Higher dietary intakes of choline and betaine are associated with a lower risk of liver cancer

The dietary intake of methyl donors is favorably associated with many diseases, but the findings regarding primary liver cancer (PLC) risk are limited. This study investigated the association between the intake of choline, betaine and methionine and PLC risk in adults. This 1:1 matched case-control study enrolled 644 hospital-based PLC patients and 644 community-based controls who were matched by sex and age, in Guangzhou, China. An interviewer-administered questionnaire and a food-frequency questionnaire were used to collect general information and dietary intake information. Conditional logistic regression showed a significantly inverse association between total choline and betaine intakes and PLC risk. The multivariable-adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) for PLC for the top (vs. bottom) tertile were 0.34 (0.24-0.49; P -trend < 0.001) for total choline and 0.67 (0.48-0.93; P -trend = 0.011) for betaine. No significant association was observed between the intake of methionine and PLC risk (P > 0.05). For individual choline compounds, higher consumptions of free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine and sphingomyelin were associated with a lower PLC risk (all P-trend < 0.05). The studied associations were not significantly modified by the folate intake (P-interactions: 0.488-0.890). Our findings suggest that higher choline and betaine intakes may be associated with a lower risk of PLC.

Zhou, R. F., et al. (2017). "Higher dietary intakes of choline and betaine are associated with a lower risk of primary liver cancer: a case-control study." Sci Rep 7(1): 679.

Nonalcoholic Steatohepatitis is associated with a state of betaine-insufficiency

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD) develops from a complex process, which includes changes in the liver methylome. Betaine plays a pivotal role in the regulation of methylogenesis. We performed a two-stage case-control study, which included patients with biopsy-proven NAFLD in order to explore circulating levels of betaine and its association with the histological spectrum. We also explored the association between a missense p.Ser646Pro variant in DMGDH (dimethylglycine dehydrogenase mitochondrial) and NAFLD severity (n =390).
RESULTS: In the discovery phase (n = 48), betaine levels were associated with the disease severity (p = 0.0030), including liver inflammation (Spearman R: - 0.51, p = 0.001), ballooning degeneration (R: - 0.50, p = 0.01), and fibrosis (R: - 0.54, p = 0.0008). Betaine levels were significantly decreased in nonalcoholic steatohepatitis (NASH) in comparison with nonalcoholic fatty liver (NAFL). Further replication (n = 51) showed that betaine levels were associated with advanced NAFLD (p = 0.0085), and patients with NASH had a 1.26-fold decrease in betaine levels compared with those with NAFL. The rs1805074 was significantly associated with the disease severity (p = 0.011).
CONCLUSION: NAFLD severity is associated with a state of betaine-insufficiency.

Sookoian, S., et al., Nonalcoholic Steatohepatitis is associated with a state of betaine-insufficiency. Liver Int, 2016.

Betaine prevented fructose-induced NAFLD by regulating LXRalpha/PPARalpha pathway and alleviating ER stress in rats

Betaine has been proven effective in treating nonalcoholic fatty liver disease (NAFLD) in animal models, however, its molecular mechanisms remain elusive. The aims of this study were to explore the mechanisms mediating the anti-inflammatory and anti-lipogenic actions of betaine in fructose-fed rats. In this study, betaine improved insulin resistance, reduced body weight gain and serum lipid levels, and prevented hepatic lipid accumulation in fructose-fed rats. It up-regulated hepatic expression of liver X receptor-alpha (LXRalpha) and peroxisome proliferator-activated receptor-alpha (PPARalpha), with the attenuation of the changes of their target genes, including hepatic carnitine palmitoyl transferase (CPT) 1alpha, glycosylphosphatidylinositol anchored high density lipoprotein binding protein 1, apolipoprotein B, sterol regulatory element-binding protein 1c and adipocyte differentiation-related protein, involved in fatty acid oxidation and lipid storage in these model rats. Furthermore, betaine alleviated ER stress and inhibited acetyl-CoA carboxylase alpha, CPT II, stearoyl-CoA desaturase 1 and fatty acid synthase expression involved in fatty acid synthesis in the liver of fructose-fed rats. Betaine suppressed hepatic gluconeogenesis in fructose-fed rats by moderating protein kinase B -forkhead box protein O1 pathway, as well as p38 mitogen-activated protein kinase and mammalian target of rapamycin activity. Moreover, betaine inhibited hepatic nuclear factor kappa B /nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 inflammasome activation-mediated inflammation in this animal model. These results demonstrated that betaine ameliorated hepatic lipid accumulation, gluconeogenesis, and inflammation through restoring LXRalpha and PPARalpha expression and alleviating ER stress in fructose-fed rats. This study provides the potential mechanisms of betaine involved in the treatment of NAFLD.

