L-methylfolate, a new option in psychiatric treatment, would it be linked to psoriasis relapse?

We report a case of a 61-years-old woman in remission of psoriasis for 20 years. She presented recurrence of psoriasis in the form of plaques few days after taking L-methylfolate 15mg/day. The L-methylfolate was prescribed as an adjuvant for the treatment of depression in a patient with the methylenetetrahydrofolate reductase gene polymorphism (MTHFR).

L-methylfolate, a new option in psychiatric treatment, would it be linked to psoriasis relapse? / L-metilfolato, uma nova opção no tratamento psiquiátrico, estaria ligado à recaída de psoríase?

ABSTRACT We report a case of a 61-years-old woman in remission of psoriasis for 20 years. She presented recurrence of psoriasis in the form of plaques few days after taking L-methylfolate 15mg/day. The L-methylfolate was prescribed as an adjuvant for the treatment of depression in a patient with the methylenetetrahydrofolate reductase gene polymorphism (MTHFR).

RESUMO Paciente do sexo feminino, 61 anos, em remissão da psoríase por 20 anos. Apresentou recidiva de psoríase em forma de placas poucos dias após início de tratamento L-metilfolato na dose diária de 15mg. O L-metilfolato foi prescrito como terapêutica coadjuvante para tratamento de depressão em paciente portadora do polimorfismo do gene metilenotetrahidrofolato redutase.

Folate biosynthesis pathway: mechanisms and insights into drug design for infectious diseases.

Folate pathway is a key target for the development of new drugs against infectious diseases since the discovery of sulfa drugs and trimethoprim. The knowledge about this pathway has increased in the last years and the catalytic mechanism and structures of all enzymes of the pathway are fairly understood. In addition, differences among enzymes from prokaryotes and eukaryotes could be used for the design of specific inhibitors. In this review, we show a panorama of progress that has been achieved within the folate pathway obtained in the last years. We explored the structure and mechanism of enzymes, several genetic features, strategies, and approaches used in the design of new inhibitors that have been used as targets in pathogen chemotherapy.

Heterologous expression of Homo sapiens alpha-folate receptors in E. coli by fusion with a trigger factor for enhanced solubilization.

The role of Alpha folate receptors (FRα) in folate metabolism and cancer development has been extensively studied. The reason for this is not only associated to its direct relation to disease development but also to its potential use as a highly sensitive and specific biomarker for cancers therapies. Over the recent years, the crystal structures of human FRα complexed with different ligands were described relying on an expensive and time-consuming production process. Here, we constructed an efficient system for the expression and purification of a human FRα in E. coli. Unlike a conventional expression method we used a specific protein fusion expressing the target protein together with a trigger factor (TF). This factor is a chaperone from E. coli that assists the correct folding of newly synthesized polypeptide chains. The activity of rTFFRα was comparable to glycosylphosphatidylinositol (GPI) anchored proteins extracted from HeLa tumor cells. Our work demonstrates a straightforward and versatile approach for the production of active human FRα by heterologous expression; this approach further enhances the development of inhibition studies and biotechnological applications. The purified product was then conjugated to liposomes, obtaining a 35% higher signal from densitometry measurement on the immunoblotting assay in the contruct containing the Ni-NTA tag, as a mimesis of an exosome, which is of vital importance to nanotherapeutic techniques associated to treatment and diagnosis of tumors.

Expression of the tetrahydrofolate-dependent nitric oxide synthase from the green alga Ostreococcus tauri increases tolerance to abiotic stresses and influences stomatal development in Arabidopsis.

