Betaine or taurine administration prevents fibrosis and lipid peroxidation induced by rat liver by ethanol plus carbon tetrachloride intoxication

The role of taurine through endoplasmic reticulum in physiology and pathology

Taurine is a sulfur-containing amino acid found in many cell organelles that plays a wide range of biological roles, including bile salt production, osmoregulation, oxidative stress reduction, and neuromodulation. Taurine treatments have also been shown to ameliorate the onset and development of many diseases, including hypertension, fatty liver, neurodegenerative diseases and ischemia-reperfusion injury, by exerting antioxidant, anti-inflammatory, and antiapoptotic effects. The endoplasmic reticulum (ER) is a dynamic organelle involved in a wide range of cellular functions, including lipid metabolism, calcium storage and protein stabilization. Under stress, the disruption of the ER environment leads to the accumulation of misfolded proteins and a characteristic stress response called the unfolded protein response (UPR). The UPR protects cells from stress and helps to restore cellular homeostasis, but its activation promotes cell death under prolonged ER stress. Recent studies have shown that ER stress is closely related to the onset and development of many diseases. This article reviews the beneficial effects and related mechanisms of taurine by regulating the ER in different physiological and pathological states, with the aim of providing a reference for further research and clinical applications.

Identification of a novel enzyme and the regulation of key enzymes in mammalian taurine synthesis

Taurine has many pharmacological roles on various tissues. The maintenance of abundant taurine content in the mammalian body through endogenous synthesis, in addition to exogenous intake, is the essential factor for morphological and functional maintenances in most tissues. The synthesis of taurine from sulfur-containing amino acids is influenced by various factors. Previous literature findings indicate the influence of the intake of proteins and sulfur-containing amino acids on the activity of the rate-limiting enzymes cysteine dioxygenase and cysteine sulfinate decarboxylase. In addition, the regulation of the activity and expression of taurine-synthesis enzymes by hormones, bile acids, and inflammatory cytokines through nuclear receptors have been reported in liver and reproductive tissues. Furthermore, flavin-containing monooxygenase subtype 1 was recently identified as the taurine-synthesis enzyme that converts hypotaurine to taurine. This review introduces the novel taurine synthesis enzyme and the nuclear receptor-associated regulation of key enzymes in taurine synthesis.

Establishment of a Rat Model of Alcoholic Liver Fibrosis with Simulated Human Drinking Patterns and Low-Dose Chemical Stimulation

Although alcohol is a well-known causal factor associated with liver diseases, challenges remain in inducing liver fibrosis in experimental rodent models. These challenges include rodents' natural aversion to high concentrations of alcohol, rapid alcohol metabolism, the need for a prolonged duration of alcohol administration, and technical difficulties. Therefore, it is crucial to establish an experimental model that can replicate the features of alcoholic liver fibrosis. The objective of this study was to develop a feasible rat model of alcoholic liver fibrosis that emulates human drinking patterns and combines low-dose chemicals within a relatively short time frame. We successfully developed an 8-week rat model of alcoholic liver fibrosis that mimics chronic and heavy drinking patterns. Rats were fed with a control liquid diet, an alcohol liquid diet, or alcohol liquid diet combined with multiple binges via oral gavage. To accelerate the progression of alcoholic liver fibrosis, we introduced low-dose carbon tetrachloride (CCl4) through intraperitoneal injection. This model allows researchers to efficiently evaluate potential therapeutics in preclinical studies of alcoholic liver fibrosis within a reasonable time frame.

Betaine protects against sodium arsenite-induced diabetes and hepatotoxicity in mice

Epidemiological evidence has associated chronic exposure to inorganic arsenic with an increased occurrence of glucose intolerance and diabetes mellitus. Furthermore, inorganic arsenic induces oxidative stress in organs such as the liver. Betaine, as a methyl donor, plays a pivotal role in homocysteine metabolism. Betaine has antioxidant and anti-inflammatory properties. Therefore, the aim of this study was to evaluate the effects of betaine against sodium arsenite-induced diabetes and hepatotoxicity in mice. Forty-eight male mice were divided into 6 groups of 8. Group 1, received distilled water every day for 4 weeks by gavage. Group 2 received 500 mg/kg betaine every day for 4 weeks by gavage. Group 3 was given 10 mg/kg NaAsO₂ every day for 4 weeks by gavage. Groups 4, 5, and 6 were co-treated with 125, 250, and 500 mg/kg betaine half an hour before NaAsO₂ (10 mg/kg), respectively, daily for up to 4 weeks by gavage. After 28 days of the study, the mice were fasted overnight and on day 29, fasting blood glucose was measured and glucose tolerance test was performed. On day 30, the mice were anesthetized and a blood sample was taken from the heart. Serum factors (alanine aminotransferase, aspartate transaminase, and alkaline phosphatase activities), oxidative stress factors (malondialdehyde and glutathione levels, and the activity of superoxide dismutase, glutathione peroxidase, and catalase enzymes) and hepatic inflammatory factors (nitric oxide and tumor necrosis factor α) were measured. Histopathological studies were also performed on the liver and pancreas. In this study, it was shown that arsenic causes glucose intolerance, and oxidative/inflammatory hepatic damage. Co-administration of betaine prevents hepatotoxicity and glucose intolerance induced by arsenic in mice. Co-treatment of betaine with arsenic improved glucose intolerance and protected the liver against arsenic induced-oxidative damage and inflammation. Betaine at the dose of 500 mg/kg showed better results than the other doses. Accordingly, betaine can be suggested as a therapeutic agent against diabetogenic and hepatotoxic effects of arsenic.

