Choline and betaine consumption lowers cancer risk: a meta-analysis of epidemiologic studies

A number of human and animal in vitro or in vivo studies have investigated the relationship between dietary choline and betaine and cancer risk, suggesting that choline and betaine consumption may be protective for cancer. There are also a few epidemiologic studies exploring this relationship, however, with inconsistent conclusions. The PubMed and Embase were searched, from their inception to March 2016, to identify relevant studies and we brought 11 articles into this meta-analysis eventually. The pooled relative risks (RRs) of cancer for the highest versus the lowest range were 0.82 (95% CI, 0.70 to 0.97) for choline consumption only, 0.86 (95%CI, 0.76 to 0.97) for betaine consumption only and 0.60 (95%CI, 0.40 to 0.90) for choline plus betaine consumption, respectively. Significant protective effect of dietary choline and betaine for cancer was observed when stratified by study design, location, cancer type, publication year, sex and quality score of study. An increment of 100 mg/day of choline plus betaine intake helped reduce cancer incidence by 11% (0.89, 95% CI, 0.87 to 0.92) through a dose-response analysis. To conclude, choline and betaine consumption lowers cancer incidence in this meta-analysis, but further studies are warranted to verify the results.

Sun, S., et al. (2016). "Choline and betaine consumption lowers cancer risk: a meta-analysis of epidemiologic studies." Sci Rep 6: 35547.

Higher Dietary Choline and Betaine Intakes Are Associated with Better Body Composition

BACKGROUND: Choline is an essential nutrient and betaine is an osmolyte and methyl donor. Both are important to maintain health including adequate lipid metabolism. Supplementation of dietary choline and betaine increase muscle mass and reduce body fat in animals. However, little data is available regarding the role of dietary choline and betaine on body composition in humans.
OBJECTIVE: To investigate the association between dietary choline and betaine intakes with body composition in a large population based cross-sectional study. DESIGN: A total of 3214 subjects from the CODING (Complex Disease in Newfoundland population: Environment and Genetics) study were assessed. Dietary choline and betaine intakes were computed from the Willett Food Frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry following a 12-hour fast. Major confounding factors including age, sex, total calorie intake and physical activity level were controlled in all analyses.
RESULT: Significantly inverse correlations were found between dietary choline and betaine intakes, with all obesity measurements: total percent body fat (%BF), percent trunk fat (%TF), percent android fat (%AF), percent gynoid fat (%GF) and anthropometrics: weight, body mass index, waist circumference, waist-to-hip ratio in both women and men (r range from -0.13 to -0.47 for choline and -0.09 to -0.26 for betaine. Dietary choline intake had stronger association than betaine. Moreover, obese subjects had the lowest dietary choline and betaine intakes, with overweight subjects in the middle, and normal weight subjects consumed the highest dietary choline and betaine. Vice versa, when subjects were ranked according to dietary choline and betaine intakes, subjects with the highest intake of both had the lowest %TF, %AF, %GF, %BF and highest %LM among the groups in both sexes.
CONCLUSION: Our findings indicate that high dietary choline and betaine intakes are significantly associated with favorable body composition in humans.

Gao, X., et al. (2016). "Higher Dietary Choline and Betaine Intakes Are Associated with Better Body Composition in the Adult Population of Newfoundland, Canada." PLoS ONE 11(5): e0155403.

Higher dietary intakes of choline and betaine are associated with a lower risk of liver cancer

The dietary intake of methyl donors is favorably associated with many diseases, but the findings regarding primary liver cancer (PLC) risk are limited. This study investigated the association between the intake of choline, betaine and methionine and PLC risk in adults. This 1:1 matched case-control study enrolled 644 hospital-based PLC patients and 644 community-based controls who were matched by sex and age, in Guangzhou, China. An interviewer-administered questionnaire and a food-frequency questionnaire were used to collect general information and dietary intake information. Conditional logistic regression showed a significantly inverse association between total choline and betaine intakes and PLC risk. The multivariable-adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) for PLC for the top (vs. bottom) tertile were 0.34 (0.24-0.49; P -trend < 0.001) for total choline and 0.67 (0.48-0.93; P -trend = 0.011) for betaine. No significant association was observed between the intake of methionine and PLC risk (P > 0.05). For individual choline compounds, higher consumptions of free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine and sphingomyelin were associated with a lower PLC risk (all P-trend < 0.05). The studied associations were not significantly modified by the folate intake (P-interactions: 0.488-0.890). Our findings suggest that higher choline and betaine intakes may be associated with a lower risk of PLC.

