Metadoxine prevents damage produced by ethanol and acetaldehyde in hepatocyte and hepatic stellate cells in culture

Metallofullerenol alleviates alcoholic liver damage via ROS clearance under static magnetic and electric fields

Alcoholic liver disease (ALD) is a common chronic redox disease caused by increased alcohol consumption. Abstinence is a major challenge for people with alcohol dependence, and approved drugs have limited efficacy. Therefore, this study aimed to explore a new treatment strategy for ALD using ferroferric oxide endohedral fullerenol (Fe3O4@C60(OH)n) in combination with static magnetic and electric fields (sBE). The primary hepatocytes of 8-9-week-old female BALB/c mice were used to evaluate the efficacy of the proposed combination treatment. A mouse chronic binge ethanol feeding model was established to determine the alleviatory effect of Fe3O4@C60(OH)n on liver injury under sBE exposure. Furthermore, the ability of Fe3O4@C60(OH)n to eliminate •OH was evaluated. Alcohol-induced hepatocyte and mitochondrial damage were reversed in vitro. Additionally, the combination therapy reduced liver damage, alleviated oxidative stress by improving antioxidant levels, and effectively inhibited liver lipid accumulation in animal experiments. Here, we used a combination of magnetic derivatives of fullerenol and sBE to further improve the ROS clearance rate, thereby alleviating ALD. The developed combination treatment may effectively improve alcohol-induced liver damage and maintain redox balance without apparent toxicity, thereby enhancing therapy aimed at ALD and other redox diseases.

Erk1/2 signaling mediates the HGF-induced protection against ethanol and acetaldehyde-induced toxicity in the pancreatic RINm5F cell line

Alcohol-induced pancreas damage remains as one of the main risk factors for pancreatitis development. This disorder is poorly understood, particularly the effect of acetaldehyde, the primary alcohol metabolite, in the endocrine pancreas. Hepatocyte growth factor (HGF) is a protective protein in many tissues, displaying antioxidant, antiapoptotic, and proliferative responses. In the present work, we were focused on characterizing the response induced by HGF and its protective mechanism in the RINm5F pancreatic cell line treated with ethanol and acetaldehyde. RINm5F cells were treated with ethanol or acetaldehyde for 12 h in the presence or not of HGF (50 ng/ml). Cells under HGF treatment decreased the content of reactive oxygen species and lipid peroxidation induced by both toxics, improving cell viability. This effect was correlated to an improvement in insulin expression impaired by ethanol and acetaldehyde. Using a specific inhibitor of Erk1/2 abrogated the effects elicited by the growth factor. In conclusion, the work provides mechanistic evidence of the HGF-induced-protective response to the alcohol-induced damage in the main cellular component of the endocrine pancreas.

Dihydromyricetin Protects Against Ethanol-Induced Toxicity in SH-SY5Y Cell Line: Role of GABAA Receptor

Toxicity induced by binge alcohol drinking, particularly in adolescent and young adults, is of major medical and social consequence. Recently, we reported that butyrate, a short chain fatty acid, can protect against ethanol (ETOH)-induced toxicity in an in vitro model. In this study, we sought to evaluate the potential effectiveness of dihydromyricetin (DHM), a natural bioactive flavonoid, alone or in combination with butyrate in the same model. Exposure of SH-SY5Y cells for 24 h to 500 mM ETOH resulted in approximately 40% reduction in cell viability, which was completely prevented by 0.1 μM DHM. Combinations of DHM and butyrate provided synergistic protection against alcohol toxicity. Whereas butyrate effect was shown to be mediated primarily through fatty acid receptor 3 activation, DHM protection appears to be mediated primarily via benzodiazepine receptor site of GABA_A receptor. This is based on the finding that DHM's effect could be completely prevented by pretreatment with flumazenil, a selective antagonist at this site, but not by bicuculline, a selective antagonist at the actual GABA_A receptor binding site. These findings suggest potential utility of DHM alone or in combination with butyrate against ETOH-induced toxicity.

Research Progress on the Pharmacological Action of Schisantherin A

Schisantherin A (Sch A) is a dibenzocyclooctadiene lignan monomer isolated from the fruit of Schisandra chinensis (Turcz.) Baill. (S. chinensis). At present, many studies have shown that Sch A has a wide range of pharmacological effects, including its anti-Parkinson and anti-inflammatory effects and ability to protect the liver, protect against ischemia-reperfusion (I/R) injury, suppress osteoclast formation, and improve learning and memory. Its mechanism may be related to the antioxidant, anti-inflammatory, and antiapoptotic properties of Sch A through the MAPK, NF-κB, AKT/GSK3β, and PI3K/AKT pathways. This is the first review of the recent studies on the pharmacological mechanism of Sch A.

