Determination of Vitamin B12 and Folate Compounds in Commercially Available Edible Seaweed Products

BACKGROUND

Information on the contents of both vitamin B12 and folate in edible seaweeds is limited, of which deficiencies disrupt methionine biosynthesis to accumulate homocysteine as a risk factor of cardiovascular diseases.

METHODS

Both vitamins were determined in commercially available edible seaweed products using high-performance liquid chromatography.

RESULTS

Dried purple laver (Neopyropia yezoensis) products contain higher levels of vitamin B12 (approximately 30-60 μg/100 g dry weight) and folate compounds (approximately 880-1300 μg/100 g dry weight) than other seaweed products, such as kombu (Saccharina japonica), hijiki (Sargassum fusiformis), and wakame (Undaria pinnatifida). 5-methyltetrahydrofolate was the major folate compound in purple laver products. 5-formyltetrahydrofolate was found at a moderate level, whereas tetrahydrofolate, 5,10-metenyltetrahydrofolate, 10-formyltetrahydrofolate, and folic acid were found to be minor folate compounds.

CONCLUSIONS

These findings suggest that dried purple laver (nori) products are suitable sources of vitamin B12 and folate compounds for humans, especially vegetarians.

Production and characterization of cyanocobalamin-enriched tomato (Solanum lycopersicum) fruits grown using hydroponics

BACKGROUND

Vitamin B₁₂ is an essential vitamin that is absent in plant-derived foods such as fruits and vegetables. This can result in an increased risk of developing vitamin B₁₂ deficiency in strict vegetarians (vegans). There are several studies that have aimed to enhance nutrients in food crops. The purpose of the present study was to fortify tomato fruits with vitamin B₁₂ (or cyanocobalamin).

RESULTS

Tomato plants were grown for 70 days in hydroponic culture pots and treated with 5 μm of cyanocobalamin on days 1-24 after the fruiting, and then harvested for tomato fruits. The ripened tomato fruits contained 4.0 × 10^-7  g of cyanocobalamin per 100 g of dry weight and showed a significant increase in glucose and lycopene levels.

CONCLUSION

The present study highlights the use of a cyanocobalamin-supplementation system for the production of B₁₂ fortified tomato fruits that can help prevent B₁₂ deficiency in vegetarians. © 2022 Society of Chemical Industry.

NAD+ enhances the activity and thermostability of S-adenosyl-L-homocysteine hydrolase from Pyrococcus horikoshii OT3

S-Adenosyl-L-methionine (SAM) and S-adenosyl-L-homocysteine (SAH) are important biochemical intermediates. SAM is the major methyl donor for diverse methylation reactions in vivo. The SAM to SAH ratio serves as a marker of methylation capacity. Stable isotope-labeled SAM and SAH are used to measure this ratio with high sensitivity. SAH hydrolase (EC 3.13.2.1; SAHH), which reversibly catalyzes the conversion of adenosine and L-homocysteine to SAH, is used to produce labeled SAH. To produce labeled SAH with high efficiency, we focused on the SAHH of Pyrococcus horikoshii OT3, a thermophilic archaeon. We prepared recombinant P. horikoshii SAHH using Escherichia coli and investigated its enzymatic properties. Unexpectedly, the optimum temperature and thermostability of P. horikoshii SAHH were much lower than its optimum growth temperature. However, addition of NAD+ to the reaction mixture shifted the optimum temperature of P. horikoshii SAHH to a higher temperature, suggesting that NAD+ stabilizes the structure of the enzyme.

Epidemiology of adverse events attributed to airway management in paediatric anaesthesia: protocol for the prospective, multicentre, registry-based, cross-sectional Japan Pediatric Difficult Airway in Anesthesia study (J-PEDIA)

INTRODUCTION

Failure to secure an airway during general anaesthesia is a major cause of adverse events (AEs) in children. The safety of paediatric anaesthesia may be improved by identifying the incidence of AEs and their attributed risk factors. The aim of the current study is to obtain real-world data on the incidence of adverse peri-intubation events and assess their association with patient characteristics (including the prevalence of difficult airway features) and choice of anaesthesia management. These data can be used to develop a targeted education programme for anaesthesia providers towards quality improvement activities.

METHODS AND ANALYSIS

This prospective, multicentre, registry-based, cross-sectional study will be conducted in four tertiary care hospitals in Japan from June 2022 to May 2025. Children <18 years of age undergoing surgical and/or diagnostic test procedures under general anaesthesia or sedation by anaesthesiologists will be enrolled in this study. Data on patient characteristics, discipline of anaesthesia providers and methodology of airway management will be collected through a standardised verification system. The exposure of interest is the presence of difficult airway features defined based on the craniofacial appearance. The primary and secondary endpoints are all AEs associated with airway management and reduced peripheral capillary oxygen saturation values. Potential confounders are related to the failure to secure the airway and variations in the anaesthesia providers' levels, adjusted using hierarchical multivariable regression models with mixed effects. The sample size was calculated to be approximately 16 000 assuming a 99% probability of obtaining a 95% Wilson CI with±0.3% of the half-width for the 2.0% of the incidence of critical AEs.

ETHICS AND DISSEMINATION

The study protocol was approved by the Institutional Review Board at Aichi Children's Health and Medical Center (2021051). The results will be reported in a peer-reviewed journal and a relevant academic conference.

TRIAL REGISTRATION NUMBER

UMIN000047351.

