Background The effects of high dose folic acid (FA) supplementation in healthy individuals on blood folate concentrations and immune response are unknown. Objective The aim of the study was to evaluate the effects of daily consumption of a tablet containing 5 mg of FA on serum folate; number and cytotoxicity of natural killer (NK) cells; mRNA expression of dihydrofolate reductase (DHFR), methylenetetrahydrofolate reductase (MTHFR), interferon-γ (IFNG), tumor necrosis factor-α (TNFA) and interleukin-8 (IL8) genes; and concentrations of serum inflammatory markers. Methods This prospective clinical trial was conducted in 30 healthy Brazilian adults, (15 women), aged 27.7 y (95% CI: 26.4, 29.1 y), with a body mass index (in kg/m2) of 23.1 (95% CI: 22.0, 24.3). Blood was collected at baseline and after 45 and 90 d of intervention. Serum folate concentrations were measured by microbiologic assay and HPLC-tandem mass spectrometry [folate forms, including unmetabolized folic acid (UMFA)]. We used real-time polymerase chain reaction to assess mononuclear leukocyte mRNA expression and flow cytometry to measure the number and cytotoxicity of NK cells. Results Serum folate concentration increased by ~5-fold after the intervention (P < 0.001), and UMFA concentrations increased by 11.9- and 5.9-fold at 45 and 90 d, respectively, when compared with baseline (P < 0.001). UMFA concentrations increased (> 1.12 nmol/L) in 29 (96.6%) participants at day 45 and in 26 (86.7%) participants at day 90. We observed significant reduction in the number (P < 0.001) and cytotoxicity (P = 0.003) of NK cells after 45 and 90 d. Compared with baseline, DHFR mRNA expression was higher at 90 d (P = 0.006) and IL8 and TNFA mRNA expressions were higher at 45 and 90 d (P = 0.001 for both). Conclusion This noncontrolled intervention showed that healthy adults responded to a high dose FA supplement with increased UMFA concentrations, changes in cytokine mRNA expression, and reduced number and cytotoxicity of NK cells. This trial was registered at www.ensaiosclinicos.gov.br as RBR-2pr7zp.
Acetonitrile recovery from a residual aqueous solution was performed by different techniques. Particularly, a residual acetonitrile‐water solution used in high‐performance liquid chromatography analyses at the School of Pharmaceutical Sciences of the University of São Paulo was investigated with the aim to identify the most feasible way to treat such a waste and recover acetonitrile within its dependencies. Three procedures were set up and tested, which consisted of different combinations of well‐known separation techniques, such as fractional distillation, cooling, salting‐out, and sugaring‐out. Cooling followed by distillation and subsequent addition of calcium chloride allowed to recover the highest amount of acetonitrile with a purity greater than 95 %.
AMORIM, Patrícia Mendonça da Silva. Strategies for the treatment of chemical waste generated by FCF/USP. 2018. 105 f. Dissertação (Mestrado em Tecnologia Bioquímico
Background Folic acid (FA) is the synthetic form of folate, a B complex vitamin which plays an important role in several reactions in the body. Folate deficiency produces several clinical complications including anemia and is associated with an increased risk of cancer, cardiovascular disease and neural tube defects. With the advent of FA and iron fortification of wheat and corn flour (150 µg of folic acid and 4.2 mg of iron/100 grams) in Brazil since 2004, the population was exposed to amounts of folate beyond that normally present in foods. The form present in fortified food is taken up by cells and reduced by the enzyme dihydrofolate reductase (DHFR) first to dihydrofolate (DHF) and then tetrahydrofolate (THF). DHF is the preferred natural substrate. Amounts of FA higher than the defined tolerable upper intake of 1 mg/day could impair the ability of DHFR