Ge, C.X., et al., Betaine prevented fructose-induced NAFLD by regulating LXRalpha/PPARalpha pathway and alleviating ER stress in rats. Eur J Pharmacol, 2015.

The beneficial effects of betaine on dysfunctional adipose tissue and N6-methyladenosine mRNA methylation requires the AMP-activated protein kinase alpha1 subunit

The current study was conducted to determine whether betaine could improve fatty acid oxidation, mitochondrial function and N6-methyladenosine (m6A) mRNA methylation in adipose tissue in high-fat-induced mice and how AMP-activated protein kinase alpha1 subunit (AMPKalpha1) was involved. AMPKalpha1 knockout mice and wild-type mice were fed either a low-fat diet, high-fat diet or high-fat diet supplemented with betaine in the drinking water for 8weeks. Our results showed that mitochondrial genes (PGC1alpha) and beta-oxidation-related genes (CPT1a) at protein level were increased in wild-type mice supplemented with betaine when compared with those in mice with high-fat diet. Betaine also decreased FTO expression and improved m6A methylation in adipose tissue of wild-type mice with high-fat diet. However, betaine failed to exert the abovementioned effects in AMPKalpha1 knockout mice. In adipocytes isolated from mice with high-fat diet, betaine treatment increased lipolysis and lipid oxidation. Moreover, betaine decreased FTO expression and increased m6A methylation. However, while AMPKalpha1 was knockdown, no remarkable changes in adipocytes were observed under betaine treatment. Our results indicated that betaine supplementation rectified mRNA hypomethylation and high FTO expression induced by high-fat diet, which may contribute to its beneficial effects on impaired adipose tissue function. Our results suggested that the AMPKalpha1 subunit is required for the beneficial effects of betaine on dysfunctional adipose tissue and m6A methylation. These results may provide the foundation for a mechanism that links m6A methylation status in RNA, AMPKalpha1 phosphorylation and dysfunctional adipose tissue induced by high-fat diet.

Zhou, X., et al., The beneficial effects of betaine on dysfunctional adipose tissue and N6-methyladenosine mRNA methylation requires the AMP-activated protein kinase alpha1 subunit. J Nutr Biochem, 2015

FTO-dependent function of N6-methyladenosine is involved in the hepatoprotective effects of betaine on adolescent mice

Nonalcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease among children and adolescents in the developed world. Betaine, as a methyl donor, recently has been demonstrated to exert its hepatoprotective effects through rectifying the genomic DNA hypomethylation state. However, whether betaine supplementation affects N6-methyladenosine (m6A) mRNA methylation in NAFLD is still unknown. We conducted the current study to investigate the effects of betaine supplementation during adolescence on high-fat diet-induced pathological changes in liver of mice, and we further identified the effects of betaine supplementation on expression of the fat mass and obesity-associated gene (FTO) and hepatic m6A mRNA methylation. Our results showed that betaine supplementation across adolescence significantly alleviated high-fat-induced impairment of liver function and morphology as well as ectopic fat accumulation. Surprisingly, no significant effects on serum TG and NEFA level, as well as fat mass, were observed in mice supplemented with betaine. We also found that high-fat diet upregulated ACC1 and FAS gene expression and downregulated HSL and ATGL gene expression. However, these alterations were rectified by betaine supplementation. Moreover, an m6A hypomethylation state and increased FTO expression were detected in mice fed with high-fat diet, while betaine supplementation prevented these changes. Our results suggested that betaine supplementation during adolescence could protect mice from high-fat-induced NAFLD by decreasing de novo lipogenesis and increasing lipolysis. Furthermore, a novel FTO-dependent function of m6A may involve in the hepatoprotective effects of betaine.