Association Between Plasma Fibrinogen Concentration After Cardiopulmonary Bypass and Postoperative Blood Loss in Children Undergoing Cardiac Surgery: A Retrospective Cohort Study

Background Intraoperative hypofibrinogenemia is a major factor associated with increased postoperative blood loss in adult cardiac surgery. However, previous pediatric studies on this topic did not sufficiently adjust for potential confounders and variations in surgeons' techniques. Therefore, evidence for the association between hypofibrinogenemia and postoperative blood loss after cardiac surgery in children remains insufficient. In this study, we aimed to evaluate the association between postoperative blood loss and hypofibrinogenemia by adjusting for potential confounders and the effects of differences in surgeons' techniques. Methodology This single-center, retrospective, cohort study included children who underwent cardiac surgery with cardiopulmonary bypass from April 2019 to March 2022. Multilevel logistic regression models with mixed effects were used to evaluate the association of major blood loss in the first six hours postoperatively with fibrinogen concentration at the end of cardiopulmonary bypass. The difference in the surgeon's techniques was adjusted as a random effect for the model. The model included potential confounders identified as risk factors in previous studies. Results A total of 401 patients were included. A fibrinogen concentration ≤150 mg/dL (adjusted odds ratio (aOR) = 2.08; 95% confidence interval (CI) = 1.18-3.67; p = 0.011) and the presence of cyanotic disease (aOR = 2.34; 95% CI = 1.10-4.97; p = 0.027) were associated with major blood loss in the first six postoperative hours. Conclusions A fibrinogen concentration ≤150 mg/dL and the presence of cyanotic disease were associated with postoperative blood loss in pediatric cardiac surgery. Maintaining a fibrinogen concentration >150 mg/dL is recommended, especially for patients with cyanotic diseases.

Efficacy of in-situ simulation training using evaluation checklists for sudden oxygen supply failure during general anesthesia: A preliminary report

Introduction

Sudden oxygen supply failure (OSF) is a life-threatening consequence that may be triggered by natural disasters. Anesthesiologists are required to manage OSF promptly in such catastrophic situations. However, the current evidence regarding the efficacy of anesthesia training for sudden OSF is insufficient. This preliminary study aimed to introduce our in-situ simulation training utilizing evaluation checklists for a sudden OSF situation during general anesthesia and to evaluate the efficacy of the training program for anesthesia providers.

Methods

This is a preliminary single-center, prospective study. We developed an OSF simulation scenario utilizing evaluation checklists with key actions to manage OSF. The training session comprised four components: orientation, benchmark evaluation (pre-test) according to the checklists, a short didactic lecture, and post-lecture evaluation (post-test). The scenario comprised two steps wherein the participants were supposed to utilize different oxygen supply sources immediately after OSF (Step 1) and minimize the amount of oxygen consumption (Step 2).

Results

Fifteen anesthesia providers were enrolled. The score for all anesthesia providers in the post-test was significantly higher than that in the pre-test (median 8 [IQR: 8, 8], 3 [IQR: 3, 4], P < 0.001, respectively). The successful performance rates of all anesthesia providers in one key action of all the four in Step 1 and four of all the six in Step 2 were significantly higher in the post-test than in the pre-test.

Conclusions

Our in-situ training method utilizing evaluation checklists for a sudden OSF situation improved overall performance of anesthesia providers.

Ultrasound-guided femoral vascular access in pediatric cardiac catheterization

BACKGROUND

In pediatric catheterization, the palpation and landmark (PL) technique is widely used for femoral arterial and venous (FAV) cannulation. Over the past decade, the ultrasound-guided (US) technique has replaced the PL technique. This study aimed to assess the clinical impact of application of the US technique on the success rate and completion time of FAV cannulation during cardiac catheterization in children.

METHODS

This is a retrospective observational study of consecutive pediatric patients who underwent cardiac catheterization in a tertiary care children's hospital from April 2016 to March 2022. The association between FAV cannulation success rate and the US technique was analyzed using multiple logistic regression analysis by adjusting for potential confounders, including patient and operator characteristics and procedural details.

RESULTS

A total of 749 patients (PL, 371; US, 378) were analyzed. The odds ratio of the US technique success rate for FAV cannulation was 2.03 (95% confidence interval [CI], 1.10-3.73; p = 0.02). The odds ratio of the cannulation success rate of children aged <1 year was 0.16 (95% CI, 0.03-0.97; p = 0.046).

CONCLUSIONS

The US-guided technique was associated with an increased success rate of FAV cannulation, compared with the PL technique. Moreover, age <1 year was an independent factor associated with a lower success rate of FAV cannulation. The US-guided technique might be an effective procedure in FAV cannulation during cardiac catheterization in children.

Discovery of CH7057288 as an Orally Bioavailable, Selective, and Potent pan-TRK Inhibitor

Kinase fusions involving tropomyosin receptor kinases (TRKs) have been proven to act as strong oncogenic drivers and are therefore recognized as attractive therapeutic targets. We screened an in-house kinase-focused library and identified a promising hit compound with a unique tetracyclic scaffold. Compound 1 showed high TRK selectivity but moderate cell growth inhibitory activity as well as a potential risk of inducing CYP3A4. In this report, chemical modification intended to improve TRK inhibition and avoid CYP3A4 induction enabled us to identify an orally bioavailable, selective, and potent TRK inhibitor 7.

