High homocysteine induces betaine depletion

Betaine is the substrate of the liver- and kidney-specific betaine-homocysteine (Hcy) methyltransferase (BHMT), an alternate pathway for Hcy remethylation. We hypothesized that BHMT is a major pathway for homocysteine removal in cases of hyperhomocysteinaemia (HHcy). Therefore, we measured betaine in plasma and tissues from patients and animal models of HHcy of genetic and acquired cause. Plasma was collected from patients presenting HHcy without any Hcy interfering treatment. Plasma and tissues were collected from rat models of HHcy induced by diet and from a mouse model of cystathionine beta-synthase (CBS) deficiency. S-adenosyl-methionine (AdoMet), S-adenosyl-homocysteine (AdoHcy), methionine, betaine and dimethylglycine (DMG) were quantified by ESI-LC-MS/MS. mRNA expression was quantified using quantitative real-time (QRT)-PCR. For all patients with diverse causes of HHcy, plasma betaine concentrations were below the normal values of our laboratory. In the diet-induced HHcy rat model, betaine was decreased in all tissues analysed (liver, brain, heart). In the mouse CBS deficiency model, betaine was decreased in plasma, liver, heart and brain, but was conserved in kidney. Surprisingly, BHMT expression and activity was decreased in liver. However, in kidney, BHMT and SLC6A12 expression was increased in CBS-deficient mice. Chronic HHcy, irrespective of its cause, induces betaine depletion in plasma and tissues (liver, brain and heart), indicating a global decrease in the body betaine pool. In kidney, betaine concentrations were not affected, possibly due to overexpression of the betaine transporter SLC6A12 where betaine may be conserved because of its crucial role as an osmolyte.

Imbard, A., et al., High homocysteine induces betaine depletion. Biosci Rep, 2015. 35(4).

Betaine prevents homocysteine-induced memory impairment via matrix metalloproteinase-9 in the frontal cortex

Betaine plays important roles that include acting as a methyl donor and converting homocysteine (Hcy) to methionine. Elevated plasma Hcy levels are known as hyperhomocysteinemia (HHcy) and contribute to impairments of learning and memory. Although it is commonly known that betaine plays an important role in Hcy metabolism, the effects of betaine on Hcy-induced memory impairment have not been investigated. Previously, we demonstrated the beneficial effects of betaine on acute stress and lipopolysaccharide-induced memory impairment. In the present study, we investigated whether betaine ameliorates Hcy-induced memory impairment and the underlying mechanisms of this putative effect. Mice were treated with Hcy (0.162mg/kg, s.c.) twice a day for nine days, and betaine (25mg/kg, s.c.) was administered 30min before the Hcy injections. The memory functions were evaluated using a spontaneous alternation performance test (Y-maze) at seven days and a step-down type passive avoidance test (SD) at nine and 10 days after Hcy injection. We found that betaine suppressed the memory impairment induced by repeated Hcy injections. However, the blood concentrations of Hcy were significantly increased in the Hcy-treated mice immediately after the passive avoidance test, and betaine did not prevent this increase. Furthermore, Hcy induces redox stress in part by activating matrix metalloproteinase-9 (MMP-9), which leads to BBB dysfunction. Therefore, we tested whether betaine affected MMP-9 activity. Interestingly, treatment with betaine significantly inhibited Hcy-induced MMP-9 activity in the frontal cortex but not in the hippocampus after acute Hcy injection. These results suggest that the changes in MMP-9 activity after betaine treatment might have been partially responsible for the amelioration of the memory deficits and that MMP-9 might be a candidate therapeutic target for HHcy.

Kunisawa, K., et al., Betaine prevents homocysteine-induced memory impairment via matrix metalloproteinase-9 in the frontal cortex. Behav Brain Res, 2015.

