One-Carbon Metabolism Nutrients, Genetic Variation, and Diabetes Mellitus.

Diabetes mellitus (DM) affects about 9.3% of the population globally. Hyperhomocysteinemia (HHcy) has been implicated in the pathogenesis of DM, owing to its promotion of oxidative stress, ß-cell dysfunction, and insulin resistance. HHcy can result from low status of one-carbon metabolism (OCM) nutrients (e.g., folate, choline, betaine, vitamin B6, B12), which work together to degrade homocysteine by methylation. The etiology of HHcy may also involve genetic variation encoding key enzymes in OCM. This review aimed to provide an overview of the existing literature assessing the link between OCM nutrients status, related genetic factors, and incident DM. We also discussed possible mechanisms underlying the role of OCM in DM development and provided recommendations for future research and practice. Even though the available evidence remains inconsistent, some studies support the potential beneficial effects of intakes or blood levels of OCM nutrients on DM development. Moreover, certain variants in OCM-related genes may influence metabolic handling of methyl-donors and presumably incidental DM. Future studies are warranted to establish the causal inference between OCM and DM and examine the interaction of OCM nutrients and genetic factors with DM development, which will inform the personalized recommendations for OCM nutrients intakes on DM prevention.

Effects of vitamin B12, folate, and entacapone on homocysteine levels in levodopa-treated Parkinson's disease patients: A randomized controlled study.

INTRODUCTION: Previous studies have suggested a significant increase in plasma homocysteine (Hcy) levels in levodopa-treated Parkinson's disease (PD) patients, and vitamin B12 and folate supplementation may decrease Hcy levels. However, the effects of catechol-O-methyltransferase inhibitors on levodopa-induced increase in Hcy levels were conflicting. The aim of this study was to evaluate whether Hcy levels are increased in levodopa-treated PD patients and to evaluate the effects of vitamin B12 and folate or entacapone on Hcy levels in levodopa-treated PD patients. METHODS: We analyzed and compared plasma Hcy levels in 20 levodopa-naïve PD patients and 42 levodopa-treated PD patients, followed by randomized assignment of 42 levodopa-treated patients to treatment groups with either vitamin B12 and folate, entacapone, or no medication. RESULTS: Plasma Hcy levels in levodopa-treated PD patients were higher than those in the control group, but the difference was not statistical significant (15.25 ± 6.70 and 13.13 ± 4.68, P = 0.216). Patients treated with vitamin B12 and folate had a significant decrease in plasma Hcy levels (P < 0.001). In the entacapone group, Hcy levels were mildly decreased, but the change did not reach statistical significance. CONCLUSION: Levodopa-treated PD patients had higher plasma Hcy than levodopa-naive PD patients. Unlike entacapone, combination supplementation with vitamin B12 and folate was associated with significantly decreased plasma Hcy. We suggest that plasma Hcy levels should be monitored during levodopa treatment, and supplementation with inexpensive vitamin B12 and folate is beneficial for levodopa-treated patients.

Nicorandil reversed homocysteine-induced coronary microvascular dysfunction via regulating PI3K/Akt/eNOS pathway.

OBJECTIVE: Nicorandil exerts a protective effect against coronary microvascular dysfunction in acute myocardial infarction (AMI) patients. However, the mechanism and effect of nicorandil in hyperhomocysteinemia (HHcy) AMI patients remain unclear. METHODS: C57/BL6 mice with mild to moderate HHcy and human coronary artery endothelial cells (HCAECs) cotreated with HHcy (1 mmol/L) for 24 h and hypoxia for 6 h were selected as models. Small animal ultrasound detection was used to compare cardiac function. CD31 immunofluorescence staining and tomato lectin staining were used to assess the number of microcirculation changes in vivo. MTT, tube formation and western blotting assays were used to evaluate the effect of nicorandil on HCAECs and the PI3K/Akt/eNOS pathway. RESULTS: The results showed that nicorandil improved cell viability and p-PI3K/PI3K, p-Akt/Akt, and p-eNOS/eNOS expression in the vitro HHcy and hypoxia models. The beneficial effects of nicorandil on HCAECs could be inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and the nitric oxide synthase (NOS) inhibitor L-NAME. In vivo, nicorandil improved the left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) in the post-HHcy + MI model, and the levels of CD31 and tomato lectin expression were higher in the nicorandil treatment group. The effectiveness of nicorandil was inhibited in the PI3K and L-NAME groups. CONCLUSION: The results suggest that nicorandil improves Hcy-induced coronary microvascular dysfunction through the PI3K/Akt/eNOS signalling pathway.