Zhou, R. F., et al. (2017). "Higher dietary intakes of choline and betaine are associated with a lower risk of primary liver cancer: a case-control study." Sci Rep 7(1): 679.

High dietary choline and betaine intake is associated with low insulin resistance

OBJECTIVE: Dietary betaine supplement could ameliorate insulin resistance (IR) in animals, but no data are available for choline. Reports on humans are rare. The aim of this study was to investigate the association between dietary choline and betaine intake and IR in humans.
METHODS: We assessed 2394 adults from the CODING (Complex Diseases in the Newfoundland population: Environment and Genetics) study. Intake of dietary choline and betaine was evaluated from the Willett Food Frequency Questionnaire. IR was estimated by homeostatic model assessment (HOMA-IR) and the quantitative insulin-sensitivity check index (QUICKI). Partial correlation analysis was used to determine the correlations of dietary choline and betaine intake with IR adjusted for major confounding factors.
RESULTS: Dietary choline and betaine intake was inversely correlated with levels of fasting glucose and insulin, HOMA-IR, HOMA-beta (r = -0.08 to -0.27 for choline and r = -0.06 to -0.16 for betaine; P < 0.05) and positively related to QUICKI (r = 0.16-0.25 for choline and r = 0.11-0.16 for betaine; P < 0.01) in both sexes after controlling for age, total calorie intake, and physical activity level. The significant associations disappeared in men after percent trunk fat was added as a confounding factor. Furthermore, individuals with the highest tertile of dietary choline and betaine intake had the lowest IR severity. Dietary choline and betaine intake, however, was the lowest in the high IR group, intermediate in the medium group, and the highest in the low IR group.
CONCLUSION: This study demonstrated that higher intake of dietary choline and betaine is associated with lower IR in the general population.

Gao, X., et al. (2017). "High dietary choline and betaine intake is associated with low insulin resistance in the Newfoundland population." Nutrition 33: 28-34.

Nonalcoholic Steatohepatitis is associated with a state of betaine-insufficiency

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD) develops from a complex process, which includes changes in the liver methylome. Betaine plays a pivotal role in the regulation of methylogenesis. We performed a two-stage case-control study, which included patients with biopsy-proven NAFLD in order to explore circulating levels of betaine and its association with the histological spectrum. We also explored the association between a missense p.Ser646Pro variant in DMGDH (dimethylglycine dehydrogenase mitochondrial) and NAFLD severity (n =390).
RESULTS: In the discovery phase (n = 48), betaine levels were associated with the disease severity (p = 0.0030), including liver inflammation (Spearman R: - 0.51, p = 0.001), ballooning degeneration (R: - 0.50, p = 0.01), and fibrosis (R: - 0.54, p = 0.0008). Betaine levels were significantly decreased in nonalcoholic steatohepatitis (NASH) in comparison with nonalcoholic fatty liver (NAFL). Further replication (n = 51) showed that betaine levels were associated with advanced NAFLD (p = 0.0085), and patients with NASH had a 1.26-fold decrease in betaine levels compared with those with NAFL. The rs1805074 was significantly associated with the disease severity (p = 0.011).
CONCLUSION: NAFLD severity is associated with a state of betaine-insufficiency.

Sookoian, S., et al., Nonalcoholic Steatohepatitis is associated with a state of betaine-insufficiency. Liver Int, 2016.

Serum betaine but not choline is inversely associated with breast cancer risk: a case-control study in China

PURPOSE: Choline and betaine are important for DNA methylation and synthesis, and may affect tumor carcinogenesis. To our knowledge, no previous study has examined the association between serum choline and betaine and breast cancer risk. This study aimed to examine whether serum choline and betaine were inversely associated with breast cancer risk among Chinese women. METHODS: This hospital-based case-control study consecutively recruited 510 breast cancer cases and 518 frequency-matched (age and residence) controls, and blood samples were available for 500 cases and 500 controls. Serum choline and betaine were assayed by high-performance liquid chromatography-tandem mass spectrometry. Multiple unconditional logistic regression was used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs). RESULTS: An inverse association with breast cancer risk was observed for serum betaine (fourth vs first quartile adjusted OR 0.68, 95 % CI 0.47-0.97) and for the ratio of serum betaine to choline (fourth vs first quartile adjusted OR 0.70, 95 % CI 0.48-1.00), but not for serum choline (fourth vs first quartile adjusted OR 0.80, 95 % CI 0.56-1.15). Serum betaine was inversely associated with breast cancer risk in subjects with below-median dietary folate intake (fourth vs first quartile adjusted OR 0.48, 95 % CI 0.30-0.77). CONCLUSIONS: This study suggested that serum betaine but not choline was inversely associated with breast cancer risk. This result needed to be further confirmed by the prospective studies.

