The effect of betaine treatment on triglyceride levels and oxidative stress in the liver of ethanol-treated guinea pigs

Betaine alleviates doxorubicin-related cardiotoxicity via suppressing oxidative stress and inflammation via the NLRP3/SIRT1 pathway

Cardiotoxicity is one of the side effects of the anti-cancer drug doxorubicin (DOX) that limits its clinical application. Betaine (BT) is a natural agent with promising useful effects against inflammation and oxidative stress (OS). We assessed the effects of BT on DOX-induced cardiotoxicity in mice. Forty-two male NMRI mice were assigned to six groups: I: control; II: BT (200 mg/kg; orally, alone); III: DOX (2.5 mg/kg; six injections (ip)) for two weeks; IV, V, VI: BT (50 mg/kg, 100 mg/kg, and 200 mg/kg; orally, once a day for two weeks, respectively) plus DOX administration. The cardiac enzymes like cardiac troponin-I (cTn-I), lactate dehydrogenase (LDH), and creatine kinase-MB (CK-MB) were assessed in serum. Oxidative/inflammatory markers like nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reduced glutathione level (GSH), and glutathione peroxidase (GPx) activities were determined in cardiac tissue. The expressions of NOD-like receptor protein 3 (NLRP3), caspase-1, interleukin (IL)-1β, and silent information regulator 1 (SIRT1) proteins were also evaluated in cardiac tissue. The results indicated that DOX significantly increased LDH, CK-MB, cTn-I, MDA, and NO levels and also the caspase-1, NLRP3, and IL-1β expression. Furthermore, DOX caused a significant reduction in the GSH levels and SOD, CAT, GPX activities, and the expression of SIRT1 protein in heart tissue. However, BT significantly improved all studied parameters. The findings were confirmed by histopathological assessments of the heart. BT can protect against DOX-induced cardiotoxicity by suppressing the activation of NLRP3 and OS by stimulating the SIRT1 pathway.

Glycine Betaine Relieves Lead-Induced Hepatic and Renal Toxicity in Albino Rats

Lead (Pb) is a widespread and nondegradable environmental pollutant and affects several organs through oxidative mechanisms. This study was conducted to investigate the antioxidant protective effect of glycine betaine (GB) against Pb-induced renal and hepatic injury. Male albino rats (n = 45) were divided into three groups: G1 untreated control, G2 Pb-acetate (50 mg/kg/day), and G3 Pb-acetate (50 mg/kg/day) plus GB (250 mg/kg/day) administered for 6 weeks. For G3, Pb-acetate was administered first and followed by GB at least 4 h after. Pb-acetate treatment (G2) resulted in a significant decrease in renal function, including elevated creatinine and urea levels by 17.4% and 23.7%, respectively, and nonsignificant changes in serum uric acid levels. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphates (ALP) activities were significantly increased with Pb treatment by 37.6%, 59.3%, and 55.1%, respectively. Lipid peroxidation level was significantly increased by 7.8 times after 6 weeks of Pb-acetate treatment. The level of reduced glutathione (GSH-R) significantly declined after Pb-acetate treatment. Pb-acetate treatment also reduced the activities of superoxide dismutase (SOD), glutathione-S-transferase (GST), and glutathione peroxidase (GSH-PX) by 74.1%, 85.0%, and 40.8%, respectively. Treatment of Pb-intoxicated rats with GB resulted in a significant reduction in creatinine, urea, ALT, AST, and lipid peroxidation, as well as a significant increase in the level of GSH-R and in the activities of ALP, SOD, GST, and GSH-PX. The molecular interaction between GB and GSH-PX indicated that the activation of GSH-PX in Pb-intoxicated rats was not the result of GB binding to the catalytic site of GSH-PX. The affinity of GB to bind to the catalytic site of GSH-PX is lower than that of H₂O₂. Thus, GB significantly mitigates Pb-induced renal and liver injury through the activation of antioxidant enzymes and the prevention of Pb-induced oxidative damage in the kidney and liver.

Betaine in ameliorating alcohol-induced hepatic steatosis

Alcohol-associated liver disease (AALD) is one of most common chronic liver diseases. Hepatic steatosis is the earliest stage in AALD pathological spectrum, reversible by alcohol abstinence. Untreated steatosis can progress to steatohepatitis, fibrosis and/or cirrhosis. Considering the difficulties in achieving complete abstinence, challenges in disease reversal at advanced stages, high costs of AALD management and lack of standardised prescribed medications for treatment, it is essential to explore low-cost natural compounds that can target AALD at an early stage and halt or decelerate disease progression. Betaine is a non-hazardous naturally occurring nutrient. Here, we address the mechanisms of alcohol-induced hepatic steatosis, the role of betaine in reversing the effects i.e., its action against hepatic steatosis in animal models and humans, and the associated cellular and molecular processes. Accordingly, the review discusses how betaine restores the alcohol-induced reduction in methylation potential by elevating the levels of S-adenosylmethionine and methionine. It details how betaine reinstates alcohol-induced alterations in the expressions and/or activities of protein phosphtase-2A, FOXO1, PPAR-α, AMPK, SREBP-1c, fatty acid synthase, diacylglycerol transferase-2, adiponectin and nitric oxide. Interrelationships between these factors in preventing de novo lipogenesis, reducing hepatic uptake of adipose-tissue-derived free fatty acids, promoting VLDL synthesis and secretion, and restoring β-oxidation of fatty acids to attenuate hepatic triglyceride accumulation are elaborated. Despite its therapeutic potential, very few clinical trials have examined betaine’s effect on alcohol-induced hepatic lipid accumulation. This review will provide further confidence to conduct randomised control trials to enable maximum utilisation of betaine’s remedial properties to treat alcohol-induced hepatic steatosis.

Alcoholic liver disease: Current insights into cellular mechanisms

Alcoholic liver disease (ALD) due to chronic alcohol consumption is a significant global disease burden and a leading cause of mortality. Alcohol abuse induces a myriad of aberrant changes in hepatocytes at both the cellular and molecular level. Although the disease spectrum of ALD is widely recognized, the precise triggers for disease progression are still to be fully elucidated. Oxidative stress, mitochondrial dysfunction, gut dysbiosis and altered immune system response plays an important role in disease pathogenesis, triggering the activation of inflammatory pathways and apoptosis. Despite many recent clinical studies treatment options for ALD are limited, especially at the alcoholic hepatitis stage. We have therefore reviewed some of the key pathways involved in the pathogenesis of ALD and highlighted current trials for treating patients.

