Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Folate and vitamin B(12) are essential cofactors for the methionine/homocysteine cycle in the brain. These vitamins mediate the remethylation of homocysteine (Hcy), which affects the production of the universal methyl donor, S-adenosylmethionine (SAM), in the brain among other organs. Additionally, increased plasma concentrations of total Hcy (tHcy) are associated with cerebrovascular disease and can compromise the blood-brain barrier. tHcy concentrations in the brain and cerebrospinal fluid become increased in several psychiatric and neurological disorders. Disturbances in the transmethylation pathway indicated by abnormal SAM, S-adenosylhomocysteine or their ratio have been reported in many neurodegenerative diseases, such as dementia, depression or Parkinson's disease. Cobalamin is essential for neuronal generation and its deficiency can cause degeneration of the nervous system. Available data emphasize that deficiency of folate and vitamin B(12) can lead to elevated concentrations of tHcy and disturbed methylation potential in the brain. Therefore, acquired or inherited disorders in these metabolic pathways are associated with brain abnormalities and severe neurological symptoms that are mostly irreversible, even after providing the missing cofactors. This review discusses the relationship between brain and blood levels of key vitamins and metabolites related to one carbon metabolism.
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PMID:Biomarkers of folate and vitamin B(12) status in cerebrospinal fluid. 1789 39

In addition to cognitive impairment, behavioral changes such as aggressive behavior, depression, and psychosis accompany Alzheimer's Disease. Such symptoms may arise due to imbalances in neurotransmitters rather than overt neurodegeneration. Herein, we demonstrate that combined administration of N-acetyl cysteine (an antioxidant and glutathione precursor that protects against A beta neurotoxicity), acetyl-L-carnitine (which raises ATP levels, protects mitochondria, and buffers A beta neurotoxicity), and S-adenosylmethionine (which facilitates glutathione usage and maintains acetylcholine levels) enhanced or maintain cognitive function, and attenuated or prevented aggression, in mouse models of aging and neurodegeneration. Enhancement of cognitive function was rapidly reversed upon withdrawal of the formulation and restored following additional rounds supplementation. Behavioral abnormalities correlated with a decline in acetylcholine, which was also prevented by this nutriceutical combination, suggesting that neurotransmitter imbalance may contribute to their manifestation. Treatment with this nutriceutical combination was able to compensate for lack of dietary folate and vitamin E, coupled with administration of dietary iron as a pro-oxidant (which collectively increase homocysteine and oxidative damage to brain tissue), indicating that it provided antioxidant neuroprotection. Maintenance of neurotransmitter levels and prevention of oxidative damage underscore the efficacy of a therapeutic approach that utilizes a combination of neuroprotective agents.
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PMID:Effects of dietary supplementation with N-acetyl cysteine, acetyl-L-carnitine and S-adenosyl methionine on cognitive performance and aggression in normal mice and mice expressing human ApoE4. 1791 84

Circulating homocysteine is a risk factor of cardiovascular and cerebrovascular events. Hyperhomocysteinemia may be an early indicator for vitamin B12 disorders because cobalamin is a cofactor in the remethylation process of homocysteine. Serum holotranscobalamin (holoTC II) becomes decreased before the development of metabolic dysfunction. In this study, we assessed circulating holoTC II to estimate the diagnosis of vitamin B12 deficiency in the first ischemic cerebrovascular attack. We also compared the efficacy of the measurement of plasma holoTC II with the other standard biochemical and hematological markers used to reach the diagnosis of cobalamin deficiency. Forty-five patients (age 71 years (range 35-90), 16 men/29 women) within the first ischemic cerebrovascular event were included in this prospective study. All the enrolled patients have been administered vitamin B12 1 mg intramuscular injection once a day for 10 days. At the baseline and on the tenth day of treatment, plasma levels of holoTC II and the proper biochemical and hematological markers in diagnosing cobalamin deficiency were measured. After admission, anemia and diminished serum vitamin B12 levels were determined to be only 20% (9/45) and 44% (20/45), respectively; 78% (35/45) of the patients had low serum holoTC II (<37 pmol/l). Serum homocysteine was higher in patients (49% of them) who had previously suffered a stroke. Thrombocytopenia, hypersegmentated neutrophils, and indirect hyperbilirubinemia were observed in 20% of the patients. Leukopenia and macrocytosis were not evident in any of them. In 18 of 27 patients (67%) that had low holoTC II levels after joining the study and who remained in the study until the end of cobalamin treatment, serum holoTC II levels returned to normal values. Cobalamin deficiency should be considered in patients with cerebrovascular diseases, even if anemia, elevated mean cell volume, depression of the serum cobalamin, or other classic hematological and/or biochemical abnormalities are lacking. Furthermore, measurement of serum holoTC II looks promising as a first-line of tests for diagnosing early vitamin B12 deficiency.
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PMID:Measuring holotranscobalamin II, an early indicator of negative vitamin B12 balance, by radioimmunoassay in patients with ischemic cerebrovascular disease. 1799 30

