Tuesday, May 28, 2013

Plasma choline metabolites associate with metabolic stress among young overweight men in a genotype-specific manner

We aimed to test the hypotheses that (i) plasma choline metabolites differ between normal (body mass index (BMI)<25 and="and" kg="kg" m="m" overweight="overweight">/=25 kg m(-2)) men, and (ii) an elevated BMI alters associations between plasma choline metabolites and indicators of metabolic stress.
DESIGN: This was a cross-sectional study. A one-time fasting blood sample was obtained for measurements of the choline metabolites and metabolic stress indicators (that is, serum alanine aminotransferase (ALT), glucose, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides and homocysteine), and for genotype determination.
SUBJECTS: The analysis was conducted with 237 Mexican American men with a median age of 22 years.
RESULTS: Compared with men with a normal BMI (n=98), those with an elevated BMI (n=139) had 6% lower (P=0.049) plasma betaine and an 11% lower (P=0.002) plasma betaine to choline ratio. Among men with an elevated BMI, plasma betaine and the plasma betaine to choline ratio positively associated (P</=0.044) with a favorable serum cholesterol profile, and inversely associated (P=0.001) with serum ALT, a marker of liver dysfunction. The phosphatidylethanolamine N-methyltransferase (PEMT) 5465Gshort right arrowA (rs7946) genotype interacted (P</=0.007) with the plasma betaine to choline ratio to modulate indicators of metabolic stress with stronger inverse associations observed among overweight men with the PEMT 5465GG genotype.
CONCLUSIONS: Plasma choline metabolites predict metabolic stress among overweight men often in a genotype-specific manner. The diminished betaine among overweight men coupled with the inverse association between betaine and metabolic stress suggest that betaine supplementation may be effective in mitigating some of the metabolic insults arising from lipid overload.

Yan, J., et al., Plasma choline metabolites associate with metabolic stress among young overweight men in a genotype-specific manner. Nutr Diabetes, 2012. 2: p. e49

Betaine protects against oxidative damage induced by restraint stress

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.
Ganesan, B., R. Anandan, and P.T. Lakshmanan, Studies on the protective effects of betaine against oxidative damage during experimentally induced restraint stress in Wistar albino rats. Cell Stress Chaperones, 2011. 16(6): p. 641-52

Monday, May 27, 2013

Betaine may serve as a neuroprotective agent in the treatment of neurodegenerative diseases

Rotenone is an inhibitor of mitochondrial complex I-induced neurotoxicity in PC12 cells and has been widely studied to elucidate the pathogenesis of Parkinson's disease. We investigated the neuroprotective effects of betaine on rotenone-induced neurotoxicity in PC12 cells. Betaine inhibited rotenone-induced apoptosis in a dose-dependent manner, with cell viability increasing from 50 % with rotenone treatment alone to 71 % with rotenone plus 100-muM betaine treatment. Flow cytometric analysis demonstrated cell death in the rotenone-treated cells to be over 50 %; the number of live cells increased with betaine pretreatment. Betaine pretreatment of PC12 cells attenuated rotenone-mediated mitochondrial dysfunction, including nuclear fragmentation, ATP depletion, mitochondrial membrane depolarization, caspase-3/7 activation, and reactive oxygen species production. Western blots demonstrated activation of caspase-3 and caspase-9, and their increased expression levels in rotenone-treated cells; betaine decreased caspase-3 and caspase-9 expression levels and suppressed their activation. Together, these results suggest that betaine may serve as a neuroprotective agent in the treatment of neurodegenerative diseases.

Im, A.R., et al., Betaine Protects Against Rotenone-Induced Neurotoxicity in PC12 Cells. Cell Mol Neurobiol, 2013

Betaine promotes immunobiochemical plasticity and protects against low-dose pesticide-induced oxidative stress

