decreased food intake (P < 0.05). In the overall period, dietary 0.05% taurine improved feed efficiency and decreased food intake (P < 0.05). The relative weights of thymus were greater in the quails given 0.01% taurine in diet (P < 0.05). The relative weights of the bursa of Fabricius and thymus were greater in dietary 0.05% taurine compared with the control (P < 0.05).The quail serum anti-Newcastle disease virus hemagglutination antibody titer in the taurine-supplemented diet had no significant effects compared with the control (P > 0.05). The response to phytohemagglutinin measured as the foot web index was significantly increased by 0.05% taurine supplementation (P < 0.05). It is concluded that the taurine-supplemented diet has a beneficial effect on immune responses and performance in growing Japanese quail.

Superoxide anions and hydrogen peroxide inhibit proliferation of activated rat stellate cells and induce different modes of cell death

BACKGROUND

In chronic liver injury, hepatic stellate cells (HSCs) proliferate and produce excessive amounts of connective tissue causing liver fibrosis and cirrhosis. Oxidative stress has been implicated as a driving force of HSC activation and proliferation, although contradictory results have been described.

AIM

To determine the effects of oxidative stress on activated HSC proliferation, survival and signalling pathways.

METHODS

Serum-starved culture-activated rat HSCs were exposed to the superoxide anion donor menadione (5-25 micromol/L) or hydrogen peroxide (0.2-5 mmol/L). Haem oxygenase-1 mRNA expression, glutathione status, cell death, phosphorylation of mitogen-activated protein (MAP) kinases and proliferation were investigated.

RESULTS

Menadione induced apoptosis in a dose- and time-dependent, but caspase-independent manner. Hydrogen peroxide induced necrosis only at extremely high concentrations. Both menadione and hydrogen peroxide activated Jun N-terminal kinase (JNK) and p38. Hydrogen peroxide also activated extracellular signal-regulated protein. Menadione, but not hydrogen peroxide, reduced cellular glutathione levels. Inhibition of JNK or supplementation of glutathione reduced menadione-induced apoptosis. Non-toxic concentrations of menadione or hydrogen peroxide inhibited platelet-derived growth factor- or/and serum-induced proliferation.

CONCLUSION

Reactive oxygen species (ROS) inhibit HSC proliferation and promote HSC cell death in vitro. Different ROS induce different modes of cell death. Superoxide anion-induced HSC apoptosis is dependent on JNK activation and glutathione status.

Protective efficiacy of taurine against pulmonary edema progression: experimental study

Re-expansion pulmonary edema (RPE) is an acute, rare and potentially lethal complication [1,2]. Its beginning is sudden and dramatic. The mechanism is not yet fully understood [1]. Some authors suggest that it may occur after rapid re-inflation of a collapsed lung [1]. It was reported by other authors that it may relate to surfactant depletion or may result from hypoxic capillary damage, leading to increased capillary permeability [1,3]. In RPE, unilateral lung injury is initiated by cytotoxic oxygen metabolites and temporally associated with an influx of polymorphonuclear neutrophils [1]. These toxic oxygen products are the results of re-oxygenation of a collapsed lung. Treatment of re-expansion pulmonary edema is basically preventive [4].

Taurine reduces the secretion of apolipoprotein B100 and lipids in HepG2 cells

Background

Higher concentrations of serum lipids and apolipoprotein B100 (apoB) are major individual risk factors of atherosclerosis and coronary heart disease. Therefore ameliorative effects of food components against the diseases are being paid attention in the affluent countries. The present study was undertaken to investigate the effect of taurine on apoB secretion and lipid metabolism in human liver model HepG2 cells.

Results

The results demonstrated that an addition of taurine to the culture media reduces triacylglycerol (TG)-mass in the cells and the medium. Similarly, cellular cholesterol-mass was decreased. Taurine inhibited the incorporation of [¹⁴C] oleate into cellular and medium TG, suggesting the inhibition of TG synthesis. In addition, taurine reduced the synthesis of cellular cholesterol ester and its secretion, suggesting the inhibition of acyl-coenzyme A:cholesterol acyltransferase activity. Furthermore, taurine reduced the secretion of apoB, which is a major protein component of very low-density lipoprotein.

