Taurine enhances the metabolism and detoxification of ethanol and prevents hepatic fibrosis in rats treated with iron and alcohol

The Protective Effects of Taurine, a Non-essential Amino Acid, Against Metals Toxicities: A Review Article

Taurine is a non-proteinogenic amino acid derived from cysteine. It is involved in several phenomena such as the regulation of growth and differentiation, osmoregulation, neurohormonal modulation, and lipid metabolism. Taurine is important because of its high levels in several tissues such as the central nervous system (CNS), heart, skeletal muscles, retinal membranes, and platelets. In this report, we present the functional properties of taurine indicating that it has potential effects on various metal toxicities. Therefore, a comprehensive literature review was performed using the Scopus, PubMed, and Web of Science databases. According to the search keywords, 61 articles were included in the study. The results indicate that taurine protects tissues against metal toxicity through enhancement of enzymatic and non-enzymatic antioxidant capacity, modulation of oxidative stress, anti-inflammatory and anti-apoptotic effects, involvement in different molecular pathways, and interference with the activity of various enzymes. Taken together, taurine is a natural supplement that presents antitoxic effects against many types of compounds, especially metals, suggesting public consumption of this amino acid as a prophylactic agent against the incidence of metal toxicity.

Methyl donor ameliorates CCl4-induced liver fibrosis by inhibiting inflammation, and fibrosis through the downregulation of EGFR and DNMT-1 expression

Methyl donors regulate the one-carbon metabolism and have significant potential to reduce oxidative stress and inflammation. Therefore, this study aims to investigate the protective effect of methyl donors against CCl4-induced liver fibrosis. Liver fibrosis was induced in male Sprague Dawley rats using CCl4 at a dose of 1 ml/kg (twice a week for a 4-week, via intraperitoneal route). Subsequently, methyl donor treatments were given orally for the next six weeks while continuing CCl4 administration. After 10 weeks, biochemical, histopathology, immunohistochemistry, western blotting, and qRT-PCR were performed. Methyl donor treatment significantly ameliorated ALT, AST, ALP levels, and oxidative stress associated with CCl4-induced liver injury. The histopathological investigation also demonstrated the hepatoprotective effect of methyl donors against CCl4-induced liver fibrosis, showing reduced tissue damage, collagen deposition, and attenuating the expression of the COL1A1 gene. Further, methyl donors inhibited the CCl4-induced increase in DNMT-1 and NF-κB p65 expression with an upregulation of AMPK. Methyl donor downregulated the CCl4-induced increase in inflammatory and fibrosis related gene expression and inhibited the apoptosis with a downregulation of EGFR expression. Here, we provide the first evidence that methyl donor combinations prevent liver fibrosis by attenuating oxidative stress, inflammation, and fibrosis through DNMT-1 and EGFR downregulation.

Down-regulation of miR-29 improves lipid metabolism in fatty liver of dairy cows

In this study, we conducted a thorough investigation into the mechanisms by which miR-29 influences lipid metabolism. Thirty-two cows were selected and categorized into distinct groups based on their liver triglyceride (TG) content: healthy, mild fatty liver, and moderate fatty liver groups. Dairy cows with moderate fatty liver showed higher levels of hepatic lipid accumulation, MDA content and serum AST, ALT and ALP contents and lower hepatic catalase CAT and SOD activities. Subsequently, hepatocytes isolated from healthy calves were exposed to sodium oleate (SO) in the presence or absence of pre-incubation with miR-29 inhibitor or inhibitor NC. Pre-transfection with miR-29 inhibitor resulted in reduced hepatocyte lipid accumulation and MDA levels, as well as decreased levels of AST, ALT, and ALP in the supernatant. In the miR-29 inhibitor + SO group, there was an increase in the expression of SREBP-1, FAS, SCD1, and Sirt1. Meanwhile, the expression of PPARα, CPT1, CPT2, PGC-1α, NRF-1, UCP2, and miR-29 were observed to be decreased. In comparison to the miR-29 inhibitor + SO group, some of the measured indicators showed partial reversal in the miR-29 inhibitor + siSirt1 + SO group. Collectively, these findings provide evidence that miR-29 may play a crucial role in the pathogenesis of fatty liver in dairy cows.