Du, Y.F., et al., Serum betaine but not choline is inversely associated with breast cancer risk: a case-control study in China. Eur J Nutr, 2016.

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 prevented fructose-induced NAFLD by regulating LXRalpha/PPARalpha pathway and alleviating ER stress in rats

Betaine has been proven effective in treating nonalcoholic fatty liver disease (NAFLD) in animal models, however, its molecular mechanisms remain elusive. The aims of this study were to explore the mechanisms mediating the anti-inflammatory and anti-lipogenic actions of betaine in fructose-fed rats. In this study, betaine improved insulin resistance, reduced body weight gain and serum lipid levels, and prevented hepatic lipid accumulation in fructose-fed rats. It up-regulated hepatic expression of liver X receptor-alpha (LXRalpha) and peroxisome proliferator-activated receptor-alpha (PPARalpha), with the attenuation of the changes of their target genes, including hepatic carnitine palmitoyl transferase (CPT) 1alpha, glycosylphosphatidylinositol anchored high density lipoprotein binding protein 1, apolipoprotein B, sterol regulatory element-binding protein 1c and adipocyte differentiation-related protein, involved in fatty acid oxidation and lipid storage in these model rats. Furthermore, betaine alleviated ER stress and inhibited acetyl-CoA carboxylase alpha, CPT II, stearoyl-CoA desaturase 1 and fatty acid synthase expression involved in fatty acid synthesis in the liver of fructose-fed rats. Betaine suppressed hepatic gluconeogenesis in fructose-fed rats by moderating protein kinase B -forkhead box protein O1 pathway, as well as p38 mitogen-activated protein kinase and mammalian target of rapamycin activity. Moreover, betaine inhibited hepatic nuclear factor kappa B /nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 inflammasome activation-mediated inflammation in this animal model. These results demonstrated that betaine ameliorated hepatic lipid accumulation, gluconeogenesis, and inflammation through restoring LXRalpha and PPARalpha expression and alleviating ER stress in fructose-fed rats. This study provides the potential mechanisms of betaine involved in the treatment of NAFLD.

Ge, C.X., et al., Betaine prevented fructose-induced NAFLD by regulating LXRalpha/PPARalpha pathway and alleviating ER stress in rats. Eur J Pharmacol, 2015.

Betaine reduces plasma triglycerides and increases butyrylcholinesterase activity

The physiological function of butyrylcholinesterase (EC 3.1.1.8., BChE) is not clearly understood, but a role was suggested in the fat utilization process, resulting in positive correlation between plasma triglyceride (TG) levels and BChE activity. Consequently we tested the hypothesis that regular intake of betaine, a natural compound intervening in the liver TG metabolism could influence the BChE activity. The BChE activity was estimated spectrophotometrically in plasma of rats fed with betaine enriched standard (B) or high-fat diet (HFB). The results confirmed decreased TG plasma levels after betaine treatment independently on the type of diet (0.15+/-0.03 (B) vs. 0.27+/-0.08 (control) mmol/l; p=0.003 and 0.13+/-0.03 (HFB) vs. 0.27+/-0.08 (control) mmol/l; p=0.005). The BChE activity increased significantly with betaine administration, however the change was more distinct in the HFB group. In conclusion, betaine intake led to elevated BChE activity in plasma and this effect was potentiated by the HF diet. Since betaine is in general used as a supplement in the treatment of liver diseases accompanied by TG overload, its impact on the BChE activity in the role of the liver function marker should be taken into account.

Siskova, K., et al., Betaine increases the butyrylcholinesterase activity in rat plasma. Physiol Res, 2015.