Conclusion

This is a first report to demonstrate that taurine inhibits the secretion of apoB from HepG2 cells.

The protective and antidotal effects of taurine on hexavalent chromium-induced oxidative stress in mice liver tissue

Acute exposure to hexavalent chromium [Cr(VI)] compounds can cause hepatotoxicity. Reactive intermediates and free radicals generated during reduction process may be responsible for Cr(VI) toxicity. In this study, the effects of pretreatment or posttreatment of taurine on Cr(VI)-induced oxidative stress and chromium accumulation in liver tissue of Swiss Albino mice were investigated. Single intraperitoneal (ip) potassium dichromate treatment (20 mgCr/kg), as Cr(VI) compound, significantly elevated the level of lipid peroxidation as compared with control group (p < 0.05). This was accompanied by significant decreases in nonprotein sulfhydryls (NPSHs) level, superoxide dismutase (SOD), and catalase (CAT) enzyme activities as well as a significant chromium accumulation in the tissue (p < 0.05). Taurine administration (1 g/kg, ip) before or after Cr(VI) exposure resulted in reduction of lipid peroxidation (p < 0.05) showed rebalancing effect on tissue NPSH levels either in pretreatment or in posttreatment (p < 0.05). Enzyme activities of SOD and CAT were restored by taurine pretreatment (p < 0.05), whereas posttreatment had less pronounced effects on these parameters. On the other hand, taurine treatment, before or after exposure, could exert only slight decreases in tissue Cr levels (p > 0.05). In view of the results, taurine seems to exert some beneficial effects against Cr(VI)-induced oxidative stress in liver tissue.

Inhibition of hepatic stellate cell activation following Yinchenhao decoction administration to dimethylnitrosamine-treated rats

AIM

In an effort to investigate the mechanism by which Yinchenhao decoction (YCHD) acts on liver injury, we investigated the potential antifibrogenic effects of YCHD in an experimental liver fibrosis rat model, with special focus on the mechanisms inhibiting the activation and promoting apoptosis of hepatic stellate cells (HSC).

METHODS

The rats were initially randomized into two groups: the control (n = 10) and dimethylnitrosamine-treated (DMN; n = 30) groups. DMN (10 mg/kg body weight) was administered intraperitoneally to the DMN-treated rats for three consecutive days each week. At the end of the second week, three rats from the control and six rats from the DMN-treated groups were killed for the fibrosis development assessment. The remaining DMN rats were further randomized into two groups: the DMN-water group (n = 12) and the DMN-YCHD group (n = 12). Both groups continued to receive weekly DMN treatment for another 2 weeks in addition to daily administration of either water or YCHD, which were given intragastrically at a dose of 0.418 g/100 g body weight.

RESULTS

Hepatic hydroxyproline content decreased and had improved histopathology in the DMN-YCHD rats. Compared to the DMN group, alpha-smooth muscle actin (SMA) and CD68 expression in the DMN-YCHD group was reduced significantly; however, alpha-SMA-positive HSC apoptosis was not observed by confocal microscopy; Fibrogenic proteins (tissue inhibitor matrix proteinases-1 and 2 and matrix metalloproteinase [MMP]-2/14) and cytokines (tumor necrosis factor-alpha and transforming growth factor-beta(1)) were decreased; MMP-9 was significantly upregulated.

CONCLUSION

Yinchenhao administration attenuates liver fibrosis at least in part by inhibiting HSC activation directly, rather than promoting cell apoptosis of activated HSC, and the suppressive activation of Kupffer cells.

Ultrastructural changes in hepatocytes after taurine treatment in CCl4 induced liver injury

AIM: To search the organelle based changes in hepatocytes after taurine treatment in experimental liver fibrosis induced by CCl₄ administration.