Phosphodiesterase 4 mRNA Level Suppression is Important for Extract of Black Carrot to Protect Against Hepatic Injury Induced by Ethanol

Excessive alcohol use often results in alcoholic liver disease (ALD). An early change in the liver due to excessive drinking is hepatic steatosis, which may ultimately progress to hepatitis, liver fibrosis, cirrhosis, and liver cancer. Among these debilitating processes, hepatic steatosis is reversible with the appropriate treatment. Therefore, it is important to find treatments and foods that reverse hepatic steatosis. Black carrot has antioxidant and anti-inflammatory effects. In this study, we examined the effectiveness of black carrot extract (BCE) on hepatic steatosis in in vivo and in vitro ethanol-induced liver injury models. For the in vivo experiments, serum aminotransferase activities enhanced by ethanol- and carbon tetrachloride were significantly suppressed by the BCE diet. Furthermore, morphological changes in the liver hepatic steatosis and fibrosis were observed in the in vivo ethanol-induced liver injury model, however, BCE feeding resulted in the recovery to an almost normal liver morphology. In the in vitro experiments, ethanol treatment induced reactive oxygen species (ROS) levels in hepatocytes at 9 h. Conversely, ROS production was suppressed to control levels and hepatic steatosis was suppressed when hepatocyte culture with ethanol were treated with BCE. Furthermore, we investigated enzyme activities, enzyme protein levels, and messenger RNA levels of alcohol dehydrogenase (ADH), cytochrome p450 2E1 (CYP2E1), and aldehyde dehydrogenase (ALDH) using enzyme assays, western blot, and quantitative reverse transcription-polymerase chain reaction analyses. We found that the activities of ADH, CYP2E1, and ALDH were regulated through the cAMP-PKA pathway at different levels, namely, translational, posttranslational, and transcriptional levels, respectively. The most interesting finding of this study is that BCE increases cAMP levels by suppressing the Pde4b mRNA and PDE4b protein levels in ethanol-treated hepatocytes, suggesting that BCE may prevent ALD.

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.

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

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

Preventive and therapeutic role of betaine in liver disease: A review on molecular mechanisms

Betaine is a kind of water-soluble quaternary amine-type alkaloid widely existing in food, such as wheat germ, beet, spinach, shrimp and wolfberry. As an important methyl donor and osmotic pressure regulator in human body, betaine plays an important role in a variety of physiological activities. In recent years, a large number of literatures have shown that betaine has good preventive and therapeutic effects on many liver diseases, including chemical or drug-induced liver injury, nonalcoholic fatty liver disease, alcoholic fatty liver disease, liver fibrosis, hepatitis B and hepatitis C. Therefore, by searching the databases of Web of Science, PubMed, SciFinder and CNKI, this paper has summarized the molecular mechanisms of betaine in improving liver diseases. The results show that the improvement of liver diseases by betaine is closely related to a variety of molecular mechanisms, including inhibition of inflammatory response, improvement of insulin resistance, reduction of endoplasmic reticulum stress, alleviation of liver oxidative stress, increase of autophagy, remodeling of intestinal flora and regulation of epigenetic modification. More importantly, nuclear transcription factor kappa (NF-κB), AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor α/γ (PPAR-α/γ), liver X receptor α (LXRα), protein kinase B (Akt), toll-like receptor 4 (TLR4) and cysteinyl aspartate specific proteinase-3 (Caspase-3) signaling pathways are considered as important molecular targets for betaine to improve liver diseases. These important findings will provide a direction and basis for further exploring the pathogenesis of various liver diseases and tapping the potential of betaine in the clinical treatment.

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

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

Betaine Alleviates Cognitive Deficits in Diabetic Rats via PI3K/Akt Signaling Pathway Regulation

BACKGROUND

Diabetes mellitus is a metabolic disease which also causes cognitive deficits. Betaine (N,N,N-trimethylglycine), also known as trimethylglycine, has been shown to ameliorate diabetic symptoms in diabetic animals and improve cognitive ability in Alzheimer disease (AD) animals. However, the effects of betaine on cognitive deficits in diabetic animals have not been described yet. Therefore, in the current study, the effects of betaine on cognition in diabetic rats were evaluated.

METHODS

We established a diabetic rat model by injecting streptozotocin (STZ) into rats and administrated betaine to these diabetic rats. We monitored the metabolism index, and glucose and insulin levels in blood and cerebrospinal fluid. We measured inflammatory cytokine levels, including TNF-α, IL-1β, and IL-6, in serum and hippocampus. We also monitored oxidative stress in the hippocampus by measuring malondialdehyde (MDA) level and superoxide dismutase (SOD) activity. We measured the learning and memory ability of diabetic rats using the Morris water and Y maze tests and tested the phosphatidylinositol 3-kinase (PI3K)/Akt activation and p-mTOR level in the hippocampus.

RESULTS

Betaine improved glucose metabolism and suppressed the production of inflammatory cytokines, including TNF-α, IL-1β, and IL-6. Also, betaine decreased MDA concentration and increased SOD activity in the hippocampus of diabetic rats. Betaine ameliorated cognitive deficits in diabetic rats, and it promoted PI3K expression and Akt activation and decreased p-mTOR expression.

CONCLUSION

Betaine alleviates cognitive deficits in STZ-induced diabetic rats via regulating the PI3K/Akt signaling pathway.

