Pyridoxal Research Articles

Formulation of New Chewable Oral Dosage Forms of Meclizine and Pyridoxine Hydrochloride.

Nausea and vomiting are symptoms associated with a lot of diseases and oral tablets may be unprofitable for patients especially those suffering from nausea and vomiting. Therefore, this study aimed to formulate a new meclizine and pyridoxine combination formula for chewable tablets and provide rapid drug absorption and decrease motion sickness. The new chewable formulation has been prepared to provide fast action, is more acceptable, and could be used for all age categories. Seven trials haves been carried out to prepare to find the suitable one where formula 7 of the chewable gum preparation exhibited good taste and hardness, while the gelatin formulation give an accepted formula after four trials with better taste and good acceptance. The prepared formulations give a dissolution profile of meclizine (95.53-102.8%) and pyridoxine (99.25 ± 115%) and assay (98 + 0.05-99.3 ± 0.8%) for meclizine and (97 ± 0.9-100.0 ± 0.08%) for the pyridoxine in three prepared formulations of chewable tablets. Followed by the evaluation, the formulation and testing them on human volunteers are carried out to confirm their effect to ensure acceptance and fast actions. The finding is promising for preparing a new route of administration of meclizine and pyridoxine combination to be used in the market.

Metal-Pyridoxal Cooperativity in Nonenzymatic Transamination.

Coenzymes are involved in ≥30% of enzymatic reactions and likely predate enzymes, going back to prebiotic chemistry. However, they are considered poor organocatalysts, and thus their pre-enzymatic function remains unclear. Since metal ions are known to catalyze metabolic reactions in the absence of enzymes, here we explore the influence of metal ions on coenzyme catalysis under conditions relevant to the origin of life (20-75 °C, pH 5-7.5). Specifically, Fe or Al, the two most abundant metals in the Earth's crust, were found to exhibit substantial cooperative effects in transamination reactions catalyzed by pyridoxal (PL), a coenzyme scaffold used by roughly 4% of all enzymes. At 75 °C and 7.5 mol % loading of PL/metal ion, Fe3+-PL was found to be 90-fold faster at catalyzing transamination than PL alone and 174-fold faster than Fe3+ alone, whereas Al3+-PL was 85-fold faster than PL alone and 38-fold faster than Al3+ alone. Under milder conditions, reactions catalyzed by Al3+-PL were >1000 times faster than those catalyzed by PL alone. Pyridoxal phosphate (PLP) exhibited similar behavior to PL. Experimental and theoretical mechanistic studies indicate that the rate-determining step in the PL-metal-catalyzed transamination is different from metal-free and biological PL-based catalysis. Metal coordination to PL lowers the pKa of the PL-metal complex by several units and slows the hydrolysis of imine intermediates by up to 259-fold. Coenzymes, specifically pyridoxal derivatives, could have exhibited useful catalytic function even before enzymes.

Vitamin B6 regulates IL-33 homeostasis to alleviate type 2 inflammation.

Interleukin-33 (IL-33) is a crucial nuclear cytokine that induces the type 2 immune response and maintains immune homeostasis. The fine-tuned regulation of IL-33 in tissue cells is critical to control of the type 2 immune response in airway inflammation, but the mechanism is still unclear. Here, we found that healthy individuals had higher phosphate-pyridoxal (PLP, an active form of vitamin B6) concentrations in the serum than asthma patients. Lower serum PLP concentrations in asthma patients were strongly associated with worse lung function and inflammation. In a mouse model of lung inflammation, we revealed that PLP alleviated the type 2 immune response and that this inhibitory effect relied on the activity of IL-33. A mechanistic study showed that in vivo, pyridoxal (PL) needed to be converted into PLP, which inhibited the type 2 response by regulating IL-33 stability. In mice heterozygous for pyridoxal kinase (PDXK), the conversion of PL to PLP was limited, and IL-33 levels were increased in the lungs, aggravating type 2 inflammation. Furthermore, we found that the mouse double minute 2 homolog (MDM2) protein, an E3 ubiquitin-protein ligase, could ubiquitinate the N-terminus of IL-33 and sustain IL-33 stability in epithelial cells. PLP reduced MDM2-mediated IL-33 polyubiquitination and decreased the level of IL-33 through the proteasome pathway. In addition, inhalation of PLP alleviated asthma-related effects in mouse models. In summary, our data indicate that vitamin B6 regulates MDM2-mediated IL-33 stability to constrain the type 2 response, which might help develop a potential preventive and therapeutic agent for allergy-related diseases.

