Vitamin E dietary supplementation protects against carbon tetrachloride-induced chronic liver damage and cirrhosis

A biomimetic assay for antioxidant reactivity, based on liposomes and myoglobin

Antioxidant assays are typically based on non-physiologically relevant reagents. We describe here a quantitative assay based on the inhibition of the liposome autooxidation in the presence of myoglobin (ILA-Mb), an oxidative process with direct biomedical relevance. Additional advantages of the assay include the use of standard and readily available reagents (lecithin and myoglobin) and the applicability to lipophilic antioxidants. The ILA-Mb assay is based on previously reported qualitative or semi-quantitative ones that employed cytochrome c instead of myoglobin. A number of antioxidants are tested, and their IC50 parameters are discussed and interpreted to involve direct interaction with both myoglobin and the liposomes.

Effect of Cardamine violifolia on Plasma Biochemical Parameters, Anti-Oxidative Capacity, Intestinal Morphology, and Meat Quality of Broilers Challenged with Lipopolysaccharide

Cardamine violifolia is a newly discovered selenium (Se)-enriched plant rich in MeSeCys and SeCys and has a strong antioxidant capacity. This study aimed to investigate the effects of Cardamine violifolia on plasma biochemical indices, antioxidant levels, intestinal morphology, and meat quality of broilers under acute LPS-induced oxidative stress by comparing it with inorganic Se (sodaium selenite). A total of 240 one-day-old Ross 308 broilers were fed a basal diet and divided into four groups: (1) SeNa-SS, fed a diet supplied with 0.3 mg/kg Se from sodium selenite, and injected with 0.9% sterile saline, (2) SeCv-SS, fed a diet supplied with 0.3 mg/kg Se from Cardamine violifolia, and injected with 0.9% sterile saline, (3) SeNa-LPS, fed a diet supplied with 0.3 mg/kg Se from sodium selenite, and injected with 0.5 mg/kg LPS, (4) SeCv-LPS, fed a diet supplied with 0.3 mg/kg Se from Cardamine violifolia and injected with 0.5 mg/kg LPS. The experiment lasted for 42 days. Sterile saline or LPS was injected intraperitoneally two hours before slaughter, and blood and tissue samples were collected for testing. The results showed that compared with SeNa, SeCv significantly reduced the plasma levels of aspartate aminotransferase, alanine aminotransferase, and urea nitrogen after LPS challenge (p < 0.05), and increased the plasma levels of total antioxidant capacity and glutathione peroxidase, decreased malondialdehyde content in LPS-challenged broilers (p < 0.05). In addition, compared with SeNa, SeCv supplementation increased villus height and the ratio of villus height to crypt depth of jejunum and ileum after LPS challenge (p < 0.05). Additionally, SeCv could increase the redness of breast and thigh muscle, and decrease drip loss, cooking loss, and shear force (p < 0.05). In conclusion, our results indicated that supplementing with 0.3 mg/kg Se from Cardamine violifolia alleviated tissue injury after LPS challenge, increased antioxidant capacity, and improved meat quality of breast and thigh muscle after stress.

Wheat germ oil vitamin E cytoprotective effect and its nutrigenomics signature in human hepatocyte lipotoxicity

Wheat germ oil (WGO) is rich in α-tocopherol (vitamin E, VE), a vitamin that has long been suggested to exert hepatoprotective effects. In this study, this function of WGO-VE and its transcriptomics fingerprint were investigated in comparison with RRR-α-tocopherol and all-rac-α-tocopherol (nVE and sVE, respectively), in human liver cells treated with oleic acid (OA) to develop steatosis and lipotoxicity. Used in chemoprevention mode, all the VE formulations afforded significant reduction of the OA-induced steatosis and its consequent impact on lipotoxicity indicators, including ROS production and efflux (as H₂O₂), and apoptotic and necrotic cell death. A trend toward a better control of lipotoxicity was observed for WGO-VE and nVE compared to sVE. Gene microarray data demonstrated that these effects of VE formulations were associated with significantly different responses of the cellular transcriptome to compensate for the modifications of OA treatment, including the downregulation of cellular homeostasis genes and the induction of genes associated with defects of liver cell metabolism, fibrosis and inflammation, liver disease and cancer. Ingenuity Pathway Analysis data showed that WGO-VE modulated genes associated with liver carcinogenesis and steatosis, whereas nVE modulated genes involved in liver cell metabolism and viability biofunctions; sVE did not significantly modulate any gene dataset relevant to such biofunctions. In conclusion, WGO-VE prevents lipotoxicity in human liver cells modulating genes that differ from those affected by the natural or synthetic forms of pure VE. These differences can be captured by precision nutrition tools, reflecting the molecular complexity of this VE-rich extract and its potential in preventing specific cues of hepatocellular lipotoxicity.

Narrative review of current and emerging pharmacological therapies for nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is the most common cause of chronic liver disease today, and it has now emerged as the leading etiology of end-stage liver disease requiring liver transplantation. It is a progressive form of non-alcoholic fatty liver disease which can not only progress to cirrhosis of liver and hepatocellular carcinoma (HCC), but is associated with increased cardiovascular risks too. Despite all the advances in the understanding of the risk factors and the pathogenetic pathways involved in the pathogenesis and progression of NASH, an effective therapy for NASH has not been developed yet. Although lifestyle modifications including dietary modifications and physical activity remain the mainstay of therapy, there is an unmet need to develop a drug or a combination of drugs which can not only reduce the fatty infiltration of the liver, but also arrest the development and progression of fibrosis and advancement to cirrhosis of liver and HCC. The pharmacologic therapies which are being developed target the various components believed to be involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD)/NASH which includes insulin resistance, lipid metabolism oxidative stress, lipid peroxidation, inflammatory and cell death pathways, and fibrosis. In this review, we summarize the current state of knowledge on pharmacotherapy of NASH, and also highlight the recent developments in the field, for optimizing the management and treatment of NASH.