Nitric oxide (NO) is a signaling molecule with diverse biological functions in plants. NO plays a crucial role in growth and development, from germination to senescence, and is also involved in plant responses to biotic and abiotic stresses. In animals, NO is synthesized by well-described nitric oxide synthase (NOS) enzymes. NOS activity has also been detected in higher plants, but no gene encoding an NOS protein, or the enzymes required for synthesis of tetrahydrobiopterin, an essential cofactor of mammalian NOS activity, have been identified so far. Recently, an NOS gene from the unicellular marine alga Ostreococcus tauri (OtNOS) has been discovered and characterized. Arabidopsis thaliana plants were transformed with OtNOS under the control of the inducible short promoter fragment (SPF) of the sunflower (Helianthus annuus) Hahb-4 gene, which responds to abiotic stresses and abscisic acid. Transgenic plants expressing OtNOS accumulated higher NO concentrations compared with siblings transformed with the empty vector, and displayed enhanced salt, drought and oxidative stress tolerance. Moreover, transgenic OtNOS lines exhibited increased stomatal development compared with plants transformed with the empty vector. Both in vitro and in vivo experiments indicate that OtNOS, unlike mammalian NOS, efficiently uses tetrahydrofolate as a cofactor in Arabidopsis plants. The modulation of NO production to alleviate abiotic stress disturbances in higher plants highlights the potential of genetic manipulation to influence NO metabolism as a tool to improve plant fitness under adverse growth conditions.

Folates Induce Colorectal Carcinoma HT29 Cell Line Proliferation Through Notch1 Signaling.

Folic acid (FA) consumption at high levels has been associated with colon cancer risk. Several mechanisms have been proposed to explain this association. The Notch signal pathway has been implicated in the regulation of cellular proliferation. Our aim was to demonstrate that high concentrations of FA or its reduced form, 5-methyltetrahydrofolic acid (5-MTHF), increase colorectal carcinoma HT29 cell proliferation through an increase of Notch1 activation and to prove if the inhibition of Notch1 activation by gamma secretase inhibitor, reduce the effect of folic acid. HT29 cells were cultured in high (400 nM), low (20 nM), or 0 nM FA or 5-MTHF concentrations during 96 h with or without DAPT (gamma secretase inhibitor). Cell proliferation was determined by the methylthiazole tetrazolium method, and Notch1-intracellular domain (NICD) was analyzed by flow cytometry. HT29 cells exposed to 400 nM FA or 5-MTHF showed higher proliferation rate than those exposed to 20 nM of FA or 5-MTHF (P < 0.01) during 96 h. NICD expression increased at higher FA or 5-MTHF concentrations compared with lower concentrations (P < 0.01). This effect on proliferation was partially reversible when we blocked Notch1 activation with the inhibitor of γ-secretase (P < 0.05).These data suggest that high concentration of FA and 5-MTHF induce HT29 cell proliferation activating Notch1 pathway.

Folates retention in brassica vegetables consumed in Brazil after different cooking methods / Retención de folatos en hortalizas consumidas en Brasil después de diferentes métodos de cocción

The present study aimed to determine the effects of different traditional cooking methods on folate (tetrahydrofolate - THF, 5-methyltetrahydrofolate - 5- MTHF and 5-formyltetrahydrofolate - 5-FTHF) retention in leafy vegetables. The analysis of folates was carried out by high performance liquid chromatography (HPLC), with detection by fluorescence, using gradient elution, mobile phase of acetonitrile and phosphate buffer solution. The retention of isomers in vegetables after cooking ranged from 17.0 % to 87.2 % for THF, 53.4 - 94.1% for 5-MTHF and 39.0 - 107.9% for 5-FTHF. The retention of folates depended on the food matrix, the kind of isomer, and the cooking methods used. It is recommended that one should have more control over the choices for methods and time of cooking and the amount of water used at home and at foodservice as well.

El presente estudio tuvo como objetivo determinar los efectos de los diferentes métodos de cocción tradicionales sobre la retención de folatos (tetrahidrofolato - THF, 5-metiltetrahidrofolato - 5- MTHF y 5-formiltetrahidrofolato - 5 FTHF) en hortalizas. El análisis de folatos se llevó a cabo por cromatografía líquida de alta resolución (CLAR), con detección por fluorescencia, usando elución en gradiente, fase móvil de acetonitrilo y solución tampón de fosfato. La retención de los isómeros en las hortalizas después de la cocción varió de 17,0% a 87,2% para THF, 53,4 a 94,1% para 5-MTHF y de 39,0 a 107,9% para 5- FTHF. La retención de folatos dependió de la matriz del alimento, el tipo de isómero, y los métodos de cocción utilizados. Se recomienda que uno debe tener más control sobre las opciones de métodos y tiempo de cocción y la cantidad de agua utilizada en el hogar y también en los servicio de alimentación.