Crosstalk between Oxidative Stress and Inflammatory Liver Injury in the Pathogenesis of Alcoholic Liver Disease

Alcoholic liver disease (ALD) is characterized by the injury, inflammation, and scarring in the liver owing to excessive alcohol consumption. Currently, ALD is a leading cause for liver transplantation. Therefore, extensive studies (in vitro, in experimental ALD models and in humans) are needed to elucidate pathological features and pathogenic mechanisms underlying ALD. Notably, oxidative changes in the liver have been recognized as a signature trait of ALD. Progression of ALD is linked to the generation of highly reactive free radicals by reactions involving ethanol and its metabolites. Furthermore, hepatic oxidative stress promotes tissue injury and, in turn, stimulates inflammatory responses in the liver, forming a pathological loop that promotes the progression of ALD. Accordingly, accumulating further knowledge on the relationship between oxidative stress and inflammation may help establish a viable therapeutic approach for treating ALD.

The protective effects and mechanisms of modified Lvdou Gancao decoction on acute alcohol intoxication in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Acute alcohol intoxication (AAI) is a ubiquitous emergency worldwide, whereas the searching for both effective and safe drugs is still a task to be completed. Modified Lvdou Gancao decoction (MLG), a traditional Chinese medicine decoction, has been confirmed to be valid to alcohol-induced symptoms and hepatotoxicity clinically, whereas its protective mechanisms have not been determined.

MATERIALS AND METHODS

AAI mice model was established by alcohol gavage (13.25 mL/kg) and MLG (5, 10, 20 g/kg BW) was administered to mice 2 h before and 30 min after the alcohol exposure. Assay kits for alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamine transferase (GGT), total superoxide dismutase (T-SOD), malondialdehyde (MDA), nitric oxide (NO), and glutathione peroxidase (GSH-Px), as well as histopathology were used to explore the effects of MLG on acute alcohol-induced intoxication and hepatotoxicity. Mechanisms of MLG on oxidative stress and inflammatory were evaluated with RT-qPCR and Western Blot.

RESULTS

MLG remarkably decreased the drunkenness rate, prolonged the tolerance time and shortened the sober-up time of AAI mice. After acute alcohol exposure, MLG treatment induced significant increment of ADH, ALDH, T-SOD and GSH-Px activities in liver, while serum ALT, AST, GGT and NO levels as well as hepatic MDA activity were reduced, in a dose-dependent manner. In contrast to the model group, the mRNA expression of TNFα, IL-1β and NF-κB in the MLG treated groups had a downward trend while the Nrf-2 showed an upward trend simultaneously. Furthermore, the protein levels of p65, p-p65, p-IκBα in the MLG treated groups were considerably diminished, with HO-1 and Nrf2 elevated. To sum up, our results suggested that MLG could efficaciously ameliorate AAI via accelerating the metabolism of alcohol, alleviating acute hepatotoxicity, and weakening the oxidative stress coupled with inflammation response, which might be attributed to the inhibition of the NF-κB signaling pathway and the activation of the Nrf2/HO-1 signaling pathway.

CONCLUSIONS

Taken together, our present study verified the protective effect and mechanisms of MLG to AAI mice, and we further conclude that MLG may be a potent and reliable candidate for the prevention and treatment of AAI.

The Mexican consensus on alcoholic hepatitis

Alcoholic hepatitis is a frequent condition in the Mexican population. It is characterized by acute-on-chronic liver failure, important systemic inflammatory response, and multiple organ failure. The severe variant of the disease implies elevated mortality. Therefore, the Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Hepatología brought together a multidisciplinary team of health professionals to formulate the first Mexican consensus on alcoholic hepatitis, carried out utilizing the Delphi method and resulting in 37 recommendations. Alcohol-related liver disease covers a broad spectrum of pathologies that includes steatosis, steatohepatitis, different grades of fibrosis, and cirrhosis and its complications. Severe alcoholic hepatitis is defined by a modified Maddrey's discriminant function score ≥ 32 or by a Model for End-Stage Liver Disease (MELD) score equal to or above 21. There is currently no specific biomarker for its diagnosis. Leukocytosis with neutrophilia, hyperbilirubinemia (> 3 mg/dL), AST > 50 U/l (< 400 U/l), and an AST/ALT ratio > 1.5-2 can guide the diagnosis. Abstinence from alcohol, together with nutritional support, is the cornerstone of treatment. Steroids are indicated for severe disease and have been effective in reducing the 28-day mortality rate. At present, liver transplantation is the only life-saving option for patients that are nonresponders to steroids. Certain drugs, such as N-acetylcysteine, granulocyte-colony stimulating factor, and metadoxine, can be adjuvant therapies with a positive impact on patient survival.