Chen, J., et al., FTO-dependent function of N6-methyladenosine is involved in the hepatoprotective effects of betaine on adolescent mice. J Physiol Biochem, 2015.

Betaine alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet

To assess the effects of betaine on hepatic lipid accumulation and investigate the underlying mechanism, thirty-two male Sprague-Dawley rats weighing 100 (sd 2.50) g were divided into four groups, and started on one of four treatments: basal diet, basal diet with betaine administration, high-fat diet and high-fat diet with betaine administration. The results showed that no significant difference of body weight was found among experimental groups. Compared with high-fat diet-fed rats, a betaine supplementation decreased (P< 0.05) hepatic TAG accumulation induced by high-fat diet, which was also supported by hepatic histology results. Additionally, hepatic betaine-homocysteine methyltransferase activity as well as its mRNA abundance and lecithin level were found increased (P< 0.05) by betaine supplementation in both basal diet-fed rats and high-fat diet-fed rats. Betaine administration in high-fat diet-fed rats exhibited a higher (P< 0.05) activity of hepatic carnitine palmitoyltransferase 1 (CPT1) compared with high-fat diet-fed rats. High-fat diet inhibited (P< 0.05) the gene expression of hepatic PPARalpha and CPT1. However, betaine administration in high-fat diet-fed rats elevated (P< 0.05) the gene expression of PPARalpha and CPT1. Moreover, concentration, gene and protein expressions of hepatic fibroblast growth factor 21 (FGF21) were increased (P< 0.05) in response to betaine administration in high-fat diet group; meanwhile the gene expression of hepatic AMP-activated protein kinase was increased (P< 0.05) as well. The results suggest that betaine administration enhanced hepatic lipid export and fatty acid oxidation in high-fat diet-fed rats, thus effectively alleviating fat accumulation in the liver.

Xu, L., et al., Betaine alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet. Br J Nutr, 2015: p. 1-9

Betaine supplementation prevents fatty liver induced by a high-fat diet: effects on one-carbon metabolism

The purpose of this study was to examine the effects of betaine supplementation on the regulation of one-carbon metabolism and liver lipid accumulation induced by a high-fat diet in rats. Rats were fed one of three different liquid diets: control diet, high-fat diet and high-fat diet supplemented with betaine. The control and high-fat liquid diets contained, respectively, 35 and 71 % of energy derived from fat. Betaine supplementation involved the addition of 1 % (g/L) to the diet. After three weeks on the high-fat diet the rats had increased total liver fat concentration, liver triglycerides, liver TBARS and plasma TNF-alpha. The high-fat diet decreased the hepatic S-adenosylmethionine concentration and the S-adenosylmethionine/S-adenosylhomocysteine ratio compared to the control as well as altering the expression of genes involved in one-carbon metabolism. Betaine supplementation substantially increased the hepatic S-adenosylmethionine concentration (~fourfold) and prevented fatty liver and hepatic injury induced by the high-fat diet. It was accompanied by the normalization of the gene expression of BHMT, GNMT and MGAT, which code for key enzymes of one-carbon metabolism related to liver fat accumulation. In conclusion, the regulation of the expression of MGAT by betaine supplementation provides an additional and novel mechanism by which betaine supplementation regulates lipid metabolism and prevents accumulation of fat in the liver.

Deminice, R., et al., Betaine supplementation prevents fatty liver induced by a high-fat diet: effects on one-carbon metabolism. Amino Acids, 2015

Maternal dietary betaine supplementation modifies hepatic expression of cholesterol metabolic genes via epigenetic mechanisms in newborn piglets