Effect of Betaine Supplementation on Liver Tissue and Ultrastructural Changes in Methionine-Choline-Deficient Diet-Induced NAFLD

Nonalcoholic fatty liver disease (NAFLD) represents a hepatic manifestation of metabolic syndrome. The aim of this study was to examine the effect of betaine on ultrastructural changes in the mouse liver with methionine- and choline-deficient (MCD) diet-induced NAFLD. Male C57BL/6 mice were divided into groups: Control-fed with standard chow, BET-standard chow supplemented with betaine (1.5% w/v drinking water), MCD-fed with MCD diet, and MCD + BET-MCD diet with betaine supplementation for 6 weeks. Liver samples were taken for pathohistology and transmission electron microscopy. The MCD diet-induced steatosis, inflammation, and balloon-altered hepatocytes were alleviated by betaine. MCD diet induced an increase in mitochondrial size versus the control group (p < 0.01), which was decreased in the betaine-treated group. In the MCD diet-fed group, the total mitochondrial count decreased versus the control group (p < 0.01), while it increased in the MCD + BET group versus MCD (p < 0.01). Electron microscopy showed an increase in the number of autophagosomes in the MCD and MCD + BET group versus control, and a significant difference in autophagosomes number was detected in the MCD + BET group by comparison with the MCD diet-treated group (p < 0.05). Betaine decreases the number of enlarged mitochondria, alleviates steatosis, and increases the number of autophagosomes in the liver of mice with NAFLD.

Effect of Lactobacillus paracasei HII01 Supplementation on Total Cholesterol, and on the Parameters of Lipid and Carbohydrate Metabolism, Oxidative Stress, Inflammation and Digestion in Thai Hypercholesterolemic Subjects

Hypercholesterolemia is one of the leading causes of cardiovascular disease. Probiotics can help to improve high blood lipid levels in hypercholesterolemia patients. Lactobacillus paracasei has been reported to have beneficial effects in several subjects; however, there is a lack of studies on Thai hypercholesterolemic subjects. Thus, this study was conducted in order to investigate the effect of L. paracasei HII01 on cholesterol, oxidative stress, and other biomarkers. Fifty-two subjects were randomized into two groups: the L. paracasei treatment group and the placebo group. The study was conducted over an intervention period of 12 weeks of supplementation. The results show that L. paracasei HII01 significantly reduced the total cholesterol (TCH), triglycerides (TGs), tumor necrosis factor (TNF)-α and lipopolysaccharide (LPS) of the patients, and increased their HDL, total antioxidant capacity (TAC) and propionic acid compared to the placebo group. Moreover, the supplementation of L. paracasei HII01 significantly increased lactic acid, IL-10 and IFN-γ, and substantially decreased malondialdehyde (MDA) at the end of the treatment. The results suggest that L. paracasei HII01 improves the blood lipid profile, reduces oxidative stress, and is beneficial for health among Thai hypercholesterolemic subjects.

Highly Water-Preserving Zwitterionic Betaine-Incorporated Collagen Sponges With Anti-oxidation and Anti-inflammation for Wound Regeneration

A core problem in wound healing – with both fundamental and technological significance – concerns the rational design of bioactive and moist microenvironments. Here, we design a new class of zwitterionic betaine-incorporated collagen sponges (BET@COL) with integrated anti-oxidation and anti-inflammatory properties for promoting wound healing in a full-thickness wound model. The presence of zwitterionic betaine in a 3D network structure of collagen enables tightly bound and locked water molecules inside sponges via ionic solvation and confinement effect, while the integration of this amino acid also empowers the sponge with anti-oxidation and anti-inflammatory functions. In vitro results demonstrated that BET@COL collagen sponges strongly preserved water content up to 33.78 ± 0.78% at the 80th min at 37°C (only 0.44 ± 0.18% in control), and also exhibited high cell biocompatibility. Further, BET@COL collagen sponges with different betaine contents were applied to a full-thickness cutaneous wound model in mice, followed by a systematical evaluation and comparison of the effect of preserved water on wound healing efficiency in vivo. The optimal BET@COL collagen sponges were able to maintain high water content (e.g., moist microenvironment), suppress oxidative stress, improve anti-inflammation, all of which impose synergetic healing effects to promote wound closure, granulation formation, re-epithelization, collagen deposition and angiogenesis. This work demonstrates a new material as a promising candidate for wound dressing.

Betaine treatment decreased serum glucose and lipid levels, hepatic and renal oxidative stress in streptozotocin-induced diabetic rats

Objective

The present study was aimed to investigate the effects of betaine (BET) on streptozotocin (STZ)-induced diabetes mellitus (DM) in rats. Additionally, the efficiency of BET was compared with metformin (MET), a standard oral antidiabetic drug.

Methods

STZ (55 mg/kg body weight; i.p.) was injected to male Wistar rats. Rats with DM were treated with BET (1 g/kg body weight/day;) or MET (500 mg/kg body weight/day;) for 4 weeks. Blood glycated hemoglobin (HbA1c), serum glucose, lipids, hepatic and renal function tests and urinary protein levels were examined. Reactive oxygen species (ROS) formation, malondialdehyde (MDA), glutathione (GSH) levels, and ferric reducing antioxidant power (FRAP) were also determined in liver and kidney.

Results

Glucose, HbA1c, and serum lipids increased and liver and kidney function tests were impaired in diabetic rats. Hepatic and renal ROS formation and MDA levels were elevated, hepatic, but not renal GSH and FRAP levels were decreased. BET decreased blood HbA1c, serum glucose and lipid levels and urine protein levels. BET diminished hepatic and renal prooxidant status.

Conclusion

Our results indicate that BET may be effective in decreasing STZ-induced high levels of blood HbA1c, and serum glucose and lipid levels and prooxidant status in liver and kidney tissues.