High homocysteine induces betaine depletion

Betaine is the substrate of the liver- and kidney- specific betaine-homocysteine methyltransferase (BHMT), an alternate pathway for homocysteine remethylation. We hypothesized that BHMT is a major pathway for homocysteine removal in cases of hyperhomocysteinemia (HHcy). Therefore, we measured betaine in plasma and tissues from patients and animal models of HHcy of genetic and acquired cause. Plasma was collected from patients presenting HHcy without any homocysteine interfering treatment. Plasma and tissues were collected from rat models of HHcy induced by diet and from a mouse model of CBS deficiency. S-adenosyl-methionine, S-adenosyl-homocysteine, methionine, betaine, and dimethylglycine were quantified by ESI-LC-MS/MS. mRNA expression was quantified using quantitative real-time PCR. For all patients with diverse causes of HHcy, plasma betaine concentrations were below the normal values of our laboratory. In the diet-induced HHcy rat model, betaine was decreased in all tissues analysed (liver, brain, heart). In the mouse CBS deficiency model, betaine was decreased in plasma, liver, heart and brain, but was conserved in kidney. Surprisingly, BHMT expression and activity was decreased in liver. However, in kidney, BHMT and SLC6A12 expression was increased in CBS-deficient mice. Chronic HHcy, irrespective of its cause, induces betaine depletion in plasma and tissues (liver, brain and heart), indicating a global decrease of the body betaine pool. In kidney, betaine concentrations were not affected, possibly due to overexpression of the betaine transporter SLC6A12 where betaine may be conserved because of its crucial role as an osmolyte.

Imbard, A., et al., High homocysteine induces betaine depletion. Biosci Rep, 2015.

Betaine protected against thrombotic coagulation events in vivo and in vitro and decreased plasma lipid peroxidation

Betaine (N,N,N-trimethylglycine) is an important food component with established health benefits through its homocysteine-lowering effects, and is used to lower total homocysteine concentration in plasma of patients with homocystinuria. It is well established that hyperhomocysteinemia is an established risk factor for cardiovascular disease and stroke. However, the possible protective effect of betaine on coagulation events in vivo and in vitro has thus far not been studied. Betaine was given to mice at oral doses of either 10 mg/kg (n = 6) or 40 mg/kg (n = 6) for seven consecutive days, and control mice (n = 6) received water only. The thrombotic occlusion time in photochemically induced thrombosis in pial arterioles was significantly delayed in mice pretreated with betaine at doses of 10 mg/kg (P < 0.001) and 40 mg/kg (P < 0.01). Similar effects were observed in pial venules with 10 mg/kg (P < 0.05) and 40 mg/kg (P < 0.05) betaine. In vitro, in whole blood samples collected from untreated mice (n = 3-5), betaine (0.01-1 mg/mL) significantly reversed platelet aggregation induced by adenosine diphosphate (5 microM). The number of circulating platelets and plasma concentration of fibrinogen in vivo were not significantly affected by betaine pretreament compared with the control group. Lipid peroxidation (LPO) in mice pretreated with betaine was significantly reduced compared with the control group. Moreover, betaine (0.01-1 mg/mL) caused a dose-dependent and significant prolongation of PT (n = 5) and aPTT (n = 4-6). In conclusion, our data show that betaine protected against coagulation events in vivo and in vitro and decreased LPO in plasma.

Nemmar, A., et al., Betaine (N,N,N-trimethylglycine) averts photochemically-induced thrombosis in pial microvessels in vivo and platelet aggregation in vitro. Exp Biol Med (Maywood), 2015

Betaine showed beneficial brain antioxidant effects following administration of levodopa and benserazide (used in the treatment of Parkinson's disease)

The present study was designed to evaluate antioxidant effects of betaine in the brain following administration of levodopa and benserazide, which are routinely used in the treatment of Parkinson's disease. Sprague-Dawley male rats were divided into levodopa (LD), Betaine (Bet.), levodopa plus betaine (LD/Bet.), levodopa plus benserazide (LD/Ben.), levodopa plus betaine-benserazide (LD/Bet.-Ben.) and control groups. The experimental groups received LD 300 mg/kg, Bet. 1.5 % w/w of the total diet, Ben. 75 mg/kg and distilled water to controls for 10 consecutive days, orally. The concentration of plasma total homocysteine significantly increased in LD/Ben.-treated rats when compared to the other groups. Brain glutathione peroxidase (GPx) activity and glutathione content both elevated with betaine treatment in LD/Bet. and LD/Bet.-Ben groups. Superoxide dismutase activity was also higher in controls and betaine-treated rats in comparison with LD and LD/Ben. groups. Likewise, catalase activity significantly increased in control and betaine groups when compared to LD- and LD/Ben.-treated rats. In contrast, brain lipid peroxidation significantly increased in response to LD and LD/Ben. treatments. Regarding metabolism of LD in peripheral tissues, serumic dopamine concentration significantly increased in LD-treated rats in comparison with LD/Ben. group. The present results show beneficial antioxidant and methyl donor properties of betaine versus oxidative stress and hyperhomocysteinemia induced by levodopa and benserazide in an animal model.