Biomarkers for Prostate Cancer Bone Metastasis Detection and Prediction.

Prostate cancer (PCa) causes deaths worldwide, ranking second after lung cancer. Bone metastasis (BM) frequently results from advanced PCa, affecting approximately 90% of patients, and it also often results in severe skeletal-related events. Traditional diagnostic methods for bone metastases, such as tissue biopsies and imaging, have substantial drawbacks. This article summarizes the significance of biomarkers in PCa accompanied with BM, including (1) bone formation markers like osteopontin (OPN), pro-collagen type I C-terminal pro-peptide (PICP), osteoprotegerin (OPG), pro-collagen type I N-terminal pro-peptide (PINP), alkaline phosphatase (ALP), and osteocalcin (OC); (2) bone resorption markers, including C-telopeptide of type I collagen (CTx), N-telopeptide of type I collagen (NTx), bone sialoprotein (BSP), tartrate-resistant acid phosphatase (TRACP), deoxypyridinoline (D-PYD), pyridoxine (PYD), and C-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP); (3) prostate-specific antigen (PSA); (4) neuroendocrine markers, such as chromogranin A (CgA), neuron-specific enolase (NSE), and pro-gastrin releasing peptide (ProGRP); (5) liquid biopsy markers, such as circulating tumor cells (CTCs), microRNA (miRNA), circulating tumor DNA (ctDNA), and cell-free DNA (cfDNA) and exosomes. In summary, some of these markers are already in widespread clinical use, while others still require further laboratory or clinical studies to validate their value for clinical application.

Pharmacological correction of hepatotoxicity induced by Kinmiks

Improper usage of pyrethroid pesticides, non-compliance with the rules of storage and transportation can lead to negative consequences (poisoning, allergic reactions, chronic disorders of body systems, death). In recent decades, the attention of scientists has been attracted by the problem of toxic damage to the liver by pesticides. Kinmiks is a pyrethroid insecticide, the active ingredient is beta-cypermethrin (50 g/l). Conducted complex experimental studies have shown that Kinmiks, when administered intragastrically to animals, provokes the development of pathological reactions and has a toxic effect on the liver. It was concluded that in the complex treatment of poisoning with pesticides containing β-cypermethrin, the dipyroxime and pyridoxine hydrochloride should be used. For early diagnosis of pesticide poisoning the indicators of bilirubin, albumin, ALT, alkaline phosphatase and the ratio of ALT to alkaline phosphatase can be used as markers.

4'-Deoxypyridoxine disrupts vitamin B6 homeostasis in Escherichia coli K12 through combined inhibition of cumulative B6 uptake and PLP-dependent enzyme activity.

Pyridoxal 5'-phosphate (PLP) is the active form of vitamin B6 and a cofactor for many essential metabolic processes such as amino acid biosynthesis and one carbon metabolism. 4'-deoxypyridoxine (4dPN) is a long known B6 antimetabolite but its mechanism of action was not totally clear. By exploring different conditions in which PLP metabolism is affected in the model organism Escherichia coli K12, we showed that 4dPN cannot be used as a source of vitamin B6 as previously claimed and that it is toxic in several conditions where vitamin B6 homeostasis is affected, such as in a B6 auxotroph or in a mutant lacking the recently discovered PLP homeostasis gene, yggS. In addition, we found that 4dPN sensitivity is likely the result of multiple modes of toxicity, including inhibition of PLP-dependent enzyme activity by 4'-deoxypyridoxine phosphate (4dPNP) and inhibition of cumulative pyridoxine (PN) uptake. These toxicities are largely dependent on the phosphorylation of 4dPN by pyridoxal kinase (PdxK).