Betaine attenuates chronic alcohol‑induced fatty liver by broadly regulating hepatic lipid metabolism

Betaine has previously been demonstrated to protect the liver against alcohol‑induced fat accumulation. However, the mechanism through which betaine affects alcohol‑induced hepatic lipid metabolic disorders has not been extensively studied. The present study aimed to investigate the effect of betaine on alcoholic simple fatty liver and hepatic lipid metabolism disorders. A total of 36 rats were randomly divided into control, ethanol and ethanol + betaine groups. Liver function, morphological alterations, lipid content and tumor necrosis factor (TNF)‑α levels were determined. Hepatic expression levels of diacylglycerol acyltransferase (DGAT) 1, DGAT2, sterol regulatory element binding protein (SREBP)‑1c, SREBP‑2, fatty acid synthase (FAS), 3‑hydroxy‑3‑methyl‑glutaryl (HMG)‑CoA reductase, peroxisome proliferator-activated receptor λ coactivator (PGC)‑1α, adiponectin receptor (AdipoR) 1 and AdipoR2 were quantified. Serum and adipose tissue adiponectin levels were assessed using an enzyme‑linked immunoassay. The results demonstrated that alcohol‑induced ultramicrostructural alterations in hepatocytes, including the presence of lipid droplets and swollen mitochondria, were attenuated by betaine. Hepatic triglyceride, free fatty acid, total cholesterol and cholesterol ester contents and the expression of DGAT1, DGAT2, SREBP‑1c, SREBP‑2, FAS and HMG‑CoA reductase were increased following ethanol consumption, however were maintained at control levels following betaine supplementation. Alcohol‑induced decreases in hepatic PGC‑1α mRNA levels and serum and adipose tissue adiponectin concentrations were prevented by betaine. The downregulation of hepatic AdipoR1 which resulted from alcohol exposure was partially attenuated by betaine. No significant differences in liver function, TNF‑α, phospholipid and AdipoR2 levels were observed among the control, ethanol and ethanol + betaine groups. Overall, these results indicated that betaine attenuated the alcoholic simple fatty liver by improving hepatic lipid metabolism via suppression of DGAT1, DGAT2, SREBP‑1c, FAS, SREBP‑2 and HMG‑CoA reductase and upregulation of PGC‑1α.

Effects of betaine supplementation on nitric oxide metabolism, atherosclerotic parameters, and fatty liver in guinea pigs fed a high cholesterol plus methionine diet

OBJECTIVE

The aim of this study was to investigate the effect of high cholesterol (CHOL) and CHOL + methionine (MET) diets on atherogenic and oxidative index parameters and on the factors that influence nitric oxide (NO) bioavailability. Also, attempts were made to determine whether dietary betaine (BET) resulted in any improvement in the changes that occurred after CHOL + MET administration.

METHODS

Guinea pigs were fed chow containing 1.5% CHOL with or without 2% MET for 10 wk. A third group received the CHOL + MET + BET diet. Control groups were given standard chow or standard chow + BET. Arginine, NO, nitrotyrosine (NT), and asymmetric dimethylarginine (ADMA) levels; lipid profile; and dimethylarginine dimethylaminohydrolase (DDAH) activity were measured. The liver and aorta were subjected to histopathologic analysis.

RESULTS

The CHOL + MET diet caused higher serum CHOL and homocysteine levels, but no further increases were seen in aortic CHOL and diene conjugate (DC) levels and histopathologic lesions as compared with the CHOL group. Hepatic lipids and DC levels were also higher, and histopathologic lesions were more severe. CHOL + MET feeding increased ADMA and NT levels as compared with those of the CHOL-fed group. When BET (1 g/kg body weight/d) was added to the CHOL + MET diet, homocysteine and lipid levels decreased and histopathologic changes were reversed. BET diet decreased serum ADMA and hepatic and aortic DC levels and partly restored DDAH activity.

CONCLUSIONS

BET supplementation may be effective in preventing hyperlipidemia, disturbed NO availability, oxidative stress, and the development of fatty liver and atherosclerotic lesions that might result from excess amounts of cholesterol and methionine in the diet.

Antioxidant Mechanism of Betaine without Free Radical Scavenging Ability

Betaine (BET) is a native compound widely studied as an antioxidant in agriculture and human health. However, the antioxidant mechanism of BET remains unclear. In this research, radical scavenging assays showed that BET had little free radical scavenging activity. However, the antioxidant activity of BET was confirmed by cellular antioxidant activity (CAA) and erythrocyte hemolysis assays. The results of quantitative PCR (qPCR) and enzyme activity determination kits showed that the antioxidant activity of BET was not due to the gene expression and activity of antioxidases. High-pressure liquid chromatography (HPLC) assessment of the effect of BET on sulfur-containing amino acid metabolism showed that BET increased the levels of nonenzymatic antioxidants,S-adenosylmethionine (SAM) and methionine (p < 0.05), via the regulation of the methionine-omocysteine cycle. Additionally, the three methyl groups of BET were found to play a key role in its antioxidant activity. The possible reason was that because of the hydrophobicity of the three methyl groups and hydrophilicity of the carboxyl of BET, a tight protective membrane was formed around cells to prevent oxidative stress inducer from inducing ROS generation and cell damage. In conclusion, the antioxidant mechanism of BET was found to enhance nonenzymatic antioxidant defenses via the methionine-homocysteine cycle and form a protective membrane around cells.

High-fat diet plus carbon tetrachloride-induced liver fibrosis is alleviated by betaine treatment in rats

Steatosis, the first lesion in non-alcoholic fatty liver disease (NAFLD), may progress to fibrosis, cirrhosis, and hepatocellular carcinoma. Steatosis predisposes the liver to oxidative stress, inflammation, and cytokines. Betaine (BET) has antioxidant, antiinflammatory and hepatoprotective effects. However, the effects of BET on liver fibrosis development are unknown. Rats were treated with high-fat diet (60% of total calories from fat) for 14weeks. Carbon tetrachloride (0.2mL/kg; two times per week; i.p.) was administered to rats in the last 6weeks with/without commercial food containing BET (2%; w/w). Serum liver function tests and tumor necrosis factor-α, insulin resistance, hepatic triglyceride (TG) and hydroxyproline (HYP) levels and oxidative stress parameters were determined along with histopathologic observations. Alpha-smooth muscle-actin (α-SMA), transforming growth factor-β1 (TGF-β1) and type I collagen (COL1A1) protein expressions and mRNA expressions of matrix metalloproteinase-2 (MMP-2) and its inhibitors (TIMP-1 and TIMP-2) were evaluated. BET decreased TG and HYP levels, prooxidant status and fibrotic changes in the liver. α-SMA, COL1A1 and TGF-β1 protein expressions, MMP-2, TIMP-1, and TIMP-2 mRNA expressions diminished due to BET treatment. BET has an antifibrotic effect and this effect may be related to its antioxidant and antiinflammatory actions together with suppression on HSC activation.