Alirezaei, M., et al., Beneficial antioxidant properties of betaine against oxidative stress mediated by levodopa/benserazide in the brain of rats. J Physiol Sci, 2015

Betaine or spinach completely suppress hyperhomocysteinemia induced by GAA supplementation or choline deficiency in rats

Betaine is an important natural component of rich food sources, especially spinach. Rats were fed diets with betaine or spinach powder at the same level of betaine for 10 days to investigate the dose-dependent effects of spinach powder supplementation on hyperhomocysteinemia induced by guanidinoacetic acid (GAA) addition and choline deprivation. The GAA-induced hyperhomocysteinemia in rats fed 25% casein diet (25C) was significantly suppressed by supplementation with betaine or spinach, and it was completely suppressed by taking 11.0% spinach supplementation. The choline deprivation-induced enhancement of plasma homocysteine concentration in rats fed 25% soybean protein diet (25S) was markedly suppressed by 3.82% spinach. Supplementation with betaine or spinach partially prevented the effects of GAA on hepatic concentrations of methionine metabolites. The decrease in activity of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine beta-synthase (CBS) in GAA-induced hyperhomocysteinemia was recovered by supplementation with betaine or spinach. Supplementation with betaine or spinach did not affect BHMT activity, whereas it partially restored CBS activity in choline-deprived 25S. The results indicated that betaine or spinach could completely suppress the hyperhomocysteinemia induced by choline deficiency resulting from stimulating the homocysteine removal by both remethylation and cystathionine formation.

Liu, Y.Q., et al., Suppression effects of betaine-enriched spinach on hyperhomocysteinemia induced by guanidinoacetic Acid and choline deficiency in rats. ScientificWorldJournal, 2014. 2014: p. 904501

Betaine suppressed amyloid-beta formation, a component of senile plaques related to Alzheimer disease

Betaine was an endogenous catabolite of choline, which could be isolated from vegetables and marine products. Betaine could promote the metabolism of homocysteine in healthy subjects and was used for hyperlipidemia, coronary atherosclerosis, and fatty liver in clinic. Recent findings shown that Betaine rescued neuronal damage due to homocysteine induced Alzheimer's disease (AD) like pathological cascade, including tau hyperphosphorylation and amyloid-beta (Abeta) deposition. Abeta was derived from amyloid precursor protein (APP) processing, and was a triggering factor for AD pathological onset. Here, we demonstrated that Betaine reduced Abeta levels by altering APP processing in N2a cells stably expressing Swedish mutant of APP. Betaine increased alpha-secretase activity, but decreased beta-secretase activity. Our data indicate that Betaine might play a protective role in Abeta production.

Liu, X.P., et al., Betaine suppressed Abeta generation by altering amyloid precursor protein processing. Neurol Sci, 2014

The relationship between betaine, homocysteine, and BHMT expression in hibernating and active mammalian brain

Elevated homocysteine is an important risk factor that increases cerebrovascular and neurodegenerative disease morbidity. In mammals, B vitamin supplementation can reduce homocysteine levels. Whether, and how, hibernating mammals, that essentially stop ingesting B vitamins, maintain homocysteine metabolism and avoid cerebrovascular impacts and neurodegeneration remain unclear. Here, we compare homocysteine levels in the brains of torpid bats, active bats and rats to identify the molecules involved in homocysteine homeostasis. We found that homocysteine does not elevate in torpid brains, despite declining vitamin B levels. At low levels of vitamin B6 and B12, we found no change in total expression level of the two main enzymes involved in homocysteine metabolism (methionine synthase and cystathionine beta-synthase), but a 1.85-fold increase in the expression of the coenzyme-independent betaine-homocysteine S-methyltransferase (BHMT). BHMT expression was observed in the amygdala of basal ganglia and the cerebral cortex where BHMT levels were clearly elevated during torpor. This is the first report of BHMT protein expression in the brain and suggests that BHMT modulates homocysteine in the brains of hibernating bats. BHMT may have a neuroprotective role in the brains of hibernating mammals and further research on this system could expand our biomedical understanding of certain cerebrovascular and neurodegenerative disease processes.