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

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

The effects of betaine supplementation in diets containing different levels of crude protein and methionine on the growth performance, blood components, total tract nutrient digestibility, excreta noxious gas emission, and meat quality of the broiler chickens

The effects of betaine supplementation on growth performance, blood components, nutrient digestibility, excreta noxious gas emission, and meat quality of broiler chickens were examined using different dietary crude protein (CP) and methionine (Met) levels. A total of 768 Ross 308 broiler chickens were allotted to four treatments, with 12 replications of each treatment conducted over 6 wk. Treatments were factorially designed, with 2 levels of CP [Starter: CP 21% (low Met) and 23% (high Met); Finisher: CP 18% (low Met) and 20% (high Met)] and 2 levels of betaine supplementation (0 and 0.12%). Body weight gain and feed conversion improved significantly as dietary levels of protein increased (P < 0.05), but the results for betaine supplementation differed. The concentrations of serum total protein, albumin, and glutathione peroxidase (GPx) were elevated by either the supplementary betaine or the CP (P < 0.05). In addition, serum albumin concentration significantly increased in groups fed low CP amounts and betaine 0.12% compared with groups fed low CP only (P < 0.05). Total tract digestibility of nitrogen in broilers fed high CP amounts or 0.12% betaine, was observed to be greater than that in groups fed low CP amounts or no betaine treatment (P < 0.05). Supplemental betaine affected excreta ammonia gas emission, and hydrogen sulfide concentrations decreased significantly in low CP-fed groups (P < 0.05). Breast meat quality and relative organ weights were not influenced by CP levels or dietary betaine supplementation. These results suggest that betaine does not increase productivity, but may affect serum total protein, albumin, GPx, excreta ammonia emission, and nitrogen digestibility in broiler chickens. In addition, betaine supplementation is more effective in increasing serum albumin concentration when it was added in low CP (low Met) diets.

Taurine attenuates Cr(VI)-induced cellular and DNA damage: an in vitro study using human erythrocytes and lymphocytes

Hexavalent chromium [(Cr(VI)] is widely used in several industries, but human exposure results in multiple organ toxicity. Enhanced generation of free radicals and reactive species is thought to play a key role in Cr(VI)-induced toxicity. We have examined the effect of taurine, a simple sulphur-containing amino acid and an antioxidant, on potassium dichromate [K₂Cr₂O₇, a Cr(VI) compound]-induced cytotoxicity and genotoxicity in human blood cells. Erythrocytes were treated with K₂Cr₂O₇, either alone or after incubation with different concentrations of taurine. Treatment of erythrocytes with K₂Cr₂O₇ alone led to marked increase in generation of reactive oxygen and nitrogen species, lipid and protein oxidation. This was accompanied by decrease in total sulfhydryl and glutathione content and lowered antioxidant power of the cells. This suggests that Cr(VI) induces oxidative stress in the cells. Incubation of erythrocytes with taurine prior to addition of K₂Cr₂O₇, resulted in a concentration-dependent decrease in the generation of reactive oxygen and nitrogen species, mitigation of oxidative stress and amelioration of antioxidant power of these cells. It also restored the activities of several metabolic, antioxidant and membrane-bound enzymes. Cr(VI)-induced damage to erythrocyte membrane and lymphocyte DNA was also significantly attenuated by prior administration of taurine. These results suggest that taurine can function as a chemoprotectant against Cr(VI)-induced oxidative injury and can be potentially used to mitigate the toxic effects of this transition metal ion.

Attenuating effects of caffeic acid phenethyl ester and betaine on abamectin-induced hepatotoxicity and nephrotoxicity

Abamectin (ABM) is a widely utilized potent anthelmintic and insecticidal agent. In this study, we investigated the protective effects of caffeic acid phenethyl ester (CAPE) and betaine (BET) against ABM-induced hepatotoxicity and nephrotoxicity in rats. Forty rats were divided into five groups, receiving either oral saline solution (normal control), oral ABM at a dose of 2 mg/kg BW (1/5 LD50), CAPE (10 μmol/kg BW intraperitoneally) followed by ABM, or BET supplementation at a dose of 250 mg/kg BW followed by ABM administration, while group V rats received a combination of i.p. CAPE and oral BET in the same doses before receiving ABM. Biochemical analysis showed that ABM administration significantly (p < 0.05) increased serum levels of aminotransferases, alkaline phosphatase, lactate dehydrogenase, and cholesterol, as well as serum creatinine and urea. Compared to the control group, ABM-intoxicated rats had significantly (p < 0.05) higher tissue concentrations of nitric oxide and malondialdehyde, as well as lower tissue glutathione concentration, total antioxidant capacity, and antioxidant enzymatic activity (glutathione peroxidase, superoxide dismutase, and catalase). Histopathological examination of hepatic and renal tissues of ABM-intoxicated rats showed acute inflammatory and necrotic changes. Pretreatment with CAPE and/or BET reversed the biochemical and histopathological alterations of ABM on the liver and kidneys. Therefore, CAPE and BET (alone or in combination) could be promising protective agents against ABM-induced hepatotoxicity and nephrotoxicity. Future studies should confirm our findings and evaluate the other molecular effects are involved in the combination chemoprotection of CAPE and BET.