Vitamin B Supplementation and Nutritional Intake of Methyl Donors in Patients with Chronic Kidney Disease: A Critical Review of the Impact on Epigenetic Machinery.

Cardiovascular morbidity and mortality are several-fold higher in patients with advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD) than in the general population. Hyperhomocysteinemia has undoubtedly a central role in such a prominent cardiovascular burden. The levels of homocysteine are regulated by methyl donors (folate, methionine, choline, betaine), and cofactors (vitamin B6, vitamin B12,). Uremia-induced hyperhomocysteinemia has as its main targets DNA methyltransferases, and this leads to an altered epigenetic control of genes regulated through methylation. In renal patients, the epigenetic landscape is strictly correlated with the uremic phenotype and dependent on dietary intake of micronutrients, inflammation, gut microbiome, inflammatory status, oxidative stress, and lifestyle habits. All these factors are key contributors in methylome maintenance and in the modulation of gene transcription through DNA hypo- or hypermethylation in CKD. This is an overview of the epigenetic changes related to DNA methylation in patients with advanced CKD and ESRD. We explored the currently available data on the molecular dysregulations resulting from altered gene expression in uremia. Special attention was paid to the efficacy of B-vitamins supplementation and dietary intake of methyl donors on homocysteine lowering and cardiovascular protection.

Hyperhomocysteinemia is key for increased susceptibility to PND in aged mice.

BACKGROUND: Postoperative neurocognitive disorder (PND) is a severe postoperative complication with no effective therapy that affects up to 19-52% of senior patients. Age and surgery type have been identified as risk factors. However, what caused the increased risk in the elderly is poorly understood. METHODS: We utilized a PND model in aged mice undergoing experimental laparotomy with general anesthesia to evaluate the causal relationship between hyperhomocysteinemia and increased PND susceptibility. PND was assessed by Novel Object Tasks, Fear Conditioning Tests, and Barnes Maze Tests. Serum homocysteine (Hcy) as well as vitamin B12 and folate acid levels were tested before, immediately after surgery and from day 1 to day 29 after surgery by ELISA. The effectiveness of preventative strategy including diet supplementation of vitamin B12 + folic acid (Vit B12 + FA) and S-adenosylmethionine (SAM) injection targeting hyperhomocysteinemia were also tested. RESULTS: PND in aged mice lasted for at least 2 weeks after experimental laparotomy, which was not observed in young adult mice. Serum Hcy results indicated a significant correlation between postoperative cognitive performance and perioperative Hcy level. Preoperative supplementation with VB12 and folic acid (FA) in the diet or S-adenosylmethionine (SAM) injection reduced perioperative serum Hcy level and inhibited the development of PND in aged mice. CONCLUSIONS: Serum homocysteine accumulation is a fundamental cause for increased susceptibility of PND in aged mice. Preoperative diet supplementation of VitB12 + FA can effectively reduce PND in aged mice, which may be a promising prophylaxis treatment in clinical settings.

Dietary Egg Protein Prevents Hyperhomocysteinemia via Upregulation of Hepatic Betaine-Homocysteine S-Methyltransferase Activity in Folate-Restricted Rats.

