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

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

Dietary betaine may help prevent NTDs

BACKGROUND: Low maternal intake of dietary choline and betaine (a choline derivative) has recently been investigated as a possible risk factor for neural tube defects (NTDs)
METHODS: This case-control study examined the NTD risk associated with choline and betaine in 409 Mexican-American women who gave birth during 1995 to 2000 in the 14-county border region of Texas RESULTS: Using data from the food frequency questionnaire and the lowest quartiles of intake as the reference categories, a protective association was suggested between higher intakes of choline and betaine and NTD risk although the 95% confidence intervals for all risk estimates included 1.0. For choline intake in the second, third, and fourth quartiles, adjusted odds ratios were 1.2, 0.80, and 0.89, respectively. Betaine appeared more protective with odds ratios of 0.62, 0.73, and 0.61, respectively, for the second, third, and fourth quartiles of intake.
CONCLUSION: Study findings suggest that dietary betaine may help to prevent NTDs.

Lavery, A.M., et al., Dietary intake of choline and neural tube defects in Mexican Americans. Birth Defects Res A Clin Mol Teratol, 2014

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

Cereal foods are the major source of betaine in the Western diet

Betaine and its precursor choline are important components of one-carbon metabolism, remethylating homocysteine into methionine and providing methyl groups for DNA methylation. Cereals are the main source of betaine in the diet, though there is little literature available on the content of betaine in cereal products, nor on betaine intake from cereals. Betaine and free-choline concentrations were measured by liquid-chromatography with tandem mass spectrometry in a wide range of commercially available cereal foods and cereal fractions. Whole grain wheat and related fractions were the best overall common source of betaine, while the pseudocereal quinoa had the highest amount of betaine measured (3900mug/g). Based on estimates of dietary intake data cereal foods provide approximately 60-67% of betaine in Western diets, and 20-40% of betaine in South-East Asian diets. Average intake of betaine was 131mg/d, well below those used in intervention studies using betaine to lower blood homocysteine.

Ross, A.B., A. Zangger, and S.P. Guiraud, Cereal foods are the major source of betaine in the Western diet - Analysis of betaine and free choline in cereal foods and updated assessments of betaine intake. Food Chem, 2014. 145C: p. 859-865

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

Maternal methyl metabolism, offspring DNA methylation, and epigenetic consequences on later disease susceptibility

Evidence is growing for the long-term effects of environmental factors during early-life on later disease susceptibility. It is believed that epigenetic mechanisms (changes in gene function not mediated by DNA sequence alteration), particularly DNA methylation, play a role in these processes. This paper reviews the current state of knowledge of the involvement of C1 metabolism and methyl donors and cofactors in maternal diet-induced DNA methylation changes in utero as an epigenetic mechanism. Methyl groups for DNA methylation are mostly derived from the diet and supplied through C1 metabolism by way of choline, betaine, methionine or folate, with involvement of riboflavin and vitamins B6 and B12 as cofactors. Mouse models have shown that epigenetic features, for example DNA methylation, can be altered by periconceptional nutritional interventions such as folate supplementation, thereby changing offspring phenotype. Evidence of early nutrient-induced epigenetic change in human subjects is scant, but it is known that during pregnancy C1 metabolism has to cope with high fetal demands for folate and choline needed for neural tube closure and normal development. Retrospective studies investigating the effect of famine or season during pregnancy indicate that variation in early environmental exposure in utero leads to differences in DNA methylation of offspring. This may affect gene expression in the offspring. Further research is needed to examine the real impact of maternal nutrient availability on DNA methylation in the developing fetus.

Dominguez-Salas, P., et al., Maternal nutritional status, C(1) metabolism and offspring DNA methylation: a review of current evidence in human subjects. Proc Nutr Soc, 2012. 71(1): p. 154-65

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

High fat diet induces upregulation of BHMT to accommodate dietary fat processing and preserve methionine