METHODS: Thirty rats were divided into two groups. Group 1 (n = 15) was injected with CCl₄ plus taurine and Group 2 (n = 15) with CCl₄ plus saline for 12 wk. At the end of 12th wk, mitochondria, rough and smooth endoplasmic reticulum, and nuclei of hepatocytes were evaluated using a scoring system. The results were compared with histopathological findings, as well.

RESULTS: Taurine treatment reduced fibrosis scores significantly as compared to placebo. Organelle injury scores decreased significantly with taurine treatment. Ultrastructural and histopathological scores in both groups were in strong correlation (r = 0.931 for CCl₄ plus taurine and r = 0.899 for CCl₄ plus saline group).

CONCLUSION: Organelle based transmission electron microscopy findings can reflect successfully histological results as well as tissue healing in hepatocytes from hepatotoxin-induced liver fibrosis.

Pegylated interferon-alpha plus taurine in treatment of rat liver fibrosis

AIM: To investigate the antifibrotic effects of peginterferon-alpha 2b and taurine on oxidative stress markers and hepatocellular apoptosis.

METHODS: Sixty rats with CCl4-induced liver fibrosis were divided into 4 groups (n = 15). Group 1 was left for spontaneous recovery (SR). Groups 2-4 received peginterferon-alpha 2b, taurine, and their combination, respectively, for four weeks. Histological fibrosis scores, histomorphometric analysis, tissue hydroxyproline, tissue MDA, GPx and SOD activities were determined. Activated stellate cells and hepatocellular apoptosis were also evaluated.

RESULTS: The degree of fibrosis decreased in all treatment groups compared to spontaneous recovery group. Taurine alone and in combination with peginterferon-alpha 2b reduced oxidative stress markers, but peginterferon-alpha 2b alone did not. Apoptotic hepatocytes and activated stellate cells were higher in groups 2-4 than in group 1. Combined taurine and peginterferon-alpha 2b further reduced fibrosis and increased activated stellate cell apoptosis, but could not improve oxidative stress more than taurine alone.

CONCLUSION: Peginterferon-alpha 2b exerts anti-fibrotic effects on rat liver fibrosis. It seems ineffective against oxidative stress in vivo. Peginterferon-alpha 2b in combination with taurine seems to be an antifibrotic strategy.

Expression of MMPs and TIMPs in liver fibrosis - a systematic review with special emphasis on anti-fibrotic strategies

In liver tissue matrix metalloproteinases (MMPs) and their specific inhibitors (tissue inhibitors of metalloproteinases, TIMPs) play a pivotal role in both, fibrogenesis and fibrolysis. The current knowledge of the pathophysiology of liver fibrogenesis with special emphasis on MMPs and TIMPs is presented. A systematic literature search was conducted. All experimental models of liver fibrosis that evaluated a defined anti-fibrotic intervention in vivo or in vitro considering MMPs and TIMPs were selected. The methodological quality of all these publications has been critically appraised using an objective scoring system and the content has been summarized in a table.

Partial portal vein ligation plus thioacetamide: a method to obtain a new model of cirrhosis and chronic portal hypertension in the rat

To obtain a new model of chronic portal hypertension in the rat, two classical methods to produce portal hypertension, partial portal vein ligation and the oral administration of thioacetamide (TAA), have been combined. Male Wistar rats were divided into four groups: 1 (control; n = 10), 2 [triple partial portal vein ligation (TPVL); n = 9], 3 (TAA; n = 11), and 4 (TPVL plus TAA; n = 9). After 3 months, portal pressure, types of portosystemic collateral circulation, laboratory hepatic function tests (aspartate aminotransferase, alanine aminotransferase, bilirubin, alkaline phosphatase, and gamma-glutamyl transpeptidase) and liver histology were studied. The animals belonging to group 2 (TPVL) developed extrahepatic portosystemic collateral circulation, associated with mesenteric venous vasculopathy without hepatic destructurization or portal hypertension. Animals from group 3 (TAA) developed cirrhosis and portal hypertension but not extrahepatic portosystemic collateral circulation, or mesenteric venous vasculopathy. Finally, the animals from group 4 (TPVL + TAA) developed cirrhosis, portal hypertension, portosystemic collateral circulation, and mesenteric venous vasculopathy. The association of TPVL and TAA can be used to obtain a model of chronic portal hypertension in the rat that includes all the alterations that patients with hepatic cirrhosis usually have. This could, therefore, prove to be a useful tool to study the pathophysiological mechanisms involved in these alterations.