To elucidate the effects of maternal dietary betaine supplementation on hepatic expression of cholesterol metabolic genes in newborn piglets and the involved epigenetic mechanisms, we fed gestational sows with control or betaine-supplemented diets (3 g/kg) throughout pregnancy. Neonatal piglets born to betaine-supplemented sows had higher serum methionine concentration and hepatic content of betaine, which was associated with significantly up-regulated hepatic expression of glycine N-methyltransferase. Prenatal betaine exposure increased hepatic cholesterol content and modified the hepatic expression of cholesterol metabolic genes in neonatal piglets. Sterol regulatory element-binding protein 2 was down-regulated at both mRNA and protein levels, while 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) was down-regulated at the mRNA level, but up-regulated at the protein level, in betaine-exposed piglets. The transcriptional repression of HMGCR was associated with CpG island hypermethylation and higher repressive histone mark H3K27me3 (histone H3 lysine 27 trimethylation) on the promoter, whereas increased HMGCR protein content was associated with significantly decreased expression of miR-497. Furthermore, LDL receptor was significantly down-regulated at both mRNA and protein levels in the liver of betaine-exposed piglets, which was associated with promoter CpG hypermethylation. In addition, the expression of cholesterol-27alpha-hydroxylase (CYP27alpha1) was up-regulated at both mRNA and protein levels, while the expression of cholesterol-7alpha-hydroxylase (CYP7alpha1) was increased at the mRNA level, but unchanged at the protein level associated with increased expression of miR-181. These results indicate that maternal betaine supplementation increases hepatic cholesterol content in neonatal piglets through epigenetic regulations of cholesterol metabolic genes, which involve alterations in DNA and histone methylation and in the expression of microRNA targeting these genes.

Cai, D., et al., Maternal dietary betaine supplementation modifies hepatic expression of cholesterol metabolic genes via epigenetic mechanisms in newborn piglets. Br J Nutr, 2014: p. 1-10

Methyl-donor supplementation in obese mice prevents the progression of NAFLD, activates AMPK and decreases acyl-carnitine levels

Non-alcoholic fatty liver disease (NAFLD) results from increased hepatic lipid accumulation and steatosis, and is closely linked to liver one-carbon (C1) metabolism. We assessed in C57BL6/N mice whether NAFLD induced by a high-fat (HF) diet over 8 weeks can be reversed by additional 4 weeks of a dietary methyl-donor supplementation (MDS). MDS in the obese mice failed to reverse NAFLD, but prevented the progression of hepatic steatosis associated with major changes in key hepatic C1-metabolites, e.g. S-adenosyl-methionine and S-adenosyl-homocysteine. Increased phosphorylation of AMPK-alpha together with enhanced beta-HAD activity suggested an increased flux through fatty acid oxidation pathways. This was supported by concomitantly decreased hepatic free fatty acid and acyl-carnitines levels. Although HF diet changed the hepatic phospholipid pattern, MDS did not. Our findings suggest that dietary methyl-donors activate AMPK, a key enzyme in fatty acid beta-oxidation control, that mediates increased fatty acid utilization and thereby prevents further hepatic lipid accumulation.

Dahlhoff, C., et al., Hepatic Methionine Homeostasis Is Conserved in C57BL/6N Mice on High-Fat Diet Despite Major Changes in Hepatic One-Carbon Metabolism. PLoS One, 2013. 8(3): p. e57387

Betaine is a potential agent for the treatment of hepatopathy associated with short bowel syndrome

Background: The hepatopathy associated with short bowel syndrome (SBS) is a multifactorial disease associated with poor prognosis. Besides intestinal transplantation, no other treatment has been shown effective. The current study evaluated the efficacy of betaine for the treatment of hepatopathy associated with SBS.
Methods: A prospective, unicentric, non-placebo controlled trial was carried out. After initial evaluation, 10g of betaine anhydrous was administrated to SBS patients in two divided doses for three months. The hepatic steatosis was assessed through nuclear magnetic resonance (NMR), the inflammatory response by interleukin- 6 (IL-6), tumor necrosis factor-(TNF-) and ferritin, besides the hepatic lesion through hepatic enzymes and bilirubin. Furthermore, the effect of betaine on homocysteine was evaluated as well as its safety and tolerability in this group of patients.
Results: After three months supplementation, patients showed decreased percentage of hepatic fat (p = 0.03) through triphasic NMR examination. There was no significant reduction of serum levels for inflammatory proteins and hepatic lesion markers. Homocysteinemia also did not present significant decrease. The most prevalent side effects were diarrhea and nausea, reported in 62% of the participants; however, these symptoms were transient and not severe enough to justify the treatment interruption. Parenteral nutrition-dependent patients did not present different hepatic lesion degree compared to patients who do not need the prolonged use of it.
Conclusions: Betaine was shown to be a potential agent for the treatment of hepatopathy associated with SBS, which was evidenced by NMR, although the markers for hepatic lesion have not presented significant decrease.

