• 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.

• 한국식품영양과학회지
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• 제27권2호
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• pp.286-290
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• 1998

The effects of cooking methods and storage time on folate content in spinach were determined by boiling for 1, 2, 3, 4, 5, 10 and 20min in distilled water or by microwave blanching for 20, 40, 60, 80, 100 sec. The folate content of cooked spinach was decreased to 80.7% after 1min boiling, and to 5.5% after 20min boiling. The folate recovered from the cooked spinach and cooking water was 101.1% after 1min, 68.0% after 2min and 51.3% after 3min. The relative folate content leached out of the cooked spinach into the cooking water varied from 20.2% after 1min boiling to 88.8% after 20min boiling. Total folate content of spinach was decreased to 45% by microwave heating for 40sec. However, the spinach cooked by microwave heating retained more folate due to the minimal loss of folate into cooking water. More than 90% of folate content of spinach was retained during 1 to 2 weeks of storage at 4$^{\circ}C$.

• Nutrition Research and Practice
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• 제14권2호
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• pp.95-101
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• 2020

BACKGROUND/OBJECTIVES: Folate plays a critical role in DNA synthesis and methylation. Intracellular folate homeostasis is maintained by the enzymes folylpolyglutamate synthase (FPGS) and γ-glutamyl hydrolase (GGH). FPGS adds glutamate residues to folate upon its entry into the cell through a process known as polyglutamylation to enhance folate retention in the cell and to maintain a steady supply of utilizable folate derivatives for folate-dependent enzyme reactions. Thereafter, GGH catalyzes the hydrolysis of polyglutamylated folate into monoglutamylated folate, which can subsequently be exported from the cell. The objective of this review is to summarize the scientific evidence available on the effects of intracellular folate homeostasis-associated enzymes on cancer chemotherapy. METHODS: This review discusses the effects of FPGS and GGH on chemosensitivity to cancer chemotherapeutic agents such as antifolates, such as methotrexate, and 5-fluorouracil. RESULTS AND DISCUSSION: Polyglutamylated (anti)folates are better substrates for intracellular folate-dependent enzymes and retained for longer within cells. In addition to polyglutamylation of (anti)folates, FPGS and GGH modulate intracellular folate concentrations, which are an important determinant of chemosensitivity of cancer cells toward chemotherapeutic agents. Therefore, FPGS and GGH affect chemosensitivity to antifolates and 5-fluorouracil by altering intracellular retention status of antifolates and folate cofactors such as 5,10-methylenetetrahydrofolate, subsequently influencing the cytotoxic effects of 5-fluorouracil, respectively. Generally, high FPGS and/or low GGH activity is associated with increased chemosensitivity of cancer cells to methotrexate and 5-fluorouracil, while low FPGS and/or high GGH activity seems to correspond to resistance to these drugs. Further preclinical and clinical studies elucidating the pharmocogenetic ramifications of these enzyme-induced changes are warranted to provide a framework for developing rational, effective, safe, and customized chemotherapeutic practices.

• Journal of Nutrition and Health
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• 제31권7호
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• pp.1121-1129
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• 1998

The critical role of folate vitamin in the remethylation pathway for methionine synthesis from homocysteine has been well documented. Hyperhomocysteinemia resulting from inadequate folate nutrition has been implicated in increased incidence of macrovascular diseases, colorectal cancer, neural tube defects, etc. Chronic exposure to ethanol impairs folate nutrition and one-carbon metabolism in the liver, which often results in fatty liver due to a defective remethylation process. This study was carried out to investigate the chronic effects of moderate levels of alcohol and dietary 131ate on plasma homocysteine levels, and on histopathology and biochemical functions of the liver Rats were raised on experimental diets with three levels of folate(0, 2, 8mg/kg diet), and 50% ethanol(1.8m1/kg body weight) was administered intragastrically by intubation tubes three times a week for 10 weeks. Plasma homocysteine concentrations were found to be significantly influenced by dietary folate intake and alcohol administration. Among all treatment groups, Plasma homocysteine levels were highest in the animals receiving a combined treatment of folate deficient diet and alcohol administration. Plasma homocysteine concentration was negatively correlated with folate concentration in the plasma(p<0.01) and liver(p<0.05). Among alcohol treated rats, increase in plasma homocysteine values due to ethanol was prevented by 131ate supplementation. When liver histological tests were performed, macrovascular and microvascular fatty changes and spotted necrosis were observed more frequently in folate-deficient animals diet than those on folate-adequate and folate-supplemented diets in alcohol-treated rats. These results indicate that folate supplementation above the recommended level might be beneficial in the prevention of alcohol-related hyperhomocystei-nemia and abnormal histologic changes in the liver due. (Korean J Nutrition 31(7) : l121-l129, 1998)

• Journal of Nutrition and Health
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• 제48권1호
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• pp.94-104
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• 2015