Hepatoprotective Effect of Metadoxine on Acetaminophen-induced Liver Toxicity in Mice

Background:

Metadoxine (pyridoxine pyrrolidone carboxylate) is considered to be a beneficial agent for the treatment of experimental hepatotoxicity due to alcohol, CCl4, and bile duct ligation. Hence, the therapeutic effect of metadoxine and N-acetylcysteine (NAC) as reference drug was investigated in mice exposed to acute hepatotoxicity induced by a single oral toxic dose of acetaminophen (650 mg/kg).

Materials and Methods:

Metadoxine (200 and 400 mg/kg) and NAC (300 mg/kg) were given orally (p. o.), 2 h after acetaminophen administration. Serum aminotransferases, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin, hepatic glutathione (GSH), and malondialdehyde (MDA) levels were determined for evaluating the extent of hepatotoxicity due to acetaminophen and its protection by metadoxine.

Results:

Findings indicated that metadoxine significantly reduced the level of serum ALT, AST, and ALP but not total bilirubin which increased by acetaminophen intoxication. Administration of metadoxine also attenuated oxidative stress by suppressing lipid peroxidation (MDA) and prevented the depletion of reduced GSH level which caused by acetaminophen toxicity. Besides, metadoxine ameliorated histopathological hepatic tissue injury induced by acetaminophen.

Conclusion:

In most parameters examined, the effect of metadoxine was comparable to NAC. Hence, metadoxine could be considered as a beneficial therapeutic candidate to protect against acute acetaminophen hepatotoxicity.

Altering ethanol pharmacokinetics to treat alcohol use disorder: Can you teach an old dog new tricks?

Disulfiram was the first pharmacotherapy approved to treat alcohol use disorder in the 1950s. Disulfiram alters ethanol pharmacokinetics and causes uncomfortable reactions (e.g. headache, tachycardia, nausea, flushing and hypotension) when alcohol is consumed. Subsequently, a better understanding of the neurobiological pathways involved in alcohol use disorder led to the development of other medications (e.g. naltrexone and acamprosate). These neurobiological-based medications act on alcohol use disorder-related phenotypes including craving, stress, and/or withdrawal. The original approach to treat alcohol use disorder, by altering ethanol pharmacokinetics has been much less investigated. Recent research on ethanol pharmacokinetics has shed light on the mechanisms of action underlying alcohol use disorder and how some medications that alter ethanol pharmacokinetics may be helpful in treating alcohol use disorder. This review summarizes and discusses the complex pharmacokinetics of ethanol, and proposes that altering ethanol pharmacokinetics via novel pharmacological approaches may be a viable approach to treat alcohol use disorder.

Effects of aqueous extracts from Panax ginseng and Hippophae rhamnoides on acute alcohol intoxication: An experimental study using mouse model

ETHNOPHARMACOLOGICAL RELEVANCE

Acute alcohol intoxication (AAI) is a frequent emergency, but therapeutic drugs with superior efficacy and safety are lacking. Panax ginseng (PG) and Hippophae rhamnoides (HR) respectively has a wide application as a complementary therapeutic agent in China for the treatment of AAI and liver injury induced by alcohol. We investigated the effects of aqueous extracts from PG and HR (AEPH) on AAI mice and identified its underlying mechanisms.

MATERIALS AND METHODS

Models of AAI were induced by intragastric administration of ethanol (8g/kg). Seventy-two Specific pathogen-free (SPF) male Kunming mice were randomly divided into six groups: normal group, positive control group, AEPH of low dosage (100mg/kg) group, AEPH of medium dose (200mg/kg) group, AEPH of high dosage (400mg/kg) group and model group. The mice were treated with metadoxine (MTD, 500mg/kg) and AEPH. Thirty minutes later, the normal group was given normal saline, while the other groups were given ethanol (i.g., 8g/kg). The impact of AEPH was observed. In the same way, another seventy-two Kunming mice were randomly divided into six groups equally. The blood ethanol concentration at 0.5, 1, 1.5, 2, 3 and 6h after ethanol intake was determined by way of gas chromatography. The activity of alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH) and microsomal ethanol oxidase (EO) in liver, and the concentration of β-endorphin (β-EP), leucine-enkephalin (LENK) in the brain were determined by enzyme-linked-immunosorbent serologic assay (ELISA).