Fe (III)@TA@IGF-2 microspheres loaded hydrogel for liver injury treatment

As one of the most commonly used materials in liver tissue engineering, hydrogel has received much attention in recent years. In this work, we prepared a gelatin methacrylate (GelMA)/oxidized hyaluronic acid (OHA)/galactosylated chitosan (Gal-CS)/Fe (III)@TA@IGF-2 200 (TA200) hydrogel loaded with insulin-like growth factor 2 (IGF-2) for regeneration of damaged hepatocytes. Fe (III)@TA microspheres served as carrier to achieve sustained release of IGF-2 to promote hepatocytes regeneration. Galactose ligands could bind to the asialoglycoprotein receptor (ASGPR) on the surface of hepatocytes. Galactosylated chitosan could significantly increase the specific function of hepatocytes. The hydrogel we prepared had a storage modulus of 1100 Pa and was suitable for migration of hepatocytes. The release ratio of IGF-2 could reach up to 90% within 14 days. For carbon tetrachloride (CCl₄) induced human hepatic stellate cell line LX2 damage, GelMA/OHA/Gal-CS/TA200 hydrogel could significantly improve the survival of LX2 cells. The expression of HNF-4α and transferrin was detected in LX2 cells treated with hydrogel, indicating that the specific function of the liver was also restored. In summary, the GelMA/OHA/Gal-CS/TA200 hydrogels could be used as new tissue engineering scaffolds for the construction of artificial livers.

A Review Of Current And Upcoming Treatment Modalities In Non-Alcoholic Fatty Liver Disease And Non-Alcoholic Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the West. Non-alcoholic steatohepatitis (NASH) is the progressive form of NAFLD and can lead to cirrhosis, hepatocellular carcinoma, and is associated with increased cardiovascular risks. Multiple components and risk factors are thought to be involved in the pathogenesis of NAFLD and NASH. Optimal therapy has not yet been found, but many advances have been made with the discovery of potential therapeutic options. In this paper, we aim to provide a comprehensive review of approved, studied, and upcoming treatment options for NAFLD and NASH. Non-pharmacologic therapy (lifestyle modifications and bariatric surgery) and pharmacologic therapy are both reviewed. Pharmacologic therapy target components thought to be involved in the pathogenesis of this disease process including insulin resistance, oxidative stress, inflammation, lipid metabolism, and fibrosis are reviewed in this paper. Results of the emerging treatment targets in phase 2 and 3 clinical trials are also included.

Diallyl sulfide ameliorates carbon tetrachloride-induced hepatotoxicity in rats via suppressing stress-activated MAPK signaling pathways

The underlined effects of diallyl sulfide (DAS) against CCL₄ -induced oxidative, inflammatory, and apoptotic acute hepatic damage were assessed. Administration of DAS (50, 100, and 200 mg/kg) along with CCL ₄ effectively mitigated serum aspartate aminotransferase, alanine aminotransferase activities, MDA, TNF-α, IL-1β, and MCP-1 levels, as well as significantly restored HO-1, GSH levels and SOD activity in liver tissues compared with those in rats treated with CCL ₄ . Moreover, DAS inhibited CCL ₄ -induced increase of liver NF-κB (p65), Bax, p38 MAPK, and JNK protein expression. In addition, DAS accelerated protein expression of Nrf2 and Bcl-2. The hepatoprotective properties of DAS were further confirmed by the reduced severity of hepatic damage as demonstrated by histopathological findings. In conclusion, DAS achieved its protective potential against CCL4-induced hepatotoxicity through antiapoptotic activity, as well as the synchronized modulation of NF-κB and Nrf2 for the favor of antioxidant/anti-inflammatory effects via suppression of the upstream stress-activated MAPKs pathways.

Chlorophyllin supplementation modulates hyperglycemia-induced oxidative stress and apoptosis in liver of streptozotocin-administered mice

Chlorophyllin is a water-soluble mixture of sodium-copper salts of chlorophyll with antioxidant and antimutagen properties. In this study, an attempt has been made to evaluate the effect of chlorophyllin on hyperglycemia-induced oxidative stress and apoptosis in liver of streptozotocin (STZ)-administered mice. In STZ-induced diabetes, two causative factors for pancreatic β-cell deaths are DNA alkylation and profound reactive oxygen species (ROS) generation. In this study, chlorophyllin treatment was found to be able to modulate oxidative stress and apoptosis in liver of diabetic mice. Diabetic mice exhibited a significant reduction of ROS, malondialdehyde (MDA), and protein carbonyl levels upon treatment with the chlorophyllin. However, antioxidant enzymes, such as copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), and catalase (CAT) showed enhanced activity as well as expression in chlorophyllin-administered diabetic mice. The hepatoprotective effect of chlorophyllin was confirmed from the decreased activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). The histological and ultrastructural studies revealed the ability of chlorophyllin to restore morphological and cellular alterations as observed in STZ-induced diabetic mice. The effect of chlorophyllin on apoptosis showed the downregulation of cysteine-dependent aspartate-specific protease (caspase) 3 and caspase 9, whereas upregulation of B-cell lymphoma-2 (Bcl-2) protein, and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) assay demonstrated a few apoptotic cells. In conclusion, it can be stated that chlorophyllin treatment can exert hepatoprotective effect via modulating hyperglycemia-induced oxidative stress and apoptosis in STZ-administered diabetic mice. © 2018 BioFactors, 44(5):418-430, 2018.