Unique metabolomic signature associated with hepatorenal dysfunction and mortality in cirrhosis

The application of nontargeted metabolomic profiling has recently become a powerful noninvasive tool to discover new clinical biomarkers. This study aimed to identify metabolic pathways that could be exploited for prognostic and therapeutic purposes in hepatorenal dysfunction in cirrhosis. One hundred three subjects with cirrhosis had glomerular filtration rate (GFR) measured using iothalamate plasma clearance, and were followed until death, transplantation, or the last encounter. Concomitantly, plasma metabolomic profiling was performed using ultrahigh performance liquid chromatography-tandem mass spectrometry to identify preliminary metabolomic biomarker candidates. Among the 1028 metabolites identified, 34 were significantly increased in subjects with high liver and kidney disease severity compared with those with low liver and kidney disease severity. The highest average fold-change (2.39) was for 4-acetamidobutanoate. Metabolite-based enriched pathways were significantly associated with the identified metabolomic signature (P values ranged from 2.07E-06 to 0.02919). Ascorbate and aldarate metabolism, methylation, and glucuronidation were among the most significant protein-based enriched pathways associated with this metabolomic signature (P values ranged from 1.09E-18 to 7.61E-05). Erythronate had the highest association with measured GFR (R-square = 0.571, P <0.0001). Erythronate (R = 0.594, P <0.0001) and N6-carbamoylthreonyladenosine (R = 0.591, P <0.0001) showed stronger associations with measured GFR compared with creatinine (R = 0.588, P <0.0001) even after controlling for age, gender, and race. The 5 most significant metabolites that predicted mortality independent of kidney disease and demographics were S-adenosylhomocysteine (P = 0.0003), glucuronate (P = 0.0006), trans-aconitate (P = 0.0018), 3-ureidopropionate (P = 0.0021), and 3-(4-hydroxyphenyl)lactate (P = 0.0047). A unique metabolomic signature associated with hepatorenal dysfunction in cirrhosis was identified for further investigations that provide potentially important mechanistic insights into cirrhosis-altered metabolism.

Taurine mitigates nitrite-induced methemoglobin formation and oxidative damage in human erythrocytes

Nitrite is present as a noxious contaminant in drinking water and causes oxidative damage in various tissues of humans and animals. It is a well-known methemoglobin-forming agent that has been shown to damage blood cells. The protective effect of taurine, a semi-essential sulfur-containing amino acid, was studied on sodium nitrite (NaNO₂)-induced oxidative damage in human erythrocytes. Erythrocytes were incubated with NaNO₂, in the presence and absence of taurine, and changes in oxidative stress parameters determined. Pretreatment with taurine significantly ameliorated NaNO₂-induced oxidative damage to lipids, proteins, and plasma membrane. It also reduced the NaNO₂-induced increase in methemoglobin levels and ROS production. Taurine improved the antioxidant capacity of cells, restored the alterations in the activities of various metabolic enzymes, and prevented morphological changes in erythrocytes. Thus, taurine can be potentially used as a protective agent against the damaging effects of nitrite.

Chronic Alcohol Exposure Differentially Alters One-Carbon Metabolism in Rat Liver and Brain

BACKGROUND

Epigenetic mechanisms such as DNA methylation play an important role in regulating the pathophysiology of alcoholism. Chronic alcohol exposure leads to behavioral changes as well as decreased expression of genes associated with synaptic plasticity. In the liver, it has been documented that chronic alcohol exposure impairs methionine synthase (Ms) activity leading to a decrease in S-adenosyl methionine/S-adenosyl homocysteine (SAM/SAH) ratio which results in DNA hypomethylation; however, it is not known whether similar alterations of SAM and SAH levels are also produced in brain.

METHODS

Male adult Sprague Dawley rats were fed chronically with Lieber-DeCarli ethanol (EtOH) (9% v/v) or control diet. The EtOH-diet-fed rats were withdrawn for 0 and 24 hours. The cerebellum and liver tissues were dissected and used to investigate changes in one-carbon metabolism, SAM, and SAH levels.

RESULTS

We found that chronic EtOH exposure decreased SAM levels, SAM/SAH ratio, Ms, methylene tetrahydrofolate reductase, and betaine homocysteine methyltransferase (Bhmt) expression and increased methionine adenosyltransferase-2b (Mat2b) but not Mat2a expression in the liver. In contrast, chronic EtOH exposure decreased SAH levels, increased SAM/SAH ratio and the expression of Mat2a and S-adenosyl homocysteine hydrolase, while the levels of SAM or Bhmt expression in cerebellum remained unaltered. However, in both liver and cerebellum, chronic EtOH exposure decreased the expression of Ms and increased Mat2b expression. All chronic EtOH-induced changes of one-carbon metabolism in cerebellum, but not liver, returned to near-normal levels during EtOH withdrawal.

CONCLUSIONS

These results indicate a decreased "methylation index" in liver and an increased "methylation index" in cerebellum. The opposing changes of the "methylation index" suggest altered DNA methylation in liver and cerebellum, thus implicating one-carbon metabolism in the pathophysiology of alcoholism.

