• Journal of Nutrition and Health
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• 제31권4호
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• pp.708-715
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• 1998

Chronic abuse of alcohol can lead to the development of folate deficiency due to inadequate folate intaike, excessive urinary excretion and from effects of ethanol on folate absorption and metabolism . To investigate the effects of alcohol and folate intake on folate metabolism, the rates were raised for 4 and 10 weeks on experimental diets containing 0, 2 8mg folate/kg diet, and were administered 50% ethanol(1.8$m\ell$/kg body weight) three times a week intragastrically. Plasma and tissue folate concentrations were found to be significantly influenced by dietary folate level. In animals fed on folate-deficient diet, concentrations of folate in the plasma, liver and kidney were decreased by 60-89% compared to those on folate-adequate diet, and ther values were further decreased with experimental period. Folate supplementation increased plasma and tissue folate levels significantly by 16-78% compared to those on folate-adequate diet, and the folate levels in the plasma and liver were affected most by the supplementation. Alcohol administration did not seem to influence folate status in the body significantly when animals were raised on folate-deficient diet. However, when rats were fed folate-adequate or folate-supplemented diet, alcohol was shown to decrease plasma and tissue folate concentrations. Among the animals receiving alcohol, folate concentrations in the plasma and tissues were significantly higher when animals fed folate-supplemented diet compared to folate adequate diet. Alcohol seems to exert differential effects on urinary foalte excretion by experimental period it increased urinary folate in the 4-week period, but lowered foalte excretion in the urine when the experimental period was extended to 10 weeks. Alcohol did not seem to influence folate excretion in the feces. These results indicate that folate supplementation might be beneficial in ameliorating the inadequate folate status that might occur with chronic alcoholism.

• Nutritional Sciences
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• 제9권2호
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• pp.106-111
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• 2006

Chronic alcohol consumption is associated with perturbation of hepatic metabolism of sulphur-containing amino acid. The goal of present study was to evaluate the influence of dietary supplementation of methionine or folate to chronically ethanol-fed mts on the metabolism of sulfur-containing amino acids and one-carbon metabolism. Sprague-Dawley male mts were fed Lieber-Decarli liquid diet with 0% ethanol (control), 36% ethanol (E), 36% ethanol combined with methionine supplement (EM) or folate supplement (EF) for 8 weeks. Hepatic S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), plasma folate and homocysteine (Hcy), urinary excretion of folate and formiminoglutamate were investigated after feeding experimental diets. Growth was retarded by 36% ethanol consupmtion (E, EM and EF) (p<0.01). Liver total fat (p<0.05) and plasma ALT (P<0.01) were increased by methionine supplementation (EM), implicating fatty liver and liver injury. Liver folate was increased slightly by folate supplementation (EF) (p=0.077). Urinary folate loss was increased 2.3 fold by ethanol consumption (E) and 17.2 fold by folate supplementation (EF), while decreased by methionine supplementation (EM) (p<0.000l). Plasma Hcy was increased 1.9 fold by methionine supplementation (EM) in ethanol-fed mts (p<0.05), which was related with decreased methionine synthase activity (p<0.05). Hepatic SAM/SAH ratio was depressed by methionine supplementation in ethanol-fed mts (EM) (p<0.05). Urinary formininoglutamate (Figlu) excretion after histidine loading was increased by ethanol ingestion and reduced by methionine supplementation (p<0.00l). Based on these data, methionine supplementation appears to accelerate histidine oxidation. In conclusion, dietary supplementation of methionine to ethanol-fed mts exacerbates alcoholic liver injury possibly by complicating sulphur-containing amino acid metabolism, as while it may have beneficial effects on folate and histidine metabolism.

• Journal of Nutrition and Health
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• 제32권4호
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• pp.376-383
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• 1999

The effects of $\beta$-carotene substitutionl for vitamin A and the chronic consumption of ethanol of ethanol on hepatic folate metabolism were studied it rats. The substitution of $\beta$-carotene for vitamin A depressed hepatic 10-formyl-tetreahydrofolate dehydrogenase(10-formyl-tetrahydrofolate : NADP oxidoreductase, E.C. 1.5. 1.6)activity to 65% of controls(p<0.001) and enhanced hepatic 5, 10-methy-lenetetrahydrofolate reductase(E. C. 6.3.3.2)activity by 56% with respect to control levels(p<0.001). Hepatic activity of 10-formyltertrahydrofolate dehydrogenase was depressed to about half that of control levels by ethanol administration to rats(36% ethanol diet, p<0.001). The activity of 5, 10-methyleneterahydrofolate reductase was not changed by ethanol consumption. The increased activity of 5, 10-methyleneterahydrofolate reductase and the decreased activity of 10-formyltetrahydrofolate dehydrogenase appeared to decrease the level of nonmethyl folate conezyme and the rate of one-carbon metabolism. Plasma homocysteine concentrations were significantly higher in rats fed ethanol(p<0.01) o $\beta$-carotene(p<0.001) than in controls, which suggests that increased activity of 5, 10-methylenetetrahydrofolate reductase can depress homocysteine metabolism. We concluded that dietary substitution of $\beta$-carotene for vitamin A or chronic administration of ethanol resulted in changes in the activity of hepatic folate-dependent enzymes, which could affect the distribution of folate derivatives, plasma homocysteine levels and one-carbon metabolism.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5333-5338
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• 2012