An experiment was conducted to evaluate the role of different lipotropes in modulating immunity and biochemical plasticity under conditions of sublethal low-dose pesticide-induced stress in fish. Labeo rohita fish fingerlings were divided in two sets with one set of fish continuously exposed to low-dose endosulfan (1/10th of 96-h LC50) for 21 days, the other was unexposed, and both sets of fish were fed with practical diets supplemented with either 2 % lecithin, 0.5 % betaine, or 0.1 % choline and compared against unsupplemented diet. Low-dose endosulfan exposure had adverse effects (P < 0.05/P < 0.01) on hematological profile (erythrocyte count, hemoglobin, and hematocrit), serum protein (total protein, albumin, and globulin) and lipid profile (cholesterol and triglyceride), anti-oxidative status (ascorbic acid content of muscle, liver, brain, and kidney and activity of anti-oxidative enzymes: catalase and superoxide dismutase), neurotransmission (acetylcholinesterase activity in muscle and brain), immunological attributes (WBC count, albumin to globulin ratio, phagocytic activity, and serum cortisol), and metabolic plasticity as revealed from enzyme activities (muscle lactate dehydrogenase, liver and kidney glucose-6-phosphatase dehydrogenase-G6PDH activity). Dietary lipotropes prevented these effects completely or partially and the effects were lipotrope dependent. Kinetics (maximum velocity value V max, catalytic efficiency and Michaelis constant K m) of G6PDH enzyme from crude extracts of liver and kidney indicated inhibition due to endosulfan but lipotropes could protect enzyme and showed a stabilizing effect. The supplements also helped maintain integrity of histoarchitecture of the hepatocytes in endosulfan-exposed fish to a great extent. Feeding lipotropes to fish reared in endosulfan-free water also improved hematological and serum protein and lipid profiles and were immunostimulatory. In conclusion, dietary lipotropes, especially betaine and lecithin at the levels used, improve erythropoiesis, serum protein and lipid profile, anti-oxidant status, immunocompetence, neurotransmission, and protect the livers of L. rohita fingerlings even when continuously exposed to low-dose endosulfan.
Muthappa, N.A., et al., Lipotropes promote immunobiochemical plasticity and protect fish against low-dose pesticide-induced oxidative stress. Cell Stress Chaperones, 2013

Saturday, May 18, 2013

Maternal BHMT polymorphism 742G>A is associated with decreased risk of having a Down syndrome child

Down syndrome (DS) is the most common form of mental retardation of genetic etiology. Several polymorphisms in genes involved with the folic acid cycle have been associated to the risk of bearing a DS child; however, the results are controversial. Betaine-homocysteine methyltransferase (BHMT) is a key enzyme of folate pathway, and catalyzes the remethylation of homocysteine into methionine. Recent studies suggest that the polymorphism BHMT 742G>A may be associated with a decreased risk of having a DS child. We herein investigate the association of this polymorphism with the occurrence of DS in a Brazilian population. We have genotyped 94 mothers of DS infants (DSM) and 134 control mothers (CM) for this polymorphism through PCR-RFLP, and found significant differences for both BHMT 742G>A genotype (P = 0.04) and allele (P = 0.03) frequencies between DSM and CM. The observed genotypic frequencies were GG = 0.45; GA = 0.45 and AA = 0.10 in CM, and GG = 0.54; GA = 0.38 and AA = 0.02 in DSM. Allelic frequencies were G = 0.68 and A = 0.32 in CM and G = 0.78 and A = 0.22 in DSM. The presence of the mutant BHMT 742 A allele decreases 40 % the risk of bearing a DS child (OR = 0.61; 95 % CI: 0.40-0.93; P = 0.03), and the risk is diminished up to >80 % in association with the homozygous genotype (OR = 0.17; 95 % CI: 0.04-0.80; P = 0.01). Our results indicate that women harboring the single nucleotide polymorphism BHMT 742G>A have a decreased risk of a DS pregnancy, and further studies are necessary to confirm this protective effect.

Amorim, M.R., et al., Betaine-homocysteine methyltransferase 742G>A polymorphism and risk of down syndrome offspring in a Brazilian population. Mol Biol Rep, 2013

Wednesday, May 8, 2013

Plant-based foods as a source of lipotropes for human nutrition: a survey of in vivo studies

Increased consumption of plant products is associated with lower chronic disease prevalence. This is attributed to the great diversity of healthy phytochemicals present in these foods. The most investigated physiological effects have been their antioxidant, anti-carcinogenic, hypolipidemic, and hypoglycemic properties. Although less studied in humans, some compounds were very early on shown to be lipotropic in animals, i.e., the capacity to hasten the removal of fat from liver and/or reduce hepatic lipid synthesis or deposits by mainly increasing phospholipid synthesis via the transmethylation pathway for triglyceride-rich lipoprotein exportation from the liver and enhanced fatty acid beta-oxidation and/or down- and up-regulation of genes involved in lipogenic and fatty acid oxidation enzyme synthesis, respectively. The main plant lipotropes are choline, betaine, myo-inositol, methionine, and carnitine. Magnesium, niacin, pantothenate, and folates also indirectly support the overall lipotropic effect. The exhaustive review of rat studies investigating phytochemical effect on hepatic lipid metabolism suggests that some fatty acids, acetic acid, melatonin, phytic acid, some fiber compounds, oligofructose, resistant starch, some phenolic acids, flavonoids, lignans, stilbenes, curcumin, saponins, coumarin, some plant extracts, and some solid foods may be lipotropic. However, this remains to be confirmed in humans, for whom intervention studies are practically non-existent.