to convert DHF to THF. Some patients with hemolytic anemia, such as hereditary spherocytosis (HS), need larger amounts of FA to compensate for their increase in erythropoiesis and have been receiving 5mg/day of supplemental FA, the only formulation available in Brazil, in addition to being exposed to compulsory food fortification with FA. Objective The aim of this study was to compare the effects of 5mg/day FA on serum folate levels, mRNA expression of DHFR, MTHFR, interferon-γ, TNF-α and interleukin-8 genes; and cytotoxicity of lymphocytes and NK cells in patients with HS and healthy individuals not receiving supplemental FA. Material and Methods Twenty-five patients with HS exposed to mandatory fortification and in use or not of 5 mg/day of FA were included in this study. Forty-five healthy people were recruited as a control group, and matched with HS patients according to age, gender, body mass index and self-reported skin color. Blood count, including reticulocytes, C-reative protein and lactic dehydrogenase (LDH) were performed. Serum folate (SF) and vitamin B12 were determined by a microbiological method. The mRNA expression of DHFR, MTHFR, interferon-γ, TNF-α and interleukin-8 genes in mononuclear cells were performed in duplicate, using Real Time PCR. Cytotoxicity of lymphocytes and NK cells were also carried out using a flow cytometric assay. Results Eight HS patients did not use FA 5 mg everyday (4 declared no use anytime and 4 reported intermittent use) and none of control group used FA supplementation. Reticulocytes and LDH were higher in HS group (P<0.05), however no difference was found between levels of C-reative protein (P=0.173) and vitamin B12 (P= 0.699) when compared with control group. The HS group had higher SF levels and elevated mRNA expression of DHFR, MTHFR, interferon-γ, TNF-α and interleukin-8 when compared with controls (P<0.05, Figure 1). It is not clear whether FA use or underlying disease was be responsible for increasing of mRNA expression of these genes. To verify the effect of SF levels on HS patients, this group was classified into two subgroups according to median SF (< 46.6 and ≥ 46.6 nmol/L). Interestingly, the subgroup with higher SF levels showed significantly elevated DHFR mRNA expression but no difference was found in the mRNA expression of the other genes studied. The two subgroups were similar according to WBC, RBC, hemoglobin, MCV, reticulocytes, LDH, C-reative protein, vitamin B12 and cytotoxic capacity of lymphocytes and NK cells. Conclusions Elevated SF concentrations were associated with higher mRNA expression of DHFR gene in HS patients, suggesting that the use of higher amounts of FA might influence the expression and activity of DHFR and thus affect folate metabolism in these patients. It is not known whether normal subjects receiving similar high doses of FA show the same effects. Financing: FAPESP 2012/12912-1 and CNPq 4826412012-6 Figure 1 – Serum folate levels (A) and DHFR mRNA (B) in hereditary spherocytosis and control group. The DHFR mRNA expressions in HS patients according to serum folate levels were shown (C). Figure 1 – Serum folate levels (A) and DHFR mRNA (B) in hereditary spherocytosis and control group. The DHFR mRNA expressions in HS patients according to serum folate levels were shown (C). The line in each graphic is the median. The median and percentiles 25 and 75 (P25 – P75) for control and hereditary spherocytosis groups were, respectively: A- serum folate: 22.1 (14.5 – 36.6 nmolL) and 51.5 (19.5 – 95.2 nmolL), B- DHFR mRNA expression: 1.59 (1.00 – 2.48) and 35.8 (19.0 – 52.7). In Figure C, the median and percentiles 25 and 75 (P25 – P75) for DHFR mRNA expression, according to serum folate levels (SF <46.6 and SF ≥ 46.6 nmol/L), were, respectively: 19.6 (1.4 – 38.6) and 50.3 (23 – 66.8). Disclosures No relevant conflicts of interest to declare.