Determination of cobalamin and related compounds in foods

The microbiological assay of total cobalamin (vitamin B₁₂) by Lactobacillus delbrueckii subsp. lactis ATCC7830 is now used worldwide in food analysis because of its high sensitivity, low running cost, and no expensive instruments. It has been recently reported that some foods contain a substantial number of inactive corrinoid compounds, some of which are active in this bacterium. These results indicate that the microbiological method must be replaced with high-performance liquid chromatography or liquid chromatography/electrospray ionization-tandem mass spectrometry as there can specifically determine biologically active cobalamin. Nowadays, powerful tools, such as immunoaffinity columns, purify cobalamin simply and specifically. In this chapter, we summarized the determination methods of cobalamin and related compounds in foods. Various inactive corrinoids found in foods were also characterized.

Sedation with dexmedetomidine and propofol in children with Fontan circulation undergoing cardiac catheterization: A descriptive study

Background:

A combination of dexmedetomidine and propofol is considered advantageous for maintaining spontaneous breathing with a satisfactory depth of anesthesia. However, the incidence of upper airway obstruction under sedation with dexmedetomidine and propofol in patients with Fontan circulation remains unanswered. This study aimed to evaluate upper airway patency and oxygen desaturation during sedation with dexmedetomidine and propofol for cardiac catheterization in pediatric patients with Fontan circulation.

Methods:

In this descriptive study, we reviewed medical records of patients with Fontan circulation who underwent cardiac catheterization between December 2018 and August 2020 at a single-center 200-bed academic children's hospital in Japan.

Results:

A total of 35 patients with Fontan circulation sedated with a departmental protocol of dexmedetomidine and propofol infusion for cardiac catheterization were reviewed. Overall, the incidence of airway interventions and oxygen desaturation were 31.4% and 28.6%, respectively. In children with a history of snoring and additional use of intravenous midazolam, the rates of airway interventions were 50% and 100%, respectively. In patients ≤2 years old with recent upper respiratory infection (URI) symptoms, oxygen desaturation rate was 75%.

Conclusions:

In children with Fontan circulation, the incidence rate of upper airway obstruction was high under sedation with dexmedetomidine and propofol during cardiac catheterization, which is commonly considered safe in children without Fontan circulation. A history of snoring, an additional bolus of IV midazolam, and the presence of recent URI symptoms in patients ≤2 years old are potential risks for upper airway obstruction.

Dityrosine Crosslinking of Collagen and Amyloid-β Peptides Is Formed by Vitamin B12 Deficiency-Generated Oxidative Stress in Caenorhabditis elegans

(1) Background: Vitamin B12 deficiency in Caenorhabditis elegans results in severe oxidative stress and induces morphological abnormality in mutants due to disordered cuticle collagen biosynthesis. We clarified the underlying mechanism leading to such mutant worms due to vitamin B12 deficiency. (2) Results: The deficient worms exhibited decreased collagen levels of up to approximately 59% compared with the control. Although vitamin B12 deficiency did not affect the mRNA expression of prolyl 4-hydroxylase, which catalyzes the formation of 4-hydroxyproline involved in intercellular collagen biosynthesis, the level of ascorbic acid, a prolyl 4-hydroxylase coenzyme, was markedly decreased. Dityrosine crosslinking is involved in the extracellular maturation of worm collagen. The dityrosine level of collagen significantly increased in the deficient worms compared with the control. However, vitamin B12 deficiency hardly affected the mRNA expression levels of bli-3 and mlt-7, which are encoding crosslinking-related enzymes, suggesting that deficiency-induced oxidative stress leads to dityrosine crosslinking. Moreover, using GMC101 mutant worms that express the full-length human amyloid β, we found that vitamin B12 deficiency did not affect the gene and protein expressions of amyloid β but increased the formation of dityrosine crosslinking in the amyloid β protein. (3) Conclusions: Vitamin B12-deficient wild-type worms showed motility dysfunction due to decreased collagen levels and the formation of highly tyrosine-crosslinked collagen, potentially reducing their flexibility. In GMC101 mutant worms, vitamin B12 deficiency-induced oxidative stress triggers dityrosine-crosslinked amyloid β formation, which might promote its stabilization and toxic oligomerization.

Valvular changes after aortic valve neo-cuspidization in children: A case series

BACKGROUND

Aortic valve neo-cuspidization (AVNeo), a procedure wherein the aortic valve is reconstructed utilizing an autologous pericardium, has recently been more commonly performed in children. However, the postoperative morphological changes in the aortic valve of pediatric patients remain unknown. The current study aimed to describe the intraoperative and postoperative findings of aortic regurgitation (AR) and stenosis (AS) after AVNeo in children.

METHODS

This case series describes the morphological changes in AR and AS, and their severity, between the perioperative period and 3 months postoperative period after AVNeo in children (<18 years) who underwent AVNeo between April 2016 and March 2020. Data were collected at two measurement points: (i) intraoperative transesophageal echocardiography after weaning from cardiopulmonary bypass (io-TEE); (ii) postoperative transthoracic echocardiography 3 months after the procedure (po-TTE).

RESULTS

Seven patients were included in this case series. The number of postoperative AR sites and the ratio of AR jet area to the left ventricular outflow tract area showed a tendency to decrease between io-TEE and po-TTE. All AR sites were integrated during the postoperative period. One patient identified developed intraoperative AS, which maintained its severity after AVNeo.

