Disrupted de novo pyrimidine biosynthesis impairs adult hippocampal neurogenesis and cognition in pyridoxine-dependent epilepsy.

Despite seizure control by early high-dose pyridoxine (vitamin B6) treatment, at least 75% of pyridoxine-dependent epilepsy (PDE) patients with ALDH7A1 mutation still suffer from intellectual disability. It points to a need for additional therapeutic interventions for PDE beyond pyridoxine treatment, which provokes us to investigate the mechanisms underlying the impairment of brain hemostasis by ALDH7A1 deficiency. In this study, we show that ALDH7A1-deficient mice with seizure control exhibit altered adult hippocampal neurogenesis and impaired cognitive functions. Mechanistically, ALDH7A1 deficiency leads to the accumulation of toxic lysine catabolism intermediates, α-aminoadipic-δ-semialdehyde and its cyclic form, δ-1-piperideine-6-carboxylate, which in turn impair de novo pyrimidine biosynthesis and inhibit NSC proliferation and differentiation. Notably, supplementation of pyrimidines rescues abnormal neurogenesis and cognitive impairment in ALDH7A1-deficient adult mice. Therefore, our findings not only define the important role of ALDH7A1 in the regulation of adult hippocampal neurogenesis but also provide a potential therapeutic intervention to ameliorate the defective mental capacities in PDE patients with seizure control.

Contribution of Beef to Key Nutrient Intakes and Nutrient Adequacy in Pregnant and Lactating Women: NHANES 2011-2018 Analysis.

Beef is an important source of high-quality protein and several micronutrients, including iron, zinc, and B-vitamins. The objective was to assess the association of beef intake with nutrient intake and adequacy among pregnant and lactating women using 24-h dietary recall data. Usual intakes from foods were determined with the National Cancer Institute (NCI) method and % population below Estimated Average Requirement (EAR) or above Adequate Intake (AI) were estimated. A high proportion of pregnant and lactating women had inadequate intakes for vitamin D (94%), vitamin E (82%), vitamin C (52%), and vitamin A (50%), magnesium (35%), folate (31%), zinc (25%), and vitamin B6 (22%); only 4% and 35% met AI for choline and potassium, respectively. About 67% of pregnant and lactating women were beef consumers, consuming 49 g beef/day. Beef consumers had higher intakes (p < 0.05) of energy, protein, calcium, iron, phosphorus, selenium, sodium, zinc, thiamin, riboflavin, and niacin, and a higher proportion (p < 0.05) met nutrient recommendations for protein, calcium, iron, zinc, thiamin, riboflavin, niacin, vitamin B6, and vitamin B12 compared to non-consumers. In conclusion, pregnant and lactating women generally have inadequate nutrient intakes from their diets. Beef consumers have higher intakes and adequacy for certain nutrients, many of which are inherently available in beef or in foods eaten with beef.

Pyridoxal 5'-Phosphate Biosynthesis by Pyridox-(am)-ine 5'-Phosphate Oxidase: Species-Specific Features.

Enzymes reliant on pyridoxal 5'-phosphate (PLP), the metabolically active form of vitamin B6, hold significant importance in both biology and medicine. They facilitate various biochemical reactions, particularly in amino acid and neurotransmitter metabolisms. Vitamin B6 is absorbed by organisms in its non-phosphorylated form and phosphorylated within cells via pyridoxal kinase (PLK) and pyridox-(am)-ine 5'-phosphate oxidase (PNPOx). The flavin mononucleotide-dependent PNPOx enzyme converts pyridoxine 5'-phosphate and pyridoxamine 5'-phosphate into PLP. PNPOx is vital for both biosynthesis and salvage pathways in organisms producing B6 vitamers. However, for those depending on vitamin B6 as a nutrient, PNPOx participates only in the salvage pathway. Transferring the PLP produced via PNPOx to client apo-enzymes is indispensable for their catalytic function, proper folding and targeting of specific organelles. PNPOx activity deficiencies due to inborn errors lead to severe neurological pathologies, particularly neonatal epileptic encephalopathy. PNPOx maintains PLP homeostasis through highly regulated mechanisms, including structural alterations throughout the catalytic cycle and allosteric PLP binding, influencing substrate transformation at the active site. Elucidation at the molecular level of the mechanisms underlying PNPOx activity deficiencies is a requirement to develop personalized approaches to treat related disorders. Finally, despite shared features, the few PNPOx enzymes molecularly and functionally studied show species-specific regulatory properties that open the possibility of targeting it in pathogenic organisms.