Folates retention in brassica vegetables consumed in Brazil after different cooking methods.

The present study aimed to determine the effects of different traditional cooking methods on folate (tetrahydrofolate - THF, 5-methyltetrahydrofolate - 5- MTHF and 5-formyltetrahydrofolate - 5-FTHF) retention in leafy vegetables. The analysis of folates was carried out by high performance liquid chromatography (HPLC), with detection by fluorescence, using gradient elution, mobile phase of acetonitrile and phosphate buf- fer solution. The retention of isomers in vegetables after cooking ranged from 17.0 % to 87.2 % for THF, 53.4 - 94.1% for 5-MTHF and 39.0 - 107.9% for 5-FTHF. The retention of folates depended on the food matrix, the kind of isomer, and the cooking methods used. It is recommended that one should have more control over the choices for methods and time of cooking and the amount of water used at home and at foodservice as well.

Folate levels and polyglutamylation profiles of papaya (Carica papaya cv. Maradol) during fruit development and ripening.

Folates are essential micronutrients for humans, and their deficiency causes several detrimental effects on human health. Papaya fruit is an important natural source of some micronutrients. This paper presents a first complete characterization of folate derivatives accumulated in cv. Maradol papaya during fruit development and ripening processes. During postharvest ripening, the fruit accumulated up to 24.5% of the daily folate recommended dietary allowance (RDA) for an adult in a 1 cup (145 g) portion. Tetrahydrofolate (THF) and 5-methyl-THF were the predominant folate classes observed. Surprisingly, an unusually long polyglutamylation profile of tentatively up to 17 glutamates linked to 5-methyl-THF was detected; to the authors' knowledge, this very long polyglutamyl tail has not been reported for any organism, and it is probably characteristic of this plant species. This polyglutamylation degree changed throughout fruit development and ripening, showing the largest differences at the onset of ripening. This work raises questions about the functional role of folate derivatives in fruit development.

Natural killer cell cytotoxicity is not regulated by folic acid in vitro.

OBJECTIVES: Folate supplementation may be associated with an increased risk of developing several types of cancer and a derangement of immune function. Among the latter, Natural killer (NK) cells are involved in non-MHC-restricted natural immunity against malignant target cells. Abnormalities in NK cell number or function have been associated with a higher cancer risk. The aim of this study was to study in vitro the possible effect of different concentrations of 5-methyltetrahydrofolic acid (5-MTHF) or folic acid on NK cell cytotoxic function, and expression of the stimulatory and inhibitory receptors KIRDL4, KIRDL3, and NKG2D. METHODS: Volunteer-derived peripheral mononuclear cells (PBMC) and highly enriched NK cells (95% CD56+ CD16+) were grown in folic acid free-RPMI 1640, supplemented either with folic acid or 5-MTHF (15-100 nM) during 72 h to 96 h. RESULTS: No differences in the cytolytic activity of PBMC and enriched NK cells were observed. After 96 h of in vitro culture without folate or supplemented with FA or 5-MTHF (30 or 100 nM), there were no changes in the percentage of HPNK receptor-positive cells. CONCLUSIONS: Our data indicate that a high dose of 5-MTHF or folic acid does not influence NK cell function in vitro.

Investigation of protocols to extraction and quantification of folates in vegetables matrices split into liquor and fiber fraction using factorial design.

