Pharmacokinetic profiles of methylcobalamin in rats after multiple administration routes by a simple LC-MS/MS assay with a small volume of plasma.

Methylcobalamin (MBL) is a vitamin B12 coenzyme and is effective for treating peripheral neuropathies. Little is known about pharmacokinetics (PK) of MBL in animals, we have developed a simple assay for MBL by using only 0.01 mL of plasma for PK of MBL in rats. Under minimal light exposure (<5 lx), MBL was extracted by a simple protein precipitation using methanol and detected by liquid chromatography with tandem mass spectrometry. MBL in rat plasma at 20-10,000 ng/mL was quantified using only 0.01 mL of plasma. Relative error and relative standard deviation met the acceptance criteria in reproducibility assessments, indicating the robustness of the assay. PK of MBL was evaluated after intravenous, intramuscular, and subcutaneous administration. PK of MBL was dose proportional at 5-20 mg/kg in both intramuscular and subcutaneous administrations. Bioavailability after the two dosing routes was complete (ca. 100 %). The incurred sample reanalysis also supported that the assay is robust. The established assay was successfully applied to PK studies in rats to find that MBL showed high bioavailability after intramuscular and subcutaneous administrations.

Nanoparticles of nucleotide-free analogue of vitamin B12 formed in protein nanocarriers and their neuroprotective activity in vivo.

Recently, we have described the first supermolecular nanoentities of vitamin B12 derivative, viz. monocyano form of heptabutyl cobyrinate, unique nanoparticles with strong noncovalent intermolecular interactions, emerging optical and catalytic properties. Their nearest analogue, heptamethyl cobyrinate (ACCby), exhibits bioactivity. Here, we demonstrate the first example of the formation of nanoparticles of this nucleotide-free analogue of vitamin B12 in protein nanocarriers and neuroprotective activity in vivo of the own nanoform of the drug. The preparation and characterization of nanocarriers based on bovine serum albumin (BSA) loaded with vitamin B12 (viz. cyano- and aquacobalamins) and ACCby were performed. Nucleotide-free analogue of vitamin B12 is tightly retained by the protein structure and exists in an incorporated state in the form of nanoparticles. The effect of encapsulated drugs on the character and severity of primary generalized seizures in rats induced by the pharmacotoxicant thiosemicarbazide was studied. Cyanocobalamin and ACCby exhibited a neuroprotective effect. The best influence of the encapsulation on the effectiveness of the drugs was achieved in the case of AСCby, whose bioavailability as a neuroprotector did not change upon introduction in BSA particles, i.e., 33 % of surviving animals were observed upon ACCby administration in free form and in encapsulated state. No surviving rats were observed without the administration of drugs. Thus, BSA nanocarriers loaded by nanoparticles of nucleotide-free analogues of vitamin B12, including hydrophobic ones, can be recommended for neuroprotection and targeted delivery.

Nutritional vitamin B12 regulates RAS/MAPK-mediated cell fate decisions through one-carbon metabolism.

Vitamin B12 is an essential nutritional co-factor for the folate and methionine cycles, which together constitute one-carbon metabolism. Here, we show that dietary uptake of vitamin B12 modulates cell fate decisions controlled by the conserved RAS/MAPK signaling pathway in C. elegans. A bacterial diet rich in vitamin B12 increases vulval induction, germ cell apoptosis and oocyte differentiation. These effects are mediated by different one-carbon metabolites in a tissue-specific manner. Vitamin B12 enhances via the choline/phosphatidylcholine metabolism vulval induction by down-regulating fat biosynthesis genes and increasing H3K4 tri-methylation, which results in increased expression of RAS/MAPK target genes. Furthermore, the nucleoside metabolism and H3K4 tri-methylation positively regulate germ cell apoptosis and oocyte production. Using mammalian cells carrying different activated KRAS and BRAF alleles, we show that the effects of methionine on RAS/MAPK-regulated phenotype are conserved in mammals. Our findings suggest that the vitamin B12-dependent one-carbon metabolism is a limiting factor for diverse RAS/MAPK-induced cellular responses.

Trait-based study predicts glycerol/diol dehydratases as a key function of the gut microbiota of hindgut-fermenting carnivores.