Salecan protected against concanavalin A-induced acute liver injury by modulating T cell immune responses and NMR-based metabolic profiles

Salecan, a water-soluble extracellular β-glucan produced by Agrobacterium sp. ZX09, has been reported to exhibit a wide range of biological effects. The aims of the present study were to investigate the protective effect of salecan against Concanavalin A (ConA)-induced hepatitis, a well-established animal model of immune-mediated liver injury, and to search for possible mechanisms. C57BL/6 mice were pretreated with salecan followed by ConA injection. Salecan treatment significantly reduced ConA-induced acute liver injury, and suppressed the expression and secretion of inflammatory cytokines including interferon (IFN)-γ, interleukin (IL)-6 and IL-1β in ConA-induced liver injury model. The high expression levels of chemokines and adhesion molecules such as MIP-1α, MIP-1β, ICAM-1, MCP-1 and RANTES in the liver induced by ConA were also down-regulated after salecan treatment. Salecan inhibited the infiltration and activation of inflammatory cells, especially T cells, in the liver induced by ConA. Moreover, salecan reversed the metabolic profiles of ConA-treated mice towards the control group by partly recovering the metabolic perturbations induced by ConA. Our results suggest the preventive and therapeutic potential of salecan in immune-mediated hepatitis.

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.

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

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

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Taurine has potential as preventative & therapeutic treatment for schistosomiasis.

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

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

Alleviation of Carbon-Tetrachloride-Induced Liver Injury and Fibrosis by Betaine Supplementation in Chickens

Betaine is a food component with well-reported hepatoprotection effects. However, the effects and mechanisms of betaine on liver fibrosis development are still insufficient. Because metabolic functions of chicken and human liver is similar, we established a chicken model with carbon Tetrachloride- (CCl4-) induced fibrosis for studying antifibrotic effect of betaine in vivo and in vitro. Two-week-old male chicks were supplemented with betaine (1%, w/v) in drinking water for 2 weeks prior to the initiation of CCl4 treatment (i.p.) until sacrifice. Primary chicken hepatocytes were treated with CCl4 and betaine to mimic the in vivo supplementation. The supplementation of betaine significantly alleviated liver fibrosis development along with the inhibition of lipid peroxidation, hepatic inflammation cytokine, and transforming growth factor-β1 expression levels. These inhibitive effects were also accompanied with the attenuation of hepatic stellate cell activation. Furthermore, our in vitro studies confirmed that betaine provides antioxidant capacity for attenuating the hepatocyte necrosis by CCl4. Altogether, our results highlight the antioxidant ability of betaine, which alleviates CCl4-induced fibrogenesis process along with the suppression of hepatic stellate cells activation. Since betaine is a natural compound without toxicity, we suggest betaine can be used as a potent nutritional or therapeutic factor for reducing liver fibrosis.

Transarterial chemoembolization aggravated peritumoral fibrosis via hypoxia-inducible factor-1α dependent pathway in hepatocellular carcinoma

BACKGROUND AND AIM

It was commonly accepted that chemotherapeutic cytotoxicity was the main cause for hepatic failure in hepatocellular carcinoma patients after repeated transarterial chemoembolization (TACE). However, the effect of embolization-induced hypoxia on liver cirrhosis has rarely been concerned.

METHODS

Serum levels of alanine aminotransferase, aspartate aminotransferase, and albumin were used to detect liver injury. Hepatic artery ligation was performed in carbon tetrachloride-induced rat hepatic fibrosis model to mimic the effect of hepatic hypoxia on liver fibrosis after TACE. Sirius Red staining and immunohistochemical analysis of alpha-smooth muscle actin (α-SMA) were used to detect the activation of hepatic stellate cells. Moreover, the expression of hypoxia and fibrosis-related molecules were analyzed at protein and/or mRNA level.

RESULTS

Patients showed a significant increase in alanine aminotransferase and aspartate aminotransferase (P = 0.006), accompanied by a decrease in albumin (P = 0.005) after repeated TACE. Hepatic artery ligation significantly promoted carbon tetrachloride-induced rat liver fibrosis progression as indicated by Sirius Red and α-SMA staining, as well as increased expression of hypoxia-inducible factor (HIF)-1α, transforming growth factor (TGF)-β1, and vascular endothelial growth factor (VEGF). Conditioned media of hypoxia-treated L02 cells induced the expression of Collagen I and α-SMA in LX-2 cells, which was inhibited by HIF-1α small interfering RNA. Finally, HIF-1α inhibitor LW6 attenuated the hypoxia-induced fibrosis progression in vivo.

CONCLUSION

Our data demonstrate that TACE-induced hepatic hypoxia aggravates the fibrosis progression in peritumoral liver tissue, thus leads to the deterioration of liver function. Intervention of HIF-1α might be a valuable strategy to optimize the efficacy and reduce the complication of TACE.

The plasma S-adenosylmethionine level is associated with the severity of hepatitis B-related liver disease

Alterations in methionine metabolism that involve changes in the plasma S-adenosylmethionine (SAMe) level occur in chronic liver diseases. However, no evidence is available on whether circulating SAMe is involved in the development of liver cirrhosis and liver cancer. Cross-sectional data on clinical characteristics and plasma SAMe were collected for 130 cases of chronic hepatitis B (CHB) and HCC as well as for normal volunteers. Univariate and multivariate linear regression and receiver operating characteristic curves were introduced to determine their correlations. Serum ALB and PT levels were independent clinical factors that were correlated with the plasma SAMe levels in CHB and HCC patients. A higher SAMe concentration was observed in the HCC than in the normal and CHB. By exploring the association of the Child-Pugh score with the plasma SAMe level, we found a higher SAMe level at advanced Stage C than at stage A in CHB and HCC patients. We further assessed the diagnostic performance of SAMe with respect to the stages of liver fibrosis and Child-Pugh stage. The AUROC of SAMe for the prediction of cirrhosis was 0.721, and the sensitivity and specificity was 0.707 and 0.769, respectively. The AUROC of plasma SAMe to predict Child-Pugh stage C was 0.706 in patients with CHB and 0.825 in HCC patients. The sensitivity was 0.467 and 0.800, respectively; the specificity was 0.904 and 0.781, respectively. The plasma SAMe level was positively correlated with the severity of liver disease and might be a potential noninvasive biomarker.