본 연구에서는 엽산의 급원식품으로 보고된 식품 51종의 엽산을 분석하고, 값에 차이가 많이 있는 경우 엽산 데이터베이스를 수정하여, 수정한 데이터베이스로 어린이와 청소년의 엽산 섭취량을 추산하고 급원식품을 알아보고자 하였다. 대상자는 대전, 충청도 및 전라도에 거주하는 만 20세 미만 567명으로 비연속 2일 동안의 24시간 회상법에 의해 식품섭취조사를 실시하였다. 51종의 식품을 새롭게 분석하여 현재의 데이터베이스와 비교한 결과 현재 값의 18.7%~322.9%의 결과를 얻었다. 기존의 값이 실험한 두 값 사이에 있거나, 기존값과의 차이가 10% 미만인 경우에는 수정하지 않았으며, 그 외에 차이가 있는 40종은 새로운 분석값으로 수정하였다. 수정한 데이터베이스로 대상자들의 엽산 평균섭취량을 성별, 연령별로 나누어 계산한 결과 모든 연령층에서 평균 엽산 섭취량이 권장섭취량보다 높았으나 12~14세 남자와 12~19세 여자의 평균 엽산 섭취량은 권장섭취량보다 낮은 것으로 나타났다. 계란, 배추김치, 쌀, 귤은 모든 연령층에서 엽산 급원식품의 10위 안에 포함되었다. 본 연구에서는 일부 급원식품 51종만을 분석하였으나 한국인들이 자주 먹는 식품의 조리 후 엽산 함량을 분석하여 보완해 나감으로써 더 정확한 엽산 섭취량을 추산할 수 있도록 해야 할 것이다. 또한 12~19세 여자의 평균 엽산 섭취량이 다른 연령층에 비해 상대적으로 낮게 나타난 것을 볼 수 있었는데, 엽산은 성장기 및 가임여성에게 특히 중요한 비타민으로써 이들을 위한 엽산 영양교육이 이루어져야 할 것으로 생각된다.

• Journal of Nutrition and Health
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• 제42권2호
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• pp.107-118
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• 2009

In patients with type 2 diabetes, oxidative stress could be increased by their metabolic changes. Elevated plasma homocysteine is considered as one of markers of enhanced oxidative stress. Due to oxidative stress, some complications like cardiovascular or renal diseases may develop in type 2 diabetes patients. Plasma homocysteine concentration may be increased if folate status were inadequate. Protective effects against oxidative stress may be diminished if the status of anti-oxidative nutrient as vitamin C was poor. It is, therefore, important to maintain adequate status of folate and vitamin C in type 2 diabetes patients. Thus, this study was performed to determine the effects of supplementation of folate and/or ascorbate on blood glycated hemoglobin ($HbA_{1c}$) level, serum concentrations of homocysteine and cholesterol, plasma oxidized low density-lipoprotein (LDL), concentration and plasma glutathione peroxidase (GSH-Px) activity in the patients with type 2 diabetes. A total of 92 type 2 diabetes patients participated voluntarily with written consents. They were divided into one of the four experimental groups; Control (C), Folate-supplemented (F), Ascorbate-supplemented (A), and Folate plus ascorbate-supplemented (FA). The subjects in C were taken placebo, those in F were supplemented 1 mg of folate, those in A received 1,000 mg of ascorbate, and those in FA were given 1 mg of folate plus 1,000 mg of ascorbate daily for 4 weeks. Supplementation of folate or ascorbate resulted to increase serum folate level or plasma ascorbate concentration apparently, respectively. Folate supplementation not ascorbate seemed to decrease plasma concentrations of homocysteine and oxidized LDL and reduce plasma GSH-Px activity. There might not be synergic effect of the supplementation of folate plus ascorbate. The results indicate that oxidative stress in the patients with type 2 diabetes may lower mainly by folate supplementation.

• Nutrition Research and Practice
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• 제3권1호
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• pp.43-48
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• 2009

We investigated the nutritional state of B vitamins and the neuropsychological functions in 25 subjects, aged $63.1{\pm}6.3$ years, residing in rural areas of Korea. Nutritional states of thiamin, riboflavin, and pyridoxine were assessed enzymatically in the erythrocytes, and folate concentrations were measured microbiologically in the plasma and erythrocytes. A battery of composite neuropsychological test was administered to the subjects. Plasma folate was correlated with the total intelligence score (p=0.049). Folate levels in the erythrocytes were correlated with the performance intelligence scores such as block design (p=0.017) and picture arrangement (p=0.016). The red cell folate was correlated with memory scores such as general memory (p=0.009) and delayed recall (p=0.000). Although it did not reach statistical significance, verbal memory (p=0.053) was highly correlated with the red cell folate. The red cell folate was also correlated positively with the percent of conceptual level response number score (p=0.029), and negatively with the grooved pegboard test score for the non-dominant hand (p=0.010). Fine motor coordination was also influenced by folate nutrition, as finger tapping scores in both hands were significantly correlated with red cell folate (dominant hand; p=0.026, non-dominant hand; p=0.004). Other B vitamins such as thiamin, riboflavin, and vitamin $B_6$ were not as strongly correlated with neuropsychological function test scores as folate was. These results suggest that folate nutrition influences neuropsychological function test scores significantly in humans. Further studies are needed to explore the relationship between folate or other vitamin B nutrition and neuropsychological functions and the implications thereof.