BACKGROUND: Microbial pdu and cob-cbi-hem gene clusters encode the key enzyme glycerol/diol dehydratase (PduCDE), which mediates the transformation of dietary nutrients glycerol and 1,2-propanediol (1,2-PD) to a variety of metabolites, and enzymes for cobalamin synthesis, a co-factor and shared good of microbial communities. It was the aim of this study to relate pdu as a multipurpose functional trait to environmental conditions and microbial community composition. We collected fecal samples from wild animal species living in captivity with different gut physiology and diet (n = 55, in total 104 samples), determined occurrence and diversity of pdu and cob-cbi-hem using a novel approach combining metagenomics with quantification of metabolic and genetic biomarkers, and conducted in vitro fermentations to test for trait-based activity. RESULTS: Fecal levels of the glycerol transformation product 1,3-propanediol (1,3-PD) were higher in hindgut than foregut fermenters. Gene-based analyses indicated that pduC harboring taxa are common feature of captive wild animal fecal microbiota that occur more frequently and at higher abundance in hindgut fermenters. Phylogenetic analysis of genomes reconstructed from metagenomic sequences identified captive wild animal fecal microbiota as taxonomically rich with a total of 4150 species and > 1800 novel species but pointed at only 56 species that at least partially harbored pdu and cbi-cob-hem. While taxonomic diversity was highest in fecal samples of foregut-fermenting herbivores, higher pduC abundance and higher diversity of pdu/cbi-cob-hem related to higher potential for glycerol and 1,2-PD utilization of the less diverse microbiota of hindgut-fermenting carnivores in vitro. CONCLUSION: Our approach combining metabolite and gene biomarker analysis with metagenomics and phenotypic characterization identified Pdu as a common function of fecal microbiota of captive wild animals shared by few taxa and stratified the potential of fecal microbiota for glycerol/1,2-PD utilization and cobalamin synthesis depending on diet and physiology of the host. This trait-based study suggests that the ability to utilize glycerol/1,2-PD is a key function of hindgut-fermenting carnivores, which does not relate to overall community diversity but links to the potential for cobalamin formation. Video Abstract.

Physiological Metabolic Analysis of VB12 Accumulation in Ensifer adhaerens Casida A Enhanced by Oxygen Limitation.

Cobalamin (VB12) is in enormous demand across the fields of medicine, food, and feed additives. However, the oxygen supply plays a critical role in VB12 biosynthesis by Ensifer adhaerens Casida A and has been identified as a bottleneck for economical substrate consumption. This study elucidates the relationship between oxygen limitation and VB12 accumulation with transcriptomic and metabolomic analyses. Under oxygen limitation, E. adhaerens enhances oxygen transport and storage by increasing expression of flavin hemoglobin (Hmp), which was up-regulated 6-fold at 24 h of oxygen restriction compared to the oxygen restriction of 4 h (p < 0.01). Because of the cofactor of Hmp is heme, the demand for heme increases, leading to the upregulation of genes in the heme biosynthesis pathway. Similarly, genes involved in biosynthesis of its precursor, 5-ALA, were upregulated as well. 5-ALA is also a direct precursor of VB12, further leading to the upregulation of genes in the VB12 biosynthesis pathway. This process initiates biosynthesis and accumulation of VB12. As VB12 and heme biosynthesis progresses, genes associated with the biosynthesis and transportation pathways of compounds related to their biosynthesis were likewise upregulated, including genes involved in S-adenosyl methionine (SAM) biosynthesis, and the transport of Fe2+ and Co2+. Additionally, amino acids and organic acids associated with biosynthesis were also extensively consumed, such as methionine, which is used for synthesizing SAM, decreased by 310% after 24 h of oxygen limitation compared to 20% dissolved oxygen (p < 0.05). At the same time, genes related to growth-associated metabolic pathways, such as pentose phosphate pathway (PPP), were significantly downregulated. Therefore, the potential mechanism by which E. adhaerens accumulates VB12 under oxygen-limited conditions by enhancing Hmp expression, which facilitates the porphyrin metabolic pathway and promotes VB12 biosynthesis. This research provides valuable insights for increasing VB12 production through metabolic engineering and process optimization.

Fatty acids profile in pregnancies affected by neural tube defects.