RESULTS

AEPH markedly prolonged alcohol tolerance time and shortened sober-up time after acute ethanol administration. AEPH decreased blood ethanol levels in six tests after ethanol intake. The 7-day survival rate of AEPH group was obviously superior to model group. AEPH increased the activities of ADH, ALDH, and decreased EO activity in liver. The crucial find was that AEPH markedly decreased β-EP and LENK concentration in the brain.

CONCLUSIONS

AEPH can markedly increase the levels of ADH, ALDH, decrease EO activity in liver and decrease the concentration of β-EP and LENK in the brain to against acute alcohol intoxication in mice.

Metadoxine in the Treatment of Acute and Chronic Alcoholism: A Review

Alcohol abuse and alcoholism are responsible for a wide variety of medical problems. The pharmacotherapeutic aspect of alcoholism includes the use of drugs, with different actions and objectives. Among them, metadoxine seems to be of interest. Metadoxine is able to accelerate the elimination of alcohol from the blood and tissues, to help restore the functional structure of the liver and to relieve neuro-psychological disorders associated with alcohol intoxication. Metadoxine also seems to be safe; in more than 15 years of post-marketing surveillance only minor aspecific and reversible events were monitored in patients exposed to the treatment. In this review the preclinical and clinical results obtained using metadoxine in acute and chronic alcohol intoxication are reported.

Optimal management for alcoholic liver disease: Conventional medications, natural therapy or combination?

Alcohol consumption is the principal factor in the pathogenesis of chronic liver diseases. Alcoholic liver disease (ALD) is defined by histological lesions on the liver that can range from simple hepatic steatosis to more advanced stages such as alcoholic steatohepatitis, cirrhosis, hepatocellular carcinoma and liver failure. As one of the oldest forms of liver injury known to humans, ALD is still a leading cause of liver-related morbidity and mortality and the burden is exerting on medical systems with hospitalization and management costs rising constantly worldwide. Although the biological mechanisms, including increasing of acetaldehyde, oxidative stress with induction of cytochrome p450 2E1, inflammatory cytokine release, abnormal lipid metabolism and induction of hepatocyte apoptosis, by which chronic alcohol consumption triggers serious complex progression of ALD is well established, there is no universally accepted therapy to prevent or reverse. In this article, we have briefly reviewed the pathogenesis of ALD and the molecular targets for development of novel therapies. This review is focused on current therapeutic strategies for ALD, including lifestyle modification with nutrition supplements, available pharmacological drugs and new agents that are under development, liver transplantation, application of complementary medicines, and their combination. The relevant molecular mechanisms of each conventional medication and natural agent have been reviewed according to current available knowledge in the literature. We also summarized efficacy vs safety on conventional and herbal medicines which are specifically used for the prevention and treatment of ALD. Through a system review, this article highlighted that the combination of pharmaceutical drugs with naturally occurring agents may offer an optimal management for ALD and its complications. It is worthwhile to conduct large-scale, multiple centre clinical trials to further prove the safety and benefits for the integrative therapy on ALD.

Metadoxine improves the three- and six-month survival rates in patients with severe alcoholic hepatitis

AIM: To evaluate the impact of metadoxine (MTD) on the 3- and 6-mo survival of patients with severe alcoholic hepatitis (AH).

METHODS: This study was an open-label clinical trial, performed at the “Hospital General de México, Dr. Eduardo Liceaga”. We randomized 135 patients who met the criteria for severe AH into the following groups: 35 patients received prednisone (PDN) 40 mg/d, 35 patients received PDN+MTD 500 mg three times daily, 33 patients received pentoxifylline (PTX) 400 mg three times daily, and 32 patients received PTX+MTD 500 mg three times daily. The duration of the treatment for all of the groups was 30 d.

RESULTS: In the groups treated with the MTD, the survival rate was higher at 3 mo (PTX+MTD 59.4% vs PTX 33.3%, P = 0.04; PDN+MTD 68.6% vs PDN 20%, P = 0.0001) and at 6 mo (PTX+MTD 50% vs PTX 18.2%, P = 0.01; PDN+MTD 48.6% vs PDN 20%, P = 0.003) than in the groups not treated with MTD. A relapse in alcohol intake was the primary independent factor predicting mortality at 6 mo. The patients receiving MTD maintained greater abstinence than those who did not receive it (74.5% vs 59.4%, P = 0.02).