The Biological Active Substances of Taraxacum officinale and Arctium lappa from the Siberian Federal District.

Currently, scientists are increasingly focusing on utilizing the natural flora of the planet to search for and isolate individual bioactive substances that prevent various diseases, contribute to increased life expectancy, and affect all major life-supporting systems in the human body. This study describes the examination of the composition of plant raw materials from the Siberian Federal District. The research focuses on plant specimens from the root parts of Taraxacum officinale and Arctium lappa, collected in the Kemerovo region. The study determines the contents of the water-soluble vitamins B and C in the research subjects. The investigation includes assessing antioxidant properties, antimicrobial activity, and flavonoid content in extracts based on plant raw materials. All samples show a high percentage of antioxidant activity, with the highest antioxidant activity for T. officinale at 85.51 and that for A. lappa at 88.97. The results indicate low antimicrobial activity against Escherichia coli (growth inhibition zone up to 15.5 mm). Plant extracts contain significant amounts of B-group vitamins, with pyridoxine in T. officinale (156.40 µg/mL) and thiamine (46.20 µg/mL) and pyridoxine (357.10 µg/mL) in Arctium lappa. Flavonoids (rutin and quercetin) are identified in T. officinale and A. lappa extracts based on the study results.

Adherence to medical treatment for Wilson's disease in children and adolescents: a cohort study from Turkey.

BACKGROUND: This study aimed to assess medication adherence and demographic, clinical, and psychopathological parameters such as quality of life, depression, and anxiety levels that can affect pediatrics with Wilson's Disease (WD). METHODS: A prospective cohort study was conducted at an outpatient clinic in Turkey among pediatric patients (2 to 18 years) with WD between November 2022 and April 2023. The Medication Adherence Report Scale (MARS-5) as a subjective and Medication Possession Ratio (MPR) as an objective assessment were scored. Physical, genetic and biochemical parameters, the Pediatric Quality of Life Inventory (PedsQL) for both parents and patients, Childhood Depression Inventory, State Trait Anxiety Inventory were also administered. RESULTS: A total of 30 pediatric outpatients who were prescribed D-penicillamine (n = 27) or trientine (n = 3) as chelators and zinc (n = 29) and pyridoxine (n = 19) as supplements were included. Proteinuria (n = 3), skin rash (n = 2), and gastrointestinal upset (n = 2) were observed. When the correlation between MARS-5 and duration of follow-up was examined, a significant negative correlation was found (p = 0.014). According to MPRs, non-adherence rates (missed doses ≥ 20%) were 29.6%, 17.2% and 5.3% for D-penicillamine, zinc and pyridoxine, respectively. PedsQL scores were higher than those of parents, with a positive correlation between them (p < 0.001). Also, there was a significant positive correlation between PedsQL and State Anxiety Inventory (p < 0.001). Comparing the change in urinary copper levels between different levels of treatment knowledge, significant differences were observed between high- and low levels (p = 0.043). CONCLUSIONS: Overall, nonadherence rates were 23.3% based on MARS-5 and 5.3-29.6% based on MPR. It is essential to consider factors such as the duration of follow-up, biochemical parameters, treatment knowledge, quality of life and anxiety as potential influencers of medication adherence.

Conquering homocystinuria with engineered probiotics.

