Betaine reverses the memory impairments in a chronic cerebral hypoperfusion rat model

Vascular dementia (VaD) is the second reason for the cognitive decline in aged people, but the effective therapy is still missing. The chronic cerebral hypoperfusion (CCH) had been widely found in VaD patients and is thought to be the key reason for cognitive impairment. Betaine is a natural product that had been implicated in many biological processes and had been used for the therapy of some neurodegenerative disease, such as Alzheimer's disease. In this study, we reported that betaine treatment could rescue the memory deficits induced by two-vessel occlusion (2-VO), a widely used CCH rat model. Betaine also restored the expression of PSD93, PSD95 and MAP2 to preserve the synaptic functions. Furthermore, betaine could reduce the oxidative stress by suppressing the MDA and ROS and enhancing the SOD and GSH. Overall, betaine treatment is able to rescue the memory deficits in CCH rats, which provide an experimental basis for the therapy of VaD.

Chunjie, N., et al., Betaine reverses the memory impairments in a chronic cerebral hypoperfusion rat model. Neurosci Lett, 2015.

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.

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

SAMe plus betaine is a safe and effective tool to counteract mild depression

BACKGROUND: S-adenosyl-L-methionine (SAMe), a safe, endogenous, pleiotropic methyl donor well known for its antidepressant role, has been assumed to have a possible role in increasing plasma levels of compounds known to be able to raise cardiovascular risk. Although the issue is still being debated, betaine (trimethylglycine), a specific methyl donor involved in the homocysteine circuit, may be able to reduce such a risk and/or, by determining a sparing effect on endogenous SAMe, may be able to improve the clinical efficiency of SAMe itself. Indeed, preliminary results have shown clinical improvement determined by an add-on therapy with betaine administered along with SAMe, versus SAMe alone, to patients affected by mild/moderate depression. AIM: To evaluate the safety and antidepressant role played by the association of SAMe plus betaine versus amitriptyline administered in untreated individuals with a recent diagnosis of mild depression. METHODS: This small, open-label, randomized, observational study enrolled 64 individuals with a diagnosis of mild depression according to the Zung Self-Rating Depression Scale. After randomization, they were treated with either Laroxyl((R)) (amitriptyline, 75 mg/day) or DDM Metile((R)) (enteric-coated SAMe, 500 mg/day, plus betaine, 250 mg/day) for 12 months. Assessment of clinical scores and tolerability was performed at T=0 and after 3, 6, and 12 months. RESULTS: After 3 months, both treatments showed a small and not statistically significant improvement. After 6 and 12 months, both treated groups demonstrated a more noticeable improved response, although the group treated with SAMe plus betaine showed better results in terms of score, number of individuals in remission, and side effects. Compliance was overlapping in both treatments. CONCLUSION: The association of SAMe plus betaine seems to be a safe and effective tool to counteract mild depression and also when used as monotherapy in subjects with a recent diagnosis.

Di Pierro, F. and R. Settembre, Preliminary results of a randomized controlled trial carried out with a fixed combination of S-adenosyl-L-methionine and betaine versus amitriptyline in patients with mild depression. Int J Gen Med, 2015. 8: p. 73-8

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.

Betaine recovers hypothalamic neural injury by inhibiting astrogliosis and inflammation in fructose-fed rats

SCOPE:: Hypothalamic astrogliosis and inflammation cause neural injury, playing a critical role in metabolic syndrome development. This study investigated whether and how fructose caused hypothalamic astrogliosis and inflammation in vivo and in vitro. The inhibitory effects of betaine on hypothalamic neural injury, astrogliosis and inflammation were explored to address its improvement of fructose-induced metabolic syndrome.
METHODS AND RESULTS:: Rats or astrocytes were exposed to fructose and then treated with betaine. Neural injury, proinflammatory markers, toll-like receptor 4/nuclear factor-kappaB (TLR4/NF-kappaB) pathway and histone deacetylases (HDAC3) expression were evaluated. The reduction of pro-opiomelanocortin (POMC) and melanocortin 4 receptor (Mc4R) neurons in fructose-fed rats were ameliorated by betaine. Moreover, fructose induced astrogliosis and proinflammatory cytokines by increasing TLR4, MyD88 and NF-kappaB expression in rat hypothalamus and astrocytes. HDAC3 over-expression preserved the prolonged inflammation in fructose-stimulated astrocytes by regulating nuclear NF-kappaB-dependent transcription. Betaine suppressed TLR4/NF-kappaB pathway activation and HDAC3 expression, contributing to its inhibition of hypothalamic astrogliosis and inflammation in animal and cell models.
CONCLUSION:: These findings suggest that betaine inhibits fructose-caused astrogliosis and inflammation by the suppression of TLR4/NF-kappaB pathway activation and HDAC3 expression to protect against hypothalamic neural injury, which, at least partly, contributes to the improvement on fructose-induced metabolic syndrome.