Inhibition of insulin fibrillation by osmolytes

We have studied here using a number of biophysical tools the effects of osmolytes, betaine, citrulline, proline and sorbitol which differ significantly in terms of their physical characteristics such as, charge distribution, polarity, H-bonding abilities etc, on the fibrillation of insulin. Among these, betaine, citrulline, and proline are very effective in decreasing the extent of fibrillation. Proline also causes a substantial delay in the onset of fibrillation in the concentration range (50-250 mM) whereas such an effect is seen for citrulline only at 250 mM, and in case of betaine this effect is not seen at all in the whole concentration range. The enthalpies of interaction at various stages of fibrillation process have suggested that the preferential exclusion of the osmolyte and its polar interaction with the protein are important in inhibition. The results indicate that the osmolytes are most effective when added prior to the elongation stage of fibrillation. These observations have significant biological implications, since insulin fibrillation is known to cause injection amyloidosis and our data may help in designing lead drug molecules and development of potential therapeutic strategies.

Choudhary, S., N. Kishore, and R.V. Hosur, Inhibition of insulin fibrillation by osmolytes: Mechanistic Insights. Sci Rep, 2015. 5: p. 17599.

Maternal betaine supplementation during gestation enhances gene expression in skeletal muscle of newborn piglets

Betaine has been widely used in animal and human nutrition to promote muscle growth and performance, yet it remains unknown whether maternal betaine supplementation during gestation affects the metabolic characteristics of neonatal skeletal muscles. In the present study, feeding sows with betaine-supplemented diets throughout gestation significantly up-regulated the expression of mtDNA-encoded OXPHOS genes including COX1, COX2 and ND5, in the muscle of newborn piglets, which was associated with enhanced mitochondrial COX enzyme activity. Concurrently, maternal betaine supplementation increased plasma betaine concentration and muscle expression of methyl transfer enzymes, BHMT and GNMT in offspring piglets. Nevertheless, Dnmt3a was down-regulated at the level of both mRNA and protein, which was associated with hypomethylated mtDNA D-loop region. These results suggest that maternal betaine supplementation during gestation enhances expression of mtDNA-encoded genes through D-loop DNA hypomethylation in skeletal muscle of newborn piglets.

Jia, Y., et al., Maternal betaine supplementation during gestation enhances expression of mtDNA-encoded genes through D-loop DNA hypomethylation in skeletal muscle of newborn piglets. J Agric Food Chem, 2015.

The beneficial effects of betaine on dysfunctional adipose tissue and N6-methyladenosine mRNA methylation requires the AMP-activated protein kinase alpha1 subunit

The current study was conducted to determine whether betaine could improve fatty acid oxidation, mitochondrial function and N6-methyladenosine (m6A) mRNA methylation in adipose tissue in high-fat-induced mice and how AMP-activated protein kinase alpha1 subunit (AMPKalpha1) was involved. AMPKalpha1 knockout mice and wild-type mice were fed either a low-fat diet, high-fat diet or high-fat diet supplemented with betaine in the drinking water for 8weeks. Our results showed that mitochondrial genes (PGC1alpha) and beta-oxidation-related genes (CPT1a) at protein level were increased in wild-type mice supplemented with betaine when compared with those in mice with high-fat diet. Betaine also decreased FTO expression and improved m6A methylation in adipose tissue of wild-type mice with high-fat diet. However, betaine failed to exert the abovementioned effects in AMPKalpha1 knockout mice. In adipocytes isolated from mice with high-fat diet, betaine treatment increased lipolysis and lipid oxidation. Moreover, betaine decreased FTO expression and increased m6A methylation. However, while AMPKalpha1 was knockdown, no remarkable changes in adipocytes were observed under betaine treatment. Our results indicated that betaine supplementation rectified mRNA hypomethylation and high FTO expression induced by high-fat diet, which may contribute to its beneficial effects on impaired adipose tissue function. Our results suggested that the AMPKalpha1 subunit is required for the beneficial effects of betaine on dysfunctional adipose tissue and m6A methylation. These results may provide the foundation for a mechanism that links m6A methylation status in RNA, AMPKalpha1 phosphorylation and dysfunctional adipose tissue induced by high-fat diet.