The restorative effect of taurine on experimental nonalcoholic steatohepatitis

Our objective was to explore the restorative effect of taurine on experimental nonalcoholic steatohepatitis (NASH). Thirty-six SD rats were randomly divided into three groups, 12 in each group: the normal group was fed standard rat diet; the model group and the treatment group were both fed a high-fat rat diet for 12 weeks, and the rats in the treatment group were simultaneously injected with taurine subcutaneously for 8 weeks. Hepatic histological change was observed; TNF-alpha and TGF-beta(1) protein expression was identified by immunohistochemistry; mRNA expression of TNF-alpha, TGF-beta(1), type I procollagen, and adiponectin was measured by RT-PCR; body weight, weight gain, liver weight, and liver index were measured; and biochemical parameters monitored included serum transaminases, serum lipids, fasting plasma glucose, and hepatic level of oxidative stress. Rats in the model group showed a significant increase in liver weight, liver index, serum transaminase activities, serum triglyceride, fasting plasma glucose, and oxidative stress; the mRNA expression of TNF-alpha, TGF-beta(1), and type I procollagen increased, whereas the expression of adiponectin decreased significantly, compared with that in the normal group. The typical hepatic lesions of NASH were observed histologically in the model group. Taurine treatment resulted in a significant decrease in liver weight, liver index, serum transaminase activities, serum triglyceride, fasting plasma glucose, and oxidative stress; the mRNA expression of TNF-alpha, TGF-beta(1), and type I procollagen decreased, but the expression of adiponectin increased significantly, compared with that in the model group. Histological improvement was observed in the treatment group. In conclusion, taurine could inhibit lipid peroxidation, improve lipid and glucose metabolism, decrease synthesis of TNF-alpha and TGF-beta(1), promote synthesis of adiponectin, and have a restorative effect on experimental NASH.

Thalidomide prevents rat liver cirrhosis via inhibition of oxidative stress

This study investigated the effect of thalidomide on oxidative stress in rat liver cirrhosis. The cirrhosis of rat was induced by intraperitoneal injection of carbon tetrachloride thrice weekly; meanwhile, thalidomide (10mg/kg or 100mg/kg) was given daily by intragastric administration for 8 weeks. The content of oxidative stress parameters, including superoxide dismutase, glutathione peroxidase, and malondialdehyde, in the liver was detected by biochemical assay. Immunohistochemistry revealed alpha-smooth muscle actin (alpha-SMA), desmin, and tissue inhibitor of metalloproteinase-1 (TIMP-1) protein in the liver. Nuclear factor kappa B p65 (NF-kappaBp65) protein in nucleus and transforming growth factor beta1 (TGF-beta1) protein in cytoplasm were detected by Western blot. NF-kappaBp65, TGF-beta1, and TIMP-1 mRNA levels in the liver were studied using reverse transcriptase polymerase chain reaction. Liver histopathology was significantly improved in rats given high doses of thalidomide. The content of oxidative stress parameters and the expressions of NF-kappaBp65, TGF-beta1 and TIMP-1 protein, and mRNA were significantly decreased in these animals. The expressions of alpha-SMA and Desmin protein were also significantly decreased in them. Thalidomide might exert an effect on the inhibition of oxidative stress via downregulation of NF-kappaB signaling pathway to prevent the progression of liver cirrhosis.

Antioxidant treatment with taurine ameliorates chronic pancreatitis in an experimental rat model

OBJECTIVES

Based on the results of recent studies that reported depleted antioxidant capacity in patients with chronic pancreatitis (CP), prevention of free radical production has gained importance in antifibrotic treatment strategies in CP. The aim of this study was to investigate the effects of taurine on oxidative capacity and fibrosis in experimental chronic rat pancreatic fibrosis.