BACKGROUND: Hyperhomocysteinemia is associated with increased cardiovascular disease risk. Whole eggs contain several nutrients known to affect homocysteine regulation, including sulfur amino acids, choline, and B vitamins. OBJECTIVE: The aim of this study was to determine the effect of whole eggs and egg components (i.e., egg protein and choline) with respect to 1) homocysteine balance and 2) the hepatic expression and activity of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine ß-synthase (CBS) in a folate-restricted (FR) rat model of hyperhomocysteinemia. METHODS: Male Sprague Dawley rats (n = 48; 6 wk of age) were randomly assigned to a casein-based diet (C; n = 12), a casein-based diet supplemented with choline (C + Cho; 1.3%, wt:wt; n = 12), an egg protein-based diet (EP; n = 12), or a whole egg-based diet (WE; n = 12). At week 2, half of the rats in each of the 4 dietary groups were provided an FR (0 g folic acid/kg) diet and half continued on the folate-sufficient (FS; 0.2 g folic acid/kg) diet for an additional 6 wk. All diets contained 20% (wt:wt) total protein. Serum homocysteine was measured by HPLC and BHMT and CBS expression and activity were evaluated using real-time quantitative polymerase chain reaction, Western blot, and enzyme activity. A 2-factor ANOVA was used for statistical comparisons. RESULTS: Rats fed FR-C exhibited a 53% increase in circulating homocysteine concentrations compared with rats fed FS-C (P < 0.001). In contrast, serum homocysteine did not differ between rats fed FS-C and FR-EP (P = 0.078). Hepatic BHMT activity was increased by 45% and 40% by the EP (P < 0.001) and WE (P = 0.002) diets compared with the C diets, respectively. CONCLUSIONS: Dietary intervention with egg protein prevented elevated circulating homocysteine concentrations in a rat model of hyperhomocysteinemia, due in part to upregulation of hepatic BHMT. These data may support the inclusion of egg protein for dietary recommendations targeting hyperhomocysteinemia prevention.

The Association Between Tea Consumption and Hyperhomocysteine in Chinese Hypertensive Patients.

BACKGROUND: There is no consistent evidence for the relationship between tea-drinking and hyperhomocysteine (hHcy). Because tea-drinking habit and hHcy have prevailed in Chinese hypertensive patients, this study aimed to investigate the association between hHcy and tea consumption in patients with hypertension. METHODS: A total of 335 hypertensive participants were recruited from 7 communities. Demographic characteristics of participants were collected through face-to-face interviews using a standard questionnaire, whereas laboratory data were obtained within 1 week after patient recruitment. Multiple logistic regression analysis was performed to examine the association between tea consumption and hHcy in hypertensive patients. RESULTS: Of the 335 patients, 245 had a tea-drinking habit, and 252 of them were detected with hHcy. A significant association was found between tea consumption and hHcy in hypertensive patients (adjusted odds ratio [OR] = 1.84, 95% confidence interval [CI] = 1.01-3.36, P = 0.048). Subgroup analyses showed that black tea drinking group (adjusted OR = 8.81, 95% CI = 2.74-28.33, P < 0.001) was significantly associated with the risk of hHcy, but not oolong and green tea drinking groups (P > 0.05). Furthermore, consuming a small amount (≤1 cup per day) of green tea was negatively associated with hHcy (adjusted OR = 0.19, 95% CI = 0.07-0.51, P = 0.001), whereas a large intake (>3 cups per day) of green tea was associated with high odds of hHcy (adjusted OR = 5.00, 95% CI = 1.33-18.79, P = 0.02). CONCLUSIONS: These data suggest a hypothesis that selecting green tea or limiting tea consumption might reduce risk of hHcy in hypertensive patients and that warrants further study.

Rehydration during exercise prevents the increase of homocysteine concentrations.