Betaine treatment decreased oxidative stress, inflammation, and stellate cell activation in rats with alcoholic liver fibrosis

The aim of this study was to investigate the effect of betaine (BET) on alcoholic liver fibrosis in rats. Fibrosis was experimentally generated with ethanol plus carbon tetrachloride (ETH+CCl4) treatment. Rats were treated with ETH (5% v/v in drinking water) for 14 weeks. CCl4 was administered intraperitoneally (i.p.) 0.2mL/kg twice a week to rats in the last 6 weeks with/without commercial food containing BET (2% w/w). Serum hepatic damage markers, tumor necrosis factor-α, hepatic triglyceride (TG) and hydroxyproline (HYP) levels, and oxidative stress parameters were measured together with histopathologic observations. In addition, α-smooth muscle-actin (α-SMA), transforming growth factor-β1 (TGF-β1) and type I collagen (COL1A1) protein expressions were assayed immunohistochemically to evaluate stellate cell (HSC) activation. mRNA expressions of matrix metalloproteinase-2 (MMP-2) and its inhibitors (TIMP-1 and TIMP-2) were also determined. BET treatment diminished TG and HYP levels; prooxidant status and fibrotic changes; α-SMA, COL1A1 and TGF-β protein expressions; MMP-2, TIMP-1 and TIMP-2 mRNA expressions in the liver of fibrotic rats. In conclusion, these results indicate that the antifibrotic effect of BET may be related to its suppressive effects on oxidant and inflammatory processes together with HSC activation in alcoholic liver fibrosis.

Buckwheat Honey Attenuates Carbon Tetrachloride-Induced Liver and DNA Damage in Mice

Buckwheat honey, which is widely consumed in China, has a characteristic dark color. The objective of this study was to investigate the protective effects of buckwheat honey on liver and DNA damage induced by carbon tetrachloride in mice. The results revealed that buckwheat honey had high total phenolic content, and rutin, hesperetin, and p-coumaric acid were the main phenolic compounds present. Buckwheat honey possesses super DPPH radical scavenging activity and strong ferric reducing antioxidant power. Administration of buckwheat honey for 10 weeks significantly inhibited serum lipoprotein oxidation and increased serum oxygen radical absorbance capacity. Moreover, buckwheat honey significantly inhibited aspartate aminotransferase and alanine aminotransferase activities, which are enhanced by carbon tetrachloride. Hepatic malondialdehyde decreased and hepatic antioxidant enzymes (superoxide dismutase and glutathione peroxidase) increased in the presence of buckwheat honey. In a comet assay, lymphocyte DNA damage induced by carbon tetrachloride was significantly inhibited by buckwheat honey. Therefore, buckwheat honey has a hepatoprotective effect and inhibits DNA damage, activities that are primarily attributable to its high antioxidant capacity.

Effects of carnosine, taurine, and betaine pretreatments on diethylnitrosamine-induced oxidative stress and tissue injury in rat liver

Several chemicals such as N-diethylnitrosamine (DEN) promote hepatocellular cancer in rodents and induce hepatocyte injury. DEN affects the initiation stage of carcinogenesis together with enhanced cell proliferation accompanied by hepatocellular necrosis. DEN-induced hepatocellular necrosis is reported to be related to enhanced generation of reactive oxygen species. Carnosine (CAR), taurine (TAU), and betaine (BET) are known to have powerful antioxidant properties. We aimed to investigate the effects of CAR, TAU, and BET pretreatments on DEN-induced oxidative stress and liver injury in male rats. Rats were given CAR (2 g L−1 in drinking water), TAU (2.5% in chow), and BET (2.5% in chow) for 6 weeks and DEN (200 mg kg−1 intraperitoneally) was given 2 days before the end of this period. Serum alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and γ-glutamyl transferase activities were determined and a histopathologic evaluation was performed on the liver tissue. Oxidative stress was detected in the liver by measuring malondialdehyde, diene conjugate, protein carbonyl and nitrotyrosine levels, glutathione and glutathione peroxidase levels, and superoxide dismutase and glutathione transferase activities. Pretreatments with CAR, TAU, and BET decreased liver prooxidant status without remarkable changes in antioxidant parameters in DEN-treated rats. Pretreatments with TAU and BET, but not CAR, were also found to be effective to reduce liver damage in DEN-treated rats. In conclusion, TAU, BET, and possibly CAR may have an ameliorating effect on DEN-induced hepatic injury by reducing oxidative stress in rats.

Adverse signaling of scavenger receptor class B1 and PGC1s in alcoholic hepatosteatosis and steatohepatitis and protection by betaine in rat

Because scavenger receptor class B type 1 is the cholesterol uptake liver receptor, whereas peroxisome proliferator-activated receptor γ coactivator-1β (PGC-1β) and PGC-1α are critical for lipid synthesis and degradation, we investigated the roles of these signaling molecules in the actions of ethanol-polyunsaturated fatty acids and betaine on hepatosteatosis and steatohepatitis. Ethanol-polyunsaturated fatty acid treatment caused the following: i) hepatosteatosis, as evidenced by increased liver cholesterol and triglycerides, lipid score, and decreased serum adiponectin; ii) marked inhibition of scavenger receptor class B type 1 glycosylation, its plasma membrane localization, and its hepatic cholesterol uptake function; and iii) moderate steatohepatitis, as evidenced by histopathological characteristics, increased liver tumor necrosis factor α and IL-6, decreased glutathione, and elevated serum alanine aminotransferase. These actions of ethanol involved up-regulated PGC-1β, sterol regulatory element-binding proteins 1c and 2, acetyl-CoA carboxylase, and HMG-CoA reductase mRNAs/proteins and inactive non-phosphorylated AMP kinase; and down-regulated silence regulator gene 1 and PGC-1α mRNA/proteins and hepatic fatty acid oxidation. Betaine markedly blunted all these actions of ethanol on hepatosteatosis and steatohepatitis. Therefore, we conclude that ethanol-mediated impaired post-translational modification, trafficking, and function of scavenger receptor class B type 1 may account for alcoholic hyperlipidemia. Up-regulation of PGC-1β and lipid synthetic genes and down-regulation of silence regulator gene 1, PGC-1α, adiponectin, and lipid degradation genes account for alcoholic hepatosteatosis. Induction of proinflammatory cytokines and depletion of endogenous antioxidant, glutathione, account for alcoholic steatohepatitis. We suggest betaine as a potential therapeutic agent because it effectively protects against adverse actions of ethanol.

The effect of dietary α-lipoic acid, betaine,l-carnitine, and swimming on the obesity of mice induced by a high-fat diet

We evaluate the effect of supplementation, at 300 mg kg⁻¹body weight (BW), with the antioxidants α-lipoic acid (AL), betaine (BT),l-carnitine (LC), and the combination of these and exercise on obesity induced by a 9 week high-fat diet (HFD) in mice.