This study aimed to determine if maternal fatty acids (FA) levels during pregnancy are associated with the occurrence of neural tube defects (NTDs) and to explore the correlation between FA and maternal vitamin D, homocysteine, vitamin B12, and folate in cases. Plasma FA composition was assessed using capillary gas chromatography. Comparisons between cases and controls were performed by independent samples t-test for continuous variables. Cases had significantly higher levels of heptadecanoic acid, linolelaidic acid, and arachidonic acid (ARA):(eicosapentaenoic acid+docosahexaenoic acid) ratio than controls (p < 0.05). Nervonic acid, ARA, adrenic acid, eicosapentaenoic acid, docosahexaenoic acid, and omega-3 polyunsaturated fatty acids (n-3 PUFA) levels were significantly lower in cases (p < 0.05). Maternal 25-hydroxyvitamin D (25(OH)D) levels were positively correlated with maternal polyunsaturated fatty acids and omega-6 polyunsaturated fatty acids. RBC folate levels were negatively correlated with n-3 PUFA.Further research is required to clarify the association of FA metabolism with NTDs.

[Vitamin B9 and B12 : clinical manifestations, screening and substitution]. / Vitamine B9 et B12 : manifestations cliniques, dépistage et substitution.

Deficiency in vitamins B9 and B12 are common in general practice, due to their high prevalence in the population, especially among elderly patients. This article will present the clinical manifestations of vitamin B9 and B12 deficiencies, which can sometimes be insidious. We will discuss screening strategies, which are based on the presence of compatible symptoms as well as risk factors for deficiency. The choice of administration route for substitution depends both on severity and etiology; but the oral route has demonstrated similar effectiveness compared to intramuscular administration.

Il est courant de rencontrer des déficits en vitamines B9 et B12 en consultation de médecine de premier recours, en raison de leurs prévalences élevées dans la population générale, surtout chez les patients âgés. Cet article présente les manifestations cliniques de carences en vitamines B9 et B12, qui peuvent parfois être insidieuses et discute des stratégies de dépistage, qui se basent sur la présence de symptômes compatibles ainsi que de facteurs de risque de carence. Concernant la substitution, le choix de la voie d'administration se fait selon la sévérité et l'étiologie ; mais la forme orale a démontré une efficacité similaire à l'administration intramusculaire.

Pernicious anemia is a common cause of cobalamin deficiency-caused megaloblastic anemia in Hainan, China.

BACKGROUND: Pernicious anemia (PA) is believed to be highly prevalent in Western countries but has rarely been reported in China. The study explores whether PA, an autoimmune disease, is an uncommon cause of cobalamin (vitamin B12) deficiency anemia in China. METHODS: Clinical and hematological data were collected from 90 cobalamin deficiency-caused megaloblastic anemia (MA) patients between July 2014 and December 2021. Through anti-intrinsic factor antibody (IFA) and anti-parietal cell antibody (PCA) testing, PA was distinguished from other causes of cobalamin deficiency leading to MA. Meanwhile, 30 healthy controls (HCs) were included to estimate the positive rates of IFA and PCA. RESULTS: Of the 30 HCs, only one tested positive for IFA, and all 30 tested negative for PCA. Among the 90 patients with cobalamin deficiency-caused MA, 76.7% were positive for IFA, and 47.8% were positive for PCA; a total of 76 patients (84.4%) were diagnosed with PA. The mean follow-up time was 41.0 ± 16.3 months. During the follow-up period, no case relapsed among the continuous cobalamin-supply treatment patients, while 24.4% of patients relapsed due to the interruption of maintenance cobalamin-supplement therapy (the median recurrence time was 54.0 ± 17.7 months). CONCLUSIONS: The proportion of PA in cobalamin deficiency-caused MA patients in Hainan province was higher than 80%, which was more common than expected. Therefore, screening for IFA, PCA, endoscopic biopsy, and thyroid-related parameters are recommended for all cobalamin deficiency-caused MA patients. Furthermore, maintenance cobalamin-supplement therapy is important for PA patients.

