The effect of diet and alcohol on the development of folate deficiency in the rat

Fetal alcohol spectrum disorders: Genetic and epigenetic mechanisms

Fetal alcohol spectrum disorders (FASD) are a consequence of prenatal alcohol exposure (PAE). The etiology of the complex FASD phenotype with growth deficit, birth defects, and neurodevelopmental impairments is under extensive research. Both genetic and environmental factors contribute to the wide phenotype: chromosomal rearrangements, risk and protective alleles, environmental-induced epigenetic alterations as well as gene-environment interactions are all involved. Understanding the molecular mechanisms of PAE can provide tools for prevention or intervention of the alcohol-induced developmental disorders in the future. By revealing the alcohol-induced genetic and epigenetic alterations which associate with the variable FASD phenotypes, it is possible to identify biomarkers for the disorder. This would enable early diagnoses and personalized support for development of the affected child.

Effect of folic acid in prenatal alcohol induced behavioral impairment in Swiss albino mice

Background

Alcohol is a potent teratogen inducing oxidative stress as well as a massive wave of apoptosis in the developing brain as well as oxidative stress. It affects brain including cerebellum, hippocampus and cerebral cortex resulting into motor and cognitive deficits. Alcohol depletes folic acid from the body which is essential for synthesis of DNA, RNA and protein during cell division and proved to prevent many brain related malformations.

Purpose

The objective of the present study was to study whether folic acid reduces behavioral impairments that were induced by prenatal exposure to ethanol in mice.

Methods

Pregnant mice were divided into different experimental groups. Group I termed as control receiving distilled water, group II received ethanol, group III ethanol and folic acid and group IV folic acid only from gestational days 6 to 15. The dams were allowed to deliver their offspring naturally and until weaning the pups remained with their natural mothers. At the age of 8-9 weeks, they were subjected to battery of various behavioral tests.

Results

The alcohol exposed dams showed decreased motor activity in open field test and decreased exploration and increased anxiety in elevated maze test as compared to controls. Folic acid administration reduced the intensity of these effects of alcohol in mice.

Conclusion

The exposure to alcohol in utero produces long lasting effect on the developing pharmacological character of brain affecting postnatal behavioral expression which may be reduced by prenatal folic acid administration.

Epigenetic medicine and fetal alcohol spectrum disorders

Epigenetic medicine is still in its infancy. To date, only a handful of diseases have documented epigenetic correlates upstream of gene regulation including cancer, developmental syndromes and late-onset diseases. The finding that epigenetic markers are dynamic and heterogeneous at tissue and cellular levels, combined with recent identification of a new form of functionally distinct DNA methylation has opened a wider window for investigators to pry into the epigenetic world. It is anticipated that many diseases will be elucidated through this epigenetic inquiry. In this review, we discuss the normal course of DNA methylation during development, taking alcohol as a demonstrator of the epigenetic impact of environmental factors in disease etiology, particularly the growth retardation and neurodevelopmental deficits of fetal alcohol spectrum disorders.

Anemia em catadores de material reciclável que utilizam carrinho de propulsão humana no município de Santos

OBJETIVO: Estimar a prevalência de anemia e analisar os fatores de risco a ela associados nos catadores de material reciclável que utilizam carrinho de propulsão humana do município de Santos - São Paulo. MÉTODO: Estudo transversal com 253 catadores foi realizado em julho de 2005. A coleta de informações foi feita por meio de questionário com informações sobre características individuais, ocupacionais e dietéticas. Foi realizada avaliação antropométrica e coletado sangue venoso para hemograma completo e sorologias de HIV, HCV, HBV e sífilis. A análise estatística foi feita por análise uni e multivariada (regressão logística), relacionando a anemia aos fatores de risco. RESULTADOS: A prevalência de anemia foi de 38,3%. As variáveis que mostraram associação independente com anemia no modelo multivariado foram: sexo (OR 4,11; IC95%: 1,56-10,87), infecção pelo HIV (OR 9,23; IC95%: 2,93-29,1), IMC (OR 0,21; IC95%: 0,07-0,64), anos de trabalho como catador (OR 4,54; IC95%: 1,29-16,0), consumo de leite (OR 0,36; IC95%: 0,16-0,81) e de proteína animal (OR 0,39; IC95%: 0,15-0,97). CONCLUSÃO: A prevalência de anemia entre catadores de material reciclável é elevada mesmo após a obrigatoriedade de adição de ferro nas farinhas de trigo e milho. Os catadores são excluídos das ações de proteção à saúde do trabalhador, previstas na legislação. Ações de saúde dirigidas a essa categoria profissional devem ser implementadas, garantindo a acessibilidade aos serviços de saúde.