Oxidative stress and paraoxonase activity in experimental selenosis: effects of betaine administration

The present study was undertaken on male rats to elucidate the selenosis induced by sodium selenite and the role played by betaine in alleviating selenium toxicity. Rats were treated with sodium selenite (6 mg/kg body weight/day) with or without betaine (240 mg/kg body weight/day). Selenotoxicosis was evident from the elevated plasma levels of total bilirubin, transaminases, and alkaline phosphatase activities. Moreover, the total protein levels decreased, and this decrease associated with a decreased albumin level, whereas the globulin level increased in selenium-intoxicated rats. The development of selenosis corresponded well with the induction of oxidative stress evident from decrease of total thiol level and glutathione content. Furthermore, activities of glutathione reductase, glucose-6-phosphate dehydrogenase, catalase, and paraoxonase-1 were decreased in selenium-treated rats. In contrast, superoxide dismutase and glutathione peroxidase activities were increased by excess selenium administration compared with control animals. As well, malondialdehyde and protein carbonyl were elevated in rats treated with selenium. Supplementation of betaine simultaneously with selenium caused less marked alteration in the investigated parameters. Betaine attenuated the selenotoxicosis by restoring thiol levels that preserve enzymatic antioxidants activity and attenuate the oxidation of lipids and proteins.

Efficacy of sardinelle protein hydrolysate to alleviate ethanol-induced oxidative stress in the heart of adult rats

The present study was undertaken to examine the protective effects of sardinelle proteins hydrolysate (SPH) obtained from heads and viscera against ethanol toxicity in the heart of adult rats. Twenty-four male rats of Wistar strain, weighing at the beginning of the experiment 250 to 300 g, were used in this study. They were divided into 4 groups: group (C) served as controls, group (Eth) received 30% ethanol solution at 3 g/kg body weight, group (SPH) received only 7.27 mg of SPH/kg body weight, and group (Eth-SPH) received ethanol and sardinelle proteins hydrolysate simultaneously. All treatments were made by gavage during 15 d. Treatment with ethanol revealed a significant elevation of malondialdehyde and protein carbonyl levels in the heart and of aspartate transaminase and alanine transaminase activities in plasma. Nitric oxide levels and the activities of antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase decreased. Nonenzymatic antioxidant such as reduced glutathione did not significantly change and ascorbic acid was decreased. SPH intake concomitantly with ethanol restored these parameters to near control values. These modifications confirmed histopathological aspects of the heart. The results revealed that SPH could provide protection of the myocardium against ethanol-induced oxidative damages in rats. This may be due to the high antioxidant potential of SPH.

Betaine treatment attenuates chronic ethanol-induced hepatic steatosis and alterations to the mitochondrial respiratory chain proteome

Introduction. Mitochondrial damage and disruption in oxidative phosphorylation contributes to the pathogenesis of alcoholic liver injury. Herein, we tested the hypothesis that the hepatoprotective actions of betaine against alcoholic liver injury occur at the level of the mitochondrial proteome. Methods. Male Wister rats were pair-fed control or ethanol-containing liquid diets supplemented with or without betaine (10 mg/mL) for 4-5 wks. Liver was examined for triglyceride accumulation, levels of methionine cycle metabolites, and alterations in mitochondrial proteins. Results. Chronic ethanol ingestion resulted in triglyceride accumulation which was attenuated in the ethanol plus betaine group. Blue native gel electrophoresis (BN-PAGE) revealed significant decreases in the content of the intact oxidative phosphorylation complexes in mitochondria from ethanol-fed animals. The alcohol-dependent loss in many of the low molecular weight oxidative phosphorylation proteins was prevented by betaine supplementation. This protection by betaine was associated with normalization of SAM : S-adenosylhomocysteine (SAH) ratios and the attenuation of the ethanol-induced increase in inducible nitric oxide synthase and nitric oxide generation in the liver. Discussion/Conclusion. In summary, betaine attenuates alcoholic steatosis and alterations to the oxidative phosphorylation system. Therefore, preservation of mitochondrial function may be another key molecular mechanism responsible for betaine hepatoprotection.

Studies on the protective effects of betaine against oxidative damage during experimentally induced restraint stress in Wistar albino rats

Stress can be defined as physical and psychological modifications that disrupt the homeostasis and the balance of organisms. Stress is known as one of the most important reasons of several diseases. In the present study, the anti-stress effect of betaine was evaluated with reference to its antioxidant property. Wistar albino rats were divided into four groups such as control, betaine, restraint stress (6 h/day for 30 days), and betaine + restraint stress. The oxidative damage was assessed by measuring the protein and corticosterone in plasma, lipid peroxidation, non-enzymic (reduced glutathione), and enzymic antioxidants (glutathione peroxidase, glutathione-S-transferase, catalase, and superoxide dismutase) in the lymphoid organs of thymus and spleen. Followed by the induction of restraint stress, the non-enzymic and enzymic antioxidants were significantly decreased with concomitant increase observed in the levels of corticosterone and lipid peroxidation. Oral pretreatment with betaine (250 mg/kg body weight daily for a period of 30 days) significantly (P < 0.001) prevented the restraint stress-induced alterations in the levels of protein and corticosterone in plasma of experimental groups of rats. It counteracted the restraint stress-induced lipid peroxidation and maintained the antioxidant defense system in the lymphoid tissues at near normal. The findings suggest that betaine possesses significant anti-stress activity, which may be due to its antioxidant property.

Creatine supplementation prevents the accumulation of fat in the livers of rats fed a high-fat diet

The aim of the present study was to examine the effects of creatine supplementation on liver fat accumulation induced by a high-fat diet in rats. Rats were fed 1 of 3 different diets for 3 wk: a control liquid diet (C), a high-fat liquid diet (HF), or a high-fat liquid diet supplemented with creatine (HFC). The C and HF diets contained, respectively, 35 and 71% of energy derived from fat. Creatine supplementation involved the addition of 1% (wt:v) of creatine monohydrate to the liquid diet. The HF diet increased total liver fat concentration, liver TG, and liver TBARS and decreased the hepatic S-adenosylmethionine (SAM) concentration. Creatine supplementation normalized all of these perturbations. Creatine supplementation significantly decreased the renal activity of l-arginine:glycine amidinotransferase and plasma guanidinoacetate and prevented the decrease in hepatic SAM concentration in rats fed the HF diet. However, there was no change in either the phosphatidylcholine:phosphatidylethanolamine (PE) ratio or PE N-methyltransferase activity. The HF diet decreased mRNA for PPARα as well as 2 of its targets, carnitine palmitoyltransferase and long-chain acylCoA dehydrogenase. Creatine supplementation normalized these mRNA levels. In conclusion, creatine supplementation prevented the fatty liver induced by feeding rats a HF diet, probably by normalization of the expression of key genes of β-oxidation.