Impact of correction of homocisteinemia on clinical outcomes of lung damage associated with COVID-19 coronavirus infection

Aim. To assess the effect of serum homocysteine levels on treatment outcomes in patients with COVID19-associated lung damage, depending on the use of folic acid in complex treatment.Materials and methods. An open, prospective comparative study included 71 hospitalized adult patients with COVID-19-associated lung disease who did not require mechanical ventilation. The main group included 51 patients who received folic acid 15 mg per day in a complex treatment in a fixed combination with pyridoxine hydrochloride and cyanocobalamin. The comparison group included 20 patients in whose therapy folic acid was not used.Results. The use of folic acid was accompanied by a decrease in serum homocysteine concentration by 2.120 (-0.230; 3.680) µmol/L (p=0.004). When constructing a logistic regression model, the effect of a decrease in serum homocysteine (OR 1.289; 95% CI 1.026‒1.620; p=0.029), methylenetetrahydrofolate reductase MTHFR C677T genotype (OR 10.897; 95% CI 1.240‒95.772; p=0.031) on the achievement of 7th day of hospitalization, the cessation of isolation of SARS-CoV-2 virus RNA from the respiratory tract. Multiple linear regression analysis showed an association between the duration of hypoxemic respiratory failure, determined with SaO2≤93%, with the degree of change in serum homocysteine concentration after treatment, single nucleotide polymorphisms of methylenetetrahydrofolate reductase MTHFR C677T, methionine synthase MTR A2756G and methionine synthase reductase MTRR A66G, initial volume of lung damage ≥50% according to CT data, indicators of D-dimers, C-reactive protein, hemoglobin, platelets, concomitant hypertension, diabetes mellitus (R=0.699; R2=0.489; p=0.005).Conclusion. The dynamics of the decrease in serum homocysteine after treatment is an important predictor of the cessation of isolation from the respiratory tract of the SARS-CoV-2 virus RNA on the 7th day of treatment, reducing the duration of hypoxemic respiratory failure in patients with lung damage associated with COVID-19 infection.

Placental disorders in displaced pregnant women who are in persistent stress

Objectives: to determine morphological and immunohistochemical changes in the placentas of displaced pregnant women in order to further improve the antenatal monitoring program.Materials and methods. 96 displaced pregnant women (the main group) took part in the prospective study, who depending on the therapy were divided into: group I – 65 pregnant women who were monitored according to generally accepted recommendations and received routine therapy for prolonging pregnancy, group II – 31 pregnant women who received the proposed treatment and prophylactic complex (micronized progesterone, magnesium citrate in combination with pyridoxine hydrochloride, iron fumarate, a multivitamin complex with 200 mg of docosahexaenoic acid, complex of medical and psychological support for pregnant women). The control group consisted of 39 pregnant women living at territories controlled by Ukraine. The duration of observation was 2 years. Placentas were examined by organometric, macroscopic, general histological and immunohistochemical methods.Results. Organometrically, placentas in the group I had a significant decrease in thickness, mass and size. Edema of Wharton jelly was significantly more pronounced in this group, and in the lumen of vessels there was a more pronounced parietal formation of fibrin blood clots. Manifestations of ischemic infarcts and blood clots, which were located mainly in the paracentral and peripheral zones, were found significantly more frequently among women of the group I. Histologically, tissue changes were noted in the placentas in the group I, which are manifestations of placental damage and characterized by a partial decrease in maternal-fetal-placental perfusion. These changes were combined with focal edema in decidual tissue and dystrophy in decidual cells. In the placentas of women of the group I an uneven focal, sometimes pronounced proliferation of syncytial nodules of a more widespread nature was noted, which is a marker of cellular aging associated with adverse factors affecting the mother’s body. Also, foci of maternal infarcts were noted in the group I, which is associated with a decrease in maternal perfusion in the vessels of the placental barrier.Immunohistochemically, vacuolization and uneven chromatin arrangement were observed in the nuclei of villi cells during Ki-67 immersion, which indicated a decrease in regenerative responses in the placental barrier in groups I and II, especially with elevated cortisol levels. Immunohistochemical studies of the pro-apoptotic marker P-53 showed expression in single nuclei of villi stroma cells.Conclusions. The detected changes in the structures of the placental barrier indicate the predominance of placental disorders in the group I compared to the group II and control groups, especially in the syncytium of the villi, which led to a violation of the placenta functioning. Morphological studies confirmed the significant impact of long-term chronic stress on the formation and functioning of the uterine-placental-fetal complex, as well as the effectiveness of the proposed treatment in preventing the identified disorders.