Syndromes, disorders and maternal risk factors associated with neural tube defects (VI)

Neural tube defects (NTDs) may be associated with syndromes, disorders, and maternal and fetal risk factors. This article provides a comprehensive review of the syndromes, disorders, and maternal and fetal risk factors associated with NTDs, including maternal fumonisin consumption, periconceptional zinc deficiency, parental occupational exposure and residential proximity to pesticides, lower socioeconomic status, fetal alcohol syndrome, mutations in the VANGL1 gene, human athymic Nude/SCID fetus, and single nucleotide polymorphism in the NOS3 gene. NTDs associated with these syndromes, disorders, and maternal and fetal risk factors are a rare but important cause of NTDs. The recurrence risk and the preventive effect of maternal folic acid intake in NTDs associated with syndromes, disorders and maternal risk factors may be different from those of nonsyndromic multifactorial NTDs. Perinatal diagnosis of NTDs should alert doctors to the syndromes, disorders, and maternal and fetal risk factors associated with NTDs, and prompt thorough etiologic investigation and genetic counseling.

Effect of folic acid on prenatal alcohol-induced modification of brain proteome in mice

Maternal alcohol consumption during pregnancy can induce central nervous system abnormalities in the fetus, and folic acid supplementation can reverse some of the effects. The objective of the present study was to investigate prenatal alcohol exposure-induced fetal brain proteome alteration and the protective effect of folic acid using proteomic techniques. Alcohol (5.0 g/kg) was given intragastrically from gestational day (GD) 6 to 15, with or without 60.0 mg folic acid/kg given intragastrically during GD 1-16 to pregnant Balb/c mice. The control group received distilled water only. Results of litter evaluation on GD 18 showed that supplementation of folic acid reversed the prevalence of microcephaly induced by alcohol. Proteomic analysis indicated that, under the dosage of the present investigation, folic acid mainly reversed the alcohol-altered proteins involved in energy production, signal pathways and protein translation, which are all important for central nervous system development.

Effects of folinic acid and Vitamin B12 on ethanol-induced developmental toxicity in mouse

The objective of this study was to assess whether combined supplementation of folinic acid (FA) and Vitamin B(12) (VB(12)) could suppress ethanol-induced developmental toxicity better than FA alone in mouse embryos cultured in vitro. In this study, exposure to 4.0mg/ml ethanol for 48 h yielded growth retardation and various malformations of the embryos. FA (10(-5), 10(-4)mol/l) or VB(12) (10(-6), 10(-5)mol/l) alone supplementation improved the growth parameters moderately, however combined supplementation of the two vitamins (10(-5)mol/l FA plus 10(-6)mol/l VB(12), 10(-5)mol/l FA plus 10(-5)mol/l VB(12), 10(-4)mol/l FA plus 10(-6)mol/l VB(12) and 10(-4)mol/l FA plus 10(-5)mol/l VB(12)) showed better protective effects, including both the growth and development parameters of the embryos, than either vitamin alone at the same dosage. The present investigation indicated that combined supplementation of folic acid and VB(12) might be a better choice than folic acid alone in the prevention of ethanol-induced birth defects.

The maternal combined supplementation of folic acid and Vitamin B(12) suppresses ethanol-induced developmental toxicity in mouse fetuses

Maternal ethanol consumption during pregnancy can induce developmental defects in the fetus. The objective of this study was to assess whether combined supplementation of folic acid (FA) and Vitamin B(12) (VB(12)) in dams would suppress ethanol-induced developmental toxicity in CD-1 mice. Ethanol (5.0 g/kg) was given intragastrically from gestational day (GD) 6 to GD15. Vitamin supplementation groups were additionally given 60.0 mg/kg FA, 1.0 mg/kg VB(12), or 60.0 mg/kg FA+1.0 mg/kg VB(12) during GD1-16. The control group received distilled water only. Results of litter evaluation on GD18 showed that combined supplementation of FA and VB(12) ameliorated many of the adverse effects of ethanol. In contrast, the single vitamin supplementation groups showed little or no amelioration. These results suggest that combined supplementation of FA and VB(12) was more effective than each vitamin toward suppressing ethanol-induced developmental toxicity in CD-1 mice.