It has been suggested that an elevated serum or plasma homocysteine level may be a risk factor for neuropsychiatric conditions such as Alzheimer's disease, schizophrenia, and depression. Because depression is closely related to anxiety disorders, and because it has been suggested that stress may be associated with an elevated homocysteine level, we studied whether serum homocysteine levels are elevated in patients with posttraumatic stress disorder (PTSD). Total serum homocysteine levels in 28 male patients with PTSD were compared to those of 223 healthy controls. The effect of PTSD on the serum homocysteine level was significant (F=42.96, P<.0001). In a regression model for the PTSD patients, the duration of PTSD was found to predict serum homocysteine levels (t=2.228, P=.035). Our results suggest that elevated levels of homocysteine in male patients with PTSD may be related to pathophysiological aspects associated with the chronicity of this disorder.
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PMID:Elevated serum homocysteine levels in male patients with PTSD. 1799 87

Low blood folate and raised homocysteine concentrations are associated with poor cognitive function. Folic acid supplementation improves cognitive function. Folic acid enhances the plasma concentrations of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). EPA, DHA, and arachidonic acid (AA) are of benefit in dementia and Alzheimer's disease by up-regulating gene expression concerned with neurogenesis, neurotransmission and connectivity, improving endothelial nitric oxide (eNO) generation, enhancing brain acetylcholine levels, and suppressing the production of pro-inflammatory cytokines. EPA, DHA, and AA also form precursors to anti-inflammatory compounds such as lipoxins, resolvins, and neuroprotectin D1 (NPD1) that protect neurons from the cytotoxic action of various noxious stimuli. Furthermore, various neurotrophins and statins enhance the formation of NPD1 and thus, protect neurons from oxidative stress and prevent neuronal apoptosis Folic acid improves eNO generation, enhances plasma levels of EPA/DHA and thus, could augment the formation of NPD1. These results suggest that a combination of EPA, DHA, AA and folic acid could be of significant benefit in dementia, depression, and Alzheimer's disease and improve cognitive function.
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PMID:Folic acid and polyunsaturated fatty acids improve cognitive function and prevent depression, dementia, and Alzheimer's disease--but how and why? 1805 17

Hyperhomocysteinemia (HHcy) is related to central nervous system diseases. Epidemiological studies show a positive, dose-dependent relationship between plasma total homocysteine (tHcy) concentration and neurodegenerative disease risk. tHcy is a marker of B-vitamin (folate, B(12), B(6)) status. Hypomethylation, caused by low B-vitamin status and HHcy, is linked to key pathomechanisms of dementia; B-vitamin supplementation could potentially reduce neurological damage. In retrospective studies, the association between tHcy and cognition is impressive; there is also evidence that tHcy-lowering treatment could be effective in primary and secondary stroke prevention. Increased tHcy and low serum folate occur in patients with Parkinson's disease, especially those receiving L-dopa. There is also an association between HHcy and multiple sclerosis, and between B-vitamin status and depression. Studies also confirm a causal role for tHcy in epilepsy, and certain anti-epileptics enhance HHcy. B-vitamin status should be optimized by ensuring sufficient intake in patients with neuropsychiatric diseases. HHcy occurs commonly in the elderly and can contribute to age-related neurodegeneration. Treatment with folic acid, B(12) and B(6) lowers tHcy. For secondary and primary prevention from several neuropsychiatric disorders, it seems prudent to actively identify deficient subjects and ensure sufficient vitamin intake.
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PMID:The role of hyperhomocysteinemia and B-vitamin deficiency in neurological and psychiatric diseases. 1806 46

Within the past four decades, the efforts of investigators worldwide have established the amino acid homocysteine (Hcy) as an important factor in arteriosclerosis and ageing. The amino acid homocysteine is a unique candidate for the study of different age-related pathological conditions, namely vascular diseases, dementia disorders and late-life depression, due to its multiple roles in different pathways leading to atherosclerosis and neurotoxicity. Especially, the role of homocysteine in predicting risk for atherothrombotic vascular disease has been evaluated in several observational studies in a large number of patients. These studies show that the overall risk for vascular disease is small, with prospective, longitudinal studies reporting a weaker association between homocysteine and atherothrombotic vascular disease compared to retrospective case-control and cross-sectional studies. Furthermore, randomised controlled trials of homocysteine-lowering therapy have failed to prove a causal relationship. On the basis of these results, there is currently insufficient evidence to recommend routine screening and treatment of elevated homocysteine concentrations with folic acid and other vitamins to prevent atherothrombotic vascular disease.
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PMID:Homocysteine, folic acid and coronary artery disease: possible impact on prognosis and therapy. 1861 Jun 89