This research examines pernicious anemia (PA), a type of anemia caused by vitamin B12 deficiency, which has been widely reported in Western countries but is less known in China. The study focuses on determining if PA is also a significant cause of this deficiency in Hainan, China. Researchers gathered data from patients with megaloblastic anemia (a blood disorder) due to lack of vitamin B12, comparing them with healthy individuals to see how common PA is. The findings reveal that a very high percentage of the patients studied have PA, much higher than expected. This suggests that PA is not as rare in this region of China as previously thought. The study also highlights the importance of continuous treatment with vitamin B12 to prevent the recurrence of the anemia. Based on these results, the researchers recommend that all patients with vitamin B12 deficiency should be tested for PA and continuously receive vitamin B12 supplements to maintain their health once diagnosed with PA. This strategic insight is of paramount importance to medical practitioners in China, potentially paving the way for enhanced clinical management protocols for individuals afflicted by this ailment.

Evaluation of serum vitamin B12 and D, iron, ferritin, folate, calcium, phosphorus and magnesium levels in children in palliative care clinic: a single-center cross-sectional study.

BACKGROUND: Pediatric palliative care (PPC) patients are at an elevated risk of malnutrition. Nutritional inadequacy can also cause micronutrient deficiencies. These factors can lead to weight loss, stunted growth, and poor quality of life. Despite the prevalence of these issues, limited research exists in the micronutrient status of PPC patients. The purpose of this study was to determine the vitamin B12 and D, iron, ferritin, folate, calcium, phosphorus, and magnesium levels of PPC patients to contribute to a better understanding of their micronutrient needs as well as the appropriate management of diet and treatment approaches. METHODS: This was a single-center observational cross-sectional retrospective study. This study evaluated the levels of vitamin B12, 25-hydroxyvitamin D, iron, ferritin, folate, calcium, phosphorus, and magnesium in PPC patients. The patients were classified according to the Chronic Complex Conditions (CCC) v2 and then compared. RESULTS: A total of 3,144 micronutrient data points were collected from 822 hospitalizations of 364 patients. At least one micronutrient deficiency was identified in 96.9% of the patients. The most prevalent deficiencies were observed for iron, calcium, and phosphate. In addition, 25-hydroxyvitamin D deficiency was observed in one-third of patients. Calcium, magnesium, phosphorus, folate, and 25-hydroxyvitamin D were negatively correlated with age. CONCLUSION: The results of this study indicate that micronutrient deficiencies are highly prevalent in PPC patients. These findings have the potential to contribute to improvements in the nutritional and therapeutic management of patients.

Severe pancytopenia at the presentation of Imerslund-Gräsbeck syndrome in a 23-month-old Italian boy.

BACKGROUND: Imerslund-Gräsbeck syndrome (IGS) is a rare autosomal recessive disorder characterized by megaloblastic anemia due to selective cobalamin malabsorption and benign proteinuria. IGS is caused by a disfunction of the cubam receptor, which mediates the reabsorption of cobalamin in the ileum and the reuptake of albumin in renal proximal tubules. CASE PRESENTATION: We describe the case of a 23-month-old-italian infant presenting with severe pancytopenia and failure to thrive in whom the diagnosis of IGS was made and vitamin B12 replacement therapy was resolutive. Genetic analysis (NGS with CNV analysis including 214 genes involved in bone marrow failure and anemia), showed the presence of two pathogenetic variants in the AMN gene (c-208-2 A > G and c.1006 + 34_1007-31del). These variants have been previously described in the literature, but their combination has never been reported. CONCLUSIONS: Imerslund-Gräsbeck syndrome should be considered in the differential diagnosis of children with severe pancytopenia even in those without neurological involvement. This case emphasizes the importance of an early diagnosis and prompt treatment, to prevent irreversible neurological injury.

Investigating the potential association between micronutrient levels and non-dipper hypertension patterns in the elderly population: A retrospective analysis.