METHODS

CP was induced in male Sprague-Dawley rats by intraductal trinitrobenzene sulfonic acid (TNBS) dissolved in ethanol. Taurine was given intraperitoneally at a concentration of 1000 mg/kg. The treatment groups were as follows: group 1, TNBS plus normal saline (NS); group 2, TNBS plus taurine; group 3, ethanol plus NS; and group 4, NS plus NS. Each group contained 15 animals. Treatment was started after established CP. After 4 weeks of treatment, markers of oxidative stress and the degree of pancreatic fibrosis were determined.

RESULTS

The amount of weight loss was significantly lower in the taurine-treated group with CP (P < 0.002). Tissue malondialdehyde levels increased and superoxide dismutase and glutathione peroxidase activities decreased significantly after treatment as well (P < 0.001). Histopathologic scores were also lower in taurine-treated animals with CP (P < 0.005).

CONCLUSIONS

Taurine treatment improved the degree of oxidative stress and fibrosis in rat CP. Antioxidant treatment might be considered a novel option to alleviate the fibrotic process in CP.

Effect of Astragalus complanatus flavonoid on anti-liver fibrosis in rats

AIM: To observe the anti-liver fibrosis effect of Astragalus complanatus flavonoids (ACF) in rats.

METHODS: The liver fibrosis model in rats was established by injecting interperitoneally 0.2 mL/100 g 0.5% dimethylnitrosamine, thrice a week. Meanwhile, the rats were administered ACF (30, 60, 120 mg/kg) or colchicine (0.1 mg/kg) once a day for 1 mo. Serum N-propeptide of type I procollagen (PINP) and type III procollagen (PIIINP) was measured using ELISA. Malondialdehyde (MDA) and superoxide dismutase (SOD) in hepatic tissue were evaluated. Matrix metal protease-1 (MMP-1) mRNA expression was assayed by RT-PCR and the protein expression of tissue inhibitor of metal protease-1 (TIMP-1) was analyzed by immunohistochemistry.

RESULTS: In the ACF groups, SOD activity increased and MDA content decreased in comparison to the liver fibrosis model group. The serum PINP and PIIINP contents in ACF-2 and -3 group decreased compared to those in model group. In ACF-2 and -3 group, the expression of MMP-1 mRNA increased significantly and the protein expression of TIMP-1 decreased compared to that in model group.

CONCLUSION: The antifibrotic mechanisms of ACF are associated with its influence on lipid peroxidation and collagen synthesis and degradation.

Therapeutic role of ethanolic extract of Boschniakia Rossica in dimethylnitrosamine-induced liver fibrosis in rats

AIM: To study the effect of Boschniakia Rossica ethanolic extract (BREE) in rat liver fibrosis induced by dimethylnitrosamine (DMN).

METHODS: Hepatic fibrosis was induced by DMN administration intraperitoneally. Thirty-five male Wistar rats were randomly divided into three groups: normal control group (GA, n = 10), hepatic fibrosis model group (GB, n = 15) and BREE treatment group (GC, n = 10). From the 1st to 3rd wk, rats in GB and GC were treated with DMN (10 g/L) intraperitoneally in the first three days of each week, while rats in GA were treated with normal saline. From the 4th to 7th wk, rats in GC were treated with 50 g/L BREE (10 mL/kg) intragastrically each day, while rats in GA and GB were treated with normal saline. At the 1st d of the 8th wk, all the rats were sacrificed and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), the contents of malondialdehyde (MDA), hyaluronic acid (HA), type Ⅲ procollagen (PC Ⅲ), type Ⅳ collagen (Ⅳ.C) in serum were examined. The expression of alpha smooth muscle actin (α-SMA) in liver was also analyzed.