CONCLUSION: MTD improves the 3- and 6-mo survival rates in patients with severe AH. Alcohol abstinence is a key factor for survival in these patients. The patients who received the combination therapy with MTD were more likely to maintain abstinence than those who received monotherapy with either PDN or PTX.

Pharmacotherapy for alcoholic patients with alcoholic liver disease

PURPOSE

An update on pharmacotherapy for achieving and maintaining abstinence and mitigating hepatic damage in patients with alcoholic liver disease (ALD) is presented.

SUMMARY

Currently there are limited pharmacotherapy options for managing ALD, which encompasses a broad spectrum of disorders ranging from steatosis and alcoholic hepatitis to fibrosis, cirrhosis, and hepatocellular cancer. Individual variation in the severity, presentation, and complex pathologenesis of ALD defines barriers to effective treatment. Scoring of disease severity using validated assessment instruments should guide treatment approaches; abstinence and proper nutrition continue to be the cornerstones of management. A literature search (through December 31, 2013) identified no reports of randomized controlled trials using Food and Drug Administration (FDA)-approved medications for the treatment of alcohol dependence in ALD-spectrum disorders. Disulfiram, acamprosate, and naltrexone (oral and intramuscular), while approved by FDA for treatment of alcohol dependence, are not currently approved for use in patients with ALD. Baclofen (also not FDA-approved for use in ALD) is the only medication available in the United States with demonstrated safety and efficacy in reducing alcoholic behavior that has been formally tested in clinical trials in patients with ALD. Pharmacotherapy of alcoholic hepatitis using glucocorticoids or pentoxifylline has shown promise, but these options are reserved for severe ALD only.

CONCLUSION

Although various treatments have been investigated for ALD in patients with alcoholism, complete abstinence from alcohol is currently the only recommended form of hepatoprotection for the entire spectrum of ALD diagnoses.

Metadoxine Versus Placebo for the Treatment of Non-alcoholic Steatohepatitis: A Randomized Controlled Trial

OBJECTIVE AND DESIGN

The study aimed at assessing the therapeutic efficacy and safety of metadoxine versus placebo on the ultrasonographic and histological features of non-alcoholic steatohepatitis (NASH).

SUBJECTS

134 subjects with biopsy-confirmed NASH were randomized to receive metadoxine 500 mg two times daily (n = 75) or placebo (n = 59) added to the standard of care, over 16 weeks.

EFFICACY ENDPOINTS

Originally, the primary efficacy endpoint was the composite of: reduction in the steatosis by ≥1 grade, reduction in hepatic necro-inflammation by ≥1 grade and ALT normalization. Since >50% of patients refused the second biopsy, it was decided to analyze only the individual parameters.

RESULTS

There was no significant difference between the treatment and the placebo groups in either liver histology or ALT or AST. Overall, as expected both groups showed reduction in serum ALT and AST compared to baseline. Compared to placebo (9 out 54), patients on metadoxine (34 out of 75) had significantly higher rates of improvement in 1-point in steatosis grade on ultrasound (P-value <0.001). Safety and tolerability did not differ between treatments.

CONCLUSION

Metadoxine is not effective in improvement of liver histology or serum ALT or AST in patients with NASH. However, there was significant improvement of steatosis assessed by ultrasound. To properly estimate the effects on histology and transaminases, further studies of longer duration and at higher doses are needed.

Butein inhibits ethanol-induced activation of liver stellate cells through TGF-β, NFκB, p38, and JNK signaling pathways and inhibition of oxidative stress

BACKGROUND

Butein has been reported to prevent and partly reverse liver fibrosis in vivo; however, the mechanisms of its action are poorly understood. We, therefore, aimed to determine the antifibrotic potential of butein.

METHODS

We assessed the influence of the incubation of hepatic stellate cells (HSCs) and hepatoma cells (HepG2) with butein on sensitivity to ethanol- or acetaldehyde-induced toxicity; the production of reactive oxygen species (ROS); the expression of markers of HSC activation, including smooth muscle α-actin (α-SMA) and procollagen I; and the production of transforming growth factor-β1 (TGF-β1), metalloproteinases-2 and -13 (MMP-2and MMP-13), and tissue inhibitors of metalloproteinases (TIMPs). The influence of butein on intracellular signals in HSCs; i.e., nuclear factor-κB (NFκB), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK) induced by ethanol was estimated.