Uridine alleviates carbon tetrachloride-induced liver fibrosis by regulating the activity of liver-related cells

At present, liver fibrosis is a major challenge of global health. When hepatocyte regeneration cannot compensate for hepatocyte death, it will develop into liver fibrosis in chronic liver disease. Initially, collagen produced by myofibroblasts plays a role in maintaining liver integrity, but excessive collagen accumulation can inhibit the residual liver function, leading to liver failure. At present, many scientists are actively looking for drugs to alleviate liver fibrosis. In the current study, we investigated the potential role of uridine in the treatment of liver fibrosis (uridine is a plant/animal‐derived pyrimidine nucleoside, therefore uridine can also be ingested and absorbed by the body, accompanied by the process of food intake). For this, we systematically studied the effect of uridine on CCl4‐induced liver fibrosis in vitro and in vivo through a series of technologies, such as Western blot, laser confocal scanning microscope, ELISA and immunohistochemistry. The experimental results showed that uridine can effectively reduce the accumulation of collagen in liver. Furthermore, uridine can improve the activity of liver cells and alleviate CCl4‐induced liver injury. Furthermore, uridine can significantly alleviate the risk factors caused by hepatic stellate cell activation, uridine treatment significantly down‐regulated the expression of α‐SMA, collagen type‐I and fibronectin. In conclusion, the current research shows that uridine can alleviate CCl4‐induced liver fibrosis, suggesting that uridine can be used as a potential drug to alleviate liver fibrosis.

Taurine as a Natural Antioxidant: From Direct Antioxidant Effects to Protective Action in Various Toxicological Models

Natural antioxidants have received tremendous attention over the last 3 decades. At the same time, the attitude to free radicals is slowly changing, and their signalling role in adaptation to stress has recently received a lot of attention. Among many different antioxidants in the body, taurine (Tau), a sulphur-containing non-proteinogenic β-amino acid, is shown to have a special place as an important natural modulator of the antioxidant defence networks. Indeed, Tau is synthesised in most mammals and birds, and the Tau requirement is met by both synthesis and food/feed supply. From the analysis of recent data, it could be concluded that the direct antioxidant effect of Tau due to scavenging free radicals is limited and could be expected only in a few mammalian/avian tissues (e.g., heart and eye) with comparatively high (>15-20 mM) Tau concentrations. The stabilising effects of Tau on mitochondria, a prime site of free radical formation, are characterised and deserve more attention. Tau deficiency has been shown to compromise the electron transport chain in mitochondria and significantly increase free radical production. It seems likely that by maintaining the optimal Tau status of mitochondria, it is possible to control free radical production. Tau's antioxidant protective action is of great importance in various stress conditions in human life, and is related to commercial animal and poultry production. In various in vitro and in vivo toxicological models, Tau showed AO protective effects. The membrane-stabilizing effects, inhibiting effects on ROS-producing enzymes, as well as the indirect AO effects of Tau via redox balance maintenance associated with the modulation of various transcription factors (e.g., Nrf2 and NF-κB) and vitagenes could also contribute to its protective action in stress conditions, and thus deserve more attention.

Taurine ameliorates thioacetamide induced liver fibrosis in rats via modulation of toll like receptor 4/nuclear factor kappa B signaling pathway

Liver fibrosis is a significant health problem that can cause serious illness and death. Unfortunately, a standard treatment for liver fibrosis has not been approved yet due to its complicated pathogenesis. The current study aimed at assessing the anti-fibrotic effect of taurine against thioacetamide induced liver fibrosis in rats through the modulation of toll like receptor 4/nuclear factor kappa B signaling pathway. Both concomitant and late taurine treatment (100 mg/kg, IP, daily) significantly reduced the rise in serum ALT and AST activities and significantly reversed the decrease in serum albumin and total protein. These results were confirmed by histopathological examinations and immunehistochemical inspection of α-SMA, caspase-3 and NF-κB. The antioxidant potential of taurine was verified by a marked increase of GSH content and a reduction of MDA level in liver tissue. The anti-fibrotic effects of taurine were evaluated by investigating the expression of TLR4, NF-κB. The protein levels of IL-6, LPS, MyD88, MD2, CD14, TGF-β1 and TNF-α were determined. Docking studies were carried out to understand how taurine interacts inside TLR4-MD2 complex and it showed good binding with the hydrophobic binding site of MD2. We concluded that the anti-fibrotic effect of taurine was attributable to the modulation of the TLR4/NF-κB signaling.

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.

Therapeutic potential of a novel combination of Curcumin with Sulfamethoxazole against carbon tetrachloride-induced acute liver injury in Swiss albino mice

BACKGROUND

In the current study, we have investigated the effect of each of curcumin (CUR) and sulfamethoxazole (SMX) either separate or mixed together (CUR + SMX) on biochemical, hematological and histological alternations associated with carbon tetrachloride (CCl₄)-induced liver fibrosis in mice.