Zhang, Y., et al., Homocysteine homeostasis and betaine-homocysteine s-methyltransferase expression in the brain of hibernating bats. PLoS One, 2013. 8(12): p. e85632

Survival and psychomotor development with early betaine treatment in patients with severe methylenetetrahydrofolate reductase deficiency

IMPORTANCE The impact of betaine treatment on outcome in patients with severe methylenetetrahydrofolate reductase (MTHFR) deficiency is presently unclear.
OBJECTIVE To investigate the effect of betaine treatment on development and survival in patients with severe MTHFR deficiency. DATA SOURCES MEDLINE, EMBASE, and Cochrane databases between January 1960 and December 2012. STUDY SELECTION Studies that described patients with severe MTHFR deficiency who received betaine treatment.
DATA EXTRACTION AND SYNTHESIS We identified 15 case reports and case series, totaling 36 patients. Data included the following: (1) families with 2 or more patients with severe MTHFR deficiency, of whom at least 1 received betaine, or (2) single patients with severe MTHFR deficiency treated with betaine. To define severe MTHFR deficiency, methionine, homocysteine, MTHFR enzyme activity in fibroblasts, or mutations (in the MTHFR gene) had to be described as well as the effect of treatment (survival and/or psychomotor development). We compared the outcome in treated vs untreated patients and early- vs late-treated patients. Sensitivity analysis was performed to address definition of early treatment. To further assess the impact of treatment on mortality, we performed a subanalysis in families with at least 1 untreated deceased patient.
MAIN OUTCOMES AND MEASURES Survival and psychomotor development.
RESULTS Eleven of 36 patients (31%) died. All deaths occurred in patients who did not receive treatment or in patients in whom treatment was delayed. In contrast, all 5 early-treated patients survived. Subgroup analysis of patients with deceased siblings-their genotypically identical controls-revealed that betaine treatment prevented mortality (P = .002). In addition, psychomotor development in surviving patients treated with betaine was normal in all 5 early-treated patients but in none of the 19 surviving patients with delayed treatment (P < .001).
CONCLUSIONS AND RELEVANCE Early betaine treatment prevents mortality and allows normal psychomotor development in patients with severe MTHFR deficiency, highlighting the importance of timely recognition through newborn screening.

Diekman, E.F., et al., Survival and Psychomotor Development With Early Betaine Treatment in Patients With Severe Methylenetetrahydrofolate Reductase Deficiency. JAMA Neurol, 2013

Betaine supplementation decreases plasma homocysteine in healthy adult participants: a meta-analysis

OBJECTIVE: Betaine supplementation has been shown to be an effective agent for decreasing plasma homocysteine in healthy adults. Studies in healthy volunteers show that 6 g/d of betaine lowers plasma homocysteine concentrations by 5% to 20%. The purpose of this study was to perform a meta-analysis of randomized placebo-controlled trials that used daily betaine supplementation to identify the range in betaine's effects on lowering homocysteine. METHODS: Five randomized controlled trials published between 2002 and 2010 were identified using MEDLINE and a manual search. All 5 studies used health adult participants who were supplemented with at least 4 g/d of betaine for between 6 and 24 weeks. A meta-analysis was carried out using a random-effects model, and the overall effect size was calculated for changes in plasma homocysteine. RESULTS: The pooled estimate of effect for betaine supplementation on plasma homocysteine was a reduction of 1.23 mumol/L, which was statistically significant (95% confidence interval, - 1.61 to - 0.85; P = .01). CONCLUSION: Supplementation with at least 4g/d of betaine for a minimum of 6 weeks can lower plasma homocysteine.

McRae, M.P., Betaine supplementation decreases plasma homocysteine in healthy adult participants: a meta-analysis. J Chiropr Med, 2013. 12(1): p. 20-5

Betaine supplementation improved body composition, arm size, bench press work capacity, attenuated the rise in urinary HCTL, and tended to improve power but not strength