Evaluation of Silybum marianum seed extract and vitamin B6 derivatives on methylglyoxal and sugar-induced oxidative DNA damage

AbstractReducing sugars are known to generate reactive oxygen species (ROS), mainly by means of the glycation reaction. The hydroxyl radical, a prominent entity of ROS, is known to alter cellular DNA and induces damage to DNA, and plays a role in diseases such as diabetes mellitus. In this study, the oxidative damage of DNA induced by the lysine/Fe3+/MG reaction was investigated. Silybum marianum seeds extract (SlyE), standard silymarin (Sly), and vitamin B6 derivatives, pyridoxal-5-phosphate (PLP), pyridoxamine (PM), and pyridoxine (P) in reversing glycation-induced damage in DNA were evaluated. In addition, different sugars and sugar phosphates were incubated with plasmid pBR 322 DNA to control and compare their harmful effects. Our results revealed that SlyE protected lysine/Fe3+/MG induced oxidative DNA damage more effectively than Sly. Vitamins, on the other hand, prevented this DNA damage in the order of PLP>P>PM. The DNA altering and damaging intensity of sugars and sugar phosphates tested increased considerably in the following order: Ribose-5-phosphate > fructose-6-phosphate > ribose > fructose > fructose-1,6 biphosphate > glucose-6 phosphate > glucose. The results show that the lysine/Fe3+/MG glycation reaction can cause oxidative damage of DNA through a mechanism involving hydroxyl radicals. It also provides evidence that ribose-5-phosphate and fructose and its phosphate metabolites can alter DNA more rapidly in vitro than glucose and its phosphate metabolites.

Electrochemical preparation and the characterizations of poly(3,5-diamino 1,2,4-triazole) film for the selective determination of pyridoxine in pharmaceutical formulations.

The online version contains supplementary material available at 10.1007/s11696-023-02777-5.

Thermochemical Analysis of the Interaction between Pyridoxine and L-Carnosine, L-Histidine, and L-Asparagine in Aqueous Solutions

Calorimetry is used to study the interaction between dipeptide L-carnosine (Car) and amino acids L-histidine (His) and L-asparagine (Asn) with pyridoxine (PN) in an aqueous solution. Experimental values of the enthalpy of dissolution of amino acids and peptide in an aqueous PN solution at T = 298.15 K are obtained for the first time. The thermodynamic characteristics and stoichiometry of the formation of molecular complexes between the reactants are determined. It is found that the stability of the resulting complexes depends on the structure of the reactants and falls in the order Car Asn His. It is shown that the main contribution to the stabilization of the resulting complexes comes from the entropy component of the Gibbs energy of complexation.

Vitamin B-6 Status Indices Are Lower in Pregnant than in Nonpregnant Women but Urinary Excretion of 4-Pyridoxic Acid Does Not Differ1–4

The cause of reduced plasma pyridoxal-5'-phosphate (PLP) concentration and the validity of plasma PLP concentration as a vitamin B-6 status indicator during pregnancy are not well understood. In this study, pregnant and nonpregnant women consumed a controlled diet for 5 d to exclude dietary intake as a factor in altered vitamin B-6 metabolic utilization. Plasma PLP and pyridoxal (PL) concentrations were significantly lower and higher, respectively, and plasma PL+PLP concentration was significantly lower during pregnancy. When plasma PLP and PL concentrations were normalized based on plasma albumin concentration, the differences were less marked but were still significant. The erythrocyte aspartate aminotransferase activity coefficient was significantly greater in pregnant women which is a further indication of reduced vitamin B-6 concentrations in the blood. No difference was observed in the urinary excretion of 4-pyridoxic acid between the pregnant and nonpregnant women. Results of this study demonstrate that vitamin B-6 status indices are lower during pregnancy without differences in the urinary excretion of 4-pyridoxic acid.

Excess Dietary Vitamin B-6 Alters Startle Behavior of Rats

Excessive intakes of vitamin B-6 can produce peripheral nervous system abnormalities, but few reports of central nervous system effects exist. We measured startle response, a central nervous system reflex, in rats fed excess pyridoxine to determine if subtle effects on central nervous system function could be detected. Female Long-Evans rats (218 g; n = 12) were fed either 1, 10, 100, 200 or 300 times the requirement of pyridoxine HCl (7 mg/kg) for 7 wk. Startle behavior was assessed weekly in chambers that allowed quantification of movement in response to stimuli. Food intake and body weights did not differ among groups (P > 0.1), and urinary vitamin B-6 excretion reflected intake (P < 0.001). Overt toxicity was not observed. There was a marginally significant effect of pyridoxine intake over time (P = 0.053) on the amplitude of response to a startling acoustic stimulus (117 dB, 40 ms) administered alone; the response appeared attenuated at the three highest pyridoxine concentrations. When the same stimulus was preceded by either a 70- or 75-dB prepulse (40 ms), responses of groups fed the two highest pyridoxine concentrations were significantly reduced relative to those fed the two lowest concentrations (P < 0.05). No effect of diet was seen with a startling tactile stimulus. Changes in central nervous system function were detected in rats fed excess vitamin B-6 using techniques of startle behavior measurement.