CONCLUSIONS

Most cases exhibited spontaneous improvement in AR, while one developed postoperative AS. Further prospective investigation is, therefore, needed to explore surgical outcomes following AVNeo among children.

Lemon myrtle extract inhibits lactate production by Streptococcus mutans

Backhousia citriodora (lemon myrtle) extract has been found to inhibit glucansucrase activity, which plays an important role in biofilm formation by Streptococcus mutans. In addition to glucansucrase, various virulence factors in S. mutans are involved in the initiation of caries. Lactate produced by S. mutans demineralizes the tooth enamel. This study investigated whether lemon myrtle extract can inhibit S. mutans lactate production. Lemon myrtle extract reduced the glycolytic pH drop in S. mutans culture and inhibited lactate production by at least 46%. Ellagic acid, quercetin, hesperetin, and myricetin, major polyphenols in lemon myrtle, reduced the glycolytic pH drop and lactate production, but not lactate dehydrogenase activity. Furthermore, these polyphenols reduced the viable S. mutans cell count. Thus, lemon myrtle extracts may inhibit S. mutans-mediated acidification of the oral cavity, thereby preventing dental caries and tooth decay.

Effects of Vitamin B12 Deficiency on Amyloid-β Toxicity in Caenorhabditis elegans

High homocysteine (Hcy) levels, mainly caused by vitamin B₁₂ deficiency, have been reported to induce amyloid-β (Aβ) formation and tau hyperphosphorylation in mouse models of Alzheimer's disease. However, the relationship between B₁₂ deficiency and Aβ aggregation is poorly understood, as is the associated mechanism. In the current study, we used the transgenic C. elegans strain GMC101, which expresses human Aβ_1-42 peptides in muscle cells, to investigate the effects of B₁₂ deficiency on Aβ aggregation-associated paralysis. C. elegans GMC101 was grown on nematode growth medium with or without B₁₂ supplementation or with 2-O-α-D-glucopyranosyl-L-ascorbic acid (AsA-2G) supplementation. The worms were age-synchronized by hypochlorite bleaching and incubated at 20 °C. After the worms reached the young adult stage, the temperature was increased to 25 °C to induce Aβ production. Worms lacking B₁₂ supplementation exhibited paralysis faster and more severely than those that received it. Furthermore, supplementing B₁₂-deficient growth medium with AsA-2G rescued the paralysis phenotype. However, AsA-2G had no effect on the aggregation of Aβ peptides. Our results indicated that B₁₂ supplementation lowered Hcy levels and alleviated Aβ toxicity, suggesting that oxidative stress caused by elevated Hcy levels is an important factor in Aβ toxicity.

Pseudovitamin B12 and factor S are the predominant corrinoid compounds in edible cricket products

In this study, we determined the vitamin B₁₂ content of commercially-available edible insect products using a bioassay based on Lactobacillus delbrueckii ATCC 7830. Although the vitamin content of giant water bug, bee larva, grasshopper, and weaver ant products was low, we found that diving beetle and cricket products contained relatively high amounts of vitamin B₁₂ (approximately 89.5 and 65.8 µg/100 g dry weight, respectively). In the cricket products most widely circulated as foods, specific corrinoid (vitamin B₁₂) compounds were extracted and identified using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Despite the bioassay detecting high vitamin B₁₂ content (approximately 50-75 µg/100 g dry weight) in these cricket products, UPLC-MS/MS analysis indicated that pseudovitamin B₁₂ and 2-methylmercaptoadenyl cobamide (also known as factor S) were actually the predominant corrinoid compounds (~74% and ~21%, respectively), with authentic vitamin B₁₂ making up only 5% of total corrinoids.

High-dose folic acid supplementation results in significant accumulation of unmetabolized homocysteine, leading to severe oxidative stress in Caenorhabditis elegans

Using Caenorhabditis elegans as a model animal, we evaluated the effects of chronical supplementation with high-dose folic acid on physiological events such as life cycle and egg-laying capacity and folate metabolism. Supplementation of high-dose folic acid significantly reduced egg-laying capacity. The treated worms contained a substantial amount of unmetabolized folic acid and exhibited a significant downregulation of the mRNAs of cobalamin-dependent methionine synthase reductase and 5,10-methylenetetrahydrofolate reductase. In vitro experiments showed that folic acid significantly inhibited the activity of cobalamin-dependent methionine synthase involved in the metabolism of both folate and methionine. In turn, these metabolic disorders induced the accumulation of unmetabolized homocysteine, leading to severe oxidative stress in worms. These results were similar to the phenomena observed in mammals during folate deficiency.

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High-dose folic acid supplementation reduced egg-laying ability in worms.

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Substantial amounts of folic acid and homocysteine were accumulated in the worms.

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The mRNA expression of methylenetetrahydrofolate reductase was reduced in the treated worms.

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Folic acid was a potent inhibitor of cobalamin-dependent methionine synthase in in vitro tests.

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High-dose folic acid supplementation in worms resulted in severe oxidative stress.