RESULTS

CCl_4, caused changes of several biomarkers, proving its hepatotoxic effects, such as an increase in aminotransferases liver enzymes alanine and aspartate transaminases (ALT, AST), malondialdehyde (MDA), and nitric oxide (NO) formation, with a decrease in superoxide dismutase (SOD), glutathione reductase (GSSG), total antioxidant capacity (TAO), glutathione (GSH), total protein, and albumin, compared to a negative control mice group. Compared to the CCl₄ group of mice, the CUR and SMX separate and/or together (CUR + SMX) treatments showed significance in (p < 0.001), ameliorated liver injury (characterized by an elevation of (ALT, AST) and a decrease (p < 0.001) in serum albumin and total protein), antioxidant (characterized by a decrease in (p < 0.001) MDA, NO; an increase (p < 0.001) SOD, GSSG, TAO; and reducing GSH), hematological changes (characterized by a decrease (p < 0.001) in white blood cells count and an increase (p < 0.001) in platelets count, hematocrit levels, hemoglobin concentration, and (p < 0.05) red blood cells count), SDS-PAGE electrophoresis with a decrease in protein synthesis and changes in histological examinations.

CONCLUSIONS

CUR and SMX either separate or together (SUR + SMX) may be considered promising candidates in the prevention and treatment of liver fibrosis.

Therapeutic potential of a novel combination of Curcumin with Sulfamethoxazole against carbon tetrachloride-induced acute liver injury in Swiss albino mice

BACKGROUND

In the current study, we have investigated the effect of each of curcumin (CUR) and sulfamethoxazole (SMX) either separate or mixed together (CUR + SMX) on biochemical, hematological and histological alternations associated with carbon tetrachloride (CCl₄)-induced liver fibrosis in mice.

RESULTS

CCl_4, caused changes of several biomarkers, proving its hepatotoxic effects, such as an increase in aminotransferases liver enzymes alanine and aspartate transaminases (ALT, AST), malondialdehyde (MDA), and nitric oxide (NO) formation, with a decrease in superoxide dismutase (SOD), glutathione reductase (GSSG), total antioxidant capacity (TAO), glutathione (GSH), total protein, and albumin, compared to a negative control mice group. Compared to the CCl₄ group of mice, the CUR and SMX separate and/or together (CUR + SMX) treatments showed significance in (p < 0.001), ameliorated liver injury (characterized by an elevation of (ALT, AST) and a decrease (p < 0.001) in serum albumin and total protein), antioxidant (characterized by a decrease in (p < 0.001) MDA, NO; an increase (p < 0.001) SOD, GSSG, TAO; and reducing GSH), hematological changes (characterized by a decrease (p < 0.001) in white blood cells count and an increase (p < 0.001) in platelets count, hematocrit levels, hemoglobin concentration, and (p < 0.05) red blood cells count), SDS-PAGE electrophoresis with a decrease in protein synthesis and changes in histological examinations.

CONCLUSIONS

CUR and SMX either separate or together (SUR + SMX) may be considered promising candidates in the prevention and treatment of liver fibrosis.

Protective Effect of Glycyrrhizic Acid on Alcoholic Liver Injury in Rats by Modulating Lipid Metabolism

Glycyrrhhizic acid (GA), including 18α-glycyrrhizic acid (18α-GA) and 18β-glycyrrhizic acid (18β-GA), is the main active ingredient of licorice. GA is generally considered an effective pharmacological strategy protecting against hepatic disease; however, the optimal compatibility proportion of 18α-GA and 18β-GA against alcoholic liver disease (ALD) and the underlying mechanism are not well established. Hence, this study was designed to explore the optimal compatibility proportion of 18α-GA and 18β-GA against ALD, followed by investigating the underlying mechanisms. SD rats were administered 40% ethanol once a day, accompanied by treatment with different proportions of 18α-GA and 18β-GA for four weeks. Then all rats were anesthetized with chloral hydrate and blood samples were taken from the abdominal aorta for biochemical assay. Livers were also collected and the liver function, lipid profile, ROS production, and mRNA and protein levels of related genes involved in lipid metabolism were assessed. The results showed that 18α-GA and 18β-GA, particularly at a proportion of 4:6, significantly reduced liver damage, lipid accumulation, and oxidative stress in ethanol-induced rats, as indicated by the decreased levels of alanine aminotransferase (ALT) and aminotransferase (AST) in serum, improvement of liver histopathological changes, regulation of total cholesterol (TC), total triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), and modulation of superoxide dismutase (SOD), glutathione (GSH), and malonaldehyde (MDA). Moreover, the combination treatment with 18α-GA and 18β-GA substantially reduced the mRNA and protein levels of sterol regulatory element-binding protein-1c (SREBP-1c) and acetyl-coal carboxylase (ACC); meanwhile, increased levels of peroxisome proliferators activated receptor-α (PPAR-α) and carnitine palmitoy transferase-1 (CTP-1) in the liver tissues of ethanol-induced rats. In conclusion, our results indicated that the optimal compatibility proportion of 18α-GA and 18β-GA protecting against ALD was 4:6, and the mechanism was associated with the regulation of oxidative stress and lipid metabolism.