Effects of moderate alcohol consumption on folate and vitamin B(12) status in postmenopausal women

BACKGROUND

Although alcohol intake has been positively associated with breast cancer risk in epidemiologic studies, a causal relationship has not been established, and the mechanisms mediating this association are speculative. Alcohol may act through altered status of folate and vitamin B(12), two vitamins required for DNA methylation and nucleotide synthesis, and thus cell integrity. Although the effects of heavy alcohol intake on folate and vitamin B(12) status have been well-documented, few studies have addressed the effects of moderate alcohol intake in a controlled setting.

OBJECTIVE

The objective of this study was to determine the effects of moderate alcohol intake on folate and vitamin B(12) status in healthy, well-nourished, postmenopausal women.

DESIGN

The study design was a randomized, diet-controlled crossover intervention. Postmenopausal women (n=53) received three 8-week alcohol treatments in random order: 0, 15, and 30 g/day. Treatment periods were preceded by 2-5-week washout periods. Blood collected at baseline and week 8 of each treatment period was analyzed for serum folate, vitamin B(12), homocysteine (HCY), and methylmalonic acid (MMA) concentrations.

RESULTS

After adjusting for body mass index (BMI), a significant 5% decrease was observed in mean serum vitamin B(12) concentrations from 0 to 30 g of alcohol/day (461.45+/-30.26 vs 440.25+/-30.24 pg/ml; P=0.03). Mean serum HCY concentrations tended to increase by 3% from 0 to 30 g of alcohol/day (9.44+/-0.37 vs 9.73+/-0.37 micromol/l; P=0.05). Alcohol intake had no significant effects on serum folate or MMA concentrations.

CONCLUSIONS

Among healthy, well-nourished, postmenopausal women, moderate alcohol intake may diminish vitamin B(12) status.

Effect of maternal methionine pre-treatment on alcohol-induced exencephaly and axial skeletal dysmorphogenesis in mouse fetuses

Alcohol is known to induce folate deficiency and impair methionine synthase activity. Exogenous folic acid (FA) administered periconceptionally has been shown to prevent the first occurrence and recurrence of neural tube defects (NTD) in humans. Since folate, vitamin B(12) and methionine are metabolically interrelated, it was decided to determine the effect of methionine pre-treatment on alcohol-induced NTD and axial skeletal defects in mouse embryos. Following administration of a single dose of 70 or 150 mg/kg of methionine, 0.03 ml/g body weight of ethanol solution (25% v/v of absolute alcohol in saline) was injected intraperitoneally into pregnant mice at critical stages of neural tube development. The controls were either non-treated or saline treated and pair-fed and pair-watered. Fetuses were collected on gestation day 18. Alcohol and methionine plus alcohol numerically enhanced embryonic resorption and induced a significant reduction in fetal body weight. Alcohol alone caused a 3-fold increase in the background frequency of exencephaly in gestation days 7 and 8 treatment groups. The low dose of methionine only numerically reduced the spontaneous exencephaly. Pre-treatment with methionine only produced a numerical but not statistically significant reduction in alcohol-induced exencephaly. The higher dose of methionine did not produce a particularly beneficial effect on embryonic survival, fetal body weight and occurrence of exencephaly. Alcohol-induced cleft palate and limb malformations were ameliorated by methionine pre-treatment. Craniofacial skeleton, vertebrae and ribs were extensively malformed both in the alcohol and methionine plus alcohol groups indicating a lack of rescue effects of methionine. Whereas supernumerary ribs and extra sternal ribs were augmented by methionine, occipitalization of the atlas vertebra was a malformation unique to the pre-treatment group. Plasma levels of several amino acids including that of methionine were significantly lowered by alcohol. Pre-treatment with methionine produced a dose dependent enhancement of only methionine concentration. These data suggest that pre-administration of methionine only rescues mouse embryos of certain non-neural malformations and that the lack of ameliorative effect on NTD and axial skeletal defects may be due to the fact that alcohol lowers the concentration of a number of amino acids and therefore, supplementation should comprise a mixture of these amino acids and possibly FA and vitamin B(12).

[Dietary folates--a timely review. Stability, physiological significance, bioavailability, analytical determination methods, effect of food handling]

Because of the unequal and, in some instances, low stability of different folate vitamers against extreme conditions the analytical determination of folate and the estimation of folate losses in food processing and preparation cause considerable difficulties. HPLC allows determination of the native folate derivative patterns. As the bioavailability of folates is influenced by a variety of factors and different methods were employed for assessing bioavailability there is a considerable inconsistency in the results of these studies. Folates labeled with radioactive or stable isotopes provide new approaches to metabolic and bioavailability studies.