Protein extracts of Crassostrea gigas alleviate CCl₄-induced hepatic fibrosis in rats by reducing the expression of CTGF, TGF-β1 and NF-κB in liver tissues

Hepatic fibrosis may contribute to liver carcinoma and the mortality of patients with hepatic fibrosis is gradually increasing. However, no definitive treatment has been established for hepatic fibrosis. The hepatic fibrotic process is reversible and can be controlled; therefore, the creation of novel and effective therapeutic methods to prevent or reverse the disease is required. The aim of the present study was to identify whether protein extracts from Pacific oysters (PEPO) could alleviate the hepatic fibrosis induced by CCl4 and to examine the mechanisms involved. A total of sixty rats were randomly divided into the following experimental groups: The normal control group; the hepatic fibrosis model group; the high‑dose; medium‑dose; and low‑dose PEPO groups; and the colchicine group. The results indicated that compared with those of the model group, PEPO treatment significantly decreased the serum levels of alanine aminotransferase, aspartate aminotransferase, γ‑glutamyltransferase, alkaline phosphatase, hyaluronic acid, laminin, collagen type IV and procollagen III in rats with hepatic fibrosis. The hematoxylin and eosin staining demonstrated that PEPO markedly alleviated hepatic fibrosis. The experiments using immunohistochemistry, western blotting and quantitative PCR indicated that protein and mRNA expression levels of connective tissue growth factor (CTGF), transforming growth factor β1 (TGFβ‑1) and nuclear factor κB (NF‑κB) in the liver tissues were significantly reduced by PEPO treatment. Therefore, it was concluded that PEPO successfully alleviated hepatic fibrosis induced by CCl4 and reversed the effects of hepatotoxicity by regulating the serum levels of enzymes and decreasing the expression levels of CTGF, TGF‑β1 and NF‑κB in liver tissues. These findings may provide a novel treatment option for patients with hepatic fibrosis in the future.

NMR-based metabolomics approach to study the chronic toxicity of crude ricin from castor bean kernels on rats

Ricin, a large, water soluble toxic glycoprotein, is distributed majorly in the kernels of castor beans (the seeds of Ricinus communis L.) and has been used in traditional Chinese medicine (TCM) or other folk remedies throughout the world. The toxicity of crude ricin (CR) from castor bean kernels was investigated for the first time using an NMR-based metabolomic approach complemented with histopathological inspection and clinical chemistry. The chronic administration of CR could cause kidney and lung impairment, spleen and thymus dysfunction and diminished nutrient intake in rats. An orthogonal signal correction partial least-squares discriminant analysis (OSC-PLSDA) of metabolomic profiles of rat biofluids highlighted a number of metabolic disturbances induced by CR. Long-term CR treatment produced perturbations on energy metabolism, nitrogen metabolism, amino acid metabolism and kynurenine pathway, and evoked oxidative stress. These findings could explain well the CR induced nephrotoxicity and pulmonary toxicity, and provided several potential biomarkers for diagnostics of these toxicities. Such a (1)H NMR based metabolomics approach showed its ability to give a systematic and holistic view of the response of an organism to drugs and is suitable for dynamic studies on the toxicological effects of TCM.

Betaine Alleviates Hypertriglycemia and Tau Hyperphosphorylation in db/db Mice

Betaine supplementation has been shown to alleviate altered glucose and lipid metabolism in mice fed a high-fat diet or a high-sucrose diet. We investigated the beneficial effects of betaine in diabetic db/db mice. Alleviation of endoplasmic reticulum (ER) and oxidative stress was also examined in the livers and brains of db/db mice fed a betaine-supplemented diet. Male C57BL/KsJ-db/db mice were fed with or without 1% betaine for 5 wk (referred to as the db/db-betaine group and the db/db group, respectively). Lean non-diabetic db/db+ mice were used as the control group. Betaine supplementation significantly alleviated hyperinsulinemia in db/db mice. Betaine reduced hepatic expression of peroxisome proliferator-activated receptor gamma coactivator 1 alpha, a major transcription factor involved in gluconeogenesis. Lower serum triglyceride concentrations were also observed in the db/db-betaine group compared to the db/db group. Betaine supplementation induced hepatic peroxisome proliferator-activated receptor alpha and carnitine palmitoyltransferase 1a mRNA levels, and reduced acetyl-CoA carboxylase activity. Mice fed a betaine-supplemented diet had increased total glutathione concentrations and catalase activity, and reduced lipid peroxidation levels in the liver. Furthermore, betaine also reduced ER stress in liver and brain. c-Jun N-terminal kinase activity and tau hyperphosphorylation levels were lower in db/db mice fed a betaine-supplemented diet, compared to db/db mice. Our findings suggest that betaine improves hyperlipidemia and tau hyperphosphorylation in db/db mice with insulin resistance by alleviating ER and oxidative stress.

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.