Hepatoprotective effects of pecan nut shells on ethanol-induced liver damage

The hepatoprotective activity of the aqueous extract of the shells of pecan nut was investigated against ethanol-induced liver damage. This by-product of the food industry is popularly used to treat toxicological diseases. We evaluated the phytochemical properties of pecan shell aqueous extract (AE) and its in vitro and ex vivo antioxidant activity. The AE was found to have a high content of total polyphenols (192.4±1.9 mg GAE/g), condensed tannins (58.4±2.2 mg CE/g), and antioxidant capacity, and it inhibited Fe(2+)-induced lipid peroxidation (LP) in vitro. Rats chronically treated with ethanol (Et) had increased plasmatic transaminases (ALT, AST) and gamma glutamyl transpeptidase (GGT) levels (96%, 59.13% and 465.9%, respectively), which were effectively prevented (87; 41 and 383%) by the extract (1:40, w/v). In liver, ethanol consumption increased the LP (121%) and decreased such antioxidant defenses as glutathione (GSH) (33%) and superoxide dismutase (SOD) (47%) levels, causing genotoxicity in erythrocytes. Treatment with pecan shell AE prevented the development of LP (43%), GSH and SOD depletion (33% and 109%, respectively) and ethanol-induced erythrocyte genotoxicity. Catalase activity in the liver was unchanged by ethanol but was increased by the extract (47% and 73% in AE and AE+Et, respectively). Therefore, pecan shells may be an economic agent to treat liver diseases related to ethanol consumption.

The effect of carnosine pretreatment on oxidative stress and hepatotoxicity in binge ethanol administered rats

Carnosine is a dipeptide having strong antioxidant effects. Oxidative stress plays an important role in pathogenesis of alcohol-induced liver injury. In this study, we investigated the effect of carnosine pretreatment on ethanol-induced oxidative stress and hepatotoxicity. Rats were given carnosine (2 g/L in drinking water) for 4 weeks and then ethanol was administered orally to rats at a dose of 5 g/kg every 12 hours for 3 doses totally (binge model). All rats were killed 6 hours after last ethanol injection. Plasma alanine (ALT) and aspartate (AST) transaminase activities and liver triglyceride, malondialdehyde (MDA), diene conjugate (DC), glutathione (GSH), vitamin E and vitamin C levels and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione transferase (GST) activities were determined. Binge ethanol administration resulted in significant increases in plasma transaminase activities, hepatic triglyceride and lipid peroxide levels. However, GSH, vitamin E, vitamin C levels and GSH-Px and GST activities were found to be decreased following ethanol administration. Macromicrovesicular steatosis was also seen. Carnosine pretreatment appeared to prevent the increase of plasma ALT and AST activities and hepatic MDA and DC levels following ethanol treatment. In addition, hepatic GSH levels increased, but there were no changes in triglyceride, vitamin E, vitamin C levels and SOD, GSH-Px and GST activities, following ethanol treatment in carnosine-pretreated rats. There was also no change in liver histopathological appearance. In conclusion, carnosine prevented the increases in serum transaminase activities and lipid peroxides in liver of ethanol-treated rats, without any change on steatosis in liver.

Protective effect of betaine on changes in the levels of lysosomal enzyme activities in heart tissue in isoprenaline-induced myocardial infarction in Wistar rats

Myocardial infarction is one of the most common manifestations of cardiovascular disease. In the present study, we investigated the protective effect of betaine, a potent lipotropic molecule, on changes in the levels of lysosomal enzymes and lipid peroxidation in isoprenaline-induced myocardial infarction in Wistar rats, an animal model of myocardial infarction in man. Male albino Wistar rats were pretreated with betaine (250 mg/kg body weight) daily for a period of 30 days. After the treatment period, isoprenaline (11 mg/100 g body weight) was intraperitoneally administered to rats at intervals of 24 h for 2 days. The activities of lysosomal enzymes (beta-glucuronidase, beta-galactosidase, beta-glucosidase, and acid phosphatase) were significantly (p < 0.05) increased in plasma with a concomitant decline in the activities of these enzymes in heart tissue of isoprenaline-administered rats. Also, the level of lipid peroxidation was higher in heart lysosomes of isoprenaline-injected rats. Pretreatment with betaine daily for a period of 30 days to isoprenaline-induced rats prevented the changes in the activities of these lysosomal enzymes. Oral treatment with betaine (250 mg/kg body weight) to normal control rats did not show any significant effect in all the biochemical parameters studied. Thus, the results of our study show that betaine protects the lysosomal membrane against isoprenaline-induced myocardial infarction. The observed effects might be due to the free radical-scavenging and membrane-stabilizing properties of betaine.

Proteomics reveal a concerted upregulation of methionine metabolic pathway enzymes, and downregulation of carbonic anhydrase-III, in betaine supplemented ethanol-fed rats

We employed a proteomic profiling strategy to examine the effects of ethanol and betaine diet supplementation on major liver protein level changes. Male Wistar rats were fed control, ethanol or betaine supplemented diets for 4 weeks. Livers were removed and liver cytosolic proteins resolved by one-dimensional and two-dimensional separation techniques. Significant upregulation of betaine homocysteine methyltransferase-1, methionine adenosyl transferase-1, and glycine N-methyltransferase were the most visually prominent protein changes observed in livers of rats fed the betaine supplemented ethanol diet. We hypothesise that this concerted upregulation of these methionine metabolic pathway enzymes is the protective mechanism by which betaine restores a normal metabolic ratio of liver S-adenosylmethionine to S-adenosylhomocysteine. Ethanol also induced significant downregulation of carbonic anhydrase-III protein levels which was not restored by betaine supplementation. Carbonic anhydrase-III can function to resist oxidative stress, and we therefore hypothesise that carbonic anhydrase-III protein levels compromised by ethanol consumption, contribute to ethanol-induced redox stress.