The goal is to provide foundational data that could spearhead more extensive, prospective research into understanding the influences of micronutrient levels on the nocturnal patterns of hypertension, possibly aiding in identifying potential therapeutic strategies to reduce cardiovascular risk in this demographic. The research employed a retrospective design to analyze the micronutrient levels, including ferritin, folic acid, vitamin B12, and vitamin D, in a limited sample size from a single hospital. However, it is worth noting that the study did not scrutinize other potentially relevant micronutrients and biomarkers and lacked information on potential confounding factors such as lifestyle and dietary habits, physical activity levels, and specific details on antihypertensive medications used. The preliminary findings highlight a significant difference in ferritin levels between dipper and non-dipper groups, indicating a potential role in the development of non-dipper hypertension. Surprisingly, no notable difference was observed in vitamin D levels between the groups. The study underscores the increasing prevalence of hypertension and micronutrient deficiencies as age progresses. Despite its limitations, including limited sample size and potential influences from unaccounted variables, the study hints at a potential relationship between micronutrient levels and non-dipper hypertension. It emphasizes the necessity for larger scale, prospective research to delve deeper into the nature of this relationship, potentially fostering new therapeutic approaches in cardiovascular risk management within the elderly population.

Vitamin B12 ameliorates gut epithelial injury via modulating the HIF-1 pathway and gut microbiota.

Inflammatory bowel diseases (IBDs) are immune chronic diseases characterized by recurrent episodes, resulting in continuous intestinal barrier damage and intestinal microbiota dysbiosis. Safe strategies aimed at stabilizing and reducing IBDs recurrence have been vigorously pursued. Here, we constructed a recurrent intestinal injury Drosophila model and found that vitamin B12 (VB12), an essential co-factor for organism physiological functions, could effectively protect the intestine and reduce dextran sulfate sodium-induced intestinal barrier disruption. VB12 also alleviated microbial dysbiosis in the Drosophila model and inhibited the growth of gram-negative bacteria. We demonstrated that VB12 could mitigate intestinal damage by activating the hypoxia-inducible factor-1 signaling pathway in injured conditions, which was achieved by regulating the intestinal oxidation. In addition, we also validated the protective effect of VB12 in a murine acute colitis model. In summary, we offer new insights and implications for the potential supportive role of VB12 in the management of recurrent IBDs flare-ups.

Relationships of B12 and Homocysteine with Outcomes in the SURE-PD, SURE-PD3, and STEADY-PDIII Trials.

Background: DATATOP was a study of early Parkinson's disease (PD) conducted in the 1980 s, before mandatory folic acid fortification in the United States. Our analysis of its baseline serum samples revealed a geometric mean vitamin B12 of 369 pg/mL and homocysteine (tHcy) of 9.5µmol/l. We also found that low B12 predicted greater worsening of ambulatory capacity (AC) and elevated tHcy (>15µmol/L) predicted greater declines in cognitive function. Objective: We sought to measure B12 and tHcy in contemporary trial participants with early PD who had not started dopaminergic treatment and to determine whether these analytes were associated with clinical progression. Methods: We measured B12 and tHcy from baseline and end-of-study blood samples from three recent clinical trials. Results: Baseline geometric mean B12 levels for these studies ranged from 484- 618 pg/ml and for tHcy ranged from 7.4- 10µmol/L. Use of B12-containing supplements ranged from 41- 61%, and those taking supplements had higher B12 and lower tHcy. Those who began levodopa, but were not taking B12-supplements, had greater end-of-study tHcy. There was no association of baseline tHcy > 15µmol/L with annualized change in Montreal Cognitive Assessment and no association of baseline B12 tertiles with change in AC. Conclusions: In these longitudinal trials, B12 levels were higher than for DATATOP, due in large part to increased B12-supplement intake, while tHcy levels were similar. Initiation of levodopa was associated with increases of tHcy in those not taking a B12-containing supplement. These smaller studies did not replicate prior findings of low B12 and elevated tHcy with features of progression, possibly due to higher baseline B12.

Association between gastrectomy and the risk of type 2 diabetes in gastric cancer survivors: A nationwide cohort study.