Potential of Chlorella as a Dietary Supplement to Promote Human Health

Chlorella is a green unicellular alga that is commercially produced and distributed worldwide as a dietary supplement. Chlorella products contain numerous nutrients and vitamins, including D and B12, that are absent in plant-derived food sources. Chlorella contains larger amounts of folate and iron than other plant-derived foods. Chlorella supplementation to mammals, including humans, has been reported to exhibit various pharmacological activities, including immunomodulatory, antioxidant, antidiabetic, antihypertensive, and antihyperlipidemic activities. Meta-analysis on the effects of Chlorella supplementation on cardiovascular risk factors have suggested that it improves total cholesterol levels, low-density lipoprotein cholesterol levels, systolic blood pressure, diastolic blood pressure, and fasting blood glucose levels but not triglycerides and high-density lipoprotein cholesterol levels. These beneficial effects of Chlorella might be due to synergism between multiple nutrient and antioxidant compounds. However, information regarding the bioactive compounds in Chlorella is limited.

L-Ascorbate Biosynthesis Involves Carbon Skeleton Rearrangement in the Nematode Caenorhabditis elegans

Ascorbate (AsA) is required as a cofactor and is widely distributed in plants and animals. Recently, it has been suggested that the nematode Caenorhabditis elegans also synthesizes AsA. However, its biosynthetic pathway is still unknown. To further understand AsA biosynthesis in C. elegans, we analyzed the incorporation of the ¹³C atom into AsA using gas chromatography-mass spectrometry (GC-MS) in worms fed with D-Glc (1-¹³C)-labeled Escherichia coli. GC-MS analysis revealed that AsA biosynthesis in C. elegans, similarly to that in mammalian systems, involves carbon skeleton rearrangement. The addition of L-gulono-1,4-lactone, an AsA precursor in the mammalian pathway, significantly increased AsA level in C. elegans, whereas the addition of L-galactono-1,4-lactone, an AsA precursor in the plant and Euglena pathway, did not affect AsA level. The suppression of E03H4.3 (an ortholog of gluconolactonase) or the deficiency of F54D5.12 (an ortholog of L-gulono-1,4-lactone oxidase) significantly decreased AsA level in C. elegans. Although N2- and AsA-deficient F54D5.12 knockout mutant worm (tm6671) morphologies and the ratio of collagen to non-collagen protein did not show any significant differences, the mutant worms exhibited increased malondialdehyde levels and reduced lifespan compared with the N2 worms. In conclusion, our findings indicate that the AsA biosynthetic pathway is similar in C. elegans and mammals.

Biological Activity of Pseudovitamin B12 on Cobalamin-Dependent Methylmalonyl-CoA Mutase and Methionine Synthase in Mammalian Cultured COS-7 Cells

Adenyl cobamide (commonly known as pseudovitamin B₁₂) is synthesized by intestinal bacteria or ingested from edible cyanobacteria. The effect of pseudovitamin B₁₂ on the activities of cobalamin-dependent enzymes in mammalian cells has not been studied well. This study was conducted to investigate the effects of pseudovitamin B₁₂ on the activities of the mammalian vitamin B₁₂-dependent enzymes methionine synthase and methylmalonyl-CoA mutase in cultured mammalian COS-7 cells to determine whether pseudovitamin B₁₂ functions as an inhibitor or a cofactor of these enzymes. Although the hydoroxo form of pseudovitamin B₁₂ functions as a coenzyme for methionine synthase in cultured cells, pseudovitamin B₁₂ does not activate the translation of methionine synthase, unlike the hydroxo form of vitamin B₁₂ does. In the second enzymatic reaction, the adenosyl form of pseudovitamin B₁₂ did not function as a coenzyme or an inhibitor of methylmalonyl-CoA mutase. Experiments on the cellular uptake were conducted with human transcobalamin II and suggested that treatment with a substantial amount of pseudovitamin B₁₂ might inhibit transcobalamin II-mediated absorption of a physiological trace concentration of vitamin B₁₂ present in the medium.

5-hydroxymethyl-2-furaldehyde purified from Japanese pear (Pyrus pyrifolia Nakai cv. Nijisseiki) juice concentrate inhibits melanogenesis in B16 mouse melanoma cells

Pear juice concentrate prepared by boiling Japanese pear (Pyrus pyrifolia Nakai cv. Nijisseiki) juice can significantly inhibit the activity of tyrosinase, a key enzyme in melanin synthesis in human skin. Using the ethanol extract of pear juice concentrate, we homogeneously purified an active compound that was identified as 5-hydroxymethyl-2-furaldehyde (5-HMF) through ¹H- and ¹³C-NMR and mass spectroscopy. We observed that 5-HMF inhibited the monophenolase and diphenolase activities of mushroom tyrosinase as a mixed-type inhibitor (K _i values of 3.81 and 3.70 mmol/L, respectively). In B16 mouse melanoma cells, treatment with 170 µmol/L of 5-HMF significantly reduced α-melanocyte-stimulated melanin synthesis by suppressing the cyclic adenosine monophosphate-dependent signaling pathway involved in melanogenesis. The results of our study indicated that 5-HMF can be potentially used as a skin-lightening agent in the cosmetic industry. Abbreviations: AC: adenylate cyclase; CREB: cAMP response element-binding protein; dhFAME: S-(-)-10,11-Dihydroxyfarnesoic acid methyl ester; DMEM: dulbecco's modified eagle medium; l-DOPA: 3-(3,4-Dihydroxyphenyl)- l-alanine; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HEPES: 4-(2-Hydroxyethyl)-1-piperazine ethane sulfonic acid; 5-HMF: 5-Hydroxymethyl-2-furaldehyde; MITF: microphthalmia-associated transcription factor; α-MSH: α-Melanocyte-stimulating hormone; PKA: protein kinase A; PVDF: polyvinylidene difluoride; SDS: sodium dodecyl sulfate; TRP1: tyrosinase-related protein 1; TRP2: tyrosinase-related protein 2.