Zhou, X., et al., The beneficial effects of betaine on dysfunctional adipose tissue and N6-methyladenosine mRNA methylation requires the AMP-activated protein kinase alpha1 subunit. J Nutr Biochem, 2015

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 accumulates in human lens epithelial cells after exposure to ultraviolet A

Compatible organic osmolytes, such as betaine, myoinositol, and taurine, are involved in antioxidant defense, protein stabilization, and stress responses. This osmolyte strategy requires the expression of specific osmolyte transporters such as betaine (BGT-1), myoinositol (SMIT), and taurine (TAUT). In contrast to the kidney, keratinocytes, and neural cells, few studies have examined osmolytes in human lens epithelial cells (HLECs). We examined the expression of mRNA specific for BGT-1, SMIT, and TAUT in HLECs. In comparison to normoosmotic (305 mOsM) controls, there was a 3-5-fold time-dependent reaction of BGT-1, SMIT, and TAUT mRNA levels in HLECs exposed to hyperosmotic stress (405 mOsM). Maximal responses were obtained for BGT-1, SMIT, and TAUT mRNA expression after 3, 24 and 9 h of hyperosmotic exposure, respectively. This expression was correlated with increased osmolyte uptake. In contrast, hypoosmotic (205 mOsM) stimulation led to a significant efflux of osmolytes. Exposure to ultraviolet A (340-400 nm) radiation significantly stimulated osmolyte uptake. Increased osmolyte uptake was associated with upregulation of mRNA steady-state levels for osmolyte transporters in irradiated cells. These results demonstrate that ultraviolet A radiation leads to the accumulation of compatible organic osmolytes in HLECs as hyperosmotic pressure, which can maintain cellular environmental homeostasis.

Wu, D.Y. and J.S. Zhang, Effect of ultraviolet A exposure on transport of compatible organic osmolytes in human lens epithelial cells. Genet Mol Res, 2015. 14(2): p. 5132-40.

Higher betaine intake tended to be associated (only a trend p=0.08) with a decreased risk of coronary heart disease mortality in Japanese men after controlling for covariates.

Background: Dietary intakes of betaine and choline may reduce the risk of cardiovascular disease; however, epidemiologic evidence is limited. Seafood is a rich source of betaine and is a popular traditional food in Japan.Objective: We examined the associations of betaine and choline intakes with cardiovascular disease mortality in a population-based cohort study in Japan.
Methods: Study subjects were 13,355 male and 15,724 female residents of Takayama City, Japan, who were aged ≥35 y and enrolled in 1992. Their diets were assessed by a validated food frequency questionnaire. Deaths from coronary heart disease and stroke were identified from death certificates over 16 y.
Results: During follow-up, we documented 308 deaths from coronary heart disease and 676 deaths from stroke (393 from ischemic and 153 from hemorrhagic strokes). Compared with the lowest quartile, the second, third, and highest quartiles of betaine intake were significantly associated with a decreased risk of mortality from coronary heart disease in men after controlling for covariates. The HRs were 0.58 (95% CI: 0.36, 0.93), 0.62 (95% CI: 0.39, 0.998), and 0.60 (95% CI: 0.37, 0.97), respectively. The trend was not statistically significant (P = 0.08). There was no significant association between betaine intake and the risk of mortality from ischemic stroke. In women, betaine intake was unrelated to mortality from coronary heart disease and stroke (P = 0.32 and 0.73, respectively, for interaction by sex). There was no significant association between choline intake and cardiovascular disease mortality in men or women.
Conclusion: Overall, we found no clear evidence of significant associations between choline and betaine intakes and cardiovascular disease mortality in Japanese men and women.

Nagata, C., et al., Choline and Betaine Intakes Are Not Associated with Cardiovascular Disease Mortality in Japanese Men and Women. The Journal of Nutrition, 2015.

FTO-dependent function of N6-methyladenosine is involved in the hepatoprotective effects of betaine on adolescent mice

Nonalcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease among children and adolescents in the developed world. Betaine, as a methyl donor, recently has been demonstrated to exert its hepatoprotective effects through rectifying the genomic DNA hypomethylation state. However, whether betaine supplementation affects N6-methyladenosine (m6A) mRNA methylation in NAFLD is still unknown. We conducted the current study to investigate the effects of betaine supplementation during adolescence on high-fat diet-induced pathological changes in liver of mice, and we further identified the effects of betaine supplementation on expression of the fat mass and obesity-associated gene (FTO) and hepatic m6A mRNA methylation. Our results showed that betaine supplementation across adolescence significantly alleviated high-fat-induced impairment of liver function and morphology as well as ectopic fat accumulation. Surprisingly, no significant effects on serum TG and NEFA level, as well as fat mass, were observed in mice supplemented with betaine. We also found that high-fat diet upregulated ACC1 and FAS gene expression and downregulated HSL and ATGL gene expression. However, these alterations were rectified by betaine supplementation. Moreover, an m6A hypomethylation state and increased FTO expression were detected in mice fed with high-fat diet, while betaine supplementation prevented these changes. Our results suggested that betaine supplementation during adolescence could protect mice from high-fat-induced NAFLD by decreasing de novo lipogenesis and increasing lipolysis. Furthermore, a novel FTO-dependent function of m6A may involve in the hepatoprotective effects of betaine.