Micronutrients in Nonalcoholic Fatty Liver Disease Pathogenesis

Micronutrients include electrolytes, minerals, vitamins, and carotenoids, and are required in microgram or milligram quantities for cellular metabolism. The liver plays an important role in micronutrient metabolism and this metabolism often is altered in chronic liver diseases. Here, we review how the liver contributes to micronutrient metabolism; how impaired micronutrient metabolism may be involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), a systemic disorder of energy, glucose, and lipid homeostasis; and how insights gained from micronutrient biology have informed NAFLD therapeutics. Finally, we highlight some of the challenges and opportunities that remain with investigating the contribution of micronutrients to NAFLD pathology and suggest strategies to incorporate our understanding into the care of NAFLD patients.

Nutritional issues in patients with obesity and cirrhosis

Obesity and metabolic syndrome are considered as responsible for a condition known as the non-alcoholic fatty liver disease that goes from simple accumulation of triglycerides to hepatic inflammation and may progress to cirrhosis. Patients with obesity also have an increased risk of primary liver malignancies and increased body mass index is a predictor of decompensation of liver cirrhosis. Sarcopenic obesity confers a risk of physical impairment and disability that is significantly higher than the risk induced by each of the two conditions alone as it has been shown to be an independent risk factor for chronic liver disease in patients with obesity and a prognostic negative marker for the evolution of liver cirrhosis and the results of liver transplantation. Cirrhotic patients with obesity are at high risk for depletion of various fat-soluble, water-soluble vitamins and trace elements and should be supplemented appropriately. Diet, physical activity and protein intake should be carefully monitored in these fragile patients according to recent recommendations. Bariatric surgery is sporadically used in patients with morbid obesity and cirrhosis also in the setting of liver transplantation. The risk of sarcopenia, micronutrient status, and the recommended supplementation in patients with obesity and cirrhosis are discussed in this review. Furthermore, the indications and contraindications of bariatric surgery-induced weight loss in the cirrhotic patient with obesity are discussed.

Haemostatic potential of human bone marrow-derived mesenchymal stromal cells in Wistar rats with carbon tetrachloride induced liver cirrhosis

Background

To evaluate the haemostatic potential of human bone marrow-derived mesenchymal stromal cells (BM-MSCs) in carbon tetrachloride (CCl₄) induced liver cirrhosis in Wistar rats.

Methods

This was an experimental study. Liver cirrhosis was induced in adult female Wistar rats using CCl₄. Rats were randomly divided into 6 groups with ten rats in each group: group 1 (normal control group), group 2 (received only CCl₄), group 3 (CCl₄ + low dose BM-MSCs), group 4 (CCl₄ + high dose BM-MSCs), group 5 (CCl₄ + silymarin), group 6 (CCl₄ + high dose BM-MSCs + silymarin). Thirty days after the treatment, blood samples were collected for liver enzyme level analysis, prothrombin time test and plasma fibrinogen estimations. The rats were then sacrificed, livers were excised and used for histopathological and scanning electron microscopy (SEM) study.

Results

BM-MSCs and the combination treatment of high dose BM-MSCs and silymarin effectively decreased the prothrombin time and increased plasma fibrinogen concentration in rats with CCl₄ induced liver cirrhosis. BM-MSCs treatment produces significant anti-fibrotic effect which was supported by the liver enzyme level analysis, histopathology and SEM study.

Conclusions

Results indicate that treatment of BM-MSCs in combination with silymarin had a better haemostatic effect when compared to the administration of BM-MSCs alone.

Chlorogenic acid ameliorates alcohol-induced liver injuries through scavenging reactive oxygen species

The key role of oxidative stress in alcoholic liver disease (ALD) has been established by the large body of evidence from previous studies. Excessive consumption of ethanol induces the production of a variety of reactive oxygen species (ROS) in the liver, such as superoxide, H₂O₂, and hydroxyl radical. These products activate oxidant-sensitive signaling cascades and modulators of apoptosis. Because ROS accumulation is closely related to ALD, a number of studies have investigated the benefits of antioxidants. Recent studies demonstrated that polyphenol chlorogenic acid (CGA) has antioxidant properties and health benefits, such as reduction of relative risk of cardiovascular diseases and hepatoprotective effects against acetaminophen toxicity. However, the protective effects of CGA against ALD have not been studied in detail. We hypothesize that CGA plays a role in preventing ALD through its antioxidant properties. In this study, we investigated the protective effects of CGA against liver injuries in vivo. Reduced alcohol-induced-steatosis, apoptotic cell death, and fibrosis due to reduced levels of oxidative stress were observed. These findings suggest that CGA treatment can be an effective approach to attenuate ALD through the suppression of oxidative stress.

Many tocopherols, one vitamin E

Four tocopherols are available in nature and are absorbed with the diet, but only one RRR-α-tocopherol satisfies the criteria of being a vitamin. The biological activity of the different tocopherols studied in the rat by the resorption-gestation test has been inconsistently extrapolated to human beings where the tocopherols have no influence on a successful pregnancy. Diminution of RRR-α-tocopherol intake results in diseases characterized by ataxia, whose pathogenetic mechanism, despite vigorous claims, has not been clarified. The calculation of the Daily Reference Intake (DRI), necessary to prevent disease, is based on an obsolete test, the peroxide-induced erythrocyte hemolysis, called the gold standard, but of highly questioned validity. If many epidemiological studies have given positive results, showing prevention by high vitamin E containing diets of cardiovascular events, neurodegenerative disease, macular degeneration and cancer, the clinical confirmatory intervention studies were mostly negative. On the positive side, besides preventing vitamin E deficiency diseases, vitamin E has shown efficacy as anti-inflammatory and immune boosting compound. It has also shown some efficacy in protecting against nonalcoholic hepato-steatosis. At a molecular level, vitamin E and some of its metabolites have shown capacity of regulating cell signaling and modulating gene transcription.