Food Additives (Hypochlorous Acid Water, Sodium Metabisulfite, and Sodium Sulfite) Strongly Affect the Chemical and Biological Properties of Vitamin B12 in Aqueous Solution

Food additives, such as hypochlorous acid water, sodium metabisulfite, and sodium sulfite, strongly affect the chemical and biological properties of vitamin B₁₂ (cyanocobalamin) in aqueous solution. When cyanocobalamin (10 μmol/L) was treated with these compounds, hypochlorous acid water (an effective chlorine concentration of 30 ppm) rapidly reacted with cyanocobalamin. The maximum absorptions at 361 and 550 nm completely disappeared by 1 h, and vitamin B₁₂ activity was lost. There were no significant changes observed in the absorption spectra of cyanocobalamin for 0.01% (w/v) sodium metabisulfite; however, a small amount of the reaction product was formed within 48 h, which was subsequently identified as sulfitocobalamin through high-performance liquid chromatography. Similar results were shown for sodium sulfite. The effects of these food additives on the vitamin B₁₂ content of red shrimp and beef meats were determined, revealing no significant difference in vitamin B₁₂ content of shrimp and beef meats with or without the treatment even in hypochlorous acid water. The results suggest that these food additives could not react with food vitamin B₁₂ in food, as most of this vitamin present in food is its protein-bound form rather than the free form.

Comparison of injection pain in pediatric population; original versus generic rocuronium

Background

Rocuronium-induced injection pain causes withdrawal movements. These movements may cause accidental disruption of indwelling needles. Generic rocuronium contains low-acid concentration buffer solution compared with original rocuronium. In animal experiments, it has been suggested that the difference of the buffer solution may alleviate injection pain. The purpose of this study was to identify the difference of injection pain between original and generic rocuronium in pediatric population.

Material and Methods

Patients ranging in age from 1 to 15 years, American Society of Anesthesiologists physical status I or II, undergoing elective surgeries were randomly allocated to two groups; generic rocuronium group (Group R) and original rocuronium (Eslax®) group (Group E). Following anesthetic induction with oxygen, nitrous oxide, and sevoflurane, original or generic rocuronium (1 mg/kg) was administered via intravenous catheter. The difference of vital signs and withdrawal movement associated with rocuronium injection were evaluated.

Results

A total of 64 patients were included in the study. Three patients were excluded. Twenty-nine patients were assigned to Group E and 32 patients to Group R. There was no significant difference in mean arterial pressure and heart rate. No withdrawal movements were observed in both groups.

Conclusion

There was no significant difference in injection pain between original and generic rocuronium under inhalational induction.

Growth Response of Lactobacillus rhamnosus Chloramphenicol-Resistant Strain ATCC 27773 to Pteroyl-Mono- and -Di-Glutamates

This study investigated the effect of various concentrations of pteroyl-mono-γ-glutamate (PteGlu₁) and pteroyl-di-γ-glutamate (PteGlu₂) on the growth of Lactobacillus rhamnosus strains ATCC 7469 (wild-type strain) and ATCC 27773 (chloramphenicol-resistant strain) used for folate microbiological assays. At concentrations of 0.025-0.20 nmol/L, the growth of the chloramphenicol-resistant strain was stimulated to a greater extent by PteGlu₁ than by PteGlu₂, but the wild-type strain did not show such phenomena. L. rhamnosus ATCC 27773 bioassays were used to determine the total folate content of various foods treated with a chicken pancreas folate conjugase. This showed a significantly lower value when PteGlu₁ was used as a calibrator than with PteGlu₂. These results indicated that PteGlu₂ should be the standard folate compound when chicken pancreas folate conjugase is used in preparing samples for L. rhamnosus ATCC 27773 bioassay.

Involvement of Spermidine in the Reduced Lifespan of Caenorhabditis elegans During Vitamin B12 Deficiency

Vitamin B₁₂ deficiency leads to various symptoms such as neuropathy, growth retardation, and infertility. Vitamin B₁₂ functions as a coenzyme for two enzymes involved in amino acid metabolisms. However, there is limited information available on whether amino acid disorders caused by vitamin B₁₂ deficiency induce such symptoms. First, free amino acid levels were determined in vitamin B₁₂-deficient Caenorhabditis elegans to clarify the mechanisms underlying the symptoms caused by vitamin B₁₂ deficiency. Various amino acids (valine, leucine, isoleucine, methionine, and cystathionine, among others) metabolized by vitamin B₁₂-dependent enzymes were found to be significantly changed during conditions of B₁₂ deficiency, which indirectly affected certain amino acids metabolized by vitamin B₁₂-independent enzymes. For example, ornithine was significantly increased during vitamin B₁₂ deficiency, which also significantly increased arginase activity. The accumulation of ornithine during vitamin B₁₂ deficiency constitutes the first report. In addition, the biosynthesis of spermidine from ornithine was significantly decreased during vitamin B₁₂ deficiency, likely due to the reduction of S-adenosylmethionine as a substrate for S-adenosylmethionine decarboxylase, which catalyzes the formation of spermidine. Moreover, vitamin B₁₂ deficiency also demonstrated a significant reduction in worm lifespan, which was partially recovered by the addition of spermidine. Collectively, our findings suggest that decreased spermidine is one factor responsible for reduced lifespan in vitamin B₁₂-deficient worms.