Chen, J., et al., FTO-dependent function of N6-methyladenosine is involved in the hepatoprotective effects of betaine on adolescent mice. J Physiol Biochem, 2015.

Betaine 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 alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet

To assess the effects of betaine on hepatic lipid accumulation and investigate the underlying mechanism, thirty-two male Sprague-Dawley rats weighing 100 (sd 2.50) g were divided into four groups, and started on one of four treatments: basal diet, basal diet with betaine administration, high-fat diet and high-fat diet with betaine administration. The results showed that no significant difference of body weight was found among experimental groups. Compared with high-fat diet-fed rats, a betaine supplementation decreased (P< 0.05) hepatic TAG accumulation induced by high-fat diet, which was also supported by hepatic histology results. Additionally, hepatic betaine-homocysteine methyltransferase activity as well as its mRNA abundance and lecithin level were found increased (P< 0.05) by betaine supplementation in both basal diet-fed rats and high-fat diet-fed rats. Betaine administration in high-fat diet-fed rats exhibited a higher (P< 0.05) activity of hepatic carnitine palmitoyltransferase 1 (CPT1) compared with high-fat diet-fed rats. High-fat diet inhibited (P< 0.05) the gene expression of hepatic PPARalpha and CPT1. However, betaine administration in high-fat diet-fed rats elevated (P< 0.05) the gene expression of PPARalpha and CPT1. Moreover, concentration, gene and protein expressions of hepatic fibroblast growth factor 21 (FGF21) were increased (P< 0.05) in response to betaine administration in high-fat diet group; meanwhile the gene expression of hepatic AMP-activated protein kinase was increased (P< 0.05) as well. The results suggest that betaine administration enhanced hepatic lipid export and fatty acid oxidation in high-fat diet-fed rats, thus effectively alleviating fat accumulation in the liver.

Xu, L., et al., Betaine alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet. Br J Nutr, 2015: p. 1-9

Betaine exhibits tumoricidal effects and acts as a biological response modifier in cancer treatment by inducing apoptosis and cell cycle arrest

OBJECTIVES: To investigate the effects of betaine on HeLa cell growth and apoptosis and molecular mechanisms.
MATERIALS AND METHODS: Concentrations of 0.1, 1.0, 5.0, 20.0, 100.0 mg/ml of betaine were used to evaluate the anticancer efficacy for HeLa cells respectively, and MCF-10A was also detected as a normal diploid cell control.
RESULTS: We found that proliferation of HeLa cells was inhibited significantly upon exposure to increasing betaine levels with the MTT test. The percentage of S phase cells in the low dose groups (< 5mg/ml) were distinctly higher than in high dose groups, and the rates of Sub-G1 phase were the opposite; A high concentration of betaine (>5.0mg/ml) significantly promoted the apoptosis of HeLa cells. SOD activities of the low dose groups were slightly higher than the control group and there were obvious synchronicity and correlation among the expression of promoting apoptosis genes Bax, P53, Caspase 3 and apoptosis suppression gene Bcl-2. In response to an apoptosis-inducing stimulus, p53 and cyclin D1 could be activated with blockage of the cell cycle at G1/S or S/G2 checkpoints.
CONCLUSIONS: Our data showed that betaine could promote HeLa cells proliferation in vitro at low concentrations.In contrast, high concentrations could significantly inhibit cell growth and migration, and induce apoptosis of HeLa cells through caspase 3 signaling and further promoted necrosis. This might imply that betaine exhibits tumoricidal effects and acts as a biological response modifier in cancer treatment by inducing apoptosis and cell cycle arrest in a dose and time-dependent manner.

Guo, Y., et al., Betaine Effects on Morphology, Proliferation, and p53-induced Apoptosis of HeLa Cervical Carcinoma Cells in Vitro. Asian Pac J Cancer Prev, 2015. 16(8): p. 3195-201