This study aimed to assess the effect of rehydration during and after acute aerobic submaximal exercise on total homocysteine (tHcy) concentrations and related parameters in physically active adult males. Twenty trained males (29.4 ± 7.9 years old) completed four exercise tests: two without rehydration during exercise (NH1 and NH2), one with rehydration during exercise using water (H1) and one with rehydration during exercise using an isotonic sports drink (H2). After finishing the exercise tests, subjects followed a rehydration protocol for 2 h. Serum tHcy, vitamin B12, folate, creatine and creatinine were analysed before, after and at 2, 6 and 24 h after exercise. Data were analysed with and without correcting for haemoconcentration to assess the changes in tHcy related. The methylenetetrahydrofolate reductase (MTHFR) 677TT genotype was also analysed. THcy (uncorrected by haemoconcentration) increased significantly after exercise (P < 0.05) in the NH1 and NH2 tests [mean increase ± SD: 1.55 ± 0.33 (15.18%) and 1.76 ± 0.25 (17.69%) µmol/L, respectively], while no significant differences were found in the H1 and H2 tests [mean increase: 0.65 (6.29%) and 0.90 (8.69%) µmol/L, respectively]. The increase was partly due to haemoconcentration and partly due to the metabolism underlying acute exercise. THcy concentrations recovered to baseline after 24 h in all tests. In conclusion, adequate rehydration during acute aerobic exercise using either water or a sports drink maintains tHcy concentrations at baseline and for up to 2 h after exercise in physically active male adults and prevents further increases when compared to no rehydration.

Efficacy of Folic Acid and Vitamin B12 Replacement Therapies in the Reduction of Adverse Effects of Isotretinoin: A Randomized Controlled Trial.

Previous studies have reported elevated homocysteine levels and folic acid and/or vitamin B12 deficiencies after isotretinoin therapy, which increase the risk of cardiovascular and neuropsychiatric disorders. Homocysteine is metabolized in the liver, a process requiring folate and vitamin B12. We conducted a randomized controlled trial to investigate whether folate and vitamin B12 replacement therapy with isotretinoin would be useful for preventing hyperhomocysteinemia. A total of 66 patients with acne were randomized into two groups: group A took isotretinoin, folic acid, and vitamin B12, whereas group B took isotretinoin alone. Treatment was continued for 2 months. Blood homocysteine, folic acid, and vitamin B12 levels were measured before and after treatment. In group A, a significant decrease in homocysteine level was observed after treatment (P=.0004), although it was still within the normal range. Folic acid and vitamin B12 levels significantly increased (P=.0026 and P=.0002, respectively). In group B, no significant changes were observed in the levels of homocysteine and vitamin B12, but folic acid levels decreased significantly (P=.02). We concluded that folic acid and vitamin B12 supplementation during isotretinoin therapy could be useful for preventing folate deficiency and improving blood homocysteine levels; this might as a result reduce the risks for cardiovascular and neuropsychiatric disorders in patients taking isotretinoin.

Knockdown of Herp alleviates hyperhomocysteinemia mediated atherosclerosis through the inhibition of vascular smooth muscle cell phenotype switching.

BACKGROUND: Phenotypic switching of vascular smooth muscle cells (VSMCs) plays a key role in atherosclerosis. We aimed to investigate whether Homocysteine-responsive endoplasmic reticulum protein (Herp) was involved in VSMC phenotypic switching and affected atheroprogression. METHODS: To assess the role of Herp in homocysteine (Hcy)-associated atherosclerosis, Herp-/- and LDLR-/- double knockout mice were generated and fed with a high methionine diet (HMD) to induce Hyperhomocysteinemia (HHcy). Atherosclerotic lesions, cholesterol homeostasis, endoplasmic reticulum (ER) stress activation, and the phenotype of VSMCs were assessed in vivo. We used siRNAs to knockdown Herp in cultured VSMCs to further validate our findings in vitro. RESULTS: HMD significantly activated the activating transcription factor 6 (ATF6)/Herp arm of ER stress in LDLR-/- mice, and induced the phenotypic switch of VSMCs, with the loss of contractile proteins (SMA and calponin) and an increase of OPN protein. Herp-/-/LDLR-/- mice developed reduced atherosclerotic lesions in the aortic sinus and the whole aorta when compared with LDLR-/- mice. However, Herp deficiency had no effect on diet-induced HHcy and hyperlipidemia. Inhibition of VSMC phenotypic switching, decreased proliferation and collagen accumulation were observed in Herp-/-/LDLR-/- mice when compared with LDLR-/- mice. In vitro experiments demonstrated that Hcy caused VSMC phenotypic switching, promoted cell proliferation and migration; this was reversed by Herp depletion. We achieved similar results via inhibition of ER stress using 4-phenylbutyric-acid (4-PBA) in Hcy-treated VSMCs. CONCLUSION: Herp deficiency inhibits the phenotypic switch of VSMCs and the development of atherosclerosis, thus providing novel insights into the role of Herp in atherogenesis.