RESULTS

Butein protected HSCs and HepG2 cells against ethanol toxicity by the inhibition of ethanol- or acetaldehyde-induced production of ROS when cells were incubated separately or in co-cultures; butein also inhibited HSC activation measured as the production of α-SMA and procollagen I. As well, butein downregulated ethanol- or acetaldehyde-induced HSC migration and the production of TGF-β, TIMP-1, and TIMP-2; decreased the activity of MMP-2; and increased the activity of MMP-13. In ethanol-induced HSCs, butein inhibited the activation of the p38 MAPK and JNK transduction pathways as well as significantly inhibiting the phosphorylation of NF κB inhibitor (IκB) and Smad3.

CONCLUSIONS

The results indicated that butein inhibited ethanol- and acetaldehyde-induced activation of HSCs at different levels, acting as an antioxidant and inhibitor of ethanol-induced MAPK, TGF-β, and NFκB/IκB transduction signaling; this result makes butein a promising agent for antifibrotic therapies.

Acute alcohol intoxication

Acute alcohol intoxication is a clinically harmful condition that usually follows the ingestion of a large amount of alcohol. Clinical manifestations are heterogeneous and involve different organs and apparatuses, with behavioral, cardiac, gastrointestinal, pulmonary, neurological, and metabolic effects. The management of an intoxicated patient occurs mainly in the emergency department and is aimed at stabilizing the clinical condition of the patient, depending on his/her clinical presentation. One specific drug that is useful in the treatment of acute alcohol intoxication is metadoxine, which is able to accelerate ethanol excretion. In patients presenting an acute alcohol intoxication, alcohol-related disorders should be detected so that the patient can be directed to an alcohol treatment unit, where a personalized, specific treatment can be established.

Combined metadoxine and garlic oil treatment efficaciously abrogates alcoholic steatosis and CYP2E1 induction in rat liver with restoration of AMPK activity

Alcoholic steatosis is the earliest and most common response to heavy alcohol intake, and may precede more severe forms of liver injury. Accumulation of fat, largely triglyceride, in hepatocytes results from the inhibition of fatty acid oxidation and excessive oxidative stress involving CYP2E1. This study evaluated the therapeutic effects of metadoxine, garlic oil or their combination on alcoholic steatosis. Feeding rats an alcohol-containing diet for 4 weeks elicited an increase in hepatic triglyceride content and induced CYP2E1. The concurrent administration of metadoxine and garlic oil (MG) to rats during the last week of the diet feeding efficaciously abrogated both fat accumulation and CYP2E1 induction as compared to the individual treatment at higher doses. Histopathology confirmed the ability of MG combination to inhibit lipid accumulation. Blood biochemistry verified improvement of liver function in rats treated with MG. Alcohol administration resulted in a decrease in AMP-activated protein kinase-alpha (AMPKalpha) phosphorylation, which was restored by MG treatments. Recovery of AMPK activity by MG was supported by an increase in acetyl-CoA carboxylase phosphorylation. Hepatic fatty acid synthase (FAS) expression was markedly decreased after alcohol consumption, which correlated with a decrease in AMPK activity and a commensurate increase in lipid content. Combined MG treatments caused restoration of the FAS level. These results demonstrate that the combination of MG effectively treats alcoholic steatosis with CYP2E1 inhibition, which may be associated with the recovery of AMPK activity, promising that the combination therapy may constitute an advance in the development of clinical candidates for alcoholic steatosis.

Liver fibrosis in vitro: Cell culture models and precision-cut liver slices

Chronic liver injury of various etiologies can cause liver fibrosis, which is characterized by the progressive accumulation of connective tissue in the liver. As no effective treatment for liver fibrosis is available yet, extensive research is ongoing to further study the mechanisms underlying the development of disease- or toxicity-induced liver fibrosis and to identify potential pro- or anti-fibrotic properties of compounds. This review gives an overview of the in vitro methods that are currently available for this purpose. The first focus is on cell culture models, since the majority of in vitro research uses these systems. Both primary cells and cell lines as well as the use of different culture matrices and co-culture models are discussed. Second, the use of precision-cut liver slices, which recently came into attention as in vitro model for the study of fibrosis, is discussed. The overview clearly shows that continuous optimization and adaptation have extended the potential of in vitro models for liver fibrosis during the past years. By combining the use of the different cell and tissue culture models, the mechanisms underlying multicellular fibrosis development can be studied in vitro and potential pro- or anti-fibrotic properties of compounds can be identified both on single liver cell types and in human liver tissue.