Fardet, A. and J.M. Chardigny, Plant-based foods as a source of lipotropes for human nutrition: a survey of in vivo studies. Crit Rev Food Sci Nutr, 2013. 53(6): p. 535-90

Betaine may be used as a methyl-donor during fetal life

OBJECTIVE: Methylation metabolism is essential for fetus development. However, normative data for amniotic fluid (AF) concentrations of methylation metabolites at different gestational ages are lacking. We aimed to determine in AF reference values of 14 intermediates involved in methylation.
METHODS: 268 AFs sampled between 14 and 39 weeks of gestation (WG) were retrospectively selected in our AF bank. Next, we measured methionine-cycle intermediates (S-adenosyl-methionine (AdoMet), S-adenosyl-homocysteine (AdoHcy), total homocysteine, methionine, methyl malonic acid) and methyldonors and methylacceptors (betaine, dimethylglycine, sarcosine, free and total choline, free and total ethanolamine, creatine, guanidinoacetate) by liquid chromatography coupled with tandem mass spectrometry.
RESULTS: Reference ranges according to gestational age were determined for each parameter. Strong correlations between metabolites directly connected in their metabolic pathway and between total homocysteine and betaine were observed.
CONCLUSION: Methionine, an essential amino-acid required for protein synthesis is the only parameter that dramatically decreases with gestational age. The AdoMet/AdoHcy ratio exponentially increases from 25 WG, which could reflect increasing methylation capacities. The negative correlation between betaine and total homocysteine together with a constant betaine to dimethylglycine ratio during gestation suggest that betaine may be used as a methyl-donor during fetal life.

Imbard, A., et al., Methylation metabolites in amniotic fluid depend on gestational age. Prenat Diagn, 2013

Dietary Choline and Betaine Intakes Vary in an Adult Multiethnic Population

Choline and betaine are important nutrients for human health, but reference food composition databases for these nutrients became available only recently. We tested the feasibility of using these databases to estimate dietary choline and betaine intakes among ethnically diverse adults who participated in the Multiethnic Cohort (MEC) Study. Of the food items (n = 965) used to quantify intakes for the MEC FFQ, 189 items were exactly matched with items in the USDA Database for the Choline Content of Common Foods for total choline, choline-containing compounds, and betaine, and 547 items were matched to the USDA National Nutrient Database for Standard Reference for total choline (n = 547) and 148 for betaine. When a match was not found, choline and betaine values were imputed based on the same food with a different form (124 food items for choline, 300 for choline compounds, 236 for betaine), a similar food (n = 98, 284, and 227, respectively) or the closest item in the same food category (n = 6, 191, and 157, respectively), or the values were assumed to be zero (n = 1, 1, and 8, respectively). The resulting mean intake estimates for choline and betaine among 188,147 MEC participants (aged 45-75) varied by sex (372 and 154 mg/d in men, 304 and 128 mg/d in women, respectively; P-heterogeneity < 0.0001) and by race/ethnicity among Caucasians, African Americans, Japanese Americans, Latinos, and Native Hawaiians (P-heterogeneity < 0.0001), largely due to the variation in energy intake. Our findings demonstrate the feasibility of assessing choline and betaine intake and characterize the variation in intake that exists in a multiethnic population.

Yonemori, K.M., et al., Dietary Choline and Betaine Intakes Vary in an Adult Multiethnic Population. J Nutr, 2013

Estimation of usual intake and food sources of choline and betaine in New Zealand reproductive age women

Recently, choline has been associated with neurodevelopment, cognitive function and neural tube defect incidence. However, data on usual intakes are limited, and estimates of dietary intakes of choline and its metabolite betaine, are not available for New Zealanders. The objective of the present study was to determine usual intake and food sources of choline and betaine in a group of New Zealand reproductive age women. Dietary intake data were collected from a sample of 125 women, aged 18-40 years, by means of a 3-day weighed food record, and usual choline and betaine intake distributions were determined. The mean (SD) daily intakes of choline and betaine were 316 (66) mg and 178 (66) mg, respectively. The total choline intake relative to energy intake and body weight was 0.18 mg/kcal and 5.1 mg/kg, respectively. Only 16% of participants met or exceeded the Adeuate Intake (AI) for adult women of 425 mg of choline. The top five major food contributors of choline were eggs, red meat, milk, bread and chicken; and of betaine were bread, breakfast cereal, pasta, grains and root vegetables (carrots, parsnips, beetroot, swedes). Our findings contribute towards the recent emergence of published reports on the range of dietary choline and betaine intakes consumed by free-living populations. In our sample of New Zealand women, few participants were meeting or exceeding the AI level. Given recent epidemiological evidence suggesting health benefits of increased choline and betaine intakes, recommendations should be made to encourage the consumption of choline and betaine-rich foods.

Mygind, V.L., et al., Estimation of usual intake and food sources of choline and betaine in New Zealand reproductive age women. Asia Pac J Clin Nutr, 2013. 22(2): p. 319-24