Effect of chronic alcohol ingestion on hepatic folate distribution in the rat

The mechanism by which ethanol impairs folate metabolism remains uncertain. In the present study, we used our new technique (affinity/HPLC) for folate analysis to study the effect of chronic alcohol ingestion on the content and distribution of folates in livers. Twelve male Sprague-Dawley rats (180 g) were divided into two groups, and fed for 4 weeks with Lieber-DeCarli semi-liquid isocaloric diets, with and without 5% ethanol. Livers were extracted in boiling, pH 9.3 borate buffers containing ascorbate/dithioerythritol. Folates in the supernatant fractions were purified by affinity chromatography and analyzed using ion pair high performance liquid chromatography. The data obtained showed that hepatic folate distribution in alcohol-treated rats differed from that of control animals in two ways. Livers from the ethanol-fed rats, when compared with those from control rats, exhibited increases in the percent concentrations of methylated tetrahydrofolates (21.46 +/- 2.21 vs 14.8 +/- 1.23), decreases in the percent concentrations of formylated tetrahydrofolates (25.62 +/- 4.02 vs 46.18 +/- 2.65) and higher concentrations of unsubstituted tetrahydrofolates (52.91 +/- 3.84 vs 38.88 +/- 2.50). In addition, alcohol ingestion was associated with longer glutamate chains of the folate molecules, characterized by lower relative concentrations of pentaglutamyl folates (29 vs 48%), and higher relative concentrations of hexa- and heptaglutamyl folates (55 vs 46% and 15 vs 6%) when compared with controls. The data are discussed in relation to the possibility that alcohol exerts its effect through: (1) inhibition of B12-dependent methyl transfer from methyltetrahydrofolate to homocysteine; (2) diversion of formylated tetrahydrofolates toward serine synthesis; and (3) interaction of acetaldehyde with tetrahydrofolates, thereby interfering with folate coenzyme metabolism.

Increased urinary folate excretion and decreased plasma folate levels in the rat after acute ethanol treatment

A common complication of chronic alcohol abuse is folic acid deficiency, which can result from poor dietary intake and from a direct effect of ethanol on folate metabolism, such as the acute decrease in serum folate levels. Ethanol (4 g/kg body weight) was administered orally to male Sprague-Dawley rats to study the rat as a suitable animal model for the acute effects of ethanol. The concentration of folate in the urine, determined by Lactobacillus casei assay, as well as the amount of urinary folate excretion were markedly increased 4 hr after ethanol administration. After 14 hr, the total plasma folate level was significantly depressed to 50% of control levels. No significant changes were observed in the total folate levels in the liver and red cell nor in the levels of individual hepatic folate monoglutamate derivatives determined by high pressure liquid chromatography assay. These results indicate that acute ethanol administration to rats produces a marked increase in the urinary excretion of folate compounds, which leads to a decrease in plasma folate levels. The acute decrease in plasma folate levels in ethanol-treated rats is similar to that seen in humans and suggests that the rat is an appropriate model for the study of the acute effects of ethanol on folate metabolism.

Folate utilization in Friend erythroleukemia cells

In order to study the generation, factors controlling endogenous folate pools, and their functional importance, Friend erythroleukemia cells were grown in media containing 100; 1,000; and 10,000 ng/ml of tritiated pteroylglutamic acid (3H)PteGlu1 and then studied in unlabeled media with varying amounts of PteGlu1. The intracellular folate pool was directly proportional to the PteGlu1 in which the cells were incubated. At equilibrium, greater than 95% of the labeled intracellular folate pool chromatographed as polyglutamyl folate, regardless of the exogenous folate concentration. The functional importance of the intracellular folate pool was studied by varying the endogenous pool and the exogenous (media) supply. The ability of the cells to replicate in the absence of exogenous folate was directly proportional to the intracellular polyglutamyl folate pool. The maximal rate of replication, however, required exogenous PteGlu1 in addition. The cell doubling time was the most important determinant of intracellular folate turnover; changes in the intracellular pool size and the extracellular folate concentration had no effect on the turnover time. In a rapidly proliferating tissue, the onset of functional folate deficiency will be determined by dilution of intracellular polyglutamates among progeny until a critical level is reached.