Liver fibrosis: searching for cell model answers

Hepatic stellate cells (HSC) are the principal fibrogenic cell type in the liver. Progress in understanding the cellular and molecular basis for the development and progression of liver fibrosis could be possible by the development of methods to isolate HSC from rodents and human liver. Growth of stellate cells on plastic led to a phenotypic response known as activation, which paralleled closely the response of these cells to injury in vivo. Actually, much of the current knowledge of stellate cell behaviour has been gained through primary culture studies, particularly from rats. Also, different laboratories that have established hepatic stellate cell lines from rats and humans have provided a stable and unlimited source of cells that express specific functions, making them suitable for culture-based studies of hepatic fibrosis. From these in vitro models grew a large body of information characterizing stellate cell activation, cytokine signalling, intracellular pathways regulating liver fibrogenesis, production of extracellular matrix proteins and development of antifibrotic drugs.

Role of ethanol in the regulation of hepatic stellate cell Function

Evidence has accumulated to suggest an important role of ethanol and/or its metabolites in the pathogenesis of alcohol-related liver disease. In this review, the fibrogenic effects of ethanol and its metabolites on hepatic stellate cells (HSCs) are discussed. In brief, ethanol interferes with retinoid metabolism and its signaling, induces the release of fibrogenic cytokines such as transforming growth factor β-1 (TGFβ-1) from HSCs, up-regulates the gene expression of collagen I and enhances type I collagen protein production by HSCs. Ethanol further perpetuates an activated HSC phenotype through extracellular matrix remodeling. The underlying pathophysiologic mechanisms by which ethanol exerts these pro-fibrogenic effects on HSCs are reviewed.

Human hepatocytes are protected from ethanol-induced cytotoxicity by DADS via CYP2E1 inhibition

We investigated the protective effects of diallyl disulfide (DADS), a potent inhibitor of cytochrome P450 2E1 (CYP2E1), on ethanol-induced toxicity in human hepatocytes. We found a clear dose-dependent response between ethanol and CYP2E1 activity. The ethanol-dependent CYP2E1 enzyme activity and protein expression, lactate dehydrogenase and aspartate transaminase release, malondialdehyde formation and caspase-3 activity decreased dramatically in the presence of DADS. Furthermore, DADS increased the hepatocellular glutathione (GSH) content and prevented the ethanol-dependent cellular GSH depletion. Our data show that DADS reduces ethanol-induced toxicity in human hepatocytes by reducing CYP2E1 activity and/or stabilizing the cellular GSH content, which might be of therapeutic interest.

Effects of HBeAg and HBsAg on cytokine excretion and angiotensin-converting enzyme activity in HepG2 cell line

AIM: To evaluate the effects of hepatitis B virus surface and e antigens (HBeAg and HBsAg) on the activity of angiotensin-converting enzyme (ACE) and cytokines excretion in hepatocellular carcinoma cell line HepG₂.

METHODS: The eukaryotic expression plasmids, including pcDNA3.1(-)-HBsAg, pcDNA3.1(-)-HBeAg, and empty plasmid pcDNA3.1(-), were transfected into HepG₂ cells, and the levels of cytokines, such as IL-6 and IL-8, and the activity of ACE were determined in the supernatants 48 h after transfection by flow cytometry and biochemical methods, respectively.

RESULTS: The expression of HBeAg and HBsAg were detected in the supernatants, but there was no significant difference of ACE activity between the cells tranfected with pcDNA3.1(-)-HBsAg, pcDNA3.1(-)-HBeAg, and empty plasmid pcDNA3.1(-). The levels of IL-6 and IL-8 in the supernatants had no significant differences between the cells transfected with pcDNA3.1(-)-HBsAg, pcDNA3.1(-)-HBeAg and the control cells.

CONCLUSION: HBeAg and HBsAg has no significant effects on ACE activity and IL-6, IL-8 secretion in HepG₂ cells.

Application of stability-indicating HPTLC method for quantitative determination of metadoxine in pharmaceutical dosage form

A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatographic method for analysis of metadoxine both as a bulk drug and in formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of acetone-chloroform-methanol-ammonia (7.0:4.0:3.0:1.2, v/v/v/v). Densitometric analysis of metadoxine was carried out in the absorbance mode at 315 nm. This system was found to give compact spots for metadoxine (Rf value of 0.45+/-0.02, for six replicates). Metadoxine was subjected to acid, alkali and neutral hydrolysis, oxidation, dry and wet heat treatment and photo and UV degradation. The drug undergoes degradation under all stress conditions. Also, the degraded products were well resolved from the pure drug with significantly different Rf values. The method was validated for linearity, precision, robustness, LOD, LOQ, specificity and accuracy. Linearity was found to be in the range of 100-1500 ng/spot with significantly high value of correlation coefficient r2=0.9997+/-1.02. The linear regression analysis data for the calibration plots showed good linear relationship with r2=0.9999+/-0.58 in the working concentration range of 200-700 ng/spot. The mean value of slope and intercept were 0.11+/-0.04 and 18.73+/-1.89, respectively. The limits of detection and quantitation were 50 and 100 ng/spot, respectively. Statistical analysis proves that the method is repeatable and specific for the estimation of the said drug. As the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating one. Moreover, the proposed HPTLC method was utilized to investigate the kinetics of acid and base degradation process. Arrhenius plot was constructed and activation energy was calculated respectively for acid and base degradation process.