AIM: Postprandial glycemic fluctuations after gastrectomy are seen in patients with gastric cancer but, no studies have investigated the association between gastrectomy and type 2 diabetes mellitus (T2DM) in gastric cancer survivors. This study aimed to elucidate the relationship between gastrectomy (total or subtotal) and incident T2DM. In addition, we explored whether vitamin B12 supplementation modulates this risk among patients who have undergone total gastrectomy. METHODS: In this large nationwide population-based retrospective cohort study using the National Health Insurance Service database of South Korea, we identified patients aged >20 years who underwent gastrectomy from 2008 to 2015 (n = 150,074) and age- and sex-matched controls without gastrectomy (n = 301,508). A Cox proportional hazards model was used. RESULTS: During the median follow-up duration of 4.4 years after the 2-year time lag after gastrectomy, of the 78,006 subjects, 4,597 (5.9 %) developed T2DM. Compared with matched controls, the adjusted hazard ratio (AHR[95 % confidence interval]) for T2DM of patients with total gastrectomy was 1.34[1.23;1.47]. The corresponding AHR after subtotal gastrectomy was 0.81[0.76;0.86]. Among the patients with total gastrectomy, the risk of T2DM was significantly increased in those who did not receive any vitamin B12 supplementation (AHR=1.60[1.33;1.92]), whereas the risk of T2DM was lower (close to being statistically significant) in those who received continuous vitamin B12 supplementation after gastrectomy (AHR=0.70[0.49;1.01]). CONCLUSION: These results show a significantly reduced risk of T2DM in gastric cancer patients undergoing subtotal gastrectomy and a significantly increased risk of T2DM in gastric cancer patients undergoing total gastrectomy, which is mitigated by continuous vitamin B12 supplementation.

Management of Alzheimer's disease and related neurotoxic pathologies: Role of thiamine, pyridoxine and cobalamin.

Alzheimer's disease (AD) remains one of the most debilitating disease and most common neurological disorder in the world at large. However, with many years of multiple research and billions of dollars invested for the purpose of research, not many therapeutic options exist for the management of this disease. As at 2023, the number has only increased to 7, one of which is a combination of two existing therapies. However, research has continued still in the search for a cure. The roles and functions of thiamine, pyridoxine and cobalamin in the proper function of the nervous system has been well researched over time and their role in the management of neurological diseases have been of interest in the last decade. This review describes the roles of the aforementioned chemicals in the management of different models of AD and AD-like pathologies as mono-therapeutic agents and prospective adjuvant for combination therapy.

Low concentration of serum vitamin B12 may be a strong predictor of large-artery atherosclerosis stroke: A case-control study.

INTRODUCTION: Identifying controllable risk factors for large-artery atherosclerosis (LAA) stroke is crucial due to its significant role as a leading cause of ischemic stroke. We aimed to validate the correlation of serum vitamin B12 with LAA stroke. METHODS: Inpatients with LAA stroke and healthy controls were retrospectively collected for a case-control study from January 2020 to May 2022. Serum vitamin B12 concentration and other blood indicators, demographic, lifestyle factors and comorbidities were investigated. Logistic regression analysis was used to identify the correlation of serum vitamin B12 concentrations with LAA stroke, meanwhile adjusted for confounding factors. RESULTS: Patients with LAA stroke had significantly lower serum vitamin B12 concentrations in comparison to those of controls. In the fully adjusted model, vitamin B12 (per 1 interquartile range increase, odds ratio [OR] = 0.84, 95 % confidence interval [CI]: 0.77-0.91), vitamin B12 < 200 pg/mL (OR=7.70, 95 %CI: 2.19-27.03) and vitamin B12 < 300 pg/mL (OR=4.19, 95 %CI: 1.82-9.66) were independently factors for LAA stroke. Furthermore, the optimal cut-off values for vitamin B12 to predict LAA stroke were 305.25 pg/mL (area under the curve [AUC] = 0.71) when unadjusted and 308.25 pg/mL when adjusted for age and sex (AUC=0.68). Lower vitamin B12 concentrations were significantly associated with male sex, smoking, older age, higher neutrophil count, higher creatinine, lower folate and higher total homocysteine. CONCLUSION: Results indicate that low concentration of serum vitamin B12 may be a strong predictor for the risk of LAA stroke.

Vitamin B12 supplementation improved memory impairment following nicotine withdrawal in adolescent male rats: The role of oxidative stress, inflammatory, BDNF, GFAP, and AChE activity.