BACKGROUND: This study investigated the effects of long term betaine supplementation on body composition, performance, and homocysteine thiolactone (HCTL) in experienced strength trained men. METHODS: Twenty-three subjects were matched for training experience (4.8 +/- 2.3 years) and body fat percentage (BF%: 16.9 +/- 8.0%), randomly assigned to either a placebo (PL; n = 12) or betaine group (BET; n = 11; 2.5 g/day), and completed a 6 week periodized training program consisting of 3 two-week micro-cycles. Bench press and back squat training volumes were recorded and changes in training volume were assessed at each micro-cycle. Fasting urine was collected at baseline (BL), weeks 2, 4 and 6, and assayed for HCTL. Subjects were tested prior to and following 6 weeks of treatment. Arm and thigh cross sectional area (CSA) was estimated via girth and skin fold measurements. Body density was estimated via skin fold calipers and used to estimate BF%, fat mass (FM), and lean body mass (LBM). Performance was assessed via vertical jump (VJ), bench press 1 RM (BP), and back squat 1 RM (BS).
RESULTS: Arm CSA increased significantly (p < .05) in BET but not PL. No differences existed between group and time for changes in thigh CSA. Back squat training volume increased significantly (p < .05) for both groups throughout training. Bench press training volume was significantly (p < .05) improved for BET compared to PL at microcycles one and three. Body composition (BF%, FM, LBM) improved significantly (p < .05) in BET but not PL. No differences were found in performance variables (BP, BS, VJ) between groups, except there was a trend (p = .07) for increased VJ power in BET versus PL. A significant interaction (p < .05) existed for HCTL, with increases from BL to week 2 in PL, but not BET. Additionally, HCTL remained elevated at week 4 in PL, but not BET.
CONCLUSION: Six-weeks of betaine supplementation improved body composition, arm size, bench press work capacity, attenuated the rise in urinary HCTL, and tended to improve power (p = .07) but not strength.

Cholewa, J.M., et al., Effects of betaine on body composition, performance, and homocysteine thiolactone. J Int Soc Sports Nutr, 2013. 10(1): p. 39

Lower level of serum betaine is associated with an increased risk of microangiopathy in diabetics

BACKGROUND: Diabetes represents one of the greatest medical and socioeconomic emergencies worldwide and pathogenesis involved is complicated. The effect of methyl donors and genetic polymorphisms in metabolic enzymes on the risk of microangiopathy in patients with diabetes is not well understood. This study aims to investigate the association of homocysteine, choline, and betaine levels and phosphatidylethanolamine N-methyltransferase (PEMT) G774C (rs12325817) genotypes with the risk of diabetes and its related microangiopathic complications.
METHODS: Between January 2009 and June 2010, 184 diabetic patients and 188 non-diabetic control subjects were enrolled in the hospital-based case-control study. Serum concentrations of betaine and choline were determined by high performance liquid chromatography-mass spectrometry (HPLC-MS). Serum concentration of homocysteine was assayed using HPLC. PEMT gene mutations were detected by polymerase chain reaction and restriction fragment length polymorphism.
RESULTS: After adjustment for the potential confounders, serum total homocysteine had a significant dose-dependent positive association, and serum choline had an inverse association with the risks of diabetes and its microangiopathic complications (both p < 0.001). Although serum betaine was not associated with the risk of diabetes, it had a significant inverse association with diabetic microangiopathy. Compared with GG genotype, the CC genotype of PEMT G774C was associated with a decreased risk of diabetes (OR 0.559, 95%CI 0.338, 0.926) and its microangiopathy (OR 0.452, 95%CI 0.218, 0.937).
CONCLUSION: The GG genotype of the PEMT G774C polymorphism, higher level of serum homocysteine, and lower level of serum betaine are associated with an increased risk of microangiopathy in patients with diabetes.

Chen, L., et al., Higher homocysteine and lower betaine increases the risk of microangiopathy in patients with diabetes mellitus carrying the GG genotype of PEMT G774C. Diabetes Metab Res Rev, 2013

Low folate status enhances pregnancy changes in plasma betaine and dimethylglycine concentrations and the association between betaine and homocysteine

BACKGROUND: Folate, choline, and betaine participate in homocysteine metabolism. It is not known whether they interact during pregnancy. OBJECTIVE: The objective was to investigate how folate status affects choline, betaine, and dimethylglycine during pregnancy. 

DESIGN: Fasting plasma folate, cobalamin, free choline, betaine, dimethylglycine, and total homocysteine (tHcy) were measured longitudinally at >12, 15, 24-27, and 34 gestational weeks (GW); at labor (nonfasting); and in the cord in participants (n = 522) from the Reus-Tarragona Birth Cohort (NUTricio i Creixement Intrauteri Retardat phase). Timing, dose, and duration of folic acid supplement use were recorded. Folate status was classified as below (low) or above (high) median plasma folate at baseline (27.6 nmol/L) and at 24-27 GW (11.4 nmol/L). Associations between folate or betaine with tHcy were investigated by using multiple linear regression analysis. 