The anti-fatty liver effects of garlic oil on acute ethanol-exposed mice

The protective effects of single dose of garlic oil (GO) on acute ethanol-induced fatty liver were investigated. Mice were treated with ethanol (4.8 g/kg bw) to induce acute fatty liver. The liver index, the serum and hepatic triglyceride (TG) levels and the histological changes were examined to evaluate the protective effects. Hepatic malondialdehyde (MDA), glutathione (GSH) levels and superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) activities were determined for the antioxidant capacity assay. Acute ethanol exposure resulted in the enlargement of the liver index and the increase of the serum and hepatic TG levels (P<0.01), which were dramatically attenuated by GO pretreatment in a dose-dependent manner (P<0.01). GO treatment (simultaneously with ethanol exposure) exhibited similar effects to those of pretreatment, while no obviously protective effects were displayed when it was used at 2h after ethanol intake. Histological changes were paralleled to these indices. Beside this, GO dramatically prolonged the drunken time and shortened the waking time, and these effects were superior to those of silymarin and tea polyphenol. In addition, GO dose-dependently suppressed the elevation of MDA levels, restored the GSH levels and enhanced the SOD, GR and GST activities. Compared with the ethanol group, the MDA levels decreased by 14.2% (P<0.05), 29.9% and 32.8% (P<0.01) in GO groups 50, 100 and 200 mg/kg, respectively. The GST activity increased by 9.97%, 19.94% (P<0.05) and 42.12% (P<0.01) of the ethanol group in GO groups 50, 100 and 200 mg/kg, respectively, while the GR activity increased by 28.57% (P<0.05), 37.97% (P<0.01), 50.45% (P<0.01) of the ethanol group in GO groups 50, 100 and 200 mg/kg, respectively. These data indicated that single dose of GO possessed ability to prevent acute ethanol-induced fatty liver, but may lose its capacity when used after ethanol exposure. The protective effects should be associated with its antioxidative activities.

Identification of genes that regulate multiple cellular processes/responses in the context of lipotoxicity to hepatoma cells

Background

In order to devise efficient treatments for complex, multi-factorial diseases, it is important to identify the genes which regulate multiple cellular processes. Exposure to elevated levels of free fatty acids (FFAs) and tumor necrosis factor alpha (TNF-α) alters multiple cellular processes, causing lipotoxicity. Intracellular lipid accumulation has been shown to reduce the lipotoxicity of saturated FFA. We hypothesized that the genes which simultaneously regulate lipid accumulation as well as cytotoxicity may provide better targets to counter lipotoxicity of saturated FFA.

Results

As a model system to test this hypothesis, human hepatoblastoma cells (HepG2) were exposed to elevated physiological levels of FFAs and TNF-α. Triglyceride (TG) accumulation, toxicity and the genomic responses to the treatments were measured. Here, we present a framework to identify such genes in the context of lipotoxicity. The aim of the current study is to identify the genes that could be altered to treat or ameliorate the cellular responses affected by a complex disease rather than to identify the causal genes. Genes that regulate the TG accumulation, cytotoxicity or both were identified by a modified genetic algorithm partial least squares (GA/PLS) analysis. The analyses identified NADH dehydrogenase and mitogen activated protein kinases (MAPKs) as important regulators of both cytotoxicity and lipid accumulation in response to FFA and TNF-α exposure. In agreement with the predictions, inhibiting NADH dehydrogenase and c-Jun N-terminal kinase (JNK) reduced cytotoxicity significantly and increased intracellular TG accumulation. Inhibiting another MAPK pathway, the extracellular signal regulated kinase (ERK), on the other hand, improved the cytotoxicity without changing TG accumulation. Much greater reduction in the toxicity was observed upon inhibiting the NADH dehydrogenase and MAPK (which were identified by the dual-response analysis), than for the stearoyl-CoA desaturase (SCD) activation (which was identified for the TG-alone analysis).

Conclusion

These results demonstrate the applicability of GA/PLS in identifying the genes that regulate multiple cellular responses of interest and that genes regulating multiple cellular responses may be better candidates for countering complex diseases.

Methionine-supplemented diet augments hepatotoxicity and prooxidant status in chronically ethanol-treated rats

The purpose of this study was to investigate whether high methionine (HM) diet may influence the development of ethanol-induced hepatotoxicity and prooxidant-antioxidant balance in the liver. Rats received drinking water containing ethanol (20% v/v) and/or methionine supplemented diet (2% w/w) for 75 days. Although prooxidant-antioxidant balance did not change in the liver of rats in HM group, ethanol treatment was observed to increase plasma transaminase activities, and malondialdehyde (MDA) and protein carbonyl (PC) levels, but not glutathione (GSH), vitamin E and vitamin C levels, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione transferase (GST) activities in the liver of rats as compared to controls. However, ethanol plus HM diet caused further increases in plasma transaminase activities and hepatic MDA and PC levels. In addition, SOD, GSH-Px and GST activities were observed to decrease, but GSH, vitamin E and vitamin C levels remained unchanged in the liver as compared to ethanol, HM and control groups. Our results show that HM diet may augment hepatotoxicity and oxidative stress in the liver of chronically ethanol-treated rats.

Whole-grain and refined wheat flours show distinct metabolic profiles in rats as assessed by a 1H NMR-based metabonomic approach

The protection against diabetes and cardiovascular disease provided by whole-grain cereal consumption has been attributed to the fiber and micronutrients present in the bran. But exactly how this occurs remains unclear due to both diversity of bran constituents and the complexity of the metabolic responses to each of these constituents. We investigated the metabolic responses of 2 groups of rats (n = 10/group) fed 2 diets, for 2 wk each, in a crossover design. One diet contained 60 g/100 g whole-grain wheat flour (WGF) and the other contained 60 g/100 g refined wheat flour (RF). Markers of oxidative stress [urinary isoprostanes and malondialdehydes (MDA), plasma ferric-reducing ability of plasma, MDA, and vitamins E and C] and lipid status (liver and plasma triglycerides and cholesterol) were measured. Urine samples collected during the feeding periods and plasma and liver samples collected at the end of experiment were analyzed by (1)H NMR spectroscopy. Metabonomic analyses showed that each group reached a new metabolic balance within 48 h of changing the diet. Urinary excretion of some tricarboxylic acid cycle intermediates, aromatic amino acids, and hippurate was significantly greater in rats fed the WGF diet. Although the diets did not affect conventional lipid and oxidative stress markers, there were decreases in some liver lipids and increases in liver reduced glutathione and betaine as shown by metabonomic analyses. These suggest that the WGF diet improved the redox and lipid status.