Homocysteine as a non-classical risk factor for atherosclerosis in relation to pharmacotherapy of type 2 diabetes mellitus.

AIMS: The aim of our study was to evaluate which of the pharmacotherapeutic methods that are frequently used to treat type 2 diabetes is associated with the most beneficial profile in relation to pro-atherogenic homocysteine levels. PATIENTS AND METHODS: We measured the serum homocysteine level in 182 patients with type 2 diabetes treated with metformin (89), treated with insulin in combination with metformin (31), receiving sulfonylureas (31) and treated conventionally with insulin (31). The total homocysteine levels in the serum were assayed. To exclude the influence of selected metabolic and anthropometric factors on the differences between the examined groups, multivariate analysis of covariance was used (ANCOVA). In this analysis, serum homocysteine concentration was the dependent variable, while diabetes duration, waist circumference, HbA1c, 1,5-anhydro-D-glucitol, fasting glycaemia and peptide C were used as covariates. RESULTS: The serum homocysteine levels in patients treated with insulin in monotherapy were significantly higher than what was observed in the metformin treated subjects and in the patients receiving insulin combined with metformin. The analysis of covariance also confirmed that the differences between the therapeutic groups were affected by waist circumference and the C-peptide levels. CONCLUSION: We conclude that conventional insulin therapy may have a negative effect on pro-atherogenic homocysteine levels in patients with type 2 diabetes. This study revealed that pro-atherogenic homocysteine levels may not only be modified by pharmacotherapy of type 2 diabetes, but also by beta cell secretory function and abdominal obesity.

Higher intake of fish and fat is associated with lower plasma s-adenosylhomocysteine: a cross-sectional study.

Several B-vitamins act as co-factors in one-carbon metabolism, a pathway that plays a central role in several chronic diseases. However, there is a lack of knowledge of how diet affects markers in one-carbon metabolism. The aim of this study was to explore dietary patterns and components associated with one-carbon metabolites. We hypothesized that intake of whole-grains and fish would be associated with lower Hcy, and higher SAM:SAH ratio due to their nutrient content. We assessed dietary information using a four-day dietary record in 118 men and women with features of the metabolic syndrome. In addition we assessed whole-blood fatty acid composition and plasma alkylresorcinols. Plasma s-adenosylmethionine (SAM), s-adenosylhomocysteine (SAH), homocysteine (Hcy) and vitamin B12 was included as one-carbon metabolism markers. We used principal component analysis (PCA) to explore dietary patterns and multiple linear regression models to examine associations between dietary factors and one-carbon metabolites. PCA separated subjects based on prudent and unhealthy dietary patterns, but the dietary pattern score was not related to the one-carbon metabolites. Whole grain intake was found to be inversely associated to plasma Hcy (-4.7% (-9.3; 0.0), P=.05) and total grain intake tended to be positively associated with SAM and SAH (2.4% (-0.5; 5.5), P=.08; 5.8% (-0.2; 12.1), P=.06, respectively, per SD increase in cereal intake). Fish intake was inversely associated with plasma Hcy and SAH concentrations (-5.4% (-9.7; -0.8), P=.02 and -7.0% (-12.1; -1.5), P=.01, respectively) and positively associated with the SAM:SAH ratio (6.2% (1.6; 11.0), P=.008). In conclusion, intake and fish and whole-grain appear to be associated with a beneficial one-carbon metabolism profile. This indicates that dietary components could play a role in regulation of one-carbon metabolism with a potential impact on disease prevention.