Pyridoxine-unresponsive homocystinuria has lifelong implications for health. In this issue, Perreault and colleagues present evidence that orally delivered engineered probiotic Escherichia Coli Nissle SYNB1353 is a promising candidate in reducing homocysteine, with successful trials in mice, monkeys, and humans. However, further probiotic optimization and safety assessments are required.

A Gadolinium(III) Complex Based on Pyridoxine Molecule with Single-Ion Magnet and Magnetic Resonance Imaging Properties.

Pyridoxine (pyr) is a versatile molecule that forms part of the family of B vitamins. It is used to treat and prevent vitamin B6 deficiency and certain types of metabolic disorders. Moreover, the pyridoxine molecule has been investigated as a suitable ligand toward metal ions. Nevertheless, the study of the magnetic properties of metal complexes containing lanthanide(III) ions and this biomolecule is unexplored. We have synthesized and characterized a novel pyridoxine-based GdIII complex of formula [GdIII(pyr)2(H2O)4]Cl3 · 2 H2O (1) [pyr = pyridoxine]. 1 crystallizes in the triclinic system and space group Pi. In its crystal packing, cationic [Gd(pyr)2(H2O)4]3+ entities are connected through H-bonding interactions involving non-coordinating water molecules and chloride anions. In addition, Hirshfeld surfaces of 1 were calculated to further investigate their intermolecular interactions in the crystal lattice. Our investigation of the magnetic properties of 1, through ac magnetic susceptibility measurements, reveals the occurrence of a slow relaxation in magnetization in this mononuclear GdIII complex, indicating an unusual single-ion magnet (SIM) behavior for this pseudo-isotropic metal ion at very low temperatures. We also studied the relaxometric properties of 1, as a potential contrast agent for high-field magnetic resonance imaging (MRI), from solutions of 1 prepared in physiological serum (0.0-3.2 mM range) and measured at 3 T on a clinical MRI scanner. The values of relaxivity obtained for 1 are larger than those of some commercial MRI contrast agents based on mononuclear GdIII systems.

Chitosan-Supported ZnO Nanoparticles: Their Green Synthesis, Characterization, and Application for the Removal of Pyridoxine HCl (Vitamin B6) from Aqueous Media.

A composite of chitosan-supported ZnO nanoparticles (ZnO/CS) was green-synthesized via an easy and cost-effective method using Chicory (Cichorium intybus) plant extract. The synthesis was confirmed using uv-vis spectrometry at a λmax of 380 nm, and the surface of the material was characterized via FT-IR spectroscopy, and finally via SEM, which confirmed the distribution of ZnO nanoparticles on the surface of chitosan biopolymer (CS). The synthesized material was applied in the adsorptive removal of residues of the pyridoxine hydrochloride (vitamin B6) pharmaceutical drug from aqueous media using the batch technique. The material's removal capacity was studied through several adjustable parameters including pH, contact time, the dose of the adsorbent, and the capacity for drug adsorption under the optimal conditions. Langmuir and Freundlich isotherms were applied to describe the adsorption process. The removal was found to obey the Freundlich model, which refers to a chemisorption process. Different kinetic models were also studied for the removal process and showed that the pseudo-second-order model was more fitted, which indicates that the removal was a chemisorption process. Thermodynamic studies were also carried out. The maximum removal of vitamin B6 by the nano-ZnO/CS composite was found to be 75% at optimal conditions. The results were compared to other reported adsorbents. Reusability tests showed that the nano-ZnO/CS composite can be efficiently reused up to seven times for the removal of PDX drugs from aqueous media.

Pyridoxine challenge reflects pediatric hypophosphatasia severity and thereby examines tissue-nonspecific alkaline phosphatase's role in vitamin B6 metabolism.