Teixeira Araujo, G., et al., Betaine: A Potential Agent for the Treatment of Hepatopathy Associated with Short Bowel Syndrome. Nutr Hosp, 2014. 29(n06): p. 1366-1371

Hepatoprotective effects of Lycium chinense Miller fruit and its constituent betaine in CCl-induced hepatic damage in rats.

The hepatoprotective activities of Lycium chinense Miller (LC) fruit extract and its component betaine were investigated under carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. The treatment of LC fruit extract significantly suppressed the increase of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the sera of CCl4 injured rats, and restored the decreased levels of anti-oxidant enzymes such as total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and suppressed the expression of inflammatory mediators including inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-1 and -2. To visualize the potential activity of betaine, a component of LC fruit, betaine was substituted for LC extract in CCl4 injured rats. The biochemical profile in CCl4 injured rats co-treated with betaine matched those of LC fruit treated CCl4 injured rats. The ameliorative effects of LC extract, as well as betaine, were also confirmed by histopathological examination. Collectively, the present findings imply that LC fruit, via its component betaine, mitigate CCl4-induced hepatic injury by increasing antioxidative activity and decreasing inflammatory mediators including iNOS and COX-1/COX-2.

Ahn, M., et al., Hepatoprotective effects of Lycium chinense Miller fruit and its constituent betaine in CCl-induced hepatic damage in rats. Acta Histochem, 2014

Betaine is a potential therapeutic agent because it effectively protects against adverse actions of ethanol

Because scavenger receptor class B type 1 is the cholesterol uptake liver receptor, whereas peroxisome proliferator-activated receptor gamma coactivator-1beta (PGC-1beta) and PGC-1alpha 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 alpha and IL-6, decreased glutathione, and elevated serum alanine aminotransferase. These actions of ethanol involved up-regulated PGC-1beta, sterol regulatory element-binding proteins 1c and 2, acetyl-CoA carboxylase (ACC), and HMG-CoA reductase mRNAs/proteins and inactive non-phosphorylated AMP kinase; and down-regulated silence regulator gene 1 and PGC-1alpha 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-1beta and lipid synthetic genes and down-regulation of silence regulator gene 1, PGC-1alpha, 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.

Varatharajalu, R., et al., Adverse Signaling of Scavenger Receptor Class B1 and PGC1s in Alcoholic Hepatosteatosis and Steatohepatitis, and Protection by Betaine in Rat. Am J Pathol, 2014

Improvement of adipose tissue function may contribute to the hepatoprotective role of betaine in ALD

BACKGROUND AND PURPOSE: Overactive adipose lipolysis contributes to the pathogenesis of alcoholic liver disease (ALD), however, mechanisms remain to be elucidated. We previously reported that chronic alcohol drinking resulted in a hypomethylation status in adipose tissue. This study aims to investigate mechanistic involvement of adipose tissue hypomethylation in alcohol-induced lipolysis and whether its correction contributes to the well-established hepatoprotective effect of betaine in ALD.
EXPERIMENTAL APPROACH: Male C57BL/6 mice were divided into four groups and started on one of four treatments for five weeks: isocaloric pair-fed (PF), alcohol-fed (AF), PF supplemented with betaine (BT/AF), and AF supplemented with betaine (BT/AF). Betaine was supplemented in the liquid diet at a concentration of 0.5% (wt/vol.). Both primary adipocytes and mature 3T3-L1 adipocytes were exposed to demethylation reagents and lipolytic response was determined.
KEY RESULTS: Betaine alleviated alcohol-induced hepatic pathological changes and rectified impaired adipose tissue methylation status, which is concomitant with attenuated lipolysis. In adipocytes, the induction of cellular hypomethylation activates lipolysis through a mechanism involving protein phosphatase 2A (PP2A) suppression, resulting from PP2A C subunit hypomethylation, leading to hormone-sensitive lipase (HSL) activation. In line with in vitro observations, reduced adipose tissue PP2A C subunit methylation and activity, as well as enhanced HSL activation, were observed in alcohol-fed mice. Betaine attenuated alcohol-induced adipose tissue PP2A suppression and HSL activation.
CONCLUSIONS AND IMPLICATIONS: Adipose tissue hypomethylation state contributes to alcohol-induced adipose tissue dysfunction and improvement of adipose tissue function may contribute to the hepatoprotective role of betaine in ALD.