Vitamin E: Emerging aspects and new directions

The discovery of vitamin E will have its 100th anniversary in 2022, but we still have more questions than answers regarding the biological functions and the essentiality of vitamin E for human health. Discovered as a factor essential for rat fertility and soon after characterized for its properties of fat-soluble antioxidant, vitamin E was identified to have signaling and gene regulation effects in the 1980s. In the same years the cytochrome P-450 dependent metabolism of vitamin E was characterized and a first series of studies on short-chain carboxyethyl metabolites in the 1990s paved the way to the hypothesis of a biological role for this metabolism alternative to vitamin E catabolism. In the last decade other physiological metabolites of vitamin E have been identified, such as α-tocopheryl phosphate and the long-chain metabolites formed by the ω-hydroxylase activity of cytochrome P-450. Recent findings are consistent with gene regulation and homeostatic roles of these metabolites in different experimental models, such as inflammatory, neuronal and hepatic cells, and in vivo in animal models of acute inflammation. Molecular mechanisms underlying these responses are under investigation in several laboratories and side-glances to research on other fat soluble vitamins may help to move faster in this direction. Other emerging aspects presented in this review paper include novel insights on the mechanisms of reduction of the cardiovascular risk, immunomodulation and antiallergic effects, neuroprotection properties in models of glutamate excitotoxicity and spino-cerebellar damage, hepatoprotection and prevention of liver toxicity by different causes and even therapeutic applications in non-alcoholic steatohepatitis. We here discuss these topics with the aim of stimulating the interest of the scientific community and further research activities that may help to celebrate this anniversary of vitamin E with an in-depth knowledge of its action as vitamin.

Compromised redox homeostasis, altered nitroso-redox balance, and therapeutic possibilities in atrial fibrillation

Although the initiation, development, and maintenance of atrial fibrillation (AF) have been linked to alterations in myocyte redox state, the field lacks a complete understanding of the impact these changes may have on cellular signalling, atrial electrophysiology, and disease progression. Recent studies demonstrate spatiotemporal changes in reactive oxygen species production shortly after the induction of AF in animal models with an uncoupling of nitric oxide synthase activity ensuing in the presence of long-standing persistent AF, ultimately leading to a major shift in nitroso–redox balance. However, it remains unclear which radical or non-radical species are primarily involved in the underlying mechanisms of AF or which proteins are targeted for redox modification. In most instances, only free radical oxygen species have been assessed; yet evidence from the redox signalling field suggests that non-radical species are more likely to regulate cellular processes. A wider appreciation for the distinction of these species and how both species may be involved in the development and maintenance of AF could impact treatment strategies. In this review, we summarize how redox second-messenger systems are regulated and discuss the recent evidence for alterations in redox regulation in the atrial myocardium in the presence of AF, while identifying some critical missing links. We also examine studies looking at antioxidants for the prevention and treatment of AF and propose alternative redox targets that may serve as superior therapeutic options for the treatment of AF.

Effects of Pistacia Atlantica Extract on Erythrocyte Membrane Rigidity, Oxidative Stress, and Hepatotoxicity Induced by CCl4 in Rats

BACKGROUND

Previous findings have suggested that antioxidants may reduce the levels of free radicals, which induce oxidative damage and play a key role in various diseases. Thus, we evaluated the protective activity of a Pistacia atlantica extract on erythrocyte membrane rigidity, oxidative stress, and hepatotoxicity induced by carbon tetrachloride (CCl4) in rats.

MATERIALS & METHODS

Fresh leaves of P.atlantica were collected from the mountains in Yasuj, Iran. Acute oral toxicity (LD50) was evaluated in Wistar rats (200-230 g). Animals were randomly divided into 4 groups, out of which the negative and plant control groups received distilled water and P. atlantica extracts (500 mg/kg), respectively. The toxic rat group received CCl4, while the treatment group received CCl4+P. atlantica extract. Blood plasma was utilized for the estimation of enzyme markers and lipid peroxidation, whereas hemolysate was applied for the determination of superoxide dismutase (SOD) and catalase activities. The levels of cholesterol and phospholipids in erythrocyte membranes were also determined. Rats were killed under anesthesia by cervical dislocation; liver was isolated from each rat and tissues homogenization was prepared for biochemical parameters such as malondialdehyde (MDA) and reduced glutathione (GSH) levels.

RESULTS

LD50 values were determined for doses>3000 mg/kg (p.o.). The activities of glutamic pyruvate transaminase (GPT), glutamic oxaloacetate transaminase (GOT), alkaline phosphatase (ALP) and GSH in the protected group were significantly (p<0.001) reduced compared with those of toxic rats. In addition, we observed a decrease in the cholesterol level and an increase in red blood cell membrane phospholipids, SOD, and catalase activities (p<0.001) in the protected group, as compared with toxic rats. Administration of Pistacia atlantica extract normalized liver tissue MDA level (p<0.01) when compared to CCl4 treated group.

CONCLUSION

The P. atlantica extract was able to normalize the levels of biochemical markers, including liver enzyme markers, first-line defense enzymes, and lipid peroxidation markers.