RESULTS: Plasma betaine decreased by 34.8% (1.0%) throughout pregnancy, and dimethylglycine increased by 39.7% (2.7%) between 24-27 GW and labor (all P < 0.001). Low folate status was associated with a higher dimethylglycine/betaine ratio from 15 GW and with lower plasma betaine and higher dimethylglycine from 24 to 27 GW, for the rest of pregnancy, compared with high status. Regression analysis showed that by 24-27 GW, both plasma folate and betaine were inversely associated with tHcy when folate status was low and that the association between betaine and tHcy depended on folate status at 24-27 and 34 GW (interaction terms: P < 0.001 and P < 0.01). Betaine was inversely associated with tHcy at labor regardless of folate status. 

CONCLUSION: Low folate status enhances the reduction in betaine and the increase in dimethylglycine during pregnancy and strengthens the association between betaine and tHcy. This trial was registered at clinicaltrials.gov as NCT01778205. 

Fernandez-Roig, S., et al., Low folate status enhances pregnancy changes in plasma betaine and dimethylglycine concentrations and the association between betaine and homocysteine. Am J Clin Nutr, 2013

Lower seasonal maternal dietary betaine intake and resultant lower blood levels correlates with previously reported reduced DNA methylation in offspring

BACKGROUND: Animal models show that periconceptional supplementation with folic acid, vitamin B-12, choline, and betaine can induce differences in offspring phenotype mediated by epigenetic changes in DNA. In humans, altered DNA methylation patterns have been observed in offspring whose mothers were exposed to famine or who conceived in the Gambian rainy season.

OBJECTIVE:The objective was to understand the seasonality of DNA methylation patterns in rural Gambian women. We studied natural variations in dietary intake of nutrients involved in methyl-donor pathways and their effect on the respective metabolic biomarkers.

DESIGN:In 30 women of reproductive age (18-45 y), we monitored diets monthly for 1 y by using 48-h weighed records to measure intakes of choline, betaine, folate, methionine, riboflavin, and vitamins B-6 and B-12. Blood biomarkers of these nutrients, S-adenosylhomocysteine (SAH), S-adenosylmethionine (SAM), homocysteine, cysteine, and dimethylglycine were also assessed monthly.

RESULTS:Dietary intakes of riboflavin, folate, choline, and betaine varied significantly by season; the most dramatic variation was seen for betaine. All metabolic biomarkers showed significant seasonality, and vitamin B-6 and folate had the highest fluctuations. Correlations between dietary intakes and blood biomarkers were found for riboflavin, vitamin B-6, active vitamin B-12 (holotranscobalamin), and betaine. We observed a seasonal switch between the betaine and folate pathways and a probable limiting role of riboflavin in these processes and a higher SAM/SAH ratio during the rainy season.

CONCLUSIONS:Naturally occurring seasonal variations in food-consumption patterns have a profound effect on methyl-donor biomarker status. The direction of these changes was consistent with previously reported differences in methylation of metastable epialleles. This trial was registered at www.clinicaltrials.gov as NCT01811641.

Dominguez-Salas, P., et al., DNA methylation potential: dietary intake and blood concentrations of one-carbon metabolites and cofactors in rural African women. Am J Clin Nutr, 2013

Co-administration of methyl donors (including betaine) with GAA increases serum creatine without development of hyperhomocysteinaemia

Guanidinoacetic acid (GAA) is the natural biosynthetic precursor of creatine, in a metabolic reaction that requires only a methyl group transfer. The use of GAA as a food additive for restoring creatine load in human tissues is rather unexplored and data on efficacy and safety are limited. In particular, an increase in serum homocysteine after GAA administration can be regarded as critical and should be prevented. The present study evaluated the effects of orally administered GAA with and without methyl group donors on serum and urine creatine concentrations, and the occurrence of adverse events during an intervention in healthy human subjects. A total of twenty male and female volunteers were randomised in a double-blind design to receive either GAA (2.4 g/d) or GAA with methyl donors (2.4 g/d of GAA and 1.6 g/d of betaine HCl, 5 mug/d of vitamin B12, 10 mg/d of vitamin B6 and 600 mug/d of folic acid) by oral administration for 8 weeks. Serum and urine creatine increased significantly from before to after administration in both groups (P< 0.001). The proportion of participants who reported minor adverse events was 33.3 % in the GAA group, and 10.0 % in the GAA with methyl donors group (P= 0.30). Hyperhomocysteinaemia was found in 55.6 % of participants supplemented with GAA, while no participant experienced hyperhomocysteinaemia in the group supplemented with GAA and methyl donors (P= 0.01). In summary, both interventions strongly influenced creatine metabolism, resulting in a significant increase in fasting serum creatine. The concomitant supplementation of methyl donors along with GAA largely precluded the elevation of serum homocysteine caused by GAA administration alone.