• 대한화학회지
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• 제37권4호
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• pp.448-452
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• 1993

Folate 유사체의 anti-folate 활성과 물리적 성질의 상관성을 찾기 위하여 기하구조 파라미터, 쌍극자 모멘트, net charg, HOMO, LUMO 에너지 등 전자의 구조적 특성을 MM2와 MOT에 의해 검토하였다. 전자적 성질은 folate 유사체의 inhibition과 어떠한 상관성도 보이지 않았으며 형태분석에 의한 기하구조 파라미터가 상관성을 나타내었다.

• 한국식품영양과학회지
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• 제33권2호
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• pp.331-338
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• 2004

임신초기 모체의 엽산영양은 태아의 신경관 손상을 예방하는 측면에서는 물론이고 엽산 필요량이 증가하는 임신후기를 대비한다는 점에서도 중요하다. 그러므로 본 연구에서는 임신초기에 있는 151명의 임신부들을 대상으로, 이들이 식사를 통해 얼마의 엽산을 섭취하는지를 조사하고, 혈청과 적혈구의 엽산 농도와 혈장 호모시스테인 농도를 분석하여 엽산영양상태를 평가하고, 이들의 엽산영양상태에 영향을 미치는 인자들이 무엇인지 분석하고자 하였다. 본 연구대상자의 조사당시 임신기간은 9.1$\pm$2.3주이었으며, 초산부가 46%이었고 나머지는 경산부이었다. 에너지 및 엽산 섭취량은 각각 1559$\pm$589 ㎉/day 및 230.8$\pm$145.2 $\mu$g/day로 각 권장량의 72.5%및 46.2%로 낮았다 혈청과 적혈구의 엽산 농도는 각각 5.5$\pm$1.9 ng/mL 및 266.6$\pm$75.0 ng/mL으로, 연구 대상자의 7.8%가 혈청 엽산 수준이 3 ng/mL미만인 결핍상태에 해당하였고 60.3%는 경계역(3∼5.9 ng/mL)에 속하였으며, 적혈구 엽산 농도가 l57 ng/mL미만인 결핍상태에는 4.3%가 해 당하였다. 그러나 혈청 호모시스테인 농도는 정상범위이었다. 따라서 본 연구대상자의 엽산영양상태는 비교적 양호하다고 판정되었다. 혈청 엽산 농도에 영향을 끼칠 수 있는 유의한 인자는 건강상태점 수(+), 혈장 호모시스테인 농도(-), 연령 (-), 임신기간(-) 및 엽산 섭취량(+) 순으로 그 영향력이 높았고, 적혈구 엽산 농도의 영향인자는 교육수준(-), 혈장 호모시스테인 농도(-), 지난번 출산 영아의 출생시 신장(+),연령(-)및 에너지 섭취량(+)이었고, 혈장 호모시스테인 농도의 영향인자는 지난번 출산 영아의 출생시 신장(-), 경제수준(+),혈청 엽산 농도(-)와 임신전 체중(+)이었다. 이러한 결과는, 혈장이나 적혈구의 엽산 농도나 혈장 호모시스테인 농도를 분석하지 않고도, 임신초기에 있는 모체의 엽산영양상태를 개략적으로 판정하는데 있어 주관적으로 평가한 불량한 건강상태, 높은 교육수준 또는 경제수준, 지난번 출산에서 작은 체위의 영아를 출산한 경력, 고연령 또는 엽산이나 에너지섭취량 부족을 위험 인자로 활용할 수 있음을 시사한다. 아울러 임신기간이 진행되었을수록 엽산영양상태가 저하되었을 가능성이 있음도 나타내준다. 앞으로 임신초기 임신부의 엽산영양상태를 어떤 위험인자를 몇 가지나 가졌느냐에 따라 평가하는 연구결과가 나와야 이들 위험 인자의 실용성 을 확인할 수 있을 것이다. 그러나 우선 이들 위험 인자를 많이 지닌 임신부라면 임신초기부터 엽산 섭취량을 늘리거나 엽산보충제 섭취를 일찍 시작하는 등의 방법으로 엽산영양상태를 양호하게 유지하도록 하는 것이 바람직할 것이다.