Li, J.M., et al., Betaine recovers hypothalamic neural injury by inhibiting astrogliosis and inflammation in fructose-fed rats. Mol Nutr Food Res, 2014

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

Betaine raises brain serotonin levels and produces antidepressant-like effects in rats

The purpose of the present study was to examine the effect of Lycii Radicis Cortex (LRC) and betaine (BT) on immobility and neurochemical change in the forced swimming test (FST) in the rat. LRC, BT or fluoxentine was administered intraperitoneally to Sprague-Dawley rats three times (1, 5 and 23.5 h) before the FST. To investigate antidepressant-like effect, serotonin (5-HT) and norepinephrine (NE) were examined in the hippocampus and hypothalamus of rats. LRC (100 mg/kg) and BT (30, 100 mg/kg) significantly decreased the immobility time in the FST. LRC (100 mg/kg) significantly increased both 5-HT and NE levels in the hypothalamus of rats exposed to FST. BT (100 mg/kg) significantly increased 5-HT levels in the hypothalamus and hippocampus of rats. Taken together, these results demonstrated that improvement in the behavioral changes after LRC and BT administration may be mediated by elevation of 5-HT level in the hypothalamus and hippocampus, indicating a possible antidepressant-like activity. The present results suggest that the efficacy of LRC and BT in an animal model of depression may provide anti-depressant effects in human, which remains to be determined.

Kim, S.J., et al., Antidepressant-like effects of lycii radicis cortex and betaine in the forced swimming test in rats. Biomol Ther (Seoul), 2013. 21(1): p. 79-83

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

Higher plasma betaine in children is associated with better language score

Choline is an essential nutrient that is found in many food sources and plays a critical role in the development of the central nervous system. Animal studies have shown that choline status pre- and postnatally can have long-lasting effects on attention and memory; however, effects in human subjects have not been well studied. The aim of the present study was to examine the association between plasma concentrations of free choline and its related metabolites in children and their neurodevelopment in the Seychelles Child Development Nutrition Study, an ongoing longitudinal study assessing the development of children born to mothers with high fish consumption during pregnancy. Plasma concentrations of free choline, betaine, dimethylglycine (DMG), methionine and homocysteine and specific measures of neurodevelopment were measured in 210 children aged 5 years. The children's plasma free choline concentration (9.17 (sd 2.09) mumol/l) was moderately, but significantly, correlated with betaine (r 0.24; P= 0.0006), DMG (r 0.15; P= 0.03), methionine (r 0.24; P= 0.0005) and homocysteine (r 0.19; P= 0.006) concentrations. Adjusted multiple linear regression revealed that betaine concentrations were positively associated with Preschool Language Scale - total language scores (beta = 0.066; P= 0.04), but no other associations were evident. We found no indication that free choline concentration or its metabolites, within the normal physiological range, are associated with neurodevelopmental outcomes in children at 5 years of age. As there is considerable animal evidence suggesting that choline status during development is associated with cognitive outcome, the issue deserves further study in other cohorts.

Strain, J.J., et al., Choline status and neurodevelopmental outcomes at 5 years of age in the Seychelles Child Development Nutrition Study. Br J Nutr, 2013: p. 1-7.

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).

Recognition of betaine as an inhibitor of lipopolysaccharide-induced nitric oxide production in activated microglial cells

Background: Neuroinflammation, as a major outcome of microglia activation, is an important factor for progression of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. Microglial cells, as the first-line defense in the central nervous system, act as a source of neurotoxic factors such as nitric oxide (NO), a free radical which is involved in neuronal cell death. The aim of this study was to inhibit production of NO in activated microglial cells in order to decrease neurological damages that threat the central nervous system. Methods: An in vitro model of a newborn rat brain cell culture was used to examine the effect of betaine on the release of NO induced by lipopolysaccharide (LPS). Briefly, primary microglial cells were stimulated by LPS and after 2 minutes, they were treated by different concentrations of betaine. The production of NO was assessed by the Griess assay while cell viability was determined by the MTT assay. Results: Our investigations indicated that LPS-induced NO release was attenuated by betaine, suggesting that this compound might inhibit NO release. The effects of betaine on NO production in activated microglial cells after 24 h were "dose-dependent". It means that microglial cells which were treated with higher concentrations of betaine, released lower amounts of NO. Also our observations showed that betaine compound has no toxic effect on microglial cells. Conclusion: Betaine has an inhibitory effect on NO release in activated microglial cells and may be an effective therapeutic component to control neurological disorders.

Amiraslani, B., et al., Recognition of betaine as an inhibitor of lipopolysaccharide-induced nitric oxide production in activated microglial cells. Iran Biomed J, 2012. 16(2): p. 84-9.