N/A

N/A

A new approach to drug therapy in non-alcoholic steatohepatitis (NASH)

Liver steatosis is a common human disease, most often caused by long-term alcohol consumption. Non-alcoholic steatohepatitis (NASH) is characterized by similar histopathological features to those observed in alcoholic liver disease, but occurs in the absence of significant alcohol consumption. Several aetiological factors contribute to NASH: obesity, type 2 diabetes mellitus, hyperlipidaemia, pregnancy, different chemical intoxications, parenteral nutrition, jejeuno-ileal bypass, chronic inflammatory bowel disease, nutritional protein deficiency and congenital metabolic disorders. Biochemically, oxidative stress and lipid peroxidation and their ensuing damage are implicated in the pathogenesis of NASH and alcoholic steatohepatitis (probably resulting from free fatty acids in the mitochondria, and induction of the cytochrome P450 isoform CYP2E1 in hepatocytes and Kupffer's cells). This paper deals with the pathomechanisms, clinical findings and currently available therapies for NASH. The potential use of metadoxine in the treatment of NASH is also discussed.

Smad4 antisense gene transfer into ito cells and suppressed extracellular matrix production

AIM

To investigate possible role of antisense Smad4 RNA in the regulation of Smad4 and ECM production in Ito cells after blockade of TGF-β1 signal transmission by antisense Smad4.

METHODS

A rat Smad4 cDNA (2.5 kb) was inserted in reverse orientation into the adenoviral shuttle vector pAdv5SR (+), and so pAdvATSmad4 was obtained. PAdvATSmad4 was transfected, together with pJM17, into 293 cells by a liposome-mediated technique. We acquired the recombinant virus (AdvATSmad4) containing the anti-Smad4 gene by PCR detecting method. AdvATSmad4 was amplified and purified and then introduced into the rat Ito cell line CFSC.

RESULTS

The presence of antisense Smad4 RNA was detected by RT-PCR. The expression of Smad4 and the production of extracellular matrix were markedly decreased in the antisense Smad4 transfected cultured cells by in situ hybridization and immunohistochemistry.

CONCLUSION

Antisense RNA of Smad4 can be used successfully to inhibit Ito cell activation, endogenous Smad4 mRNA and extracellular matrix production, and may provide a basis for the development of anti-fibrosis gene therapy.

Fibrosis and glycogen stores depletion induced by prolonged biliary obstruction in the rat are ameliorated by metadoxine

BACKGROUND/AIMS

To evaluate liver-beneficial properties of metadoxine, not related with alcohol metabolism, bioactivation of external toxins or antioxidant mechanisms, the chronic bile duct ligation (BDL) model was used and results were compared with colchicine.

METHODS

Seven groups (n=6) of male Wistar rats were used. Four groups were BDL and received metadoxine (60 mg/kg/12 h i.p.), colchicine (10 microg/rat/day/p.o.), both or vehicles; three groups were sham-appropriate controls. Collagen content was determined by measuring hydroxyproline in liver samples; malondialdehyde (MDA) was used to estimate lipid peroxidation levels; glycogen was determined utilizing the anthrone reagent; gomory's trichromic stains of liver sections were performed.

RESULTS

Collagen increased four-fold by BDL, metadoxine, colchicine or both prevented fibrosis partially; MDA levels increased three-fold by BDL and no treatment had any significant effect; glycogen was almost depleted in the cirrhotic group, metadoxine preserved glycogen; bilirubins, and alanine aminotransferase and gamma-glutamyltranspeptidase activities increased several-fold in the BDL group, and both drugs prevented these effects partially. The histopathological analysis correlated with biochemical data.

CONCLUSIONS

Both compounds showed similar antifibrotic properties; metadoxine was more effective in preserving glycogen. Besides its antioxidant effects and its ability to induce alcohol metabolism, metadoxine possesses important antifibrotic and antinecrotic properties, and maintains energy stores efficiently.