A lemon myrtle extract inhibits glucosyltransferases activity of Streptococcus mutans

Streptococcus mutans is a bacterium found in human oral biofilms (dental plaques) that is associated with the development of dental caries. Glucosyltransferases (GTFs) are key enzymes involved in dental plaque formation, and compounds that inhibit their activities may prevent dental caries. We developed a screening system for GTF-inhibitory activities, and used it to profile 44 types of herbal tea extracts. Lemon myrtle (Backhousia citriodora) extract exhibited the highest GTF-inhibitory activity, with an IC₅₀ for GTF in solution of 0.14 mg mL^-1. Furthermore, lemon myrtle extracts had the third-highest polyphenol content of all tested extracts, and strongly inhibited S. mutans biofilm. Interestingly, lemon myrtle extracts did not inhibit cell growth.

Determination of Cobalamin and Related Compounds in Foods

Cobalamin, also known as the red-colored vitamin B12, is found in animal-based foods such as meat, milk, and fish. Various cobalamin compounds are extracted from foods and converted into cyanocobalamin, which is most stable, to be analyzed by various methods. Traditionally, the cobalamin content of foods is determined by microbiological assay with Lactobacillus delbrueckii subsp. lactis American Type Culture Collection 7830. However, this lactic acid bacterium can substitute deoxyribosides or deoxynucleotides (known as an alkali-resistant factor) for cobalamin. Therefore, cobalamin contents determined by this microbiological assay are often incorrect in some foods. The difficulty of evaluating whether certain foods contain cobalamin or inactive corrinoids (or both) may be easily resolved by the use of bioautography with a cobalamin-dependent Escherichia coli after separation of the sample by silica gel TLC. LC/electrospray ionization-tandem mass spectrometry is also used to analyze corrinoid compounds, and various inactive corrinoid compounds have been identified in foods.

Bioactive Compounds of Edible Purple Laver Porphyra sp. (Nori)

Porphyra sp. (nori) is widely cultivated as an important marine crop. Dried nori contains numerous nutrients, including vitamin B₁₂, which is the only vitamin absent from plant-derived food sources. Vegetarian diets are low in iron and vitamin B₁₂; depletion of both causes severe anemia. Nori also contains large amounts of iron compared with other plant-derived foods and eicosapentaenoic acid, which is an important fatty acid found in fish oils. In nori, there are also many bioactive compounds that exhibit various pharmacological activities, such as immunomodulation, anticancer, antihyperlipidemic, and antioxidative activities, indicating that consumption of nori is beneficial to human health. However, Porphyra sp. contains toxic metals (arsenic and cadmiun) and/or amphipod allergens, the levels of which vary significantly among nori products. Further evidence from human studies of such beneficial or adverse effects of nori consumption is required.

Vitamin B12 sources and microbial interaction

Vitamin B₁₂ is synthesized only by certain bacteria and archaeon, but not by plants. The synthesized vitamin B₁₂ is transferred and accumulates in animal tissues, which can occur in certain plant and mushroom species through microbial interaction. In particular, the meat and milk of herbivorous ruminant animals (e.g. cattle and sheep) are good sources of vitamin B₁₂ for humans. Ruminants acquire vitamin B₁₂, which is considered an essential nutrient, through a symbiotic relationship with the bacteria present in their stomachs. In aquatic environments, most phytoplankton acquire vitamin B₁₂ through a symbiotic relationship with bacteria, and they become food for larval fish and bivalves. Edible plants and mushrooms rarely contain a considerable amount of vitamin B₁₂, mainly due to concomitant bacteria in soil and/or their aerial surfaces. Thus, humans acquire vitamin B₁₂ formed by microbial interaction via mainly ruminants and fish (or shellfish) as food sources. In this review, up-to-date information on vitamin B₁₂ sources and bioavailability are also discussed. Impact statement To prevent vitamin B₁₂ (B₁₂) deficiency in high-risk populations such as vegetarians and elderly subjects, it is necessary to identify foods that contain high levels of B₁₂. B₁₂ is synthesized by only certain bacteria and archaeon, but not by plants or animals. The synthesized B₁₂ is transferred and accumulated in animal tissues, even in certain plant tissues via microbial interaction. Meats and milks of herbivorous ruminant animals are good sources of B₁₂ for humans. Ruminants acquire the essential B₁₂ through a symbiotic relationship with bacteria inside the body. Thus, we also depend on B₁₂-producing bacteria located in ruminant stomachs. While edible plants and mushrooms rarely contain a considerable amount of B₁₂, mainly due to concomitant bacteria in soil and/or their aerial surfaces. In this mini-review, we described up-to-date information on B₁₂ sources and bioavailability with reference to the interaction of microbes as B₁₂-producers.