Alkaline phosphatase (ALP) is detected in most human tissues. However, ALP activity is routinely assayed using high concentrations of artificial colorimetric substrates in phosphate-free laboratory buffers at lethal pH. Hypophosphatasia (HPP) is the inborn-error-of-metabolism caused by loss-of-function mutation(s) of the ALPL gene that encodes the ALP isoenzyme expressed in bone, liver, kidney, and elsewhere and is therefore designated "tissue-nonspecific" ALP (TNSALP). Consequently, HPP harbors clues concerning the biological function of this phosphohydrolase that is anchored onto the surface of cells. The biochemical signature of HPP features low serum ALP activity (hypophosphatasemia) together with elevated plasma levels of three natural substrates of TNSALP: i) phosphoethanolamine (PEA), a component of the linkage apparatus that binds ALPs and other proteins to the plasma membrane surface; ii) inorganic pyrophosphate (PPi), an inhibitor of bone and tooth mineralization; and iii) pyridoxal 5'-phosphate (PLP), the principal circulating vitameric form of vitamin B6 (B6). Autosomal dominant and autosomal recessive inheritance involving several hundred ALPL mutations underlies the remarkably broad-ranging expressivity of HPP featuring tooth loss often with muscle weakness and rickets or osteomalacia. Thus, HPP associates the "bone" isoform of TNSALP with biomineralization, whereas the physiological role of the "liver", "kidney", and other isoforms of TNSALP remains uncertain. Herein, to examine HPP's broad-ranging severity and the function of TNSALP, we administered an oral challenge of pyridoxine (PN) hydrochloride to 116 children with HPP. We assayed both pre- and post-challenge serum ALP activity and plasma levels of PLP, the B6 degradation product pyridoxic acid (PA), and the B6 vitamer pyridoxal (PL) that can enter cells. Responses were validated by PN challenge of 14 healthy adults and 19 children with metabolic bone diseases other than HPP. HPP severity was assessed using our HPP clinical nosology and patient height Z-scores. PN challenge of all study groups did not alter serum ALP activity in our clinical laboratory. In HPP, both the post-challenge PLP level and the PLP increment correlated (Ps < 0.0001) with the clinical nosology and height Z-scores (Rs = +0.6009 and + 0.4886, and Rs = -0.4846 and - 0.5002, respectively). In contrast, the plasma levels and increments of PA and PL from the PN challenge became less pronounced with HPP severity. We discuss how our findings suggest extraskeletal TNSALP primarily conditioned the PN challenge responses, and explain why they caution against overzealous B6 supplementation of HPP.

Relationship of Low Vitamin B6 Status with Sarcopenia, Frailty, and Mortality: A Narrative Review.

Marginal vitamin B6 (B6) deficiency is a widespread global concern. Inadequate B6 levels have been linked to an increased risk of age-related chronic diseases such as cardiovascular diseases and cancers. In recent years, the growing concern over sarcopenia (the age-related loss of muscle mass and strength) and frailty (a decline in physiological resilience and increased vulnerability associated with aging) is particularly relevant due to the emergence of super-aged societies in developed countries. Notably, among the thirty-one studies included in this review, twenty-five showed a significant association of B6 status with sarcopenia, frailty, and all-cause mortality in adults (p < 0.05), while six showed no association. Emerging studies have suggested novel mechanisms underlying this association. These mechanisms involve P2X7 receptor-mediated NLRP3 inflammasome signaling, AMPK signaling, PD-L1 signaling, and satellite cell-mediated myogenesis. Furthermore, the modulation of PLP-dependent enzymes due to B6 deficiency is associated with impaired metabolic processes, affecting energy utilization, imidazole peptide production, and hydrogen sulfide production, as well as the kynurenine pathway, all of which play vital roles in skeletal muscle health and pathophysiology. This narrative review provides an up-to-date assessment of our current understanding of the potential role of nutritional B6 status in combating sarcopenia, frailty, and mortality.

Factors influencing vitamin B6 status in domestic cats: age, disease, and body condition score.