Plasma free choline, betaine and cognitive performance: the Hordaland Health Study

Choline and betaine are nutrients involved in one-carbon metabolism. Choline is essential for neurodevelopment and brain function. We studied the associations between cognitive function and plasma concentrations of free choline and betaine. In a cross-sectional study, 2195 subjects (55 % women), aged 70-74 years, underwent extensive cognitive testing including the Kendrick Object Learning Test (KOLT), Trail Making Test (part A, TMT-A), modified versions of the Digit Symbol Test (m-DST), Block Design (m-BD), Mini-Mental State Examination (m-MMSE) and Controlled Oral Word Association Test (COWAT). Compared with low concentrations, high choline (>8.4 mumol/l) was associated with better test scores in the TMT-A (56.0 v. 61.5, P = 0.004), m-DST (10.5 v. 9.8, P = 0.005) and m-MMSE (11.5 v. 11.4, P = 0.01). A generalised additive regression model showed a positive dose-response relationship between the m-MMSE and choline (P = 0.012 from a corresponding linear regression model). Betaine was associated with the KOLT, TMT-A and COWAT, but after adjustments for potential confounders, the associations lost significance. Risk ratios (RR) for poor test performance roughly tripled when low choline was combined with either low plasma vitamin B12 ( </= 257 pmol/l) concentrations (RRKOLT = 2.6, 95 % CI 1.1, 6.1; RRm-MMSE = 2.7, 95 % CI 1.1, 6.6; RRCOWAT = 3.1, 95 % CI 1.4, 7.2) or high methylmalonic acid (MMA) ( >/= 3.95 mumol/l) concentrations (RRm-BD = 2.8, 95 % CI 1.3, 6.1). Low betaine ( </= 31.1 mumol/l) combined with high MMA was associated with elevated RR on KOLT (RRKOLT = 2.5, 95 % CI 1.0, 6.2). Low plasma free choline concentrations are associated with poor cognitive performance. There were significant interactions between low choline or betaine and low vitamin B12 or high MMA on cognitive performance.

Nurk, E., et al., Plasma free choline, betaine and cognitive performance: the Hordaland Health Study. Br J Nutr, 2012 (May 1): p. 1-9

Effects of betaine on lipopolysaccharide-induced memory impairment in mice and the involvement of GABA transporter 2

BACKGROUND: Betaine (glycine betaine or trimethylglycine) plays important roles as an osmolyte and a methyl donor in animals. While betaine is reported to suppress expression of proinflammatory molecules and reduce oxidative stress in aged rat kidney, the effects of betaine on the central nervous system are not well known. In this study, we investigated the effects of betaine on lipopolysaccharide (LPS)-induced memory impairment and on mRNA expression levels of proinflammatory molecules, glial markers, and GABA transporter 2 (GAT2), a betaine/GABA transporter.

METHODS: Mice were continuously treated with betaine for 13 days starting 1 day before they were injected with LPS, or received subacute or acute administration of betaine shortly before or after LPS injection. Then, their memory function was evaluated using Y-maze and novel object recognition tests 7 and 10-12 days after LPS injection (30 ug/mouse, i.c.v.), respectively. In addition, mRNA expression levels in hippocampus were measured by real-time RT-PCR at different time points.

RESULTS: Repeated administration of betaine (0.163 mmol/kg, s.c.) prevented LPS-induced memory impairment. GAT2 mRNA levels were significantly increased in hippocampus 24 hr after LPS injection, and administration of betaine blocked this increase. However, betaine did not affect LPS-induced increases in levels of mRNA related to inflammatory responses. Both subacute administration (1 hr before, and 1 and 24 hr after LPS injection) and acute administration (1 hr after LPS injection) of betaine also prevented LPS-induced memory impairment in the Y-maze test.

CONCLUSIONS: These data suggest that betaine has protective effects against LPS-induced memory impairment and that prevention of LPS-induced changes in GAT2 mRNA expression is crucial to this ameliorating effect.

Miwa, M., et al., Effects of betaine on lipopolysaccharide-induced memory impairment in mice and the involvement of GABA transporter 2. J Neuroinflammation. 8(1): p. 153.