Genetic polymorphisms and folate status.

Moderate hyperhomocysteinemia-induced low folate status is an independent risk factor for cardiovascular disease, dementia, and depression. Folate is an essential cofactor in the one-carbon metabolism pathway and is necessary in amino acid metabolism, purine and thymidylate synthesis, and DNA methylation. In the folate cycle and homocysteine metabolism, folate, vitamin B12, vitamin B6, and vitamin B2 are important cofactors. Many enzymes are involved in folate transport and uptake, the folate pathway, and homocysteine (Hcy) metabolism, and various polymorphisms have been documented in these enzymes. Serum folate and total Hcy (tHcy) levels are influenced by folate intake and genetic polymorphisms in 5,10-methylenetertahydrofolate reductase (MTHFR) such as C677T. The prevalence of the MTHFR 677TT genotype varies across ethnic groups and regions, with a frequency of approximately 15% in Japanese populations. Individuals with the TT genotype have significantly higher tHcy levels and lower folate levels in serum than those with the CT and TT genotypes. However, administration of folic acid has been shown to eliminate these differences. Moreover, data have suggested that interventions based on genotype may be effective for motivating individuals to change their lifestyle and improve their nutrition status. Accordingly, in this review, we discuss the effects of MTHFR C677T polymorphisms on serum tHcy and folate levels with folic acid intervention and evaluate approaches for overcoming folic acid deficiency and related symptoms.

Prenatal Hyperhomocysteinemia Impairs Hypothalamic Regulation of Reproductive Cycles in Rat Progeny.

Effects of prenatal hyperhomocysteinemia on hypothalamic regulation of estrous cycles were studied in female rats. In mature rats exposed to prenatal hyperhomocysteinemia, changes in the catecholamine content in hypothalamic areas responsible for the formation of the preovulatory surge of gonadotropin-releasing hormone were revealed: the level of norepinephrine in the medial preoptic area decreased and concentration of dopamine in the median eminence with arcuate nuclei increased. Administration of melatonin attenuated the observed changes, which can be related to neuroprotective effects of this hormone determined by its antioxidant properties.

Potential Links between Impaired One-Carbon Metabolism Due to Polymorphisms, Inadequate B-Vitamin Status, and the Development of Alzheimer's Disease.

Alzheimer's disease (AD) is the major cause of dementia and no preventive or effective treatment has been established to date. The etiology of AD is poorly understood, but genetic and environmental factors seem to play a role in its onset and progression. In particular, factors affecting the one-carbon metabolism (OCM) are thought to be important and elevated homocysteine (Hcy) levels, indicating impaired OCM, have been associated with AD. We aimed at evaluating the role of polymorphisms of key OCM enzymes in the etiology of AD, particularly when intakes of relevant B-vitamins are inadequate. Our review indicates that a range of compensatory mechanisms exist to maintain a metabolic balance. However, these become overwhelmed if the activity of more than one enzyme is reduced due to genetic factors or insufficient folate, riboflavin, vitamin B6 and/or vitamin B12 levels. Consequences include increased Hcy levels and reduced capacity to synthetize, methylate and repair DNA, and/or modulated neurotransmission. This seems to favor the development of hallmarks of AD particularly when combined with increased oxidative stress e.g., in apolipoprotein E (ApoE) ε4 carriers. However, as these effects can be compensated at least partially by adequate intakes of B-vitamins, achieving optimal B-vitamin status for the general population should be a public health priority.