Non-alcoholic fatty liver disease: need for a balanced nutritional source

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are an increasingly common chronic liver disease closely associated with diabetes and obesity that have reached epidemic proportions. Reports on the prevalence of NAFLD have suggested that 27-34% of the general population in the USA and 40-90% of the obese population worldwide have this disease. Increasing urbanisation rate and associated inappropriate lifestyle changes are not only the risk factors of diabetes, but also unmask genetic predisposition in various populations for the metabolic syndrome and its manifestations including NAFLD and NASH. Lifestyle modifications and balanced nutrition are among the foremost management strategies along with ursodeoxycholic acid, metformin, vitamin E and pentoxifylline. Although weight reduction associated with current therapeutic strategies has shown some promise, maintaining it in the long run is largely unsuccessful. With the safety of pharmacotherapy still being uncertain and can be started only after confirmation, other reasonable interventions such as nutrition hold promise in preventing disease progression. The role of dietary components including branched-chain amino acids, methionine, choline and folic acid is currently being evaluated in various clinical trials. Nutritional approaches sought to overcome the limitations of pharmacotherapy also include evaluating the effects of natural ingredients, such as silymarin and spirulina, on liver disease. Understanding the specific interaction between nutrients and dietary needs in NAFLD and maintaining this balance through either a diet or a nutritional product thus becomes extremely important in providing a more realistic and feasible alternative to treat NAFLD. A planned complete nutritional combination addressing specific needs and helping to prevent the progression of NAFLD is the need of the hour to avert people from ending up with complications.

Effects of dietary selenium on the pathological changes and oxidative stress in loach (Paramisgurnus dabryanus)

In this study, loach (Paramisgurnus dabryanus) were fed artificial diets containing 0.31 (control), 0.39, 0.48, 0.50 and 0.62 mg kg(-1) of selenium (Se) for 60 days, respectively. Liver histopathology, hepatocyte ultrastructure, blood indices, biochemical parameters of liver functions and oxidative stress in the Se-treated loach were then assayed. The results showed the following: histopathological and ultrastructural lesions in liver were only observed in loach fed the 0.62 mg Se kg(-1) diet; Haemoglobin and total protein were significantly increased in the 0.50 mg Se kg(-1) group; albumin and high-density lipoprotein were increased significantly in the 0.48-0.50 mg Se kg(-1) groups. However, white blood cell count was significantly decreased in the 0.48 mg Se kg(-1) group; alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase were decreased in the 0.39-0.50 mg Se kg(-1) groups. In liver tissue, the content of hydrogen peroxide was lower than that of controls in the 0.48-0.50 mg Se kg(-1) groups, and the malondialdehyde level was lowest in the 0.48 mg Se kg(-1) group. The activities of superoxide dismutase and glutathione peroxidase were significantly increased in the 0.50 mg Se kg(-1) group; catalase and total antioxidant capacity were markedly increased in the 0.48-0.50 mg Se kg(-1) group. These present results indicated that the dietary Se requirement for loach is 0.48-0.50 mg Se kg(-1) diet.

The protective effect of Phoenix dactylifera L. seeds against CCl4-induced hepatotoxicity in rats

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Egyptian medicine, Phoenix dactylifera L. (date palm) seeds are listed in folk remedies for the management of diabetes, liver diseases and gastrointestinal disorders. The present study was conducted to investigate the protective effect of Phoenix dactylifera L. seeds aqueous suspension against the chemically-induced hepatic injury in rats.

METHODS

Liver injury was achieved by exposing Wistar rats to CCl4 (10% in olive oil; 0.5 mL/rat; IP) twice a week for 4 weeks. Along with CCl4, aqueous suspensions of raw or roasted Phoenix dactylifera seeds (1.0 g/kg) were administered orally in a daily manner.

RESULTS

Our results demonstrated that Phoenix dactylifera seeds significantly improved the CCl4-induced alterations in liver function parameters (AST, ALT, ALP and albumin). Moreover, the CCl4-induced oxidative stress, represented by elevated thiobarbituric acid reactive substance (TBARS), nitric oxide and oxidative DNA damage, was ameliorated by Phoenix dactylifera seeds treatment. In addition, Phoenix dactylifera seeds restored the activities of hepatic antioxidant enzymes (superoxide dismutase and glutathione S-transferase) that were declined after CCl4 treatment. Examination of liver histopathology revealed that Phoenix dactylifera seeds attenuate the incidence of liver lesions (including vacuolization and fibroblast proliferation) triggered by CCl4 intoxication.

CONCLUSION

The Phoenix dactylifera seeds could be a promising candidate for protection against the CCl4-induced liver intoxication, and this hepatoprotective effect might be attributed to the antioxidant and free radical scavenging activities.

Comparison of 4-hydroxynonenal-induced p53-mediated apoptosis in prostate cancer cells LNCaP and DU145

AIM OF THE STUDY

To explore the mechanism of oxidative stress in the development of prostate cancer, here we compared 4-hydroxynonenal (4-HNE)- treated LNCaP (hormone-sensitive) and DU145 (hormone insensitive) cells with significant differences in sensitivity to androgen.

MATERIAL AND METHODS

The prostate cancer cell line LNCaP and late cell line DU145 were treated with different concentrations of 4-HNE. The cell proliferation, apoptosis and mitochondrial transmembrane potential were detected at different time points, and expression of related molecules in cell proliferation and apoptosis signal pathway was analyzed by Western blot, and the over-expression of glutathione S-transferase (GSTA-4) was used to validate the changes of the effects of 4-HNE on the two kinds of cells.

RESULTS

LNCaP cells showed greater antiproliferative and proapoptotic activities of HNE in a time- and dose-dependent manner corresponding to the activation of p53-mediated intrinsic apoptotic signaling, but JNK activation was not observed. In contrast, HNE-treated DU145 cells showed less apoptosis and proliferation was not inhibited; instead there was sustained activation of JNK, but activation of p53, p-p53, p21, Bax and caspase-3 was not observed. In addition, their effect of induction of apoptosis can be inhibited by overexpression of GSTA-4.

CONCLUSIONS

These studies suggest that 4-HNE promotes prostate cancer cell apoptosis through the p53 signaling pathway; the differences of sensitivity to 4-HNE in LNCaP and DU145 cells may be related to the androgen sensitivity of prostate cancer cells; and the 4-HNE-induced p53-mediated apoptosis signal is regulated by GSTA-4.