The role of the enterohepatic cycle in folate supply to tumour in rats

The importance of the folate enterohepatic cycle in governing the supply of folate to implants of a rapidly-growing tumour were studied in a new animal model. Following enteric administration of tritiated pteroylglutamic acid, [3H]PteGlu1, tumour uptake of labelled folate was limited to CH3[3H]H4PteGlu1 produced by the gut mucosal cells during absorption or subsequently recirculated through the enterohepatic cycle. 50% of the labelled folate reaching the tumour nodules in the first 6 h after enteric administration first circulated through the enterohepatic cycle. In addition, labelled folate taken up by tumour was immediately incorporated into a polyglutamyl folate pool. There was no evidence for a release of labelled folate from tumour for recirculation to the liver. Therefore the liver and folate enterohepatic cycle appear to play a major role in regulating the supply of folate to rapidly proliferating tissues such as tumour by acutely storing folate from the diet and then secreting it into bile for reabsorption and transport to tissue.

Macrocytosis in alcohol-related liver disease: its value for screening

The incidence of macrocytosis, defined as a mean corpuscular volume (MCV) of greater than 95 fl and large red cells on peripheral blood film, was determined in 303 alcoholics with liver disease (95 females: 208 males), 60 non-alcoholics with chronic liver disease (44 females: 16 males) and 35 control subjects (15 females: 20 males). Macrocytosis was found in 70.3% (213/303) of alcoholics with liver disease and in 23.3% (14/60) of non-alcoholics with liver disease, P less than 0.001. MCV values greater than 100 fl were seen in 49.5% (150/303) of alcoholics, but in only 3.3% (2/60) of non-alcoholics, P less than 0.001. Macrocytosis was more frequent in female, 86.3% (82/95) than in male alcoholics 63.0% (131/208), P less than 0.001. Serum folate values less than 3 microgram/l were found in 14.5% (44/303) of alcoholics and in 11.7% (7/60) of non-alcoholics. Low serum folate values were found in 18.3% (39/213) of alcoholics with macrocytosis and in 35.9% (28/78) of those with macrocytic anaemia. Twenty alcoholics with pre-cirrhotic liver disease were followed over three months. Macrocytosis was present in 85.0% (17/20) at the outset and in 40% (8/20) 3 months later. The changes in MCV were independent of alcohol intake and serum folate values. Macrocytosis is a useful diagnostic indicator of alcoholism. MCV values greater than 100 fl in patients with liver disease almost invariably indicate alcohol-related disease. In the short-term, changes in MCV are of little use in monitoring alcohol intake.

Folic acid metabolism in normal, folate deficient and alcoholic man

Folate metabolism was studied in normal, folate-deficient and alcoholic man by tracer measurements of plasma clearance, urinary excretion, tissue storage and release of folate using both [3H]pteroylglutamic acid (3H-PteGlu) and 14C-methyl-H4PteGlu. Alcohol ingestion did not adversely affect tissue uptake of folates. Whether in normal or folate deficient subjects, the relative clearance rates of 3H-PteGlu and 14C-methyl-H4PteGlu were maintained in the face of alcohol ingestion and there was no evidence of increased urinary loss of intact vitamin or labelled breakdown products. As measured by the flushing technique, the rate of storage or tissue binding of 3H-PteGlu was not influenced by folate deficiency, folate store depletion or alcohol ingestion. However, alcohol may retard the release of methyl-H4PteGlu from tissue stores to plasma. A significantly greater recovery of 14C-methyl-H4PteGly with flush was observed in those normal subjects who ingested alcohol for 6 d. A partial block in the rate of release of tissue folate stores would be a possible mechanism behind the rapid depression in serum methyl-H4PteGlu levels and early induction of megaloblastic erythropoiesis which has been observed following acute alcohol ingestion.

Drug-induced anaemias

Many drugs have been reported to have caused anaemia. The most serious form involves marrow aplasia, but the way in which this is produced is not understood. A number of drugs lead to megaloblastic anaemia and where this is caused by interference with dihydrofolate reductase the explanation is obvious. However, some substances, notably anticonvulsants, cause megaloblastic anaemia by some other mechanism. A number of drugs cause intestinal bleeding with anaemia as a result. Sideroblastic anaemia is a relatively rare condition, sometimes caused by drugs, particularly those used in the treatment of tuberculosis. Leukaemia very occasionally supervenes in patients with drug-induced aplastic anaemia.