Pyridoxamine reduces methylglyoxal and markers of glycation and endothelial dysfunction, but does not improve insulin sensitivity or vascular function in abdominally obese individuals: A randomized double-blind placebo-controlled trial.

To investigate the effects of pyridoxamine (PM), a B6 vitamer and dicarbonyl scavenger, on glycation and a large panel of metabolic and vascular measurements in a randomized double-blindplacebo-controlled trial in abdominally obese individuals. Individuals (54% female; mean age 50 years; mean body mass index 32 kg/m2 ) were randomized to an 8-week intervention with either placebo (n=36), 25 mg PM (n=36) or 200 mg PM (n=36). We assessed insulin sensitivity, β-cell function, insulin-mediated microvascular recruitment, skin microvascular function, flow-mediated dilation, and plasma inflammation and endothelial function markers. PM metabolites, dicarbonyls and advanced glycation endproducts (AGEs) were measured using ultra-performance liquid chromatography tandem mass spectrometry. Treatment effects were evaluated by one-way ANCOVA. In the high PM dose group, we found a reduction of plasma methylglyoxal (MGO) and protein-bound Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine(MG-H1), as compared to placebo. We found a reduction of the endothelial dysfunction marker soluble vascular celladhesion molecule-1 (sVCAM-1) in the low and high PM dose group and of soluble intercellularadhesion molecule-1(sICAM-1) in the high PM dose, as compared to placebo. We found no treatment effects on insulin sensitivity, vascular function or other functional outcome measurements. This study shows that PM is metabolically active and reduces MGO, AGEs, sVCAM-1 and sICAM-1, but does not affect insulin sensitivity and vascular function in abdominally obese individuals. The reduction in adhesion markers is promising because these are important in the pathogenesis of endothelial damage and atherosclerosis.

Determination of pyridoxine HCl by oxidative coupling using N,N-di methyl paraphenylene diamine dihydrochloride (DMPPH) presence of potassium hexacynoferrate(III) in basic medium

This research involves the development of spectrophotometric method for determination of pyridoxine hydrochloride by oxidative coupling reaction with N,N-dimethylparaphenylenediamine dihydrochloride (DMPPDAD ( in a basic medium (pH 11.6) in the presence of potassium ferricyanide to produce an intense green colour, soluble in water, stable product and absorbs at 650 nm. Beer's law was in the linear range 6-30 μg/ml of pyridoxine hydrochloride, the molar extinction coefficint, Sandellʼs sensitivity index and detection limit were 4.338 × 103 L. mol-1.cm-1 , 0.0474 μg.cm-2 and 0.756 μg/ml respectively. The RSD value was 0.63 - 1.41% depending on the concentration. This method was applied successfully to the determination of pyridoxine hydrochloride in pharmaceutical preparation samavite B6 tablet with recovery of not less than 99.5%.

Determination Micro Spectrohotometric of Pyridoxine Hydrochloride and Nicotinamide via Derivative Spectrophotometry First and Second

A simple, sensitive and accurate spectrophotometric method for determination of PYR.HCl and NTA in pure and pharmaceutical forms. The method based on group of known digital data used to separate the response signals for sample contains the two components without need to separating via first and second derivative of spectra. The method obtained obeying to the Beers law in the concentration range between )5-45 µg.ml-1( for two components in the presence of PYR. HCl )15µg.ml-1( and NTA (5µg.ml-1) with another components at wavelength (210 nm ) respectively . The Rec % range was between ) 98.5354 - 103.4335 % (and RSD% (0.0864 - 0.1487 %), LOD) 1.0822 µg.ml-1, ( LOQ ( 3.6075 µg.ml-1 (PYR.HCl in presence of NTA, The Rec% range was between )96.1418 - 102.9273 % (and RSD% (0.2165–0.4933 % ), LOD (0.7273µg.ml-1 ,(LOQ (2.4252 µg.ml-1( NTA in presence of PYR. HCl .