Obesity is an underlying risk factor in the development of cardiovascular disease, dyslipidemia and non-alcoholic fatty liver disease (NAFLD). Increased hepatic lipid accumulation is a hallmark in the progression of NAFLD and impairments in liver phosphatidylcholine (PC) metabolism may be central to the pathogenesis. Hepatic PC biosynthesis, which is linked to the one-carbon (C1) metabolism by phosphatidylethanolamine N-methyltransferase, is known to be important for hepatic lipid export by VLDL particles. Here, we assessed the influence of a high-fat (HF) diet and NAFLD status in mice on hepatic methyl-group expenditure and C1-metabolism by analyzing changes in gene expression, protein levels, metabolite concentrations, and nuclear epigenetic processes. In livers from HF diet induced obese mice a significant downregulation of cystathionine beta-synthase (CBS) and an increased betaine-homocysteine methyltransferase (BHMT) expression were observed. Experiments , using hepatoma cells stimulated with peroxisome proliferator activated receptor alpha (PPARalpha) agonist WY14,643, revealed a significantly reduced Cbs mRNA expression. Moreover, metabolite measurements identified decreased hepatic cystathionine and L-alpha-amino-n-butyrate concentrations as part of the transsulfuration pathway and reduced hepatic betaine concentrations, but no metabolite changes in the methionine cycle in HF diet fed mice compared to controls. Furthermore, we detected diminished hepatic gene expression of DNA methyltransferase 3b but no effects on hepatic global genomic DNA methylation or hepatic DNA methylation in the Cbs promoter region upon HF diet. Our data suggest that HF diet induces a PPARalpha-mediated downregulation of key enzymes in the hepatic transsulfuration pathway and upregulates BHMT expression in mice to accommodate to enhanced dietary fat processing while preserving the essential amino acid methionine.

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

Effects of dietary supplementation with betaine on 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

Thermal and refining processes, not fermentation, tend to reduce lipotropic capacity of plant-based foods

Plant-based foods (PBF) are relevant and diversified sources of lipotropes, which are compounds preventing excess hepatic fat deposits. In a first study, we defined the lipotropic capacity (LC, %) of raw PBF as the means of 8 lipotrope densities (LD, mg/100 kcal), each expressed relative to that of a reference food ranking the highest considering its mean 8 LD ranks (LCraw asparagus = 100%) (A. Fardet, J.-F. Martin and J. M. Chardigny, J. Food Comp. Anal., 2011, DOI: 10.1016/j.jfca.2011.1003.1013). We showed that vegetables appeared as the best source of lipotropes on a 100 kcal-basis compared to legumes, cereals, fruits and nuts. The main objective of this second study was to quantify the effect of processing on LD and LC of raw PBF based on lipotrope contents collected in a USDA (United State Department of Agriculture) database and the literature, i.e. betaine, choline, myo-inositol, methionine, magnesium, niacin, pantothenic acid and folate contents. Choline and betaine densities were not significantly affected by processing while methionine and lipotropic micronutrient densities were significantly decreased, especially for magnesium, pantothenate and folates. Myo-inositol density decreases were insignificant due to lower product number resulting from limited literature data. Lipotropic micronutrient densities were more affected by processing than other densities. Fermentations increased betaine (median change of +32%) and choline (+34%) densities. Canning and boiling vegetables increased choline densities (+26%). Globally, processing significantly reduced LC by 20%, fermentations being less drastic (median change of −5%) than refining (−33%) and thermal treatments (−16%). More specifically, canning increased LC of beetroot (536 vs 390%) and common bean (40 vs 36%) as fermentation towards LC grape (14 vs 7% for wine). Results were then mainly discussed based on percentages of lipotrope content changes on a dry-weight basis. Results of this study also showed that the LC is quite a relevant index to estimate effect of processing on lipotropic potential of PBF.

Fardet, A., J.F. Martin, and J.M. Chardigny, Thermal and refining processes, not fermentation, tend to reduce lipotropic capacity of plant-based foods. Food Funct, 2011. 2(8): p. 483-504.

Application of NMR-based metabonomics suggests a relationship between betaine absorption and elevated creatine plasma concentrations in catheterised sows

The objective of the present explorative study was to determine the absorption dynamics when feeding diets varying in types and levels of dietary fibre in a catheterised animal model. A total of six sows were fed a diet low in fibre (LF), a diet high in soluble fibre and a diet high in insoluble fibre in a repeated 3 x 3 cross-over design. Plasma samples were collected from the mesenteric artery and the portal vein to determine different absorption phases by 1H NMR spectroscopy-based metabonomics. Time profiles were determined for plasma levels of specific metabolites and for the absorption of these metabolites from the small intestine. The LF diet resulted in a higher betaine concentration in the blood than the two high-fibre diets (P = 0.008). This leads to higher plasma concentrations of methionine (P = 0.0028) and creatine (P = 0.020) of endogenous origin. In conclusion, the use of NMR spectroscopy for measuring nutrient uptake in the present study elucidated the relationship between betaine uptake and elevated creatine plasma concentrations.