Regulation of hepatic EAAT-2 glutamate transporter expression in human liver cholestasis

AIM: To investigate the activity and expression of EAAT2 glutamate transporter in both in vitro and in vivo models of cholestasis.

METHODS: This study was conducted on human hepatoblastoma HepG2 cell cultures, the liver of bile duct ligated rats and human specimens from cholestatic patients. EAAT2 glutamate transporter activity and expression were analyzed using a substrate uptake assay, immunofluorescence, reverse transcription-polymerase chain reaction, and immunohistochemistry, respectively.

RESULTS: In HepG2 cells, cholestasis was mimicked by treating cells with the protein kinase C activator, phorbol 12-myristate 13-acetate. Under such conditions, EAAT2 transporter activity was decreased both at the level of substrate affinity and maximal transport velocity. The decreased uptake was correlated with intracellular translocation of EAAT2 molecules as demonstrated using immunofluorescence. In the liver of bile duct ligated rats, an increase in EAAT2 transporter protein expression in hepatocytes was demonstrated using immunohistochemistry. The same findings were observed in human liver specimens of cholestasis in which high levels of γ-glutamyl transpeptidase were documented in patients with biliary atresia and progressive familial intrahepatic cholestasis type 3.

CONCLUSION: This study demonstrates the alteration in glutamate handling by hepatocytes in liver cholestasis and suggests a potential cross-talk between glutamatergic and bile systems.

Review article: The prevention and reversal of hepatic fibrosis in autoimmune hepatitis

BACKGROUND

Immunosuppressive treatment of autoimmune hepatitis can prevent or reverse hepatic fibrosis, but these anti-fibrotic effects are inconsistent secondary gains.

AIM

To describe the anti-fibrotic effects of current therapies for autoimmune hepatitis, discuss the pathogenic mechanisms of hepatic fibrosis that might be targeted by anti-fibrotic interventions, indicate the non-invasive diagnostic tests of hepatic fibrosis that must be validated in autoimmune hepatitis and to suggest promising treatment opportunities.

METHODS

Studies cited in PubMed from 1972 to 2013 for autoimmune hepatitis, hepatic fibrosis, cirrhosis, anti-fibrotic therapy and non-invasive tests of hepatic fibrosis were selected.

RESULTS

Hepatic fibrosis improves in 53-57% of corticosteroid-treated patients with autoimmune hepatitis; progressive fibrosis slows or is prevented in 79%; and cirrhosis may be reversed. Progressive hepatic fibrosis is associated with liver inflammation, and the inability to fully suppress inflammatory activity within 12 months is associated with progression to cirrhosis (54%) and death or need for liver transplantation (15%). Liver tissue examination remains the gold standard for assessing hepatic fibrosis, but laboratory and radiological tests may be useful non-invasive methods to measure the fibrotic response. Severe liver inflammation can confound radiological assessments, and the preferred non-invasive test in autoimmune hepatitis is uncertain. Individualised treatment adjustments and adjunctive anti-fibrotic therapies are poised for study in this disease.

CONCLUSIONS

The prevention and reversal of hepatic fibrosis are achievable objectives in autoimmune hepatitis. Strategies that evaluate individualised therapies adjusted to the rapidity and completeness of the inflammatory response, and the use of adjunctive anti-fibrotic interventions, must be evaluated.

How do nutritional antioxidants really work: nucleophilic tone and para-hormesis versus free radical scavenging in vivo

We present arguments for an evolution in our understanding of how antioxidants in fruits and vegetables exert their health-protective effects. There is much epidemiological evidence for disease prevention by dietary antioxidants and chemical evidence that such compounds react in one-electron reactions with free radicals in vitro. Nonetheless, kinetic constraints indicate that in vivo scavenging of radicals is ineffective in antioxidant defense. Instead, enzymatic removal of nonradical electrophiles, such as hydroperoxides, in two-electron redox reactions is the major antioxidant mechanism. Furthermore, we propose that a major mechanism of action for nutritional antioxidants is the paradoxical oxidative activation of the Nrf2 (NF-E2-related factor 2) signaling pathway, which maintains protective oxidoreductases and their nucleophilic substrates. This maintenance of "nucleophilic tone," by a mechanism that can be called "para-hormesis," provides a means for regulating physiological nontoxic concentrations of the nonradical oxidant electrophiles that boost antioxidant enzymes, and damage removal and repair systems (for proteins, lipids, and DNA), at the optimal levels consistent with good health.

Effect of vitamin e supplementation on biochemical parameters in pesticides sprayers of grape gardens of Western maharashtra (India)

The aim of this study was to see the biochemical effects of pesticides on sprayers of grape gardens before and after 15 days of vitamin E supplementations in Western Maharashtra (India), who were occupationally exposed to various pesticides over a long period of time (about 5 to 15 years). Blood samples were collected from all study group subjects for biochemical parameters assays before and after 15 days of vitamin E supplementation. Sprayers of grape gardens were given 400 mg of vitamin E tablet/day for 15 days. After 15 days of vitamin E supplementation to sprayers of grape gardens, we observed significantly decreased aspartate transaminase (10.88 %, P < 0.05, r = 0.88), alanine transaminase (25.92 %, P < 0.01, r = 0.46) and total proteins (3.32 %, P < 0.01, r = 0.33), whereas, no statistically significant change was found in serum acetyl cholinesterase, C-reactive proteins, albumin (ALB), globulins and ALB/globulin ratio as compared to before vitamin E supplementation. Sprayers of grape gardens, who received vitamin E supplementation, showed significantly decreased serum lipid peroxide (LP) (18.75 %, P < 0.001, r = 0.63) and significantly increased RBC-superoxide dismutase (SOD) (12.88 %, P < 0.001, r = 0.85), RBC-Catalase (CAT) (24.49 %, P < 0.001, r = 0.70), plasma ceruloplasmin (CP) (4.6 %, P < 0.01, r = 0.80), serum zinc (4.57 %, P < 0.01, r = 0.83) and serum copper (4.37 %, P < 0.01, r = 0.79) as compared to values before vitamin E supplementation. These results showed that vitamin E supplementation has ameliorating effects on these transaminase enzymes, suggesting that it may have a protective effect on liver, from pesticides induced damage. In this study vitamin E supplementation might have decreased LP levels by breaking chain reaction of lipid peroxidation. Present results indicate that vitamin E plays a crucial role in restoring the antioxidant enzymes such as SOD, CAT and CP, in population exposed to pesticides. This helps to enhance its antioxidant ability. Therefore, it is suggested that farmers, pesticide applicators, workers in the pesticide industry and other pesticide users, who come in regular contact with pesticides, may be benefited by supplementation with vitamin E.