Folic Acid Supplementation and the Risk of Cardiovascular Diseases: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Results from observational and genetic epidemiological studies suggest that lower serum homocysteine levels are associated with lower incidence of cardiovascular disease (CVD). Numerous randomized controlled trials have investigated the efficacy of lowering homocysteine with folic acid supplementation for CVD risk, but conflicting results have been reported. METHODS AND RESULTS: Three bibliographic databases (Medline, Embase, and the Cochrane Database of Systematic Reviews) were searched from database inception until December 1, 2015. Of the 1933 references reviewed for eligibility, 30 randomized controlled trials involving 82 334 participants were included in the final analysis. The pooled relative risks of folic acid supplementation compared with controls were 0.90 (95% CI 0.84-0.96; P=0.002) for stroke, 1.04 (95% CI 0.99-1.09; P=0.16) for coronary heart disease, and 0.96 (95% CI 0.92-0.99; P=0.02) for overall CVD. The intervention effects for both stroke and combined CVD were more pronounced among participants with lower plasma folate levels at baseline (both P<0.02 for interaction). In stratified analyses, a greater beneficial effect for overall CVD was seen in trials among participants without preexisting CVD (P=0.006 for interaction) or in trials with larger reduction in homocysteine levels (P=0.009 for interaction). CONCLUSIONS: Our meta-analysis indicated a 10% lower risk of stroke and a 4% lower risk of overall CVD with folic acid supplementation. A greater benefit for CVD was observed among participants with lower plasma folate levels and without preexisting CVD and in studies with larger decreases in homocysteine levels. Folic acid supplementation had no significant effect on risk of coronary heart disease.

Homocysteine Levels in Parkinson's Disease: Is Entacapone Effective?

Plasma homocysteine (Hcy) levels may increase in levodopa-treated patients with Parkinson's disease (PD) as a consequence of levodopa methylation via catechol-O-methyltransferase (COMT). Results from previous studies that assessed the effect of COMT inhibitors on levodopa-induced hyperhomocysteinemia are conflicting. We aimed to evaluate the effects of levodopa and entacapone on plasma Hcy levels. A hundred PD patients were enrolled to the study and divided into three treatment groups (group I: levodopa and/or dopamine agonists; group II: levodopa, entacapone, and/or a dopamine agonist; and group III: dopamine agonist alone). We measured the serum B12, folic acid, and Hcy levels in all patients. There were no statistically significant differences between groups in terms of modified Hoehn and Yahr stages, Unified Parkinson's Disease Rating Scale II/III, Standardized Mini-Mental Test scores, and serum vitamin B12 and folic acid levels. Plasma median Hcy levels were found above the normal laboratory values in groups I and II, but they were normal in group III. However, there was no statistically significant difference in plasma Hcy levels between groups. Our results showed that levodopa treatment may cause a slight increase in the Hcy levels in PD compared with dopamine agonists and that COMT inhibitors may not have a significant effect on preventing hyperhomocysteinemia.

[IMPROVING THE EFFICACY OF THERAPY FOR PATIENTS WITH MYOCARDIAL INFARCTION COMPLICATED BY CIRCULATORY FAILURE].

The effectiveness of drug remaxol inclusion in the scheme of treatment of patients with myocardial infarction on the background of degree III - III acute cardiac insufficiency was evaluated by the analysis of clinical and laboratory data of 126 patients with newly diagnosed acute myocardial infarction including ST-segment elevation on the background of acute cardiac insufficiency. Depending on the regimen, patients were divided into two groups. The first (control) group included 60 patients who received conventional thrombolytic therapy; the second (main) group included 66 patients which, after thrombolytic therapy, received remaxol (single daily intravenous administration, 400 mL at 3 - 4 mL/min rate) with controlled central venous pressure, arterial pressure, and diuresis. The course lasted for 3 - 5 days, depending on the severity of condition. A high efficiency of the treatment regimen including remaxol was established as characterized by more rapid (in comparison to conventional therapy) stabilization of disturbed systemic hemodynamics and recovery of weakened myocardial contractility, decreased risk of cardiac arrhythmias, and relieved hyperhomocysteinemia that, in turn, reduced the risk of complications such as thrombosis and thromboembolism.

Creatine supplementation prevents hyperhomocysteinemia, oxidative stress and cancer-induced cachexia progression in Walker-256 tumor-bearing rats.