Hydrothermal assisted ultrasonic synthesis of MgFe-LDH as a simple and eco-friendly method for electrochemical detection of vitamin B6

A new eco-friendly electrochemical sensor with high sensitivity and selectivity has been introduced in the present work. The proposed sensor is a MgFe-layered double hydroxide (MgFe -LDH) synthesizing via a very simple method. This sensor for the first time was used to determine pyridoxine hydrochloride (vitamin B6) using the differential pulse voltammetry (DPV) technique. The morphology and chemical composition of the MgFe-LDH was recognized using field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDX), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET). Under optimal conditions, the calibration curve was plotted using the DPV technique. The limit of detection (LOD) was 131 nM and a linear range of 900 nM–2300 μM was obtained for vitamin B6 oxidation. Therefore, the method is sensitive, simple, and specific with a short analysis time, and the main advantages of this sensor are easy synthesis, low detection limit, excellent stability, repeatability, and good selectivity in vitamin B6. This sensor has been successfully utilized in determining vitamin B6 in human plasma, rice flour, and tablet samples.

Quantitative Determination of Ascorbic Acid in Herbal Medicinal Products by HPLC

Ascorbic acid (vitamin C) is involved in many vital biochemical processes in the human body. Rose hips are a natural source of ascorbic acid. Rose hips are used in decoctions and many vitamin herbal teas. Russian compendial methods for the quantitative determination of ascorbic acid have certain limitations precluding its objective measurement in herbal drugs, herbal drug preparations, and herbal medicinal products.The aim of the study was to develop an analytical procedure for the quantitative determination of ascorbic acid in herbal drugs, herbal medicinal preparations, and herbal medicinal products using high performance liquid chromatography (HPLC).Materials and methods. The study involved two herbal medicinal products, Rose Hips (rose hips) and Vitamin Herbal Tea 2 (rose hips and rowan fruits), and reference standards for ascorbic acid, rutoside, quercetin, gallic acid, caffeic acid, chlorogenic acid, luteolin-7-glucoside, citric acid, DL-malic acid, thiamine, and pyridoxine hydrochloride. The authors used a 1260 Infinity II chromatograph with a diode array detector by Agilent and an Inertsil ODS-3 chromatographic column (250 mm × 4.6 mm, 5 µm) by GL Sciences. The HPLC system was operated in gradient elution mode, and the detector was set at 244 nm.Results. Ascorbic acid content in herbal drugs, herbal medicinal preparations, and herbal medicinal products can be determined by HPLC. Adequate sample preparation and chromatography conditions allow for inhibiting ascorbic acid oxidation in aqueous solutions for a period sufficient to complete testing (not less than 8 h).Conclusions. The authors developed a highly sensitive and selective HPLC procedure for the quantitative determination of ascorbic acid intended for the standardisation of herbal drugs, herbal medicinal preparations, and herbal medicinal products. The procedure is worthy of inclusion in the Rose Hips and Vitamin Herbal Tea 2 monographs of the State Pharmacopoeia of the Russian Federation. Switching to HPLC should not require lowering the limit for ascorbic acid (not less than 0.2%) established in the Rose Hips and Vitamin Herbal Tea 2 monographs for the titration method. The ascorbic acid content was below this limit in the vast majority of study samples. However, this discrepancy may be explained by the presence of dog rose (Rosa canina) species low in vitamin C, which should normally be used only as choleretics.

Biochemical and cellular effects of a novel missense mutation of the AGXT gene associated with Primary Hyperoxaluria Type 1