Metabolic syndrome and hepatic resection: improving outcome

OBJECTIVE

A review of the peri-operative risk associated with hepatic resection in patients with metabolic syndrome (MetS) and identification of measures for the improvement of cardiometabolic disturbances and liver-related mortality.

BACKGROUND

MetS and its hepatic manifestation non-alcoholic fatty liver disease (NAFLD) are associated with an increased operative mortality in spite of a significant improvement in peri-operative outcome after hepatic resection.

METHODS

A review of the English literature on MetS, liver resection and steatosis was performed from 1980 to 2011 using the MEDLINE and PubMed databases.

RESULTS

MetS is a predictor of NAFLD and patients with multiple metabolic risk factors may harbour non-alcoholic steatohepatitis (NASH) predictive of operative and cardiovascular mortality. Pre-operative diagnosis of unsuspected NASH with the selective use of a liver biopsy can modify the operative strategy by limiting the extent of hepatic resection, avoiding or altering the pre-operative chemotherapy regimen and the utilization of portal vein embolization. Thiazolidinediones are therapeutic for MetS and NASH and Vitamin E for active NASH; however, their utility in improving the peri-operative outcome after hepatic resection is unknown. A short-term regimen for weight loss improves post-operative patient and liver-related outcomes in patients with >30% steatosis. Cardiovascular disease associated with MetS or NAFLD should be managed aggressively. Peri-operative measures to minimize thrombotic events and acute renal injury secondary to the pro-inflammatory, prothrombotic state of MetS may further improve the outcome.

CONCLUSION

Potential candidates for hepatic resection should be screened for MetS as the pre-operative identification of NASH, short-term treatment of significant steatosis, cardiovascular risk assessment and optimization of each component of MetS may improve the peri-operative outcome in this high-risk subset of patients.

Redox balance in the pathogenesis of nonalcoholic fatty liver disease: mechanisms and therapeutic opportunities

Nonalcoholic fatty liver disease (NAFLD) is currently the most common liver disease in the world. It encompasses a histological spectrum, ranging from simple, nonprogressive steatosis to nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis and hepatocellular carcinoma. While liver-related complications are confined to NASH, emerging evidence suggests both simple steatosis and NASH predispose to type 2 diabetes and cardiovascular disease. The pathogenesis of NAFLD is currently unknown, but accumulating data suggest that oxidative stress and altered redox balance play a crucial role in the pathogenesis of steatosis, steatohepatitis, and fibrosis. We will examine intracellular mechanisms, including mitochondrial dysfunction and impaired oxidative free fatty acid metabolism, leading to reactive oxygen species generation; additionally, the potential pathogenetic role of extracellular sources of reactive oxygen species in NAFLD, including increased myeloperoxidase activity and oxidized low density lipoprotein accumulation, will be reviewed. We will discuss how these mechanisms converge to determine the whole pathophysiological spectrum of NAFLD, including hepatocyte triglyceride accumulation, hepatocyte apoptosis, hepatic inflammation, hepatic stellate cell activation, and fibrogenesis. Finally, available animal and human data on treatment opportunities with older and newer antioxidant will be presented.

The combination of selenium and vitamin E inhibits type I collagen formation in cultured hepatic stellate cells

This study investigated the effects of sodium selenite (Se) and of vitamin E (D-α-tochopherol) on the deposition of type I collagen by human LX-2 stellate cells. The cultured cells were treated with or without Se or vitamin E and with or without transforming growth factor β1 (TGFβ1). The combination of Se and vitamin E, but not either alone, protected against hepatic fibrosis by decreasing TGFβ1-mediated collagen secretion and accumulation by the stellate cells. This protective effect is due to a combination of decreased formation, decreased stability and increased degradation of the collagen. Effects of Se and vitamin E in decreasing α(1)(I) collagen mRNA and increasing apoptosis of stellate cells indicate decreased formation of collagen, while decreases in transglutaminase 2, which catalyze cross-linking of collagen, lead to decreased stability of the secreted collagen. Effects of Se and vitamin E on reducing tissue inhibitor metalloproteinase 1 (TIMP-1) are associated with increased degradation. The combination of Se and vitamin E decreased lipid peroxidation, while Se alone increased the activity of the antioxidant enzyme thioredoxin reductase. In conclusion, the combination of Se and vitamin E protected against TGFβ1-mediated hepatic fibrosis by decreasing TGFβ1-mediated type I collagen accumulation by stellate cells. This effect is due to a combination of decreased formation, decreased stability and increased degradation of the collagen.

Novel treatment modalities for nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is the most common cause of chronic liver disease in the Western world. It can lead to cirrhosis and hepatocellular cancer, and is independently associated with an increased risk of death due to cardiovascular and liver diseases. Over the past 5 years, numerous advances in understanding its pathogenesis have been made, providing a rationale for translation of this information into clinical trials. Although the optimum therapy is still awaited, there is strong evidence to support the use of vitamin E in selected subjects. Many other potential therapeutic options are now available. In this paper, we review the status of both current and emerging therapeutic strategies for patients with NASH.