The present study aimed to assess the potential effect of vitamin B12 (Vit B12) on cognition impairment caused by nicotine (Nic) cessation in adolescent male rats. Adolescent male rats were categorized into two main groups as vehicle (normal saline, intraperitoneally), and Nic group in which received Nic (2 mg/kg) from 21 to 42 days of ages and then the Nic group were divided into three groups as withdrawal (the animals returned to regular diet without treatment), second and third groups received bupropion (20 mg/kg), and Vit B12 at three different doses including 0.5,1, and 1.5 mg/kg by oral gavage as treatments to attenuate Nic withdrawal symptoms. The last group including normal animals received the highest doses of Vit B12 just in the Nic abstinence period to compare the effect of that with vehicle. In MWM, Vit B12and bupropion increased the time spent in the target quadrant that is strongly associated with spatial memory as well as the more time spent with the NORT. Vit B12 and bupropion modulated both oxidant/antioxidant and inflammatory/anti-inflammatory balance, alongside inhibitory effect on AChE, and GFAP. However, BDNF and amyloid-B showed insignificant difference as compared to Vit B12 and bupropion. Considering the present results and similar related studies, Vit B12 can be introduced as a strong anti-oxidant, and anti-inflammatory agent by which probably improved memory impairment caused by Nic addiction accompanied by withdrawal. Further, other mechanisms including activity reduction of AChE, and GFAP should be considered; however, it needs further investigation and larger-scale evidences.

Plasma homocysteine and longitudinal change in cognitive function among urban adults.

BACKGROUND: Cross-sectional and longitudinal studies have inconsistently linked cognitive performance and change over time to an elevated level of homocysteine (Hcy), with few conducted among urban adults. METHODS: Longitudinal data [Visit 1 (2004-2009) and Visit 2 (2009-2013)] were analyzed from up to 1430 selected Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) participants. Baseline and follow-up blood Hcy was measured, while 11 cognitive function test scores were assessed at either of these two visits. Overall, sex- and race-stratified associations were evaluated using mixed-effects linear regression models, adjusting for key potential confounders. Interaction effects between Hcy and serum levels of folate and vitamin B-12 were also tested. RESULTS: We found that greater LnHcyv1 was significantly associated with poorer baseline attention based on higher Loge (TRAILS A, in seconds) [ß (SE): 0.101 (0.031), P = 0.001]. Heterogeneity was also found by sex and by race. Most notably, among men only, LnHcyv1 was associated with faster decline on the BVRT (# of errors), a measure of visuo-spatial memory (ß (SE): 0.297(0.115), P = 0.010, reduced model); while among African American adults only, an elevated and increasing LnHcy over time was associated with faster rate of decline on Loge (TRAILS B, in seconds) [ß (SE): +0.012 (0.005), p = 0.008], a measure of executive function. Interactions between Hcy, folate and vitamin B-12 blood exposures were also detected. CONCLUSIONS: In summary, sex- and race-specific adverse association between elevated Hcy and cognitive performance over time were detected among middle-aged urban adults, in domains of attention, visuo-spatial memory and executive functioning.

Bacterial mercury methylation modulated by vitamin B9: An overlooked pathway leads to increased environmental risks.

There has been a serious health and environmental concern in conversion of inorganic mercury (Hg) to the neurotoxin, methylmercury (MeHg) by anaerobic microbes, while very little is known about the potential role of vitamin B9 (VB9) regulator in the biochemical generation of MeHg. This study innovatively investigated bacterial Hg methylation by Geobacter sulfurreducens PCA in the presence of VB9 under two existing scenarios. In the low-complexing scenario, the bacterial MeHg yield reached 68 % higher than that without VB9 within 72 h, which was attributed to free VB9-protected PCA cells relieving oxidative stress, as manifested by the increased expression of Hg methylation gene (hgcAB cluster by 19-48 %). The high-complexing scenario emphasized the intracellular Hg accumulation (38-45 %) after 12 h, as indicated by the increased expression of outer membrane protein-related and mercuric reductase-encoding genes, indicating the inefficient bioavailability of Hg due to a gradual shift from Hg reduction toward Hg0 re-oxidation controlled by competitive ligand exchange. These results suggested that VB9 application significantly raised the potential for bacterial Hg methylation and cellular accumulation, thus proposing insights into the biochemical behaviors of hazardous Hg in farming environments where vulnerable organisms are more possibly co-exposed to higher levels of Hg and VB9.