Monday, January 26, 2015

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

Postprandial plasma betaine and other methyl donor-related responses after consumption of minimally processed wheat bran or aleurone

The bran and particularly the aleurone fraction of wheat are high in betaine and other physiological methyl donors, which may exert beneficial physiological effects. We conducted two randomised, controlled, cross-over postprandial studies to assess and compare plasma betaine and other methyl donor-related responses following the consumption of minimally processed bran and aleurone fractions (study A) and aleurone bread (study B). For both studies, standard pharmacokinetic parameters were derived for betaine, choline, folate, dimethylglycine (DMG), total homocysteine and methionine from plasma samples taken at 0, 0.5, 1, 2 and 3 h. In study A (n 14), plasma betaine concentrations were significantly and substantially elevated from 0.5 to 3 h following the consumption of both bran and aleurone compared with the control; however, aleurone gave significantly higher responses than bran. Small, but significant, increases were also observed in DMG measures; however, no significant responses were observed in other analytes. In study B (n 13), plasma betaine concentrations were significantly and substantially higher following consumption of the aleurone bread compared with the control bread; small, but significant, increases were also observed in DMG and folate measures in response to consumption of the aleurone bread; however, no significant responses were observed in other analytes. Peak plasma betaine concentrations, which were 1.7-1.8 times the baseline levels, were attained earlier following the consumption of minimally processed aleurone compared with the aleurone bread (time taken to reach peak concentration 1.2 v. 2.1 h). These results showed that the consumption of minimally processed wheat bran, and particularly the aleurone fraction, yielded substantial postprandial increases in plasma betaine concentrations. Furthermore, these effects appear to be maintained when aleurone was incorporated into bread.

Keaveney, E.M., et al., Postprandial plasma betaine and other methyl donor-related responses after consumption of minimally processed wheat bran or wheat aleurone, or wheat aleurone incorporated into bread. Br J Nutr, 2015: p. 1-9

Monday, January 5, 2015

Betaine is a positive regulator of mitochondrial respiration

Betaine protects cells from environmental stress and serves as a methyl donor in several biochemical pathways. It reduces cardiovascular disease risk and protects liver cells from alcoholic liver damage and nonalcoholic steatohepatitis. Its pretreatment can rescue cells exposed to toxins such as rotenone, chloroform, and LiCl. Furthermore, it has been suggested that betaine can suppress cancer cell growth in vivo and in vitro. Mitochondrial electron transport chain (ETC) complexes generate the mitochondrial membrane potential, which is essential to produce cellular energy, ATP. Reduced mitochondrial respiration and energy status have been found in many human pathological conditions including aging, cancer, and neurodegenerative disease. In this study we investigated whether betaine directly targets mitochondria. We show that betaine treatment leads to an upregulation of mitochondrial respiration and cytochrome c oxidase activity in H2.35 cells, the proposed rate limiting enzyme of ETC in vivo. Following treatment, the mitochondrial membrane potential was increased and cellular energy levels were elevated. We propose that the anti-proliferative effects of betaine on cancer cells might be due to enhanced mitochondrial function contributing to a reversal of the Warburg effect.

Lee, I., Betaine is a positive regulator of mitochondrial respiration. Biochemical and Biophysical Research Communications, 2015. 456(2): p. 621-625

Friday, December 5, 2014

Maternal betaine supplementation enhances betaine/methionine metabolism and DNA methyltransferase expression in the hippocampus of neonatal piglets

PURPOSE: The adequate supply of methyl donors is critical for the normal development of brain. The purpose of the present study was to investigate the effects of maternal betaine supplementation on hippocampal gene expression in neonatal piglets and to explore the possible mechanisms.
METHODS: Gestational sows were fed control or betaine-supplemented (3 g/kg) diets throughout the pregnancy. Immediately after birth, male piglets were killed, and the hippocampus was dissected for analyses. The mRNA abundance was determined by reverse transcription real-time polymerase chain reaction. Protein content was measured by Western blot, and DNA methylation was detected by methylated DNA immunoprecipitation assay.
RESULTS: Prenatal betaine supplementation did not alter the body weight or the hippocampus weight, but increased the hippocampal DNA content as well as the mRNA expression of proliferation-related genes. Prenatal betaine supplementation increased serum level of methionine (P < 0.05) and up-regulated (P < 0.05) the mRNA and protein expression of betaine-homocysteine methyltransferase, glycine N-methyltransferase and DNA methyltransferase 1 in the neonatal hippocampus. Hippocampal expression of insulin growth factor II (IGF2) and its receptors IGF1R and IGF2R were all significantly up-regulated (P < 0.05) in betaine-treated group, together with a significant activation (P < 0.01) of the downstream extracellular signal-regulated kinase 1/2. Moreover, the differentially methylated region (DMR) 1 and 2 on IGF2 locus was found to be hypermethylated (P < 0.05) in the hippocampus of betaine-treated piglets.
CONCLUSIONS: These results indicate that maternal betaine supplementation enhances betaine/methionine metabolism and DNA methyltransferase expression, causes hypermethylation of DMR on IGF2 gene, which was associated with augmented expression of IGF2 and cell proliferation/anti-apoptotic markers in the hippocampus of neonatal piglets.