Preventing and Mitigating Alcohol Toxicity: A Review on Protective Substances

This review covers three fundamental aspects of alcohol consumption and research efforts around the prevention and mitigation of its toxic effects in the human body. First, the sociocultural aspects of alcohol consumption are analysed, including drinking habits and strategies to combat intoxication. Second, we briefly introduce the biochemical aspects of ethanol metabolism and the biochemical pathways leading to its degradation, particularly the activation of toxic response pathways. Finally, we review current evidence and research efforts for finding compounds and substances able to prevent and mitigate the toxic effects of alcohol when over-indulgence has occurred. The toxic effects appear as a time-evolution process based on the stage of intoxication. We explore different compounds and formulations traditionally used to combat alcohol toxicity, as well as state-of-the-art research in the topic for novel molecules and formulations. Although we aimed to categorise which compounds are more effective for a particular level of alcohol intoxication, it is impossible to fully prevent or mitigate toxicity effects by only the compounds in isolation, further research is required to establish the long-term prevention and mitigation from the clinical point of view.

Synergistic Interaction of Light Alcohol Administration in the Presence of Mild Iron Overload in a Mouse Model of Liver Injury: Involvement of Triosephosphate Isomerase Nitration and Inactivation

It is well known that iron overload promotes alcoholic liver injury, but the doses of iron or alcohol used in studies are usually able to induce liver injury independently. Little attention has been paid to the coexistence of low alcohol consumption and mild iron overload when either of them is insufficient to cause obvious liver damage, although this situation is very common among some people. We studied the interactive effects and the underlining mechanism of mild doses of iron and alcohol on liver injury in a mouse model. Forty eight male Kunming mice were randomly divided into four groups: control, iron (300 mg/kg iron dextran, i.p.), alcohol (2 g/kg/day ethanol for four weeks i.g.), and iron plus alcohol group. After 4 weeks of treatment, mice were sacrificed and blood and livers were collected for biochemical analysis. Protein nitration level in liver tissue was determined by immunoprecipitation and Western blot analysis. Although neither iron overload nor alcohol consumption at our tested doses can cause severe liver injury, it was found that co-administration of the same doses of alcohol and iron resulted in liver injury and hepatic dysfunction, accompanied with elevated ratio of NADH/NAD⁺, reduced antioxidant ability, increased oxidative stress, and subsequent elevated protein nitration level. Further study revealed that triosephosphate isomerase, an important glycolytic enzyme, was one of the targets to be oxidized and nitrated, which was responsible for its inactivation. These data indicate that even under low alcohol intake, a certain amount of iron overload can cause significant liver oxidative damage, and the modification of triosephosphate isomerasemight be the important underlining mechanism of hepatic dysfunction.

A urinary metabonomics analysis of long-term effect of acetochlor exposure on rats by ultra-performance liquid chromatography/mass spectrometry

The study was to assess the long-term toxic effects of acetochlor on rats. Two different doses (42.96 and 107.4 mg/kg body weight/day) of acetochlor were administered to Wistar rats through their food for over 24 weeks. Rat urine samples were collected at two time-points for the measurements of the metabonomics profiles with ultra-performance liquid chromatography-mass spectrometry (UPLC-MSMS). The results of clinical chemistry and histopathology suggested that long-term use of acetochlor in rats caused liver and kidney damage, and dysfunction of antioxidant system. The urinary metabonomics analysis indicated that the high and low-dose exposure of acetochlor could cause alterations of these metabonomics in urine in the rat. Significant changes of the levels of hippuric acid (0.403-fold decrease), citric acid (0.430-fold decrease), pantothenic acid (0.486-fold decrease), uracil (0.419-fold decrease), β-Alanine (0.325-fold decrease), nonanedioic acid (0.445-fold decrease), L-tyrosine (0.410-fold decrease), D-glucuronic acid (8.389-fold increase) and 2-ethyl-6-methyl-N-methyl-2-chloro-acetanilide in urine were observed. In addition, it may interfere with the fatty acid synthesis, the pyrimidine degradation and pantothenate biosynthesis. The level of 2-ethyl-6-methyl-N-methyl-2-chloro-acetanilide is detected in all treated groups which is not found in the control groups, indicating which can be used as an early, sensitive marker of acetochlor exposure in rat. This study illustrates the important utility of metabonomics approaches to understand the toxicity of long-term exposure of acetochlor.