Primary Hyperoxaluria Type 1 (PH1) is a rare autosomal disease caused by mutations in AGXT that lead to the deficiency of alanine:glyoxylate aminotransferase (AGT). AGT is a liver pyridoxal 5′-phosphate (PLP)-dependent enzyme that detoxifies glyoxylate inside peroxisomes. The lack of AGT activity results in a build-up of glyoxylate that is oxidized to oxalate, then culminating in hyperoxaluria often leading to kidney failure. Most pathogenic mutations reduce AGT specific activity because of catalytic defects, improper folding, mistargeting to mitochondria, reduced intracellular stability, dimerization, and/or aggregation. Administration of pyridoxine (PN), a precursor of PLP, is a therapeutic option available for PH1 patients carrying responsive genotypes through the ability of the coenzyme to behave as a chaperone.Here, we report the clinical and biochemical characterization of the novel mutation c.1093G > T (p.Gly365Cys) identified in a Japanese patient. In silico studies predict that the p.Gly365Cys mutation causes a steric clash resulting in a local rearrangement of the region surrounding the active site, thus possibly affecting PLP binding and catalysis. Indeed, the purified p.Gly365Cys mutant displays proper folding but shows an extensive decrease of catalytic efficiency due to an altered PLP-binding. When expressed in AGXT1-KO HepG2 cells the variant shows reduced specific activity and protein levels in comparison with wild type AGT that cannot be rescued by PN treatment.Overall, our data indicate that the mutation of Gly365 induces a conformational change at the AGT active site translating into a functional and structural defect and allow to predict that the patients will not be responsive to vitamin B6, thus supporting the usefulness of preclinical studies to guide therapeutic decisions in the era of precision medicine.

The results of the use of a combined probiotic (Lactobacillus rhamnosus GG and Bifidobacterium animalis spp. lactis ВB-12) in children with gastrointestinal and skin manifestations of food allergy

At present, there are sufficient data on the influence of the gut microbiome on the development of food allergy and its progression. Changes in gut microbiome composition could positive impact on the course of allergic diseases by means of regulating the ratio of pro- and anti-inflammatory cytokines, as well as immunoglobulin E level. The purpose of the research was to study the effectiveness of combined probiotic in treatment of food allergies in children. Material and methods. The prospective randomized controlled study included 92 children aged from 4 to 5 years with symptoms of food allergy, involving the skin and gastrointestinal tract. The main group (n=46) took two chewable tablet Bifiform Kids (Lactobacillus rhamnosus GG >1x109 CFU, Bifidobacterium animalis spp. lactis BB-12 >1x109 CFU, thiamine mononitrate 0.40 mg, pyridoxine hydrochloride 0.50 mg per tablet) 2 times per day during 21 days. The control group (n=46) did not take the complex. The dynamics of the severity of food allergy skin symptoms was assessed using the SCORAD index, of gastrointestinal manifestations - on a point scale after 21 days and after 4 and 6 months (visits 2, 3 and 4). The concentration of immunoglobulin E, interleukins IL-17 and IL-10 was determined by enzyme immunoassay in blood serum at the baseline, as well as after 21 days and after 6 months (visits 1, 2 and 4) after the study initiation. Results. The SCORAD index among children from the main group decreased from 12.4±2.3 до 7.6±1.8 (р=<0.05) while taking a combined probiotic. It was significantly lower (р=<0.05) compared to the control group (SCORAD index changed from 12.1±2.4 to 12.2±1.9). On the 21st day, a statistically significant decrease in level of pro-inflammatory IL-17 (by 27%) and a statistically significant increase in the concentration of anti-inflammatory IL-10 (by 38.9%) were recorded. In children from the main group, the severity of such gastrointestinal symptoms as pain, rumbling in the abdomen, belching with air, bloating, gas discharge, increased stool and its unformularity, decreased compare to the control group of patients (р=<0.05), in which the intensity of complaints related to gastrointestinal manifestations did not change. In the main group of patients, the most clinical efficacy was noted immediately after the end of the probiotic intake. In the following five months, the intensity of symptoms increased in individual subjects from the main group, but in general, the intensity of complaints remained significantly lower than before probiotic intake (р=<0.05). Children from the main group showed a significant decrease in IgE level from 184±121 kU/l by 43.5% at visit 2 and by 38.0% at visit 4 (p=<0.05), while in children from the control group its level didn't change, amounting to 176±141, 165±121 and 178±132 kU/l, respectively. Conclusion. The results of the study show the effectiveness of the use of a combined probiotic (Lactobacillus rhamnosus GG, Bifidobacterium animalis spp. lactis ВB-12) with vitamins B1 and B6 in children with mild forms of gastrointestinal and skin manifestations of food allergy, both in relation to the severity reduction of the clinical symptoms of the disease (skin manifestations, pain, rumbling in the abdomen, belching with air, bloating, gas discharge, increased stool and its unformularity), and in relation to the dynamics of biochemical parameters - a decrease in the level of IgE.