Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.5.7.1 (methylenetetrahydrofolate reductase)
 2,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic phenytoin (PHT) treatment has long been associated with folate deficiency. It has been suggested that pH changes in the gut associated with PHT ingestion may be responsible for decreased folate uptake either by direct inhibition of folate transport into the intestinal mucosa or by inhibition of folate conjugase activity. To examine these possibilities, rats were gavaged chronically with PHT using either the sodium salt (NaPHT) or the free acid (HPHT) in the presence of folic acid as the dietary source of folate. The NaPHT caused a greater depletion of folate in the liver and brain and a significant increase in methylenetetrahydrofolate reductase activity in the liver. The HPHT caused a significantly decreased weight gain over the 8 weeks of treatment and resulted in a much higher liver PHT concentration and a slightly lower plasma PHT concentration. These data support the hypothesis that PHT-induced changes in pH in the gut affect the enterohepatic circulation of folate.
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PMID:Phenytoin-folate interactions: differing effects of the sodium salt and the free acid of phenytoin. 154 69

Almost half of the women do not follow the guidelines around folate suppletion before and during pregnancy, despite the proven benefit in the prevention of neural tube defects, miscarriages and premature births. The Belgian Superior Health Council recommends a minimum of 400 micrograms of folic acid or folate suppletion per day from 4 weeks before conception to 8 weeks thereafter. Many studies point to the importance of a wider intake period, more particularly at least 3 months before conception and throughout pregnancy and lactation. In high-risk women 4 mg is recommended until after the first 3 months of pregnancy. Afterwards the usual dose of 400 micrograms is sufficient. About half of the European population appears to have a gene mutation on the gene coding for the production of methylenetetrahydrofolate reductase, the enzyme that is involved in the formation of 5-methyltetrahydrofolate, which is, in his turn, responsible for the conversion of the toxic homocysteine in methionine. Women with such a gene polymorphism have a significantly higher risk to have a miscarriage or a baby with neural tube defects. For this reason, a search for an alternative form of synthetic folic acid supplement "pteroylmonoglutamic acid (PMG)" was conducted, particularly the calcium salt of 5-methyltetrahydrofolate (Metafolin). This offers the possibility to deliver the reduced folate immediately, which no longer needs to be converted by the reductase enzyme. Furthermore, this avoids free PMG in the circulation, lowers the risk for drug interactions and a vitamin B2 deficiency will not be masked. Despite clear guidelines regarding dietary supplements before and during pregnancy, their implementation is poor. Not only gynecologists but also GPs and pharmacists, should make more efforts to provide women of childbearing age with personal information. Especially risk groups such as adolescents, low-skilled or less well-off women and immigrants deserve special attention.
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PMID:[Does 5-methyltetrahydrofolate offer any advantage over folic acid?]. 2335 Feb 8

To personalize nutrition, the purpose of this study was to examine five key genes in the folate metabolism pathway, and dietary parameters and related interactive parameters as predictors of colorectal cancer (CRC) by measuring the healthy eating index (HEI) in multiethnic families. The five genes included methylenetetrahydrofolate reductase (MTHFR) 677 and 1298, methionine synthase (MTR) 2756, methionine synthase reductase (MTRR 66), and dihydrofolate reductase (DHFR) 19bp, and they were used to compute a total gene mutation score. We included 53 families, 53 CRC patients and 53 paired family friend members of diverse population groups in Southern California. We measured multidimensional data using the ensemble bootstrap forest method to identify variables of importance within domains of genetic, demographic, and dietary parameters to achieve dimension reduction. We then constructed predictive generalized regression (GR) modeling with a supervised machine learning validation procedure with the target variable (cancer status) being specified to validate the results to allow enhanced prediction and reproducibility. The results showed that the CRC group had increased total gene mutation scores compared to the family members (p < 0.05). Using the Akaike's information criterion and Leave-One-Out cross validation GR methods, the HEI was interactive with thiamine (vitamin B1), which is a new finding for the literature. The natural food sources for thiamine include whole grains, legumes, and some meats and fish which HEI scoring included as part of healthy portions (versus limiting portions on salt, saturated fat and empty calories). Additional predictors included age, as well as gender and the interaction of MTHFR 677 with overweight status (measured by body mass index) in predicting CRC, with the cancer group having more men and overweight cases. The HEI score was significant when split at the median score of 77 into greater or less scores, confirmed through the machine-learning recursive tree method and predictive modeling, although an HEI score of greater than 80 is the US national standard set value for a good diet. The HEI and healthy eating are modifiable factors for healthy living in relation to dietary parameters and cancer prevention, and they can be used for personalized nutrition in the precision-based healthcare era.
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PMID:Personalized Nutrition-Genes, Diet, and Related Interactive Parameters as Predictors of Cancer in Multiethnic Colorectal Cancer Families. 2992 88