Hepatoprotective role and antioxidant capacity of selenium on arsenic-induced liver injury in rats

The present study was undertaken to evaluate the protective effect of selenium against arsenic-induced oxidative damage in experimental rats. Males were randomly divided into four groups where the first was served as a control, whereas the remaining groups were respectively treated with sodium selenite (3 mg/kg b.w.), sodium arsenite (5.55 mg/kg b.w.) and a combination of sodium arsenite and sodium selenite. Changes in liver enzyme activities, thiobarbituric acid reactive substances (TBARS) level, antioxidants and reduced glutathione (GSH) contents were determined after 3 weeks experimental period. Exposure of rats to As caused a significant increase in liver TBARS compared to control, but the co-administration of Se was effective in reducing its level. The activities of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) of As-treated group were found lower compared to the control and the Se-treated group. The co-administration of Se had an additive protective effect on liver enzyme activities compared to As-treated animals. On the other hand, a significant increase in plasmatic activities of AST, ALT and ALP was observed in As-treated group. The latter was also exhibited a decrease in body weight and an increase in liver weight compared to the control. The co-administration of Se has decreased the activities of AST, AST and ALP and improved the antioxidant status as well. Liver histological studies have confirmed the changes observed in biochemical parameters and proved the beneficial role of Se. To conclude, results suggest that As exposure enhanced an oxidative stress by disturbing the tissue antioxidant defense system, but the Se co-administration protected liver tissues against As intoxication probably owing to its antioxidant properties.

Protective Effects of Vitamin E Analogs against Carbon Tetrachloride-Induced Fatty Liver in Rats

Recently, it has been reported that α-tocopherol (α-Toc) is effective for amelioration of liver damage. However, it is unknown whether other vitamin E analogs are effective. In this study, we investigated the effects of γ-tocopherol (γ-Toc) and tocotrienols (T3) in rats with fatty liver. Rats fed a vitamin E-deficient diet for four weeks were divided into eight groups: Control, carbon tetrachloride (CCl(4)), α-Toc, α-Toc + CCl(4), γ-Toc, γ-Toc + CCl(4), T3 mix, T3 mix + CCl(4). After a 24 h fast, the rats were administered 20 mg of each of the vitamin E analogs, respectively. Moreover, the CCl(4) group were given 0.5 ml/kg body weight corn oil preparation containing CCl(4) 6 h after vitamin E administration. We measured the activities of aspartate aminotransferase and alanine aminotransferase (ALT) in plasma, and the contents of triglyceride (TG), total cholesterol (T-Chol) and vitamin E analogs in the liver. Also, we determined the hepatic expression of mRNA for inflammatory cytokines. The liver TG content in the γ-Toc + CCl(4) and T3 mix + CCl(4) groups was decreased in comparison with the CCl(4) group. Moreover, ALT activity in the T3 mix + CCl(4) group was significantly lower than CCl(4) group. These findings suggest that γ-Toc and T3 are effective for amelioration of fatty liver.

The multifaceted role of pirfenidone and its novel targets

BACKGROUND

Pirfenidone (PFD) is a molecule that exhibits antifibrotic properties in a variety of in vitro and animal models of lung, liver and renal fibrosis. These pathologies share many fibrogenic pathways with an abnormal fibrous wound-healing process; consequently, tissue repair and tissue regeneration-regulating mechanisms are altered.

OBJECTIVE

To investigate the usefulness of PFD as an antifibrotic agent in clinical and experimental models of fibrotic disease.

CONCLUSIONS

There is a growing understanding of the molecular effects of PFD on the wound healing mechanism, leading to novel approaches for the management of fibrosis in lung, liver and renal tissues. Although the optimum treatment for fibrosis remains undefined, it is possible that combined therapeutic regimens that include this wide-application molecule, pirfenidone, could offer a useful treatment for fibrotic disease.

Effects of 1-O-hexyl-2,3,5-trimethylhydroquinone on carbon tetrachloride-induced hepatic cirrhosis in rats

AIM

The present study was undertaken to evaluate the effects of 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), a synthesized vitamin E derivative, on carbon tetrachloride (CCl(4))-induced cirrhosis.

METHODS

Rats were treated with hypodermic injections of CCl(4) twice a week to induce the hepatic cirrhosis, and given drinking water containing HTHQ or solvent. Primary cultures of rat hepatocytes were performed to evaluate the effects of HTHQ on the expression of inducible nitric oxide synthase (iNOS).

RESULTS

Masson's staining of rat livers showed fibrosis around pseudo-lobules in the CCl(4) group, the lesions being reduced in the CCl(4) HTHQ group. Increases in liver tissue hydroxyproline and alpha(1)(I) collagen, alpha-smooth muscle actin and iNOS induced by CCl(4), were also markedly diminished by HTHQ. Furthermore, both HTHQ and vitamin E attenuated interleukin-1beta-induced iNOS protein expression in cultured hepatocytes, the potency of HTHQ being 10-times higher than that of vitamin E.

CONCLUSION

HTHQ may inhibit development of hepatic cirrhosis in rats, more potently than vitamin E, by inhibiting the iNOS expression in hepatocytes. Because vitamin E has a radical scavenging action, roles of NO and peroxynitrite will be discussed in the effects of HTHQ on the fibrosis.

Pharmacologic therapy of non-alcoholic steatohepatitis

Specific therapy for non-alcoholic steatohepatitis (NASH) is needed because of the potential severity of this liver disease. NASH is a recognized cause of cryptogenic cirrhosis and, increasingly, of hepatocellular carcinoma. Therefore, there is an unmet medical need for the therapy of NASH. This article discusses this therapy, with particular emphasis on pharmacologic therapy.