Puerarin mediates hepatoprotection against CCl4-induced hepatic fibrosis rats through attenuation of inflammation response and amelioration of metabolic function

This study was designed to evaluate the potential effects of puerarin (PR), an effective isoflavonoid compound purified from Pueraria lobata, in treating hepatic fibrosis (HF) rats induced by carbon tetrachloride (CCl(4), 2 mL kg(-1) d(-1)). Compared to model control, PR treatment effectively lowered the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (Alb), total protein (TP) in HF rats. Masson stained analysis showed that the condition of HF rats was mitigated. Meanwhile, the tumor necrosis factor alpha (TNF-α), nuclear factor-kappa B (NF-κB) expressions were significantly down-regulated at protein level by PR intervention. Additionally, the activity of superoxide dismutase (SOD) was elevated, while the content of malondialdehyde (MDA) was lessened in liver tissue. As revealed by immunohistochemistry assay, PR therapy resulted in reduced production of transforming growth factor-βl (TGF-βl). Moreover, it also was attributed to decreased mRNA level of inducible nitric oxide synthase (iNOS) using RT-PCR analysis. These findings demonstrate that puerarin successfully reverses hepatotoxicity in CCl(4)-induced HF rats via the underlying mechanisms of regulating serum enzymes and attenuating TNF-α/NF-κB pathway for anti-inflammation response, as well as improving metabolic function in liver tissue.

Ameliorative effect of grape seed proanthocyanidin extract on thioacetamide-induced mouse hepatic fibrosis

The present study was designed to examine the effect of the grape seed proanthocyanidin extract (GSPE) on developing hepatic fibrosis that was induced by thioacetamide (TAA) in mice. Administration of TAA for 9 weeks led to a serious necrosis and apoptosis of the parenchymal cells, which resulted in an accumulation of excessive collagen in the liver and an increase of transformed hepatic stellate cells (HSCs). In addition, the mRNA expression of transforming growth factor β1 (TGF-β1), α-smooth muscle actin (α-SMA), as the marker of the activated HSCs, and α1-(I)-collagen were all up-regulated significantly when compared with the control. However, combined oral administration of GSPE at 100 mg/kg suppressed the mRNA expression of TGF-β1 and α-SMA, with decreased collagen accumulation as demonstrated by histomorphological evaluation and quantitative RT-PCR. The mRNA expression of the pro-inflammatory factors, including inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), was remarkably enhanced by TAA treatment. However, their levels displayed a down-regulated trend beyond simultaneous GSPE treatment. Moreover, GSPE administration markedly suppressed lipid peroxidation. In conclusion, as a plant antioxidant, GSPE manifested effective hepatocellular protective action to ameliorate the developing liver fibrosis induced by chronic TAA administration in mice.

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

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

Radiation protection following nuclear power accidents: a survey of putative mechanisms involved in the radioprotective actions of taurine during and after radiation exposure

There are several animal experiments showing that high doses of ionizing radiation lead to strongly enhanced leakage of taurine from damaged cells into the extracellular fluid, followed by enhanced urinary excretion. This radiation-induced taurine depletion can itself have various harmful effects (as will also be the case when taurine depletion is due to other causes, such as alcohol abuse or cancer therapy with cytotoxic drugs), but taurine supplementation has been shown to have radioprotective effects apparently going beyond what might be expected just as a consequence of correcting the harmful consequences of taurine deficiency per se. The mechanisms accounting for the radioprotective effects of taurine are, however, very incompletely understood. In this article an attempt is made to survey various mechanisms that potentially might be involved as parts of the explanation for the overall beneficial effect of high levels of taurine that has been found in experiments with animals or isolated cells exposed to high doses of ionizing radiation. It is proposed that taurine may have radioprotective effects by a combination of several mechanisms: (1) during the exposure to ionizing radiation by functioning as an antioxidant, but perhaps more because it counteracts the prooxidant catalytic effect of iron rather than functioning as an important scavenger of harmful molecules itself, (2) after the ionizing radiation exposure by helping to reduce the intensity of the post-traumatic inflammatory response, and thus reducing the extent of tissue damage that develops because of severe inflammation rather than as a direct effect of the ionizing radiation per se, (3) by functioning as a growth factor helping to enhance the growth rate of leukocytes and leukocyte progenitor cells and perhaps also of other rapidly proliferating cell types, such as enterocyte progenitor cells, which may be important for immunological recovery and perhaps also for rapid repair of various damaged tissues, especially in the intestines, and (4) by functioning as an antifibrogenic agent. A detailed discussion is given of possible mechanisms involved both in the antioxidant effects of taurine, in its anti-inflammatory effects and in its role as a growth factor for leukocytes and nerve cells, which might be closely related to its role as an osmolyte important for cellular volume regulation because of the close connection between cell volume regulation and the regulation of protein synthesis as well as cellular protein degradation. While taurine supplementation alone would be expected to exert a therapeutic effect far better than negligible in patients that have been exposed to high doses of ionizing radiation, it may on theoretical grounds be expected that much better results may be obtained by using taurine as part of a multifactorial treatment strategy, where it may interact synergistically with several other nutrients, hormones or other drugs for optimizing antioxidant protection and minimizing harmful posttraumatic inflammatory reactions, while using other nutrients to optimize DNA and tissue repair processes, and using a combination of good diet, immunostimulatory hormones and perhaps other nontoxic immunostimulants (such as beta-glucans) for optimizing the recovery of antiviral and antibacterial immune functions. Similar multifactorial treatment strategies may presumably be helpful in several other disease situations (including severe infectious diseases and severe asthma) as well as for treatment of acute intoxications or acute injuries (both mechanical ones and severe burns) where severely enhanced oxidative and/or nitrative stress and/or too much secretion of vasodilatory neuropeptides from C-fibres are important parts of the pathogenetic mechanisms that may lead to the death of the patient. Some case histories (with discussion of some of those mechanisms that may have been responsible for the observed therapeutic outcome) are given for illustration of the likely validity of these concepts and their relevance both for treatment of severe infections and non-infectious inflammatory diseases such as asthma and rheumatoid arthritis.