Yde, C.C., et al., Application of NMR-based metabonomics suggests a relationship between betaine absorption and elevated creatine plasma concentrations in catheterised sows. Br J Nutr, 2012. 107(11): p. 1603-15.

Antioxidant effect of betaine on adipose tissue when added to a high fat diet

Although well-established, the underlying mechanisms involved in obesity-related plasma adiponectin decline remain elusive. Oxidative stress is associated with obesity and insulin resistance and considered to contribute to the progression toward obesity-related metabolic disorders. In this study, we investigated the effects of 4-hydroxynonenal (4-HNE), the most abundant lipid peroxidation end product, on adiponectin production and its potential implication in obesity-related adiponectin decrease. Long-term high-fat diet feeding led to obesity in mouse, accompanied by decreased plasma adiponectin and increased adipose tissue 4-HNE content. Exposure of adipocytes to exogenous 4-HNE resulted in decreased adiponectin secretion in a dose-dependent manner, which was consistent with significantly decreased intracellular adiponectin protein abundance. In contrast, adiponectin gene expression was significantly elevated by 4-HNE treatment, which was concomitant with increased peroxisome proliferator-activated receptor gamma (PPAR-γ) gene expression and transactivity. The effect was abolished by T0070907, a PPAR-γ antagonist, suggesting that PPAR-γ activation plays a critical role in this process. To gain insight into mechanisms involved in adiponectin protein decrease, we examined the effects of 4-HNE on adiponectin protein degradation. Cycloheximide (CHX)-chase assay revealed that 4-HNE exposure accelerated adiponectin protein degradation, which was prevented by MG132, a potent proteasome inhibitor. Immunoprecipitation assay showed that 4-HNE exposure increased ubiquitinated adiponectin protein levels. These data altogether indicated that 4-HNE enhanced adiponectin protein degradation via ubiquitin–proteasome system. Finally, we demonstrated that supplementation of HF diet with betaine, an antioxidant and methyl donor, alleviated high-fat-induced adipose tissue 4-HNE increase and attenuated plasma adiponectin decline. Taken together, our findings suggest that the lipid peroxidation product 4-HNE can differentially regulates adiponectin gene expression and protein abundance and may play a mechanistic role in obesity-related plasma adiponectin decline.

Wang, Z., et al., 4-Hydroxynonenal differentially regulates adiponectin gene expression and secretion via activating PPARgamma and accelerating ubiquitin-proteasome degradation. Mol Cell Endocrinol, 2011. 349(2): p. 222-31.

Impact of high-fat and high-carbohydrate diets on liver metabolism studied in a rat model with a systems biology approach

The aim of the present study was to investigate the use of an integrated metabolomics and proteomics approach in the elucidation of diet-induced effects on hepatic metabolism in a rat model. Nuclear magnetic resonance (NMR)-based metabolomics of liver extracts revealed a pronounced effect of a high-fat diet on the hepatic betaine content, whereas a carbohydrate-rich diet induced increases in hepatic glucose. In addition, the metabolomic investigations revealed that the high-fat diet was associated with increased hepatic lipid levels, which was not evident with the carbohydrate-rich diet. The proteomic investigations revealed strong high-fat diet effects on the expression of 186 proteins in the liver including malate dehydrogenase. Comparison of malate dehydrogenase expression determined by proteomics and NMR metabolite profiles revealed correlations between malate dehydrogenase and lactate, glucose, and glutamine/glutamate signals, thereby demonstrating a diet-induced regulation that was evident at both proteomic and metabolomic levels.

Bertram, H.C., et al., Impact of High-Fat and High-Carbohydrate Diets on Liver Metabolism Studied in a Rat Model with a Systems Biology Approach. J. Agric. Food Chem., 2011. 60(2): p. 676-684.