Dou, X., et al., Rectification of impaired adipose tissue methylation status and lipolytic response contributes to hepatoprotective effect of betaine supplementation in a mouse model of alcoholic liver disease. Br J Pharmacol, 2014

Use of betaine in liver injury

Betaine, also known as trimethylglycine, is an important human nutrient obtained from a variety of foods and also can be synthesized from choline. Betaine is much more abundant in kidney and liver compared to other mammalian organs. The principal role of betaine in the kidney is osmoprotection in cells of the medulla and it enters these cells via the betaine/gamma-aminobutyric acid (GABA) transporter protein (BGT1), which is upregulated by hyperosmotic stress. This process has been studied in great detail. In liver, the main role of betaine is a methyl donor in the methionine cycle. However, recent studies showed that BGT1 is much more abundant in liver compared to kidney medulla. Despite this, the role of BGT1 in liver has received little attention. Entry of betaine into liver cells is a necessary first step for its action at the cellular level. Increased interest in betaine has developed because of a number of therapeutic uses. These include treatment of nonalcoholic fatty liver and hyperhomocysteinemia, a risk factor for atherosclerotic disease. Several important questions need to be addressed to better understand the potential of betaine as a therapeutic agent for other liver diseases, such as alcohol-induced injury. Heavy alcohol consumption is the most common cause for liver-related deaths and altered liver metabolism may contribute to hepatic, vascular, coronary, and cerebral diseases.

Kempson, S.A. et al, Betaine transport in kidney and liver: use of betaine in liver injury. Cell Physiol Biochem, 2013. 32(7): p. 32-40

Betaine attenuates hepatic steatosis by reducing methylation of the MTTP promoter and elevating genomic methylation in mice fed a high fat diet

Aberrant DNA methylation contributes to the abnormality of hepatic gene expression, one of the main factors in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Betaine is a methyl donor and has been considered to be a lipotropic agent. However, whether betaine supplementation improves NAFLD via its effect on the DNA methylation of specific genes and the genome has not been explored. Male C57BL/6 mice were fed either a control diet (CD) or high fat diet (HFD) supplemented with 0%, 1% and 2% betaine in water (wt/vol) for 12 weeks. Betaine supplementation ameliorated HFD-induced hepatic steatosis in a dose-dependent manner. HFD upregulated FAS and ACOX mRNA expression and downregulated PPARα, ApoB and MTTP mRNA expression; however, these alterations were reversed by betaine supplementation except ApoB. MTTP mRNA expression was negatively correlated with the DNA methylation of its CpG sites at -184, -156, -63 and -60. Methylation of these CpG sites was lower in both the 1% and 2% betaine-supplemented groups than in the HFD group (averages; 25.55% and 14.33% vs. 30.13%). In addition, both 1% and 2% betaine supplementation significantly restored the methylation capacity (SAM concentration and SAM/SAH ratios) and genomic methylation level which had been decreased by HFD (0.37% and 0.47% vs. 0.25%). These results suggest that the regulation of aberrant DNA methylation by betaine might be a possible mechanism of the improvements in NAFLD upon betaine supplementation.

Wang, L.-j., et al., Betaine attenuates hepatic steatosis by reducing methylation of the MTTP promoter and elevating genomic methylation in mice fed a high fat diet. The Journal of Nutritional Biochemistry, 2013

High fat-sucrose diet-induced liver fat accumulation was prevented by methyl donor supplementation