Limited studies are available on vitamin B6 status in domestic cats. To this end, we evaluated glutamate-oxaloacetate transaminase (GOT) activity in hemolysates with and without pyridoxal 5'-phosphate addition in two feline populations: a cohort of 60 healthy, domestic (sexually intact and specific pathogen-free) cats maintained under strictly controlled conditions with appropriate diets housed at the Feline Nutrition and Pet Care Center, and a cohort of 57 cats randomly selected between December 2022 to January 2023 that visited the Veterinary Medicine Teaching Hospital to seek care under different circumstances. The GOT activity expressed as the ratio with and without pyridoxal 5'-phosphate addition (primary activation ratio; PAR) decreased significantly with age in the healthy cohort. The PAR values normalized to age established a cut-off for vitamin B6 deficiency in both cohorts, identifying 17 of 101 animals as vitamin B6 deficient. Using machine learning, a partition-based model (decision tree) was built to identify the most important factors that predicted vitamin B6 deficiency while using the resulting tree to make predictions for new observations. This analysis, performed with all 101 cats, revealed that the diagnosis of an infectious, chronic or acute condition (0.55) was the main contributor, followed by age (0.26), and body condition score (optimal-overweight; 0.19). Thus, our study supports that vitamin B6 supplementation may be indicated in junior to adult animals diagnosed with an infectious, chronic, or acute conditions or healthy cats with body weight ranging from optimal to overweight. In older cats, even if healthy, underweight to optimal cats appear to be at risk of vitamin B6 deficiency.

Vitamin B6 and folate intake are associated with lower risk of severe headache or migraine in adults: An analysis based on NHANES 1999-2004.

Previous studies have shown that B vitamins can relieve migraine. However, the association between vitamin B6 and folate, 2 important B vitamins consumed in the diet, with migraine have received minimal attention. This study explored the independent relationships between dietary vitamin B6 and folate intake with migraine and the interaction effect of these 2 nutrients on migraine in US adults. We hypothesized that vitamin B6 and folate intake would be inversely associated with migraine. This study included cross-sectional data from participants aged 20 years and older who participated in the National Health and Nutrition Examination Survey from 1999 to 2004. We conducted multivariate logistic regression and restricted cubic spline regression to explore the association between dietary vitamin B6 and folate intake on migraine. Also, relative excess risk due to interaction, attributable proportion of interaction, and synergy index were used to assess additive interactions. A total of 7017 participants were included in this study, 1350 of whom were migraineurs. We determined that vitamin B6 and folate intake revealed a negative association with severe headache or migraine (0.66; 95% confidence interval [CI], 0.47-0.89; P = .01 and 0.57; 95% CI, 0.42-0.78; P = .002]), respectively. Also, a significant interaction effect between a high mass of vitamin B6 and folate intake was observed for a lower risk of migraine (relative excess risk due to interaction, 0.28 [95% CI, 0.05-0.51]; attributable proportion of interaction: 0.45 [95% CI, 0.05-0.86]; synergy index: 0.58 [95% CI, 0.40-0.83]). A high mass of vitamin B6 and folate intake (vitamin B6 intake ≥ 2.39 mg/day and folate intake ≥ 502.01 µg/day) presented a synergistic interaction with migraine, suggesting that these 2 nutrients might be beneficial in preventing migraine.

Erythromycin, retapamulin, pyridoxine, folic acid, and ivermectin inhibit cytopathic effect, papain-like protease, and MPRO enzymes of SARS-CoV-2.