Li, X., et al., Dietary betaine supplementation to gestational sows enhances hippocampal IGF2 expression in newborn piglets with modified DNA methylation of the differentially methylated regions. Eur J Nutr, 2014.

Monday, November 3, 2014

Plasma betaine was inversely associated with colorectal cancer risk

Few studies have examined associations between plasma choline metabolites and risk of colorectal cancer (CRC). Therefore, we investigated associations between plasma biomarkers of choline metabolism [choline, betaine, dimethylglycine and trimethylamine N-oxide (TMAO)] and CRC risk among postmenopausal women in a case-control study nested within the Women's Health Initiative Observational Study. We selected 835 matched case-control pairs, and cases were further stratified by tumor site (proximal, distal, or rectal) and stage (local/regional or metastatic). CRC was assessed by self-report and confirmed by medical records over the mean 5.2y of follow-up. Baseline plasma choline metabolites were measured by liquid chromatography-tandem mass spectrometry. In multivariable-adjusted conditional logistic regression models, plasma choline tended to be positively associated with rectal cancer risk [OR (95% CI)highest vs. lowest quartile=2.44 (0.93-6.40);P-trend=0.08], while plasma betaine was inversely associated with CRC overall [0.68 (0.47-0.99);P-trend=0.01] and with local/regional tumors [0.64 (0.42-0.99);P-trend=0.009]. Notably, the plasma betaine:choline ratio was inversely associated with CRC overall [0.56 (0.39-0.82);P-trend=0.004] as well as with proximal [0.66 (0.41-1.06);P-trend=0.049], rectal [0.27 (0.10-0.78);P-trend=0.02] and local/regional [0.50 (0.33-0.76);P-trend=0.001] tumors. Finally, plasma TMAO, an oxidative derivative of choline produced by intestinal bacteria, was positively associated with rectal cancer [3.38 (1.25-9.16);P-trend=0.02] and with overall CRC risk among women with lower (vs. higher) plasma vitamin B12 levels (P-interaction=0.003). Collectively, these data suggest that alterations in choline metabolism, which may arise early in disease development, may be associated with higher risk of CRC. The positive association between plasma TMAO and CRC risk is consistent with an involvement of the gut microbiome in CRC pathogenesis.

Bae, S., et al., Plasma choline metabolites and colorectal cancer risk in the Women's Health Initiative Observational Study. Cancer Res, 2014

Betaine might be applicable to the prevention of inflammation-associated colon carcinogenesis.

In this review, we will summarize the current understanding of modulation of colitis-associated colon tumorigenesis by two natural products, baicalein and betaine, which have anti-inflammatory activities. Baicalein and betaine have been shown to provide various health benefits to organism in many ways. Baicalein is a phenolic flavonoid derived originally from the root of Scutellaria baicalensis Georgi. From ancient times, baicalein has widely been used in oriental medicines as an anti-inflammatory and anti-cancer therapy. Betaine, trimethylglycine, is an essential biochemical molecule of the methionine/homocysteine cycle and is synthesized by conversion of choline. Betaine is an important human nutrient obtained from various foods including sugar beet and lycium. Betaine has provided various health benefits including disease prevention. However, the action mechanisms of their activity remain poorly understood. Recent studies reported the effects of baicalein and betaine on cytotoxicity against colon cancer cells and chemically induced colitis-associated colon tumorigenesis in mice. Administrations of baicalein and betaine containing diets significantly inhibited the incidence of tumors and hyperplasia with down-regulation of inflammation. Therefore, baicalein and betaine might be applicable to the prevention of inflammation-associated colon carcinogenesis.

Kim, D.H., et al., Modulation of Colitis-associated Colon Tumorigenesis by Baicalein and Betaine. J Cancer Prev, 2014. 19(3): p. 153-60

Betaine may be a key contributor to reduction of disease risk associated with greater intake of whole grain

Dietary fibre alone does not fully explain the frequent association between greater intake of whole grains and reduced risk of disease in observational studies, and other phytochemicals or food structure may also play an important role. For all the observational evidence for the benefits of a whole-grain-rich diet, we have only limited knowledge of the mechanisms behind this reduction in disease risk, aside from the action of specific cereal fibres on reduction of blood cholesterol and the post-prandial glucose peak. Nutritional metabolomics, the global measurement and interpretation of metabolic profiles, assesses the interaction of food with the endogenous gene-protein cascade and the gut microbiome. This approach allows the generation of new hypotheses which account for systemic effects, rather than just focusing on one or two mechanisms or metabolic pathways. To date, animal and human trials using metabolomics to investigate mechanistic changes to metabolism on eating whole grains and cereal fractions have led to new hypotheses around mechanistic effects of whole grains. These include the role of cereals as a major source of dietary glycine betaine, a possible effect on phospholipid synthesis or metabolism, the role of branched-chain amino acids and improvements in insulin sensitivity, and the possibility that whole grains may have an effect on protein metabolism. These hypotheses help explain some of the observed effects of whole grains, although mechanistic studies using stable isotopes and fully quantitative measures are required to confirm these potential mechanisms.

Ross, A.B., Whole grains beyond fibre: what can metabolomics tell us about mechanisms? Proc Nutr Soc, 2014: p. 1-8