Vitamin B6 functions as a coenzyme in >140 enzymatic reactions involved in the metabolism of amino acids, carbohydrates, neurotransmitters, and lipids. It comprises a group of three related 3-hydroxy-2-methyl-pyrimidine derivatives: pyridoxine (PN), pyridoxal (PL), pyridoxamine (PM) and their phosphorylated derivatives [pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP)], In the folate metabolism pathway, PLP is a cofactor for the mitochondrial and cytoplasmic isozymes of serine hydroxymethyltransferase (SHMT2 and SHMT1), the P-protein of the glycine cleavage system, cystathionine ${\beta}$-synthase (CBS) and ${\gamma}$-cystathionase, and betaine hydroxymethyltransferase (BHMT), all of which contribute to homocysteine metabolism either through folate-mediated one-carbon metabolism or the transsulfuration pathway. Folate cofactors carry and chemically activate single carbons for the synthesis of purines, thymidylate and methionine. So the evidence indicates that vitamin B6 plays an important role in maintenance of the genome, epigenetic stability and homocysteine metabolism. This article focuses on studies of strand breaks, micronuclei, or chromosomal aberrations regarding protective effects of vitamin B6, and probes whether it is folate-mediated one-carbon metabolism or the transsulfuration pathway for vitamin B6 which plays critical roles in prevention of cancer and cardiovascular disease.

• Journal of Nutrition and Health
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• 제24권4호
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• pp.337-343
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• 1991

엽산의 항비타민제인 9-methyl folate가 흰 쥐의 엽산 대사에 미치는 영향을 조사하기 위하여, Sprague-dawley 암컷 쥐를 엽산 결핍식이군, 대조군, x-methyl folate 투여군으로 나누어 실험하였다. 9-methyl folate는 실험동물에게 엽산 결핍증을 유발시키는 x-methyl folate의 성분 가운데 주된 항비타민제이며, 본 실험에서는 식이 1kg당 5g의 x-methyl folate를 첨가하였다. x-methyl folate를 실험동물에게 먹였을 때 히스티딘의 산화속도와 간장내의 엽산 농도가 크게 저하되었으며, $[^{3}H]folate$를 복강에 투여한 후 24시간 내에 간장에 보유되는 엽산의 양도 x-methyl folate 투여군에 있어 유의적인 감소를 보였다. 이 실험 결과에서 9-methyl folate는 흰 쥐에 있어 엽산이 간으로 유입되어 보유되는 과정을 저해하므로써 간장 내의 엽산의 양을 저하시키며, 그 결과 히스티딘의 산화속도도 저하된 것으로 보인다.

• Journal of Nutrition and Health
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• 제31권6호
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• pp.1006-1013
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• 1998

The present study was conducted to investigate the effect of different levels of ethanol ingestion on 131ate metabolism and plasma homocysteine concentration in Sprague-Dawley male rats receiving 0, 10, 30% of their caloric intake as ethanol for S weeks. Diets containing 10% ethanol had no effect on plasma and red blood cell(rbc) 131a1e. However, in rats fed a 30% ethanol diet, rbc folate increased and plasma 131ate decreased significantly, In the rats maintained first on a 30% ethanol diet for S weeks and then on a control diet for 2 weeks, the levels of plasma and rbc f31ate were normalized by withdrawal of ethanol. Urinary fo1ate excretion increased markedly in rats fed 10% and 30% ethanol diets and decreased to 51% of controls by withdrawal of ethanol. Plasma homocysteine concentration increased significantly in rats fed a 30% ethanol diet. The results suggest that chronic ingestion of ethanol increased urinary 131ate excretion markedly, which may decrease plasma 131ate and deplete liver folate.

• Nutrition Research and Practice
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• 제5권2호
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• pp.112-116
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• 2011

We investigated the effect of paternal folate status on folate content and expression of the folate transporter folate receptor ${\alpha}$ ($FR{\alpha}$) in rat placental tissues. Rats were mated after males were fed a diet containing 0 mg of folic acid/kg of diet (paternal folate-deficient, PD) or 8 mg folic acid/kg of diet (paternal folate-supplemented, PS) for 4 weeks. At 20 days of gestation, the litter size, placental weight, and fetal weight were measured, and placental folate content (n=8/group) and expression of $FR{\alpha}$ (n=10/group) were analyzed by microbiological assay and Western blot analysis, respectively. Although there was no difference observed in litter size or fetal weight, but significant reduction (10%) in the weight of the placenta was observed in the PD group compared to that in the PS group. In the PD group, placental folate content was significantly lower (by 35%), whereas $FR{\alpha}$ expression was higher (by 130%) compared to the PS group. Our results suggest that paternal folate status plays a critical role in regulating placental folate metabolism and transport.