Taurine drinking ameliorates hepatic granuloma and fibrosis in mice infected with Schistosoma japonicum

In schistosomiasis, egg-induced hepatic granuloma formation is a cytokine-mediated, predominantly CD4⁺ Th2 immune response that can give rise to hepatic fibrosis. Hepatic fibrosis is the main cause of increased morbidity and mortality in humans with schistosome infection. Taurine has various physiological functions and hepatoprotective properties as well as anti-inflammatory and immunomodulatory activity. However, little is known about the role of taurine in schistosome egg-induced granuloma formation and fibrosis. We aimed to evaluate the therapeutic potential of taurine as preventative treatment for Schistosoma japonicum infection. Mice infected with S. japonicum cercariae were supplied with taurine drinking water (1% w/v) for 4 weeks starting at 4 weeks post-infection. Taurine supplementation significantly improved the liver pathologic findings, reduced the serum levels of aminotransferases and area of hepatic granuloma, and prevented fibrosis progression. In addition, taurine decreased the expression of the granulomatous and fibrogenic mediators transforming growth factor β1, tumor necrosis factor α, monocyte chemotactic protein 1α and macrophage inflammatory protein 1α as well as the endoplasmic reticulum stress marker glucose-regulated protein 78. Thus, taurine can significantly attenuate S. japonicum egg-induced hepatic granuloma and fibrosis, which may depend in part on the downregulation of some relevant cytokine/chemokines and reducing the endoplasmic reticulum stress response.

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Taurine has potential as preventative & therapeutic treatment for schistosomiasis.

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Taurine reduced the development of liver pathology caused by S. japonicum infection.

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Taurine attenuated S. japonicum egg-induced hepatic granuloma and fibrosis.

Protective role of taurine in developing offspring affected by maternal alcohol consumption

Maternal alcohol consumption is known to affect offspring growth and development, including growth deficits, physical anomalies, impaired brain functions and behavioral disturbances. Taurine, a sulfur-containing amino acid, is essential during development, and continually found to be protective against neurotoxicity and various tissue damages including those from alcohol exposure. However, it is still unknown whether taurine can exert its protection during development of central nervous system and whether it can reverse alcohol damages on developed brain later in life. This study aims to investigate protective roles of taurine against maternal alcohol consumption on growth and development of offspring. The experimental protocol was conducted using ICR-outbred pregnant mice given 10 % alcohol, with or without maternal taurine supplementation during gestation and lactation. Pregnancy outcomes, offspring mortality and successive bodyweight until adult were monitored. Adult offspring is supplemented taurine to verify its ability to reverse damages on learning and memory through a water maze task performance. Our results demonstrate that offspring of maternal alcohol exposure, together with maternal taurine supplementation show conserved learning and memory, while that of offspring treated taurine later in life are disturbed. Taurine provides neuroprotective effects and preserves learning and memory processes when given together with maternal alcohol consumption, but not shown such effects when given exclusively in offspring.

Co-treatment of chlorpyrifos and lead induce serum lipid disorders in rats

The aim of this study was to investigate the effects of taurine (TA) on serum lipid profiles following chronic coadministration of chlorpyrifos (CP) and lead acetate (Pb) in male Wistar rats. Fifty rats randomly distributed into five groups served as subjects. Distilled water (DW) was given to DW group, while soya oil (SO; 1 mL kg−1) was given to SO group. The TA group was treated with TA (50 mg kg−1). The CP + Pb group was administered sequentially with CP (4.25 mg kg−1; 1/20th median lethal dose (LD50)) and Pb at 233.25 mg kg−1 (1/20th LD50), while the TA + CP + Pb group received TA (50 mg kg−1), CP (4.25 mg kg−1), and Pb (233.25 mg kg−1) sequentially. The treatments were administered once daily by oral gavage for 16 weeks. The rats were euthanised, and the blood samples were collected at the termination of the study. Sera obtained from the blood samples were analyzed for total cholesterol, high-density lipoprotein cholesterol, triglycerides, and malondialdehyde, and also the activities of serum antioxidant enzymes including superoxide dismutase, catalase and glutathione peroxidase were analyzed. The low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, and atherogenic index were calculated. The results showed that CP and Pb induced alterations in the serum lipid profiles and evoked oxidative stress. TA alleviated the disruptions in the serum lipid profiles of the rats partially by mitigating oxidative stress. It was concluded that TA may be used for prophylaxis against serum lipid disorders in animals that were constantly co-exposed to CP and Pb in the environment.