Betaine prevents ethanol-induced oxidative stress and reduces total homocysteine in the rat cerebellum

Oxidative stress is a hypothesis for the association of reactive oxygen species with cerebrovascular and neurodegenerative diseases. Thus, we examined whether oral betaine can act as a preventive agent in ethanol-induced oxidative stress on the cerebellum of rats. Thirty-two adult male Sprague-Dawley rats were divided into four equal groups (control, ethanol, betaine, and betaine plus ethanol) with different dietary regimens and were followed up for 1 month. Total homocysteine (tHcy) of plasma and cerebellum homogenate was determined by an Axis(®) homocysteine EIA kit, and antioxidant enzyme (glutathione peroxidase (GPx), SOD, and CAT) activities of cerebellum homogenate were measured chemically by a spectrophotometer. Lipid peroxidation of cerebellum was shown by the measurement of thiobarbituric reactive substances (TBARS) via a spectrophotometer. Ethanol-induced hyperhomocysteinemia was manifested by an increase in the concentrations of tHcy in the plasma and cerebellum homogenates of the ethanol group, while ethanol-induced oxidative stress was indicated via an increase in lipid peroxidation marker (TBARS) in cerebellum homogenates of ethanol-treated rats. In contrast, betaine prevented hyperhomocysteinemia and oxidative stress in the betaine plus ethanol group as well as the betaine group. The results of the present investigation indicated that the protective effect of betaine is probably related to its ability to strengthen the cerebellum membrane cells by enhancement of antioxidant enzyme activity principally GPx, while the methyl donor effect of betaine to reduce hyperhomocysteinemia has been explained previously and confirmed in the present study.

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.

Hepatoprotective activity of the edible snail (Bellamia bengalensis) flesh extract in carbon tetrachloride induced hepatotoxicity in rats

ETHNOPHARMACOLOGICAL RELEVANCE

In the folk-traditional medicine, snails were used to purify blood, boost immune system, prevent conjunctivitis and to treat liver problems.

OBJECTIVES

To evaluate the hepatoprotective activity of the edible snail (Bellamia bengalensis) flesh extract in male Wistar rats treated with carbon tetrachloride as an hepatotoxicant.

MATERIALS AND METHODS

Live adult Bellamia bengalensis was collected commercially from the Kolkata market. Aqueous flesh extract (BBE) was prepared in 0.9% saline and expressed in terms of wet weight basis. The aqueous flesh extract was administered orally (1, 2 g kg(-1)day(-1)) to male rats for 12 days. Liv52 was used as positive control. 24h after administration of extract, the rats were given a single oral dose of CCl(4) (1.25 ml kg(-1)), except vehicle control rats. After 24h of CCl(4) administration, all the animals were sacrificed to collect the blood and liver tissue.

RESULTS

BBE (1 and 2 g kg(-1)day(-1), p.o.×12 days) significantly prevented CCl(4) induced elevation of SGOT, SGPT, γGT, ACP, ALP, bilirubin, LDH and CCl(4) induced decrease in total protein, triglyceride level in male Wistar rats. BBE treated rat liver anti-oxidant parameters (LPO, SOD, GSH, CAT, GPx) were significantly antagonized for the pro-oxidant effect of CCl(4). Histopathological studies also supported the protective effect of BBE.

CONCLUSION

This study validated the folk and traditional use of snail in liver disorder through CCl(4)-induced rat experimental model.

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.

Experimental evidence for therapeutic potential of taurine in the treatment of nonalcoholic fatty liver disease

The incidence of obesity is now at epidemic proportions and has resulted in the emergence of nonalcoholic fatty liver disease (NAFLD) as a common metabolic disorder that can lead to liver injury and cirrhosis. Excess sucrose and long-chain saturated fatty acids in the diet may play a role in the development and progression of NAFLD. One factor linking sucrose and saturated fatty acids to liver damage is dysfunction of the endoplasmic reticulum (ER). Although there is currently no proven, effective therapy for NAFLD, the amino sulfonic acid taurine is protective against various metabolic disturbances, including alcohol-induced liver damage. The present study was undertaken to evaluate the therapeutic potential of taurine to serve as a preventative treatment for diet-induced NAFLD. We report that taurine significantly mitigated palmitate-mediated caspase-3 activity, cell death, ER stress, and oxidative stress in H4IIE liver cells and primary hepatocytes. In rats fed a high-sucrose diet, dietary taurine supplementation significantly reduced hepatic lipid accumulation, liver injury, inflammation, plasma triglycerides, and insulin levels. The high-sucrose diet resulted in an induction of multiple components of the unfolded protein response in the liver consistent with ER stress, which was ameliorated by taurine supplementation. Treatment of mice with the ER stress-inducing agent tunicamycin resulted in liver injury, unfolded protein response induction, and hepatic lipid accumulation that was significantly ameliorated by dietary supplementation with taurine. Our results indicate that dietary supplementation with taurine offers significant potential as a preventative treatment for NAFLD.