RESULTS: The activity of SOD (98.58±17.36 kNU/L, 9.99±1.69 kNU/L) and GSH-PX (117.37±45.24 U, 12.43±2.99 U) in serum and liver tissue in GB was significantly lower than those in GA (SOD: 129.05±18.55 kNU/L, 19.94±5.87 kNU/L; GSH-PX: 173.79±25.76 U, 22.66±6.99 U)(P < 0.01), while the contents of MDA in GB (10.87±1.23 μmol/L, 1.38±0.37 μmol/L) were higher than those in GA (6.63±1.05 μmol/L, 0.91±0.25 μmol/L)(P < 0.01). The concentrations of serum HA (394.83±103.28 μg/L), PC Ⅲ (13.30±1.88 mg/L) and Ⅳ.C (2.43±1.32 mg/L) in GB were markedly higher than those in GA (186.54±39.87 μg/L, 6.99±1.55 mg/L, 1.18±0.79 mg/L, P < 0.01). The concentrations of serum HA (115.87±13.96 μg/L), PC Ⅲ (6.67±1.86 mg/L) and Ⅳ.C (1.62±0.50 mg/L) in GC were significantly lower than those in GB (P < 0.05), while the activity of SOD (134.29±21.93 kNU/L, 18.99±6.86 kNU/L) and GSH-PX (171.82±37.50 U, 23.57±7.19 U) in serum and liver tissue increased significantly (P < 0.01). The contents of MDA in serum and tissue in GC (8.68±2.32 μmol/L, 0.97±0.22 μmol/L) was lower than those in GB (10.87±1.23, 1.38±0.37 μmol/L)(P < 0.01). The fibrosis index and α-SMA expression in liver decreased in GC too.

CONCLUSION: BREE plays an anti-fibrogenic role in the DMN-induced liver fibrosis of rat by its anti-oxidative effect and inhibition on hepatic stellate cells activation.

Resistance of Erythrocytes to Lipid Peroxidation in Cirrhotic Rats

BACKGROUND

The aim of the present study was to investigate erythrocyte prooxidant-antioxidant balance in relation to liver and plasma lipid peroxidation in thioacetamide (TAA)-induced liver cirrhosis in rats.

METHODS

Liver cirrhosis was produced by the administration of TAA (0.3 g/L of tap water) for a period of 3 months in rats. Serum, liver and erythrocyte lipid peroxide levels as well as liver glutathione (GSH) levels and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were determined in cirrhotic rats.

RESULTS

Hepatic cirrhosis was assessed by biochemical and histopathological findings. Serum alanine transaminase (ALT) and aspartate transaminase (AST) activities and malondialdehyde (MDA) levels increased in cirrhotic rats. This treatment caused increased MDA and diene conjugate (DC) levels as well as decreased GSH levels and GSH-Px activities in the liver of cirrhotic rats. In these conditions, no significant changes in erythrocyte cholesterol, phospholipid levels as well as endogenous DC, and GSH levels and spontaneous hemolysis values were observed in erythrocytes of rats with TAA-induced liver cirrhosis. However, H(2)O(2)-induced MDA levels were detected to decrease significantly in erythrocytes of cirrhotic rats.

CONCLUSIONS

Our results indicate that erythrocytes of TAA-induced cirrhotic rats have a resistance against peroxidative stress in contrast to the findings in plasma and liver.

Taurine inhibits oxidative damage and prevents fibrosis in carbon tetrachloride-induced hepatic fibrosis

BACKGROUND/AIMS

The aim of the study was to examine the effects of taurine on hepatic fibrogenesis and in isolated hepatic stellate cells (HSC).

METHODS

The rats of the hepatic damage (HD) group were administered carbon tetracholoride (CCl4) for 5 weeks and a subgroup received, in addition, a 2% taurine containing diet for 6 weeks (HDT). The HSC were isolated from normal rats and cultured for 4 days.

RESULTS

The hepatic taurine concentration was decreased in the HD group. This loss and the hepatic histological damage and fibrosis (particularly in the pericentral region), were reduced following taurine treatment. Furthermore, the hepatic alpha-SMA, lipid hydroperoxide and 8-OHdG levels in serum and liver, as well as hepatic TGF-beta1 mRNA and hydroxyproline levels were significantly increased in the HD group, and most of these parameters were significantly reduced following taurine treatment. In contrast to the MAP-kinase and Akt expressions, which remained unchanged, the lipid hydroperoxide and hydroxyproline concentrations, as well as TGF-beta1 mRNA levels were significantly reduced by taurine in activated HSC.