Curcumin protects against CCl4-induced liver fibrosis in rats by inhibiting HIF-1α through an ERK-dependent pathway

The ERK/HIF-1α signaling pathway is believed to play an important role in the genesis of progressive fibrosis. An increasing expression of HIF-1α and ERK accompanies CCl₄-induced liver fibrosis in rats. Curcumin is verified to have antifibrotic effects in several kinds of liver fibrosis models. There is no specific evidence illustrating a connection between curcumin and the HIF-1α/ERK pathway in rat liver fibrosis induced by CCl₄. In this study, liver fibrosis was induced by CCl₄ in treated rats. The data demonstrated that curcumin was able to attenuate liver fibrosis and inhibit the proliferation of HSC. Moreover, curcumin could remarkably elevate the hepatic function by decreasing serum levels of ALT, AST and ALP, and increasing levels of ALB, TP and α-SMA, Col III mRNA expression. Meanwhile, ECM status could also be reflected by curcumin treatment. The alleviation with curcumin treatment was associated with inhibition of HIF-1α and phosphor-ERK. This study indicates that curcumin alleviates fibrosis by reducing the expression of HIF-1α partly through the ERK pathway.

Effects of herbal infusions, tea and carbonated beverages on alcohol dehydrogenase and aldehyde dehydrogenase activity

Various alcoholic beverages containing different concentrations of ethanol are widely consumed, and excessive alcohol consumption may result in serious health problems. The consumption of alcoholic beverages is often accompanied by non-alcoholic beverages, such as herbal infusions, tea and carbonated beverages to relieve drunk symptoms. The aim of this study was to supply new information on the effects of these beverages on alcohol metabolism for nutritionists and the general public, in order to reduce problems associated with excessive alcohol consumption. The effects of 57 kinds of herbal infusions, tea and carbonated beverages on alcohol dehydrogenase and aldehyde dehydrogenase activity were evaluated. Generally, the effects of these beverages on alcohol dehydrogenase and aldehyde dehydrogenase activity are very different. The results suggested that some beverages should not be drank after excessive alcohol consumption, and several beverages may be potential dietary supplements for the prevention and treatment of problems related to excessive alcohol consumption.

Chronic ethanol ingestion induces oxidative kidney injury through taurine-inhibitable inflammation

Chronic ethanol ingestion mildly damages liver through oxidative stress and lipid oxidation, which is ameliorated by dietary supplementation with the anti-inflammatory β-amino acid taurine. Kidney, like liver, expresses cytochrome P450 2E1 that catabolizes ethanol with free radical formation, and so also may be damaged by ethanol catabolism. Sudden loss of kidney function, and not liver disease itself, foreshadows mortality in patients with alcoholic hepatitis [J. Altamirano, Clin. Gastroenterol. Hepatol. 2012, 10:65]. We found that ethanol ingestion in the Lieber-deCarli rat model increased kidney lipid oxidation, 4-hydroxynonenal protein adduction, and oxidatively truncated phospholipids that attract and activate leukocytes. Chronic ethanol ingestion increased myeloperoxidase-expressing cells in kidney and induced an inflammatory cell infiltrate. Apoptotic terminal deoxynucleotidyl transferase nick-end labeling-positive cells and active caspase-3 increased in kidney after ethanol ingestion, with reduced filtration with increased circulating blood urea nitrogen (BUN) and creatinine. These events were accompanied by release of albumin, myeloperoxidase, and the acute kidney injury biomarkers kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin, and cystatin c into urine. Taurine sequesters HOCl from myeloperoxidase of activated leukocytes, and taurine supplementation reduced renal lipid oxidation, reduced leukocyte infiltration, and reduced the increase in myeloperoxidase-positive cells during ethanol feeding. Taurine supplementation also normalized circulating BUN and creatinine levels and suppressed enhanced myeloperoxidase, albumin, KIM-1, and cystatin c in urine. Thus, chronic ethanol ingestion oxidatively damages kidney lipids and proteins, damages renal function, and induces acute kidney injury through an inflammatory cell infiltrate. The anti-inflammatory nutraceutical taurine effectively interrupts this ethanol-induced inflammatory cycle in kidney.