Ostojic, S.M., et al., Co-administration of methyl donors along with guanidinoacetic acid reduces the incidence of hyperhomocysteinaemia compared with guanidinoacetic acid administration alone. Br J Nutr, 2013: p. 1-6.

Betaine attenuates Alzheimer-like pathological changes and memory deficits induced by homocysteine

Hyperhomocysteinemia (Hhcy) may induce memory deficits with β-amyloid (Aβ) accumulation and tau hyperphosphorylation. Simultaneous supplement of folate and vitamin B12 partially restored the plasma homocysteine level and attenuated tau hyperphosphorylation, Aβ accumulation and memory impairments induced by Hhcy. However, folate and vitamin B12 treatment have no effects on Hhcy which has the methylenetetrahydrofolate reductase genotype mutation. In the present study, we investigated the effects of simultaneous supplement of betaine on Alzheimer-like pathological changes and memory deficits in hyperhomocysteinemic rats after a 2-week induction by vena caudalis injection of homocysteine (Hcy). We found that supplementation of betaine could ameliorate the Hcy-induced memory deficits, enhance LTP and increase dendritic branches numbers and the density of the dendritic spines, with upregulation of NR1, NR2A, synaptotagmin, synaptophysin and phosphorylated synapsin I protein levels. Supplementation of betaine also attenuated the Hcy-induced tau hyperphosphorylation at multiple AD-related sites through activation PP2A with decreased inhibitory demethylated PP2A(C) at Leu309 and phosphorylated PP2A(C) at Tyr307. In addition, supplementation of betaine also decreased Aβ production with decreased presenilin-1 protein levels. Our data suggest that betaine could be a promising candidate for arresting Hcy-induced AD-like pathological changes and memory deficits.

Chai, G.-S., et al., Betaine attenuates Alzheimer-like pathological changes and memory deficits induced by homocysteine. Journal of Neurochemistry, 2012 (10.1111/jnc.12094).

Plasma choline and betaine correlate with serum folate, plasma S-adenosyl-methionine and S-adenosyl-homocysteine in healthy volunteers

Background: Choline is essential for mammalian cell function. It plays a critical role in cell membrane integrity, neurotransmission, cell signaling and lipid metabolism. Moreover, choline is involved in methylation in two ways: a) its synthesis requires methyl groups donated by S-adenosyl-methionine (AdoMet); and b) choline oxidation product betaine methylates homocysteine (Hcy) to methionine (Met) and produces dimethylglycine. This later donates one carbon units to tetrahydrofolate (THF).
Methods: To evaluate the correlations of choline and betaine with folate, AdoMet, S-anenosyl-homocysteine (AdoHcy), total homocysteine (tHcy), and DNA methylation, choline, betaine and dimethylglycine were measured by LC-MS/MS in plasma of 109 healthy volunteers, in whom folate, AdoMet, AdoHcy, tHcy, and DNA methylation have previously been reported.
Results: Using a bivariate model, choline and betaine showed strong positive correlations with folate (r=0.346 and r=0.226), AdoHcy (r=0.468 and r=0.296), and correlated negatively with AdoMet/AdoHcy ratio (r=-0.246 and r=-0.379). Only choline was positively correlated with AdoMet (r=0.453). Using a multivariate linear regression model, choline correlated strongly with folate (beta=17.416), AdoMet (beta=61.272), and AdoHcy (beta=9.215). Betaine correlated positively with folate (beta=0.133) and negatively with tHcy (beta=-0.194) ratio. Choline is an integral part of folate and methylation pathways.
Conclusions: Our data highlight the importance of integrating choline in studies concerning addressing pathological conditions related to folate, homocysteine and methylation metabolism.

Imbard, A., et al., Plasma choline and betaine correlate with serum folate, plasma S-adenosyl-methionine and S-adenosyl-homocysteine in healthy volunteers. Clin Chem Lab Med, 2012.