CONCLUSIONS

Oral taurine administration enhances hepatic taurine accumulation, reduces oxidative stress and prevents progression of hepatic fibrosis in CCl4-induced HD rats, as well as inhibits transformation of the HSC.

Liver fibrosis caused by choledocholith to regress after biliary drainage

AIM: To study the correlation between liver fibrosis severity and biliary drainage in patients with choledocholith.

METHODS: A follow-up study on seven patients with liver fibrosis due to choledocholith was made. The data, including biochemical tests (aspartate aminotransferase, alanine aminotransferase) and liver histological features before and after biliary drainage, were collected and studied. The fibrosis severity was scored on a scale from 0 to 3, with 0 denoting none, 1 portal and periportal fibrosis, 2 the presence of numerous fiber septa, and 3 cirrhosis. The average liver fibrosis severity scores of the first and second biopsy were compared with statistical method.

RESULTS: The first, second liver fibrosis severity scores of these seven patients were 2,1; 2,1; 1,0; 1,1; 2,1; 2,1; 1,0 respectively. The results showed that the average liver fibrosis severity score of the second liver biopsy decreased significantly compared with the first liver biopsy (n = 7, t = 4.25, P<0.05).

CONCLUSION: Liver fibrosis due to choledocholith may regress after biliary drainage.

Protective effect of Radix Acanthopanacis Senticosi capsule on colon of rat depression model

AIM: To investigate the abnormity of rat colon caused by depression and the ameliorative effects of Radix Acanthopanacis Senticosi (RAS) capsule on colon and their mechanisms in rat depression model.

METHODS: Chronic stress-induced model of depression of Wistar rats was produced. The experimental animals were randomly divided into model control, 5-aminosalicylic acid (5-ASA) therapy group and three RAS capsule therapy groups. These five groups were intracolonically treated daily (8:00 a.m.) for 2 wk with normal saline, 5-ASA (100 mg/kg) and RAS capsule at the doses of 300, 600 and 900 mg/kg, respectively. A normal control group of rats was also included in the study. Colonic activities of nitric oxide (NO) and superoxide dismutase (SOD), levels of malondialdehyde (MDA) and inducible nitric oxide synthase (iNOS) were determined by ultraviolet spectrophotometry. The expression of cyclooxygenase-2 (COX-2) in colonic tissue was detected by immunohistochemistry.

RESULTS: Enhanced colon inflammatory response and oxidative stress were observed in the chronic stress-induced rat depression model, which manifested as the significant increase of MDA, iNOS and NO levels, as well as the expressions of COX-2 in the colon tissue, but the colonic SOD activity was significantly decreased compared with the normal control (MDA: 10.34±2.77 vs 2.55±0.70; iNOS: 1.11±0.44 vs 0.25±0.16; COX-2: 53.26±8.16 vs 4.87±1.65; NO: 11.28±5.66 vs 4.76±1.55; SOD: 53.39±11.15 vs 84.45±22.31; P<0.01). However, these parameters were significantly ameliorated in rats treated locally with RAS capsule at the doses of 300, 600 and 900 mg/kg (iNOS: 0.65±0.31, 0.58±0.22 and 0.64±0.33; NO: 5.99±2.73, 6.87±1.96 and 6.50±1.58; MDA: 2.92±0.75, 3.19±1.08 and 3.26±1.24; SOD: 70.81±12.36, 73.30±15.30 and 69.09±11.03, respectively). The expressions of COX-2 in the colon were significantly ameliorated (28.83±9.48 and 27.04±9.56, respectively) when RAS capsule was administered at the doses of 600 and 900 mg/kg.

CONCLUSION: Administration of RAS capsule intracolonically may have significant therapeutic effects on the colon of rat depression model, which are probably due to its antioxidative action and inhibition of arachidonic acid metabolism.