Betaine prevents ethanol-induced oxidative stress and reduces total homocysteine in the rat cerebellum

Oxidative stress is a hypothesis for the association of reactive oxygen species with cerebrovascular and neurodegenerative diseases. Thus, we examined whether oral betaine can act as a preventive agent in ethanol-induced oxidative stress on the cerebellum of rats. Thirty-two adult male Sprague–Dawley rats were divided into four equal groups (control, ethanol, betaine, and betaine plus ethanol) with different dietary regimens and were followed up for 1 month. Total homocysteine (tHcy) of plasma and cerebellum homogenate was determined by an Axis® homocysteine EIA kit, and antioxidant enzyme (glutathione peroxidase (GPx), SOD, and CAT) activities of cerebellum homogenate were measured chemically by a spectrophotometer. Lipid peroxidation of cerebellum was shown by the measurement of thiobarbituric reactive substances (TBARS) via a spectrophotometer. Ethanol-induced hyperhomocysteinemia was manifested by an increase in the concentrations of tHcy in the plasma and cerebellum homogenates of the ethanol group, while ethanol-induced oxidative stress was indicated via an increase in lipid peroxidation marker (TBARS) in cerebellum homogenates of ethanol-treated rats. In contrast, betaine prevented hyperhomocysteinemia and oxidative stress in the betaine plus ethanol group as well as the betaine group. The results of the present investigation indicated that the protective effect of betaine is probably related to its ability to strengthen the cerebellum membrane cells by enhancement of antioxidant enzyme activity principally GPx, while the methyl donor effect of betaine to reduce hyperhomocysteinemia has been explained previously and confirmed in the present study.

Alirezaei, M., et al., Betaine prevents ethanol-induced oxidative stress and reduces total homocysteine in the rat cerebellum. J Physiol Biochem, 2011. 67(4): p. 605-12.

Betaine protects the brain against alcohol and aspirin

Physicians recommend aspirin for prevention of heart attacks and stroke in people above the age of 40 years. In some cases, alcohol consumption accompanies aspirin intake. In this study, the in vitro effects of different doses of ethanol (50, 100, and 200 mM) and 100 μg/mL of aspirin and the possible protective role of betaine (0.5 and 1 mM) were investigated on rat cerebral synaptosomes.

Synaptosomally enriched fractions, derived from Sprague Dawley rat brains, were incubated with ethanol and aspirin so as to measure sialic acid (SA), nitric oxide levels, and adenosine deaminase (ADA) activities, which are known to be the markers of alcohol damage. When combined with aspirin, ethanol increased SA levels compared with the control group at all doses, resulting in loss of SA residue from synaptosomal membrane. Betaine (0.5 mM) decreased SA levels with respect to the ethanol (200 mM) plus aspirin group (p < .05), thereby preventing SA loss. Moreover, betaine reversed the destructive effects of ethanol by elevating reduced nitric oxide levels. Aspirin, when combined with all doses of ethanol, increased ADA activity, which is crucial for purine metabolism. ADA activities were also elevated in betaine-administered groups.

We propose that betaine is an effective compound in protecting the rat brain synaptosomes against ethanol and aspirin together.

Sogut and Kanbak (2010). "In vitro effects of ethanol with aspirin on rat brain synaptosomes: the potential protective role of betaine." Int J Neurosci 120(12): 774-83.

Protective effect of betaine on the brain

This study evaluated the cytotoxic effects of chronic ethanol consumption on brain cerebral synaptosomes and preventive role of betaine as a methyl donor and S-adenosylmethionine precursor.

24 male Wistar rats were divided into three groups: control, ethanol (8 g/kg/day) and ethanol plus betaine(0.5% w/v) group. Animals were fed 60 ml/diet per day for two months, then sacrificed. Malondialdehyde (MDA), protein carbonyl contents and adenosine deaminase (ADA) activities were determined in synaptosomal/mitochondrial enriched fraction isolated from rat cerebral cortexes. When compared to controls, ethanol containing diet significantly increased MDA levels (P < 0.05), also increased protein carbonyl levels and adenosine deaminase activities. But these were not statistically significant (P > 0.05). However, adding betaine to ethanol containing diet caused a significant decrease in MDA, protein carbonyl levels and adenosine deaminase activities (P < 0.05).

These results indicate that betaine may appear as a protective nutritional agent against cytotoxic brain damage induced by chronic ethanol consumption.

Kanbak et al (2008). "Effects of chronic ethanol consumption on brain synaptosomes and protective role of betaine." Neurochem Res 33(3): 539-44.

Prevention of amyloid β-peptide formation

S-Adenosylhomocysteine (SAH) has been implicated as a risk factor for neurodegenerative diseases such as Alzheimer's disease. SAH is a potent inhibitor of all cellular methyltransferases and this study showed that SAH increased amyloid β-peptide (Aβ) formation in a concentration-dependent manner (10–500 nM), and this effect of SAH was accompanied by significantly increased expression of APP and PS1 proteins.

Pre-incubation of cells with betaine (1.0 mM), 30 min followed by incubation with SAH (500 nM) or 5′-azc (20 μM) for 24 h markedly prevented the expression of Aβ protein (by 50%, P < 0.05) and the gene promoter hypomethylation of APP and PS1.

Lin et al (2009). "S-Adenosylhomocysteine increases beta-amyloid formation in BV-2 microglial cells by increased expressions of beta-amyloid precursor protein and presenilin 1 and by hypomethylation of these gene promoters." Neurotoxicology 30(4): 622-7.