Deletion of murine betaine-homocysteine S-methyltransferase in mice perturbs choline and 1-carbon metabolism, resulting in fatty liver and hepatocellular carcinoma

Betaine-homocysteine S-methyltransferase (BHMT) uses betaine to catalyze the degradation of homocysteine (Hcy). There are common genetic polymorphisms in the BHMT gene in humans. To model the phenotype of mice with a loss of BHMT function, we generated the first Bhmt-/- mouse. Deletion of the gene resulted in a 6-fold increase in hepatic and an 8-fold increase in plasma Hcy concentrations, suggesting the importance of BHMT in Hcy removal. Deletion of the gene resulted in a 43% reduction in hepatic S-adenosylmethionine (AdoMet) and a 3-fold increase in hepatic S-adenosylhomocysteine (AdoHcy) concentrations, resulting in a 75% reduction in methylation potential (AdoMet:AdoHcy). Bhmt-/- mice accumulated betaine in most tissues, including a 21-fold increase in the liver concentration compared to wildtype (WT). These mice had lower concentrations of choline, phosphocholine, glycerophosphocholine, phosphatidylcholine and sphingomyelin in several tissues. At 5 weeks of age, Bhmt-/- mice had 36% lower total hepatic phospholipid concentrations and a 6-fold increase in hepatic triacyglycerol concentrations compared to WT, which was due to a decrease in the secretion of very low density lipoproteins. At 1 year of age, 64% of Bhmt-/- mice had visible hepatic tumors. Histopathological analysis revealed that Bhmt-/- mice developed hepatocellular carcinoma (HCC) or carcinoma precursors. These results indicate that BHMT has an important role in Hcy, choline and one-carbon homeostasis. A lack of BHMT also affects susceptibility to fatty liver and HCC. We suggest that functional polymorphisms in BHMT that significantly reduce activity may have similar effects in humans.

Teng, Y.W., et al., Deletion of murine betaine-homocysteine S-methyltransferase in mice perturbs choline and 1-carbon metabolism, resulting in fatty liver and hepatocellular carcinoma. J Biol Chem, 2011. 286: p. 36258-67

Dietary choline and betaine intakes and risk of cardiovascular diseases: review of epidemiological evidence

BACKGROUND: Cardiovascular diseases (CVD) are the most important causes of human mortality in the world. Higher intakes of choline and betaine have been shown to be associated with lower plasma homocysteine levels (the putative CVD risk factor). This study aimed to review the evidence on the association between dietary intakes of choline and betaine and traditional/novel CVD risk factors.

METHODS: We searched in PubMed website from 1990 to 2009, with the use of following keywords: "dietary choline and betaine, cardiovascular diseases, metabolic syndrome, inflammation". The cross-sectional and prospective studies as well as the clinical trials were recruited in this investigation.

RESULTS: Dietary intakes of “choline”/“choline and betaine” were not significantly associated with CVD risk; however, the higher intakes of choline and betaine were associated with higher serum concentrations of CRP, IL-6 and TNF-α. Individuals with high plasma choline levels were obese and had elevated plasma triglycerides, HDL and non-HDL cholesterol levels; whereas high plasma betaine levels were inversely associated with these biochemical markers. Both choline and betaine supplementation resulted in increased blood lipid profiles.

CONCLUSION: Although dietary intakes of choline and betaine were not significantly associated with CVD incidence, the long-term consumption of these nutrients have been shown to prevent CVD mortality by decreasing inflammation and other risk factors.

Rajaie, S. and A. Esmaillzadeh, Dietary choline and betaine intakes and risk of cardiovascular diseases: review of epidemiological evidence. ARYA Atheroscler, 2011. 7(2): p. 78-86

Betaine excretion correlates with plasma homocysteine when plasma lipids are elevated

OBJECTIVES: To reconcile observing a positive correlation of betaine excretion with homocysteine in lipid disorder patients but not other study groups.
DESIGN AND METHODS: Correlations were estimated in subgroups of a control group and the lipid disorder patients.
RESULTS: Plasma non high-density lipoprotein (non-HDL) cholesterol differed between the groups. The correlation increased with the median plasma non-HDL cholesterol in subgroups.
CONCLUSIONS: This correlation is associated with patients with elevated plasma lipids.

Lever, M., et al., Betaine excretion correlates with plasma homocysteine when plasma lipids are elevated. Clin Biochem, 2012. 45(1-2): p. 154-6