Nutraceutical strategies for ameliorating the toxic effects of alcohol

Rodent studies reveal that oxidative stress, much of it generated via induction/activation of NADPH oxidase, is a key mediator of a number of the pathogenic effects of chronic ethanol overconsumption. The highly reactive ethanol metabolite acetaldehyde is a key driver of this oxidative stress, and doubtless works in other ways to promote alcohol-induced pathology. Effective antioxidant measure may therefore be useful for mitigating the adverse health consequences of alcohol consumption; spirulina may have particular utility in this regard, as its chief phycochemical phycocyanobilin has recently been shown to function as an inhibitor of certain NADPH oxidase complexes, mimicking the physiological role of its chemical relatives biliverdin/bilirubin in this respect. Moreover, certain nutraceuticals, including taurine, pantethine, and lipoic acid, may have the potential to boost the activity of the mitochondrial isoform of aldehyde dehydrogenase, ALDH-2, accelerating conversion of acetaldehyde to acetate (which arguably has protective health effects). Little noticed clinical studies conducted nearly three decades ago reported that pre-ingestion of either taurine or pantethine could blunt the rise in blood acetaldehyde following ethanol consumption. Other evidence suggests that lipoic acid may function within mitochondria to maintain aldehyde dehydrogenase in a reduced active conformation; the impact of this agent on ethanol metabolism has however received little or no study. Studies evaluating the impact of nutracetical strategies on prevention of hangovers - which likely are mediated by acetaldehyde - may represent a quick, low-cost way to identify nutraceutical regimens that merit further attention for their potential impact on alcohol-induced pathology. Measures which boost or preserve ALDH-2 activity may also have important antioxidant potential, as this enzyme functions physiologically to protect cells from toxic aldehydes generated by oxidant stress.

Global liver proteome analysis using iTRAQ labeling quantitative proteomic technology to reveal biomarkers in mice exposed to perfluorooctane sulfonate (PFOS)

Proteomic analysis allows detection of changes of proteins expression in organisms exposed to environmental pollutants, leading to the discovery of biomarkers of exposure and understanding of the action mechanism of toxicity. In the present study, we applied iTRAQ labeling quantitative proteomic technology for global characterization of the liver proteome in mice exposed to perfluorooctane sulfonate (PFOS). This successfully identified and quantified 1038 unique proteins. Seventy-one proteins showed a significant expression change in the treated groups (1.0, 2.5, 5.0 mg/kg of body weight) compared with the control group, and 16 proteins displayed strong dose-dependent changes. Gene ontology analysis showed that these differential proteins were significantly enriched and mainly involved in lipid metabolism, transport, biosynthetic processes, and response to stimulus. We detected significantly increased expression levels of enzymes regulating peroxisomal β-oxidation-including long-chain acyl-CoA synthetase, acyl-CoA oxidase 1, bifunctional enzyme, and 3-ketoacyl-CoA thiolase A. PFOS also significantly induced cytochrome P450s and glutathione S-transferases that are responsible for the metabolism of xenobiotic compounds. The expressions of several proteins with important biological functions-such as cysteine sulfinic acid decarboxylase, aldehyde dehydrogenase, and apolipoprotein A-I, also correlated with PFOS exposure. Together, the present results provide insight into the molecular mechanism and biomarkers for PFOS-induced effects.

Protective effect of Fufang-Liu-Yue-Qing, a traditional Chinese herbal formula, on CCl4 induced liver fibrosis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Chinese prescription Fufang-Liu-Yue-Qing (FLYQ) has long been employed clinically to treat chronic hepatitis B, and we have reported its beneficial effects on liver fibrosis in vitro. The present study was investigated to verify protective effects of FLYQ on liver fibrosis in a rat model and to investigate the underlying mechanisms which have not been explored yet.

MATERIALS AND METHODS

Liver fibrosis was established by intragastric administration of 2 ml/kg CCl(4) twice a week for 12 weeks. During the experiment, the model group received CCl(4) only, and the normal control group received an equal volume of saline. Treatment groups received not only CCl(4) for 12 weeks, but also the corresponding drugs, colchicine (1.00 mg/kg/day) or FLYQ (300, 150, 75 mg/kg/day) from 5 to 12 weeks.

RESULTS

Analysis experiments showed that FLYQ could significantly alleviate liver injury, as indicated by decreasing levels of ALT, AST, ALP, GGT, IL-6 and TNF-α. Moreover, FLYQ could effectively inhibit collagen deposition and reduce the pathological tissue damage. Research on mechanism showed that FLYQ was able to markedly reduce lipid peroxidation, recruit the anti-oxidative defense system, promote ECM degradation by modulating the levels of TIMP-1 and MMP-2, and induce HSC apoptosis by down-regulating bcl-2 mRNA, as well as inhibit the expressions of α-SMA and TGF-β(1) proteins.

CONCLUSIONS

Our results show that FLYQ is effective in attenuating hepatic injury and fibrosis in the CCl(4)-induced rat model, which should be developed as a new drug for treatment of liver fibrosis and even cirrhosis.

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.