• Journal of Nutrition and Health
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• 제32권4호
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• pp.369-375
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• 1999

Hyperthroidism in known to alter the activity of a number of enzymes involved in the catabolism of histidine to CO2. 10-Formyltetrahydrofolate dehydrogenase(EC 1.5, 1.6, 10-formyl-THE dehydrogenase) catalyzes the NADP-dependent conversion of 10-formyltetrahydrofolate to tetrahydrofolate and CO2. In previous studies, 10-formyl-THF dehydrogenase purified from rat and pig liver was coidentified with the cytosolic folate-binding protein. In this study, we investigated the effects of feeding thyroid powder (TP) and thiouracil(TU) on the folate-binding properties of 10-formyl-THE dehydrogenase, the uptake of an injected dose of [3H] folate, and the metabolism of labeled folate to pteroylopoly-${\gamma}$-glutamate in rat liver. The initial hepatic uptake(24hr) of the labeled folate dose was higher in TU-rats and slightly higher in TP-rats in controls. With longer time periods, decreased hepatic uptake of labeled folate was observed in TP-animals compared to euthroid animals, and high levels of hepatic uptake of labeled folate were maintained in TU-animals. This data shows that high levels of thyroid hormone decreased the retention of folate in rat liver. Folate polygutamate chain length was shorter in TU-rats than controls, which suggests that thyroid states do not affect the ability to synthesize pteroylpolyglutamates and that folate polyglutamate might be modulated by altered folate pool size. The ability of 10-formyl-THE dehydrogenase to bind folate in rat liver was similar in both TP-and TU-rats although dehydrogenase activity was changed by thyroid sates.

• Journal of Community Nutrition
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• 제1권1호
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• pp.60-65
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• 1999

Chronic alcoholism often leads to folate deficiency. In recent years it has been reported that mild elevation of plasma homocysteine (Hcy) is associated with an increased risk of coronary artery disease. In the present study we investigated the effects of chronic ethanol consumption on folate status and the relation between plasma folate and Hcy. A human study was conducted to determine plasma folate, total Hcy, cysteine(Cys), total cholesterol and hemoglobin(Hb) concentrations in 44 Korean alcoholics(men aged 30 to 50yr) and 45 Korean non-alcoholic subjects(men aged 30 to 50 yr). In alcoholic subjects, 52.6% were folate deficient and 34.2% were marginally deficient, which suggested that most alcoholics were subnormal in folate status. Plasma total Hcy concentration of alcoholics was twice as high as in control subjects (p<0.001). We found a negative correlation between plasma folate and plasma total Hcy(r=-0.271, p<0.05) and a positive correlation between plasma folate and plasma Cys(r=0.249, p<0.05) in total subjects. Hb concentrations in alcoholics was significantly lower than in control subjects, but there was no difference in total cholesterol concentration between alcoholics and controls. These results suggest that chronic alcohol consumption may impair the disposal of Hcy by interfering with folate metabolism.

• Journal of Nutrition and Health
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• 제36권8호
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• pp.811-818
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• 2003

We investigated the effects of dietary folate supplementation on plasma homocysteine, vitamin B$_{12}$ and hepatic levels of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) in diet-induced hyperhomocysteinemic rats. All animals were fed 0.3% homocysteine diet for 2 weeks, then they were placed either on a 0.3% homocystine or no homocystine with or without 8 mg/kg folate diet for 8 weeks. Homocystine diet induced hyperhomocysteinemia up to 3.5-fold at 10 weeks (28.0 $\pm$ 4.8 $\mu$mol/l vs. 7.9 $\pm$ 0.3 $\mu$mol/l). Dietary folate supplementation caused a significant decrease in plasma homocysteine levels which had been increased by a homocystine-diet. Also, dietary folate supplementation made them return to control levels at 4 wk when the diet was free of homocystine. Plasma folate levels were markedly decreased with homocystine diet with no folate supplementation. Plasma vitamin B$_{12}$ did not differ between groups. Dietary homocystine increased hepatic levels of SAM in folate supplementation group at 10 weeks (p<0.05). Dietary folate supplementation increased hepatic levels of SAM/SAH ratios in homocystine group (p<0.05). In conclusion, dietary folate supplementation can effectively ameliorate the detrimental effects of hyperhomocysteinemia.mia.