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

Elevated total plasma homocysteine has been established as an independent risk factor for thrombosis and cardiovascular disease. A strong relationship between plasma homocysteine levels and mortality has been reported in patients with angiographically confirmed coronary artery disease. Homocysteine is a thiol containing amino acid. It can be metabolised by different pathways, requiring various enzymes such as cystathionine beta-synthase and methylenetetrahydrofolate reductase. These reactions also require several co-factors such as vitamin B6 and folate. Medications may interfere with these pathways leading to an alteration of plasma homocysteine levels. Several drugs have been shown to effect homocysteine levels. Some drugs frequently used in patients at risk of cardiovascular disease, such as the fibric acid derivatives used in certain dyslipidaemias and metformin in type 2 (non-insulin-dependent) diabetes mellitus, also raise plasma homocysteine levels. This elevation poses a theoretical risk of negating some of the benefits of these drugs. The mechanisms by which drugs alter plasma homocysteine levels vary. Drugs such as cholestyramine and metformin interfere with vitamin absorption from the gut. Interference with folate and homocysteine metabolism by methotrexate, nicotinic acid (niacin) and fibric acid derivatives, may lead to increased plasma homocysteine levels. Treatment with folate or vitamins B6 and B12 lowers plasma homocysteine levels effectively and is relatively inexpensive. Although it still remains to be demonstrated that lowering plasma homocysteine levels reduces cardiovascular morbidity, surrogate markers for cardiovascular disease have been shown to improve with treatment of hyperhomocystenaemia. Would drugs like metformin, fibric acid derivatives and nicotinic acid be more effective in lowering cardiovascular morbidity and mortality, if the accompanying hyperhomocysteinaemia is treated? The purpose of this review is to highlight the importance of homocysteine as a risk factor, and examine the role and implications of drug induced modulation of homocysteine metabolism.
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PMID:Drugs affecting homocysteine metabolism: impact on cardiovascular risk. 1189 29

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases. The con- cept of NAFLD ranges from simple steatosis (NAFL) to non-alcoholic steatohepatitis (NASH) and cirrhosis. The majority of NAFLD has been recognized as a hepatic manifestation of metabolic syndrome with a close association with insulin resistance. Regarding the development of NAFLD/NASH, adiponectin and TNFa are thought to have key roles. Moreover, the gut microbiota may affect energy metabolism in the context of NAFLD. Genetic susceptibility to NAFLD may be determined by polymorphisms of patatin-like phospho- lipase domain-containing 3 (PNPLA3) and methylenetetrahydrofolate reductase (MTHFR). The diagnosis of NAFLD/NASH is made by liver biopsy. The differential diagnosis between NAFL and NASH has been made according to Matteoni's classification, and the progression of liver fibrosis has been determined by Brunt's staging. For the prevention and treatment of NAFLD, the modification of dietary habits and promo- tion of physical activity including aerobic and resistance training are essential. Although vitamin E, pioglita- zone, or liraglutide is used as a first-line treatment for NAFLD, pharmacotherapy for NAFLD has not been established because of the insufficient pharmacological effects of these agents. Among recently developed drugs, farnesoid X nuclear receptor ligand obeticholic acid is the most promising for first-in-class treatment of NASH. In this review, the details of recent advances in knowledge about the epidemiology, etiology, diag- nosis, and treatment of NAFLD/NASH are described. [Review].
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PMID:[Progress in the Management of NAFLD/NASH]. 3069 68