Background: Although tremendous success has been achieved in the development and deployment of effective COVID-19 vaccines, developing effective therapeutics for the treatment of those who do come down with the disease has been with limited success. To repurpose existing drugs for COVID-19, we previously showed, qualitatively, that erythromycin, retapamulin, pyridoxine, folic acid, and ivermectin inhibit SARS-COV-2-induced cytopathic effect (CPE) in Vero cells. Aim: This study aimed to quantitatively explore the inhibition of SARS-CoV-2-induced CPE by erythromycin, retapamulin, pyridoxine, folic acid, and ivermectin and to determine the effect of these drugs on SARS-CoV-2 papain-like protease and 3CL protease (MPRO) enzymes. Methods: Neutral red (3-amino-7-dimethylamino-2-methyl-phenazine hydrochloride) cell viability assay was used to quantify CPE after infecting pre-treated Vero cells with clinical SARS-Cov-2 isolates. Furthermore, SensoLyte® 520 SARS-CoV-2 papain-like protease and SensoLyte® 520 SARS-CoV-2 MPRO activity assay kits were used to evaluate the inhibitory activity of the drugs on the respective enzymes. Results: Erythromycin, retapamulin, pyridoxine, folic acid, and ivermectin dose-dependently inhibit SARS-CoV-2-induced CPE in Vero cells, with inhibitory concentration-50 (IC50) values of 3.27 µM, 4.23 µM, 9.29 µM, 3.19 µM, and 84.31 µM, respectively. Furthermore, erythromycin, retapamulin, pyridoxine, folic acid, and ivermectin dose-dependently inhibited SARS-CoV-2 papain-like protease with IC50 values of 0.94 µM, 0.88 µM, 1.14 µM, 1.07 µM, and 1.51 µM, respectively, and inhibited the main protease (MPRO) with IC50 values of 1.35 µM, 1.25 µM, 7.36 µM, 1.15 µM, and 2.44 µM, respectively. Conclusion: The IC50 for all the drugs, except ivermectin, was at the clinically achievable plasma concentration in humans, which supports a possible role for the drugs in the management of COVID-19. The lack of inhibition of CPE by ivermectin at clinical concentrations could be part of the explanation for its lack of effectiveness in clinical trials.

Vitaminas B neurotrópicas y neuropatía periférica: estado del arte y acuerdo de expertos / Neurotropic B vitamins and peripheral neuropathy: State of the art and agreement of experts

Propósito: La neuropatía periférica tiene un espectro clínico inespecífico y multifactorial, con frecuente subdiagnóstico y terapéutica de eficacia variable. Existe una heterogénea prescripción de vitaminas B, las cuales pueden desempeñar un rol importante en el manejo de diferentes neuropatías; sin embargo, en Colombia no existen guías clínicas al respecto. El propósito de este trabajo es orientar en el reconocimiento temprano de las neuropatías periféricas y generar recomendaciones sobre el uso adecuado de vitaminas B neurotrópicas. Descripción de la metodología: Acuerdo de expertos sobre la neuropatía periférica y el rol terapéutico de las vitaminas B con énfasis en la epidemiología en Colombia, diagnóstico y tratamiento. Contenidos: En Colombia, la prevalencia de neuropatía periférica se estima cercana al 10 %, sin embargo, no hay datos recientes. Dentro de las etiologías más frecuentes se encuentran la neuropatía diabética, infecciosa, inflamatoria, carenciales, toxica y farmacológica. Se recomiendan las siguientes herramientas de tamizaje en población de riesgo: DN4, MNSI, test de monofilamento, test de vibración y valoración de reflejos. Las vitaminas B1, B6 y B12 son seguras, accesibles y pueden ser eficaces en neuropatía periférica, incluso cuando el déficit no ha sido demostrado, pero con requerimientos particulares en su administración conjunta. Conclusiones: Las neuropatías periféricas son un reto diagnóstico y terapéutico que requiere la identificación oportuna para el tratamiento de la etiología subyacente y el control de síntomas. El uso de vitaminas B neurotrópicas es efectivo y seguro en neuropatía periférica carencial, y también parece ser eficaz en el manejo de neuropatías periféricas de diferentes etiologías.