The main protocols of extraction were investigated for the six folate forms in vegetable matrices, treated in two fractions, liquor and fiber. In a pilot study, it was used ammonium acetate added of 2-mercaptoetanol and ascorbic acid as extraction solution. The condition of use of protease and folate conjugase was evaluated, besides alternative treatments without enzyme use. Based on the results of this stage, it was built the factorial design 2(4), with three replications at the central point, using the following variables: temperature, time for reaction, molar concentration of the extraction solution and ratio sample/solution as independent variables and dependent variable, the amount of each folate form extracted as well as spectral and chromatographic parameters. In the pilot study it was verified that the enzyme use can cause an increase in the variability of the folate content, which enabled to build the factorial design without the enzyme use. The binomial time and temperature showed greatest impact on the extraction profile, besides high concentrations of ammonium acetate resulting in bifurcation of some peaks. 5-Methyltetrahydrofolate was extracted primordially in the liquor fraction, indicating that this treatment on the matrix provoked suitable extraction condition to this folate.

Role of an invariant lysine residue in folate binding on Escherichia coli thymidylate synthase: calorimetric and crystallographic analysis of the K48Q mutant.

Thymidylate synthase (TS) catalyzes the reductive methylation of deoxyuridine monophosphate (dUMP) using methylene tetrahydrofolate (CH(2)THF) as cofactor, the glutamate tail of which forms a water-mediated hydrogen bond with an invariant lysine residue of this enzyme. To understand the role of this interaction, we studied the K48Q mutant of Escherichia coli TS using structural and biophysical methods. The k(cat) of the K48Q mutant was 430-fold lower than wild-type TS in activity, while the K(m) for the (R)-stereoisomer of CH(2)THF was 300 microM, about 30-fold larger than K(m) from the wild-type TS. Affinity constants were determined using isothermal titration calorimetry, which showed that binding was reduced by one order of magnitude for folate-like TS inhibitors, such as propargyl-dideazafolate (PDDF) or compounds that distort the TS active site like BW1843U89 (U89). The crystal structure of the K48Q-dUMP complex revealed that dUMP binding is not impaired in the mutant, and that U89 in a ternary complex of K48Q-nucleotide-U89 was bound in the active site with subtle differences relative to comparable wild-type complexes. PDDF failed to form ternary complexes with K48Q and dUMP. Thermodynamic data correlated with the structural determinations, since PDDF binding was dominated by enthalpic effects while U89 had an important entropic component. In conclusion, K48 is critical for catalysis since it leads to a productive CH(2)THF binding, while mutation at this residue does not affect much the binding of inhibitors that do not make contact with this group.

5-methyltetrahydrofolic acid stimulates endothelin-1 production in low density lipoprotein-treated human endothelial cells.

BACKGROUND AND AIMS: Several studies have shown the beneficial effects of folate treatment in improving cardiovascular function. However, the mechanisms involved have not been clearly identified. The aim of this study is to determine the effect of folates and vitamin B12 on endothelial vasoconstriction/vasodilatation parameters in cultured human endothelial cells incubated with human low density lipoproteins (LDL). METHODS AND RESULTS: Human umbilical vein endothelial cells (HUVEC) were extracted from recently delivered umbilical cords, cultured until confluence was achieved, and then incubated for 24h with folic acid (FA), 5-methyltetrahydrofolic acid (5-MTHF) or vitamin B12 (B12) in the presence or absence of LDL that was isolated from healthy volunteers. Total nitrites (as a measure of nitric oxide production), thiobarbituric acid reactive species (TBARS, a parameter of lipid peroxidation), and endothelin-1 (ET-1) were determined in the incubation media. None of the vitamins, either in the presence or absence of LDL, was able to modify nitric oxide production by HUVEC. A significant reduction of ET-1 production was observed in LDL-treated cells. This effect was not modified by FA or B12; however, 5-MTHF caused a concentration-dependent increase on ET-1 production, an effect coincidental with reduced TBARS production. CONCLUSIONS: This study demonstrates for the first time that 5-MTHF, but not FA or B12, increases ET-1 production in LDL-treated endothelial cells. Although this effect was associated with the antioxidant properties of this folate, our results show that additional specific mechanisms involving 5-MTHF-LDL interactions may be operating to regulate endothelial function.