Background The methylenetetrahydrofolate reductase (MTHFR) and methylenetetrahydrofolate dehydrogenase (MTHFD1) enzymes play important roles in the metabolism of folate. MTHFR catalyses the reduction of 5,10-methylene-tetrahydrofolate (5,10-methylene-THF) to 5-methyl-THF and present a crucial role in the regulation of available folate to homocysteine remethylation, in a cobalamin (Cbl) dependent reaction. MTHFD1 has three distinct enzymatic activities in folate metabolism: the conversion of THF to 10-formyl-THF; the reversible conversion of 10-formyl-THF to 5,10-methenyl-THF; and the conversion of 5,10-methenyl-THF to 5,10-methylene-THF. The two enzymes were related with DNA synthesis and single nucleotides polymorphisms (SNPs) in their genes have been associated with lower folate levels. People who have increased cellular duplication could be affected by low folate levels. Hereditary spherocytosis (HS) patients had an increased erythropoiesis and need more amounts of acid folic. In Brazil, HS patients are usually treated with 5mg/day of folic acid, the only formulation available. The use of folic acid by β-thalassemia heterozygotes (β-TH) subjects is not common, and depends of the individual clinical feature. Furthermore, in Brazil, HS patients and β-TH people have been exposed to food fortification (wheat and corn flours) with 150 µg of FA since 2004. The influences of variants of MTHFR and MTHFD1 SNPs in people with increased erythropoiesis, especially in HS patients, are not known. Objective The aim of the study was to evaluate the interaction between MTHFR c. 677C>T and c. 1298A>C and MTHFD1 c. 1958G>A SNPs and the use or not of FA supplementation in HS patients. It was also our objective to compare the folate and Cbl levels according to genotypes for MTHFR and MTHFD1 SNPs in β-TH subjects and their controls. Methods Twenty-five patients with HS, 49 β-TH subjects and 98 healthy people exposed to mandatory fortification of wheat and corn flours with FA were included in this study. Serum folate and Cbl were determined by microbiologic assays. Genomic DNA was extracted from whole blood using commercial kit. The genotypes for MTHFR c. 1298A>C and MTHFD1 c.1958G>A SNPs were determined by Real Time PCR using TaqMan assays. PCR-RFLP was used for genotyping MTHFR c. 677C>T SNP. Haplotype frequencies (MTHFR c. 677C>T and c. 1298 A>G) and the standardized disequilibrium coefficient (D’) for pair-wise linkage disequilibrium were assessed by the Expectation-Maximization (EM) algorism using the Haploview Software. We considered linkage disequilibrium when D’ ≥0.50. The study of linkage disequilibrium was performed by calculating the coefficient D' of Lewontin. Results The frequencies of genotypes for MTHFR (c. 677C>T and c. 1298A>C) and MTHFD1 c. 1958G>A SNPs were similar in HS, β-TH and control groups (p>0.05). When genotypes were grouped according to the presence of the mutated allele (CC vs. CT+TT for MTHFR c. 677C>T, AA vs. AC+CC for MTHFR c. 1298A>C and GG vs. GA+AA for MTHFD1 c. 1958G>A), no differences were also found (p>0.05). The MTHFR c.677C>T and c. 1298A>C SNPs are in complete linkage disequilibrium (D'=1.0). Regarding the correlation coefficient between the two loci (r2), the value found in this analysis was equal to 0.169 in HS versus control group and 0.205 in β-TH versus control group. The haplotype CA, which is formed by the ancestral allele of MTHFR c. 677C>T and c. 1298A>C SNPs respectively, was more frequent in controls (41.9%) than in the β-TH group (28.1%). However, this finding was not observed in HS group comared with control group. No association was found between genotypes for MTHFR c. 677C>T and c. 1298A>C and MTHFD1 c. 1958G>A and alterations in folate and Cbl levels in three groups. ANCOVA was used for evaluating the interaction between the use of FA supplementation and MTHFR c.677C>T SNP on folate levels in HS patients. Only FA supplementation was associated with increased serum folate, and no associations were observed with MTHFR SNP or interaction between both. Conclusion The SNPs were not associated with reduced serum folate levels in the three groups studied. This finding suggests that FA flour fortification in β-TH and controls, as well as, the supplementation plus fortification in HS group, could offset the effect of variants of SNPs, especially for MTHFR c.677C>T. Disclosures No relevant conflicts of interest to declare.
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