The purpose of this study was to investigate (1) the impact of tumor growth on homocysteine (Hcy) metabolism, liver oxidative stress and cancer cachexia and, (2) the potential benefits of creatine supplementation in Walker-256 tumor-bearing rats. Three experiments were conducted. First, rats were killed on days 5 (D5), 10 (D10) and 14 (D14) after tumor implantation. In experiment 2, rats were randomly assigned to three groups designated as control (C), tumor-bearing (T) and tumor-bearing supplemented with creatine (TCr). A life span experiment was conducted as the third experiment. Creatine was supplied in drinking water for 21 days (8 g/L) in all cases. Tumor implantation consisted of a suspension of Walker-256 cells (8.0 × 10(7) cells in 0.5 mL of PBS). The progressive increase (P < 0.05) in tumor mass coincided with a progressively lower body weight and higher hepatic oxidative stress; plasma Hcy concentration was 80 % higher (P < 0.05) by 10 days of tumor implantation. Impaired Hcy metabolism was evidenced by decreased hepatic betaine-homocysteine methyltransferase (Bhmt), glycine N-methyltransferase (Gnmt) and cystathionine beta synthase (CBS) gene expression. In contrast, creatine supplementation promoted a 28 % reduction of tumor weight (P < 0.05). Plasma Hcy (C 6.1 ± 0.6, T 10.3 ± 1.5, TCr 6.3 ± 0.9, µmol/L) and hepatic oxidative stress were lower in the TCr group compared to T. Creatine supplementation was unable to decrease Hcy concentration and to increase SAM/SAH ratio in tumor tissue. These data suggest that creatine effects on hepatic impaired Hcy metabolism promoted by tumor cell inoculation are responsible to decrease plasma Hcy in tumor-bearing rats. In conclusion, Walker-256 tumor growth is associated with progressive hyperhomocysteinemia, body weight loss and liver oxidative stress in rats. Creatine supplementation, however, prevented these tumor-associated perturbations.

Prevention of alcohol-induced hyperhomocysteinemia by suppression of SHP.

Chronic alcohol consumption is a major public health problem that frequently leads to the development of liver steatosis, fibrosis, and eventually cirrhosis and hepatocellular carcinoma. Hyperhomocysteinemia is a pathological consequence of alcoholic liver disease (ALD) and is attributed to hepatic endoplasmic reticulum (ER) stress and insulin resistance. However, the regulatory function of nuclear receptors in ALD associated with dysregulation of homocysteine metabolism remains largely unknown. Nuclear receptor small heterodimer partner (SHP, NROB2) is a pleiotropic transcriptional repressor involved in regulating various metabolic path-ways in the liver. This study investigated a critical role of SHP in alcohol-induced hyperhomocysteinemia. . The expression and enzymatic activities of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine y -lyase (CTH) were significantly increased in the liver of SHP- knockout (SKO) mice as compared to the wild-type mice. The substrates of BHMT and CTH, such as betaine, choline and cystathionine, were decreased in SKO liver while their products including hydrogen sulfide and cysteine were increased. However, methionine and homocysteine were not altered by SHP- deficiency, suggesting that the methionine cycle is activated in SKO mice. Forkhead box A (FOXA)- binding site was identified in both the BHMT and CTH promoters. Luciferase assay demonstrated that FOXAI, but not FOXA2, activated both BHMT and CTH promoters through the FOXA-binding site. Overexpression of FOXA1 induced BHMT and CTH expression in Hepal-6 cells, which was inhibited by SHP coexpression. Consistently, alcohol-induced hyperhomocysteinemia, and homocysteine-induced hepatic ER stress and glucose intolerance were abrogated in SKO mice. These novel findings identified SHP and FOXA1 as important regulators of hepatic homocysteine metabolism. Because hyper-homocysteinemia is a risk factor for cardiovascular disease and insulin resistance, and is often associated with ALD and metabolic syndrome, SHP and FOXA1 could be used as potential targets for hyperhomocysteinemia and its related diseases. Taken together, these results shed light on the regulatory mechanism of homocysteine metabolism in the liver.