Non-alcoholic fatty liver disease is a primary hepatic manifestation of obesity and an important adverse metabolic syndrome trait. Animal models of diet-induced obesity promote liver fat accumulation putatively associated with alterations in epigenetic profile. Dietary methyl donor-supplementation may protect against this disturbance during early developmental stages affecting the molecular basis of gene regulation. The aim of this study was to investigate the transcriptomic and epigenetic mechanisms implicated in liver fat accumulation as a result of an obesogenic diet and the putative preventive role of dietary methyl donors. Forty-eight male Wistar rats were assigned into four dietary groups for 8weeks; control, control methyl-donor-supplemented with a dietary cocktail containing betaine, choline, vitamin B12 and folic acid, high-fat-sucrose and high-fat-sucrose methyl-donor-supplemented. Liver fat accumulation induced by a HFS diet was prevented by methyl donor supplementation in HFS-fed animals. A liver mRNA microarray, subsequently validated by real time-qPCR, showed modifications in some biologically relevant genes involved in obesity development and lipid metabolism (Lepr, Srebf2, Agpat3 and Esr1). Liver global DNA methylation was decreased by methyl donor supplementation in control-fed animals. Methylation levels of specific CpG sites from Srebf2, Agpat3 and Esr1 promoter regions showed changes due to the obesogenic diet and the supplementation with methyl donors. Interestingly, Srebf2 CpG23_24 methylation levels (-167bp and -156bp with respect to the transcriptional start site) correlated with HDLc plasma levels, whereas Esr1 CpG14 (-2623bp) methylation levels were associated with body and liver weights and fat content. Furthermore HFS diet-induced liver fat accumulation was prevented by methyl donor supplementation. In conclusion, both obesogenic diet and methyl donor supplementation modified the mRNA hepatic profile as well as the methylation of specific gene promoters and total DNA.

Cordero, P., et al., Transcriptomic and epigenetic changes in early liver steatosis associated to obesity: Effect of dietary methyl donor supplementation. Mol Genet Metab, 2013

Alleviation of alcoholic liver injury by betaine involves an enhancement of antioxidant defense via regulation of sulfur amino acid metabolism

Previous studies suggested that the hepatoprotective activity of betaine is associated with its effects on sulfur amino acid metabolism. We examined the mechanism by which betaine prevents the progression of alcoholic liver injury and its therapeutic potential. Rats received a liquid ethanol diet for 6 wk. Ethanol consumption elevated serum triglyceride and TNFalpha levels, alanine aminotransferase and aspartate aminotransferase activities, and lipid accumulation in liver. The oxyradical scavenging capacity of liver was reduced, and expression of CD14, TNFalpha, COX-2, and iNOS mRNAs was induced markedly. These ethanol-induced changes were all inhibited effectively by betaine supplementation. Hepatic S-adenosylmethionine, cysteine, and glutathione levels, reduced in the ethanol-fed rats, were increased by betaine supplementation. Methionine adenosyltransferase and cystathionine gamma-lyase were induced, but cysteine dioxygenase was down-regulated, which appeared to account for the increment in cysteine availability for glutathione synthesis in the rats supplemented with betaine. Betaine supplementation for the final 2 wk of ethanol intake resulted in a similar degree of hepatoprotection, revealing its potential therapeutic value in alcoholic liver. It is concluded that the protective effects of betaine against alcoholic liver injury may be attributed to the fortification of antioxidant defense via improvement of impaired sulfur amino acid metabolism.

Jung, Y.S., et al., Alleviation of alcoholic liver injury by betaine involves an enhancement of antioxidant defense via regulation of sulfur amino acid metabolism. Food Chem Toxicol, 2013

Betaine supplementation inhibited liver fat accumulation in a nonalcoholic steatohepatitis (NASH) mouse model

The effects of betaine supplementation on non-alcoholic steatohepatitis (NASH) model mice were examined by measuring the accumulation of fat in the livers of NASH model mice compared to a control. Betaine from sugar beets was provided to the model mice as a dietary supplement. After 3 wk of dietary supplementation. there were no significant differences in body weight or liver weight between the groups. However, the liver to body weight ratio in the high-fat diet with betaine (HM) group was significantly higher than that in the high-fat diet (HF) group. There were no differences in scrum triglyceride (TG) concentrations. AST and ALT activities, or hepatic glutathione concentrations between the groups. Hepatic TG level in the Ha group was significantly lower than that in the HF group. Hepatic cells obtained from the HF group showed increased occurrence of explosive puff and necrosis as compared with those in the HFB group. Betaine supplementation had an inhibitory effect on fat accumulation in the liver: the Oil red-positive area in the Ha group (0.82 +/- 0.85%) was significantly smaller than that in the HF group (9.06 +/- 2.24%). These results indicate the potential of betaine to serve as an agent for amelioration of hepatic steatosis in NASH model mice.