Purpose: Peripheral neuropathy has a nonspecific and multifactorial clinical spectrum, with frequent underdiagnosis and therapeutics of variable efficacy. There is a high but heterogeneous prescription of B vitamins, which can play an important role in the management of different neuropathies; however, in Colombia there are no clinical guidelines in this regard. The purpose of this article is to guide the early recognition of peripheral neuropathy and generate recommendations on the proper use of neurotropic B vitamins. Description of the methodology: Expert agreement on peripheral neuropathy and the therapeutic role of B vitamins with emphasis on epidemiology in Colombia, diagnosis and treatment. Contents: In Colombia, there are no recent data to estimate the prevalence of peripheral neuropathy; the main etiologies are: diabetes mellitus, nutritional deficiencies, herpes zoster and neuropathies due to chemotherapy. Given risk factors in the anamnesis, the use of DN4, MNSI, monofilament test, vibration test and assessment of reflexes is recommended. Vitamins B1, B6, and B12 are safe and can be effective in peripheral neuropathy, even when the deficit has not been demonstrated, but with special requirements in their joint administration. Conclusions: peripheral neuropathies are a diagnostic and therapeutic challenge, and require timely identification, for the treatment of the underlying etiology and symptom control. The use of neurotropic B vitamins is effective and safe in deficient peripheral neuropathy, and also appears to be effective in the management of peripheral neuropathies of different etiologies.

The Effect of Rare-Earth Elements on the Morphological Aspect of Borate and Electrocatalytic Sensing of Biological Compounds.

Adjusting the morphological characteristics of a material can result in improved electrocatalytic capabilities of the material itself. An example of this is the introduction of rare-earth elements into the borate structure, which gives a new perspective on the possibilities of this type of material in the field of (bio)sensing. In this paper, we present the preparation of borates including La, Nd and Dy and their application for the modification of a glassy carbon electrode, which is used for the non-enzymatic detection of a biologically relevant molecule, vitamin B6 (pyridoxine). Compared with the others, dysprosium borate has the best electrocatalytic performance, showing the highest current and the lowest impedance, respectively, as determined using cyclic voltammetry and impedance tests. Quantitative testing of B6 was performed in DPV mode in a Britton-Robinson buffer solution with a pH of 6 and an oxidation potential of about +0.8 V. The calibration graph for the evaluation of B6 has a linear range from 1 to 100 µM, with a correlation coefficient of 0.9985 and a detection limit of 0.051 µM. The DyBO3-modified electrode can be used repeatedly, retaining more than 90% of the initial signal level after six cycles. The satisfactory selectivity offered a potential practical application of the chosen method for the monitoring of pyridoxine in artificially prepared biological fluids with acceptable recovery. In light of all the obtained results, this paper shows an important approach for the successful design of electrocatalysts with tuned architecture and opens new strategies for the development of materials for the needs of electrochemical (bio)sensing.

Decreased liver B vitamin-related enzymes as a metabolic hallmark of cancer cachexia.

Cancer cachexia is a complex metabolic disorder accounting for ~20% of cancer-related deaths, yet its metabolic landscape remains unexplored. Here, we report a decrease in B vitamin-related liver enzymes as a hallmark of systemic metabolic changes occurring in cancer cachexia. Metabolomics of multiple mouse models highlights cachexia-associated reductions of niacin, vitamin B6, and a glycine-related subset of one-carbon (C1) metabolites in the liver. Integration of proteomics and metabolomics reveals that liver enzymes related to niacin, vitamin B6, and glycine-related C1 enzymes dependent on B vitamins decrease linearly with their associated metabolites, likely reflecting stoichiometric cofactor-enzyme interactions. The decrease of B vitamin-related enzymes is also found to depend on protein abundance and cofactor subtype. These metabolic/proteomic changes and decreased protein malonylation, another cachexia feature identified by protein post-translational modification analysis, are reflected in blood samples from mouse models and gastric cancer patients with cachexia, underscoring the clinical relevance of our findings.