Effects of Hepatic Drug-metabolizing Enzyme Induction on Clinical Pathology Parameters in Animals and Man

Hepatic drug-metabolizing enzyme (DME) induction is an adaptive response associated with changes in preclinical species; this response can include increases in liver weight, hepatocellular hyperplasia and hypertrophy, and upregulated tissue expression of DMEs. Effects of DME induction on clinical pathology markers of hepatobiliary injury and function in animals as well as humans are not well established. This component of a multipart review of the comparative pathology of xenobiotically mediated induction of hepatic metabolizing enzymes reviews pertinent data from retrospective and prospective preclinical and clinical studies. Particular attention is given to studies with confirmation of DME induction and concurrent evaluation of liver and/or serum hepatobiliary marker enzyme activities and histopathology. These results collectively indicate that in the rat, when histologic findings are limited to hepatocellular hypertrophy, DME induction is not expected to be associated with consistent or substantive changes in serum or plasma activity of hepatobiliary marker enzymes such as alanine aminotransferase, alkaline phosphatase, and gamma glutamyltransferase. In the dog and the monkey, published studies also do not demonstrate a consistent relationship across DME-inducing agents and changes in these clinical pathology parameters. However, increased liver alkaline phosphatase or gamma glutamyltransferase activity in dogs treated with phenobarbital or corticosteroids suggests that direct or indirect induction of select hepatobiliary injury markers can occur both in the absence of liver injury and independently of induction of DME activity. Although correlations between tissue and serum levels of these hepatobiliary markers are limited and inconsistent, increases in serum/plasma activities that are substantial or involve changes in other markers generally reflect hepatobiliary insult rather than DME induction. Extrahepatic effects, including disruption of the hypothalamic-pituitary-thyroid axis, can also occur as a direct outcome of hepatic DME induction in humans and animals. Importantly, hepatic DME induction and associated changes in preclinical species are not necessarily predictive of the occurrence, magnitude, or enzyme induction profile in humans.

Oxidative and nitrosative stress in experimental rat liver fibrosis: Protective effect of taurine

Taurine (TAU) has protective effects on experimental liver fibrosis. The present study investigates whether benefits of TAU are mediated through attenuation of oxidative and nitrosative stresses. Liver fibrosis was induced in male Wistar rats by simultaneous administration of iron (0.5%, w/w) and ethanol (6g/kg/day) for 60 days consecutively. Significant increases in thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides, protein carbonyl content and loss of non-protein, protein and total thiols were observed in the liver of iron plus alcohol-fed rats. Nitrosative stress was marked by increased levels of S-nitrosothiols and decreased nitrite content. Accumulation of nitrated and oxidatively modified proteins in liver was further evidenced by immunohistochemical localization with specific antibodies for 4-hydroxynonenol (4-HNE), 3-nitrotyrosine (3-NT) and dinitrophenol (DNP). Decrease in mitochondrial ion-transport enzymes and disturbances in calcium and iron levels were also observed in these rats. TAU administration (2% (w/v) in drinking water) significantly reduced the levels of lipid hydroperoxides, TBARS, protein carbonyl with concomitant elevation in thiol levels. The presence of 4-HNE, 3-NT and DNP-protein adducts was minimal. TAU also improved mitochondrial enzyme activities and regulated iron and calcium levels. These results show that the restorative effect of taurine in fibrosis involves amelioration of protein and lipid damage by decreasing oxidative and nitrosative stresses.

Mitochondrial damage, cytotoxicity and apoptosis in iron-potentiated alcoholic liver fibrosis: amelioration by taurine

Taurine effectively prevents ischemia-induced apoptosis in the cardiomyocytes and hypothalamic nuclei. The present study explores the influence of taurine on mitochondrial damage, oxidative stress and apoptosis in experimental liver fibrosis. Male albino Wistar rats were divided into six groups and maintained for a period of 60 days as follows: Group I, control; Group II, ethanol treatment [6 g/(kg/day)]; Group III, fibrosis induced by ethanol and iron (0.5% w/w); Group IV, ethanol + iron + taurine (2% w/v); Group V, ethanol + taurine treatment and Group VI, control + taurine treatment. Hepatocytes isolated from ethanol plus iron-treated rats showed decreased cell viability and redox ratio, increased reactive oxygen species formation, lipid peroxidation, DNA fragmentation, and formation of apoptotic bodies. Liver mitochondria showed increased susceptibility to swell, diminished activities of mitochondrial respiratory chain complexes and antioxidants. Taurine administration to fibrotic rats restored mitochondrial function, reduced reactive oxygen species formation, prevented DNA damage, and apoptosis. Thus taurine might contribute to the amelioration of the disease process.