Kawakami, S., et al., Effects of dietary supplementation with betaine on a nonalcoholic steatohepatitis ( NASH ) mouse model. Journal of Nutritional Science and Vitaminology, 2012. 58(5): p. 371-5

Betaine supplementation causes increase in carnitine metabolites in the muscle and liver of mice fed a high-fat diet as studied by nontargeted LC-MS metabolomics approach

SCOPE: Betaine (BET) reduces diet-induced liver lipid accumulation, and may relieve obesity-related metabolic disturbances. The aim of our study was to analyze metabolite alterations after supplementation of BET, polydextrose (PDX, a soluble dietary fiber), or their combination (BET PDX) via drinking water to C57BL/6J mice fed a high-fat (HF) diet.
METHODS AND RESULTS: BET supplementation increased BET levels in plasma, muscle, and liver (p < 0.05), and the nontargeted LC-MS metabolite profiling revealed an increase in several metabolites in the carnitine biosynthesis pathway after BET supplementation both in liver and muscle. These included carnitine and acetylcarnitine (1.4-fold, p < 0.05), propionylcarnitine and gamma-butyrobetaine (1.5-fold, p < 0.05), and several other short-chain acylcarnitines (p < 0.05) in muscle. These changes were slightly higher in the BET PDX group. Furthermore, BET reduced the HF diet induced accumulation of triglycerides in liver (p < 0.05). The supplementations did not attenuate the HF diet induced increase in body weight gain or the increase in adipose tissue mass. Instead, the combination of BET and PDX tended to increase adiposity. CONCLUSION: Our results suggest that increased availability of BET in different tissues, especially in muscle, after BET supplementation has an impact on carnitine metabolism, and this could further explain the link between BET and lipid metabolism.

Pekkinen, J., et al., Betaine supplementation causes increase in carnitine metabolites in the muscle and liver of mice fed a high-fat diet as studied by nontargeted LC-MS metabolomics approach. Mol Nutr Food Res, 2013

Betaine protects against high-fat-diet-induced NAFLD and improves liver function

BACKGROUND AND OBJECTIVES: Previous studies have shown that betaine prevents alcohol-induced liver injury and improves liver function. The purpose of this study was to investigate the hepatoprotective effects of betaine on nonalcoholic fatty liver disease (NAFLD) and to observe changes of HMGB1/TLR4 signaling.
METHODS: Thirty rats were randomly divided into control, model, and betaine groups. The rats in the model and betaine groups were fed a high-fat diet for 12 weeks to induce an animal model of NAFLD. The rats in the betaine group were then intragastrically administered betaine solution at a dose of 400 mg/kg per day for four weeks. Liver histology was examined. Serum levels of ALT, AST, TC, TG, HDL-C, LDL-C, FFA, HMGB1, NF-kappaB, TLR4, and tHcy were determined and intrahepatic TC, TG, and Hcy levels were assayed. mRNA expression and protein levels of HMGB1, NF-kappaB, and TLR4 in liver tissue were also determined.
RESULTS: Compared with the control group, rats in the model group developed severe liver injury, accompanied by significant increases in serum levels of ALT, AST, TC, TG, LDL-C, FFA, HMGB1, NF-kappaB, and TLR4, intrahepatic TC, TG, and Hcy content, histological scores for steatosis, inflammation, and necrosis, and mRNA expression and protein levels of HMGB1, NF-kappaB, and TLR4, and a significant decrease in serum HDL-C (P < 0.05). Compared with the model group, all these indicators were significantly improved by administration of betaine (P < 0.05).
CONCLUSIONS: Betaine effectively protects against high-fat-diet-induced NAFLD and improves liver function; the mechanism is probably related to inhibition of HMGB1/TLR4 signaling pathways.

Zhang, W., et al., Betaine Protects Against High-Fat-Diet-Induced Liver Injury by Inhibition of High-Mobility Group Box 1 and Toll-Like Receptor 4 Expression in Rats. Dig Dis Sci, 2013