NMR-based metabonomic studies reveal changes in the biochemical profile of plasma and urine from pigs fed high-fibre rye bread

This study presents an NMR-based metabonomic approach to elucidate the overall endogenous biochemical effects of a wholegrain diet. Two diets with similar levels of dietary fibre and macronutrients, but with contrasting levels of wholegrain ingredients, were prepared from wholegrain rye (wholegrain diet (WGD)) and non-wholegrain wheat (non-wholegrain diet (NWD)) and fed to four pigs in a crossover design. Plasma samples were collected after 7 d on each diet, and 1H NMR spectra were acquired on these. Partial least squares regression discriminant analysis (PLSDA) on spectra obtained for plasma samples revealed that the spectral region at 3·25 parts per million dominates the differentiation between the two diets, as the WGD is associated with higher spectral intensity in this region. Spiking experiments and LC–MS analyses of the plasma verified that this spectral difference could be ascribed to a significantly higher content of betaine in WGD plasma samples compared with NWD samples. In an identical study with the same diets, urine samples were collected, and1H NMR spectra were acquired on these. PLS-DA on spectra obtained for urine samples revealed changes in the intensities of spectral regions, which could be ascribed to differences in the content of betaine and creatine/creatinine between the two diets, and LC–MS analyses verified a significantly lower content of creatinine in WGD urine samples compared with NWD urine samples. In conclusion, using an explorative approach, the present studies disclosed biochemical effects of a wholegrain diet on plasma betaine content and excretion of betaine and creatinine.

Liver-protecting effects of table beet (Beta vulgaris var. rubra) during ischemia-reperfusion

OBJECTIVE

Table beet (Beta vulgaris var. rubra) contains important bioactive agents (betaine and polyphenols), which have a wide range of physiologic effects. Because nutritive antioxidants may reduce the occurrence of complications and postoperative mortality, dietary intake of polyphenols and vitamins before surgery may greatly contribute to the survival of patients. Our aim was to determine the liver-protecting properties of bioactive substances of table beet in a model of ischemia-reperfusion injury of the rat.

METHODS

Wistar rats were divided into two groups: non-treated (n = 24) and fed with table beet (n = 8). For 10 days the second group was treated with lyophilized table beet (2 g/kg body weight daily) mixed into the rat chow. Hepatic ischemia was maintained for 45 min, followed by 15 min of reperfusion. Ischemia-reperfusion was carried out on animals from both groups. Chemiluminescent intensity, H-donating ability, reducing power, free SH group concentration, Randox-total antioxidant status, glutathione peroxidase, and superoxide dismutase activities were determined by luminometry and spectrophotometry. Fatty acid (Shimadzu GC) and metal ion (inductively coupled plasma optical emission spectrometry) concentrations were observed in the liver.

RESULTS

As a result of feeding, global parameters (H-donating ability, reducing power, free SH group concentration) and enzymatic antioxidants (glutathione peroxidase and superoxide dismutase) of the liver were found to increase significantly, which indicated that the treatment had a positive effect on its redox state. The increase found in zinc and copper content may protect the hepatocytes against oxidative stress because these elements are required for the function of superoxide dismutase enzymes. In the table beet group the concentration of short-chain fatty acids decreased, whereas that of long-chain fatty acids increased. The changes in metal element and fatty acid concentrations confirmed that these elements have an essential function in cellular pathways.

CONCLUSION

It may be stated that a natural antioxidant-rich diet has a positive effect on redox homeostasis during hepatic ischemia-reperfusion.

Abnormal transsulfuration and glutathione metabolism in the micropig model of alcoholic liver disease

BACKGROUND

Alcoholic liver disease is associated with abnormalities of methionine metabolic enzymes that may contribute to glutathione depletion. Previously, we found that feeding micropigs a combination of ethanol with a folate-deficient diet resulted in the greatest decreases in S-adenosylmethionine and glutathione and increases in liver S-adenosylhomocysteine and oxidized disulfide glutathione.

METHODS

To study the mechanisms of glutathione depletion, we analyzed the transcripts and activities of enzymes involved in its synthesis and metabolism in liver and plasma specimens that were available from the same micropigs that receive folate-sufficient or folate-depleted diets with or without 40% of energy as ethanol for 14 weeks.

RESULTS

Ethanol feeding, folate deficiency, or their combination decreased liver and plasma glutathione and the activities of hepatic copper-zinc superoxide dismutase and glutathione peroxidase and increased the activity of manganese superoxide dismutase and glutathione reductase. Hepatic levels of cysteine and taurine were unchanged while plasma cysteine was increased in the combined diet group. Cystathionine beta-synthase transcripts and activity were unaffected by ethanol feeding, while the activities of other transsulfuration enzymes involved in glutathione synthesis were increased. Glutathione transferase transcripts were increased 4-fold and its mean activity was increased by 34% in the combined ethanol and folate-deficient diet group, similar in magnitude to the observed 36% reduction in hepatic glutathione.

CONCLUSIONS

Chronic ethanol feeding and folate deficiency acted individually or synergistically to affect methionine metabolism in the micropig by depleting glutathione pools and altering transcript expressions and activities of enzymes involved in its synthesis, utilization, and regeneration. The data suggest that the observed decrease in hepatic glutathione during ethanol feeding reflects its increased utilization to meet increased antioxidant demands, rather than reduction in its synthesis.

The effect of taurine or betaine pretreatment on hepatotoxicity and prooxidant status induced by lipopolysaccharide treatment in the liver of rats

BACKGROUND

Taurine or betaine have been reported to have antioxidative potential and inhibit Kupffer cell activation. These effects may play an important role in their hepatoprotective effects. Therefore, they may also have protective effects in lipopolysaccharide hepatotoxicity by both inhibiting Kupffer cell activation and behaving as antioxidants.

DESIGN

The prophylactic efficiency of taurine or betaine pretreatment for the prevention of peroxidative changes induced by lipopolysaccharide treatment in the rat liver was investigated.

METHODS

Lipopolysaccharide (10 mg/kg intraperitoneally) was given to rats pretreated with taurine (1.5%, w/v) or betaine (1.5%, w/v) in drinking water for 4 weeks and plasma transaminase activities as well as hepatic malondialdehyde, diene conjugate (DC), glutathione, alpha-tocopherol and ascorbic acid levels, and superoxide dismutase (SOD) and glutathione peroxidase activities were determined.

RESULTS

Significant increases in plasma transaminase activities and hepatic malondialdehyde and DC levels and decreases in hepatic glutathione and alpha-tocopherol levels and SOD and glutathione peroxidase activities were observed 6 h after lipopolysaccharide treatment. This treatment did not alter ascorbic acid levels in the liver compared with controls. Taurine or betaine pretreatment in lipopolysaccharide-injected rats caused significant decreases in plasma transaminase activities and hepatic malondialdehyde and DC levels, and significant increases in glutathione and alpha-tocopherol (not betaine) levels without changing ascorbic acid levels and SOD and glutathione peroxidase activities in the liver.

CONCLUSIONS

Our findings clearly indicate that taurine or betaine pretreatment was effective in the prevention of lipopolysaccharide-induced hepatotoxicity and prooxidant status.