Folate deficiency and resultant increased homocysteine levels have been linked experimentally and epidemiologically with neurodegenerative conditions like stroke and dementia. Moreover, folate deficiency has been implicated in the pathogenesis of psychiatric disorders, most notably depression. We hypothesized that the pathogenic mechanisms include uracil misincorporation and, therefore, analyzed the effects of folate deficiency in mice lacking uracil DNA glycosylase (Ung-/-) versus wild-type controls. Folate depletion increased nuclear mutation rates in Ung-/- embryonic fibroblasts, and conferred death of cultured Ung-/- hippocampal neurons. Feeding animals a folate-deficient diet (FD) for 3 months induced degeneration of CA3 pyramidal neurons in Ung-/- but not Ung+/+ mice along with decreased hippocampal expression of brain-derived neurotrophic factor protein and decreased brain levels of antioxidant glutathione. Furthermore, FD induced cognitive deficits and mood alterations such as anxious and despair-like behaviors that were aggravated in Ung-/- mice. Independent of Ung genotype, FD increased plasma homocysteine levels, altered brain monoamine metabolism, and inhibited adult hippocampal neurogenesis. These results indicate that impaired uracil repair is involved in neurodegeneration and neuropsychiatric dysfunction induced by experimental folate deficiency.
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PMID:Folate deficiency induces neurodegeneration and brain dysfunction in mice lacking uracil DNA glycosylase. 1861 92

Lowering plasma low density lipoprotein-cholesterol (LDL-C), blood pressure, homocysteine, and preventing platelet aggregation using a combination of a statin, three blood pressure lowering drugs such as a thiazide, a beta blocker, and an angiotensin converting enzyme (ACE) inhibitor each at half standard dose; folic acid; and aspirin-called as polypill- was estimated to reduce cardiovascular events by approximately 80%. Essential fatty acids (EFAs) and their long-chain metabolites: gamma-linolenic acid (GLA), dihomo-GLA (DGLA), arachidonic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and other products such as prostaglandins E1 (PGE1), prostacyclin (PGI2), PGI3, lipoxins (LXs), resolvins, protectins including neuroprotectin D1 (NPD1) prevent platelet aggregation, lower blood pressure, have anti-arrhythmic action, reduce LDL-C, ameliorate the adverse actions of homocysteine, show anti-inflammatory actions, activate telomerase, and have cytoprotective properties. Thus, EFAs and their metabolites show all the classic actions expected of the "polypill". Unlike the proposed "polypill", EFAs are endogenous molecules present in almost all tissues, have no significant or few side effects, can be taken orally for long periods of time even by pregnant women, lactating mothers, and infants, children, and adults; and have been known to reduce the incidence cardiovascular diseases including stroke. In addition, various EFAs and their long-chain metabolites not only enhance nitric oxide generation but also react with nitric oxide to yield their respective nitroalkene derivatives that produce vascular relaxation, inhibit neutrophil degranulation and superoxide formation, inhibit platelet activation, and possess PPAR-gamma ligand activity and release NO, thus prevent platelet aggregation, thrombus formation, atherosclerosis, and cardiovascular diseases. Based on these evidences, I propose that a rational combination of omega-3 and omega-6 fatty acids and the co-factors that are necessary for their appropriate action/metabolism is as beneficial as that of the combined use of a statin, thiazide, a beta blocker, and an angiotensin converting enzyme (ACE) inhibitor, folic acid, and aspirin. Furthermore, appropriate combination of omega-3 and omega-6 fatty acids may even show additional benefits in the form of protection from depression, schizophrenia, Alzheimer's disease, and enhances cognitive function; and serve as endogenous anti-inflammatory molecules; and could be administered from childhood for life long.
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PMID:Essential fatty acids and their metabolites could function as endogenous HMG-CoA reductase and ACE enzyme inhibitors, anti-arrhythmic, anti-hypertensive, anti-atherosclerotic, anti-inflammatory, cytoprotective, and cardioprotective molecules. 1892 79

Depression is common - one-fourth of the U.S. population will have a depressive episode sometime in life. Folate deficiency is also relatively common in depressed people, with approximately one-third of depressed individuals having an outright deficiency. Folate is a water-soluble B-vitamin necessary for the proper biosynthesis of the monoamine neurotransmitters serotonin, epinephrine, and dopamine. The active metabolite of folate, 5-methyltetrahydrofolate (5-MTHF, L-methylfolate), participates in re-methylation of the amino acid metabolite homocysteine, creating methionine. S-adenosylmethionine (SAMe), the downstream metabolite of methionine, is involved in numerous biochemical methyl donation reactions, including reactions forming monoamine neurotransmitters. Without the participation of 5-MTHF in this process, SAMe and neurotransmitter levels decrease in the cerebrospinal fluid, contributing to the disease process of depression. SAMe supplementation was shown to improve depressive symptoms. 5-MTHF also appears to stabilize, enhance production of, or possibly act as a substitute for, tetrahydrobiopterin (BH4), an essential cofactor in monoamine neurotransmitter biosynthesis. There are few intervention studies of folic acid or 5-MTHF as a stand-alone treatment for depression related to folate deficiency; however, the studies that have been conducted are promising. Depressed individuals with low serum folate also tend to not respond well to selective serotonin reuptake inhibitor (SSRI) antidepressant drugs. Correcting the insufficiency by dosing folate along with the SSRI results in a significantly better antidepressant response.
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PMID:The methylation, neurotransmitter, and antioxidant connections between folate and depression. 1895 Feb 48


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