Characterization and Quantitation of Vitamin B12 Compounds in Various Chlorella Supplements

Vitamin B₁₂ was determined and characterized in 19 dried Chlorella health supplements. Vitamin contents of dried Chlorella cells varied from <0.1 μg to approximately 415 μg per 100 g of dry weight. Subsequent liquid chromatography/electrospray ionization-tandem mass spectrometry analyses showed the presence of inactive corrinoid compounds, a cobalt-free corrinoid, and 5-methoxybenzimidazolyl cyanocobamide (factor IIIm) in four and three high vitamin B₁₂-containing Chlorella tablets, respectively. In four Chlorella tablet types with high and moderate vitamin B₁₂ contents, the coenzyme forms of vitamin B₁₂ 5'-deoxyadenosylcobalamin (approximately 32%) and methylcobalamin (approximately 8%) were considerably present, whereas the unnaturally occurring corrinoid cyanocobalamin was present at the lowest concentrations. The species Chlorella sorokiniana (formerly Chlorella pyrenoidosa) is commonly used in dietary supplements and did not show an absolute requirement of vitamin B₁₂ for growth despite vitamin B₁₂ uptake from the medium being observed. In further experiments, vitamin B₁₂-dependent methylmalonyl-CoA mutase and methionine synthase activities were detected in cell homogenates. In particular, methionine synthase activity was significantly increased following the addition of vitamin B₁₂ to the medium. These results suggest that vitamin B₁₂ contents of Chlorella tablets reflect the presence of vitamin B₁₂-generating organic ingredients in the medium or the concomitant growth of vitamin B₁₂-synthesizing bacteria under open culture conditions.

Vitamin B12 deficiency results in severe oxidative stress, leading to memory retention impairment in Caenorhabditis elegans

Oxidative stress is implicated in various human diseases and conditions, such as a neurodegeneration, which is the major symptom of vitamin B₁₂ deficiency, although the underlying disease mechanisms associated with vitamin B₁₂ deficiency are poorly understood. Vitamin B₁₂ deficiency was found to significantly increase cellular H₂O₂ and NO content in Caenorhabditis elegans and significantly decrease low molecular antioxidant [reduced glutathione (GSH) and L-ascorbic acid] levels and antioxidant enzyme (superoxide dismutase and catalase) activities, indicating that vitamin B₁₂ deficiency induces severe oxidative stress leading to oxidative damage of various cellular components in worms. An NaCl chemotaxis associative learning assay indicated that vitamin B₁₂ deficiency did not affect learning ability but impaired memory retention ability, which decreased to approximately 58% of the control value. When worms were treated with 1 mmol/L GSH, L-ascorbic acid, or vitamin E for three generations during vitamin B₁₂ deficiency, cellular malondialdehyde content as an index of oxidative stress decreased to the control level, but the impairment of memory retention ability was not completely reversed (up to approximately 50%). These results suggest that memory retention impairment formed during vitamin B₁₂ deficiency is partially attributable to oxidative stress.

Biochemistry, function, and deficiency of vitamin B12 in Caenorhabditis elegans

Caenorhabditis elegans is a nematode that has been widely used as an animal for investigation of diverse biological phenomena. Vitamin B12 is essential for the growth of this worm, which contains two cobalamin-dependent enzymes, methylmalonyl-CoA mutase and methionine synthase. A full complement of gene homologs encoding the enzymes associated with the mammalian intercellular metabolic processes of vitamin B12 is identified in the genome of C elegans However, this worm has no orthologs of the vitamin B12-binders that participate in human intestinal absorption and blood circulation. When the worm is treated with a vitamin B12-deficient diet for five generations (15 days), it readily develops vitamin B12 deficiency, which induces worm phenotypes (infertility, delayed growth, and shorter lifespan) that resemble the symptoms of mammalian vitamin B12 deficiency. Such phenotypes associated with vitamin B12 deficiency were readily induced in the worm.

Functional and structural characteristics of methylmalonyl-CoA mutase from Pyrococcus horikoshii

Methylmalonyl-CoA mutase (MCM) requires 5′-deoxyadenosylcobalamin (AdoCbl) as a cofactor and is widely distributed in organisms from bacteria and animals. Although genes encoding putative MCMs are present in many archaea, they are separately encoded in large and small subunits. The large and small subunits of archaeal MCM are similar to the catalytic and AdoCbl-binding domains of human MCM, respectively. In Pyrococcus horikoshii OT3, putative genes PH1306 and PH0275 encode the large and small subunits, respectively. Because information on archaeal MCM is extremely restricted, we examined the functional and structural characteristics of P. horikoshii MCM. Reconstitution experiments using recombinant PH0275 and PH1306 showed that these proteins assemble in equimolar ratios and form of heterotetrameric complexes in the presence of AdoCbl. Subsequent immunoprecipitation experiments using anti-PH0275 and anti-PH1306 antibodies suggested that PH0275 and PH1306 form a complex in P. horikoshii cells in the presence of AdoCbl.

The influence of a whole food vegan diet with Nori algae and wild mushrooms on selected blood parameters

BACKGROUND

Vegan and vegetarian diets could overcome many diseases of civilization. This study examines whether a whole food vegan diet with Nori algae and wild mushrooms can provide a sufficient quantity of critical nutrients.

METHODS

Five blood samples (Baseline to Time 5) were taken over eight months from 75 subjects (10 vegans without B12 supplementation who consumed Nori algae and wild mushrooms, 20 vegans with supplementation, 40 vegetarians, 5 meat-eaters). Blood was analyzed for blood cell counts, total vitamin B12, holotranscobalamin, homocysteine, methylmalonic acid, vitamin B6, folic acid, ferritin, TSH, zinc, creatinine, vitamin D2 and D3.

RESULTS

In the vegan group without supplementation, all means were within the tolerance (holotranscobalamin, homocystein) or normal, except for elevated methylmalonic acid and diminished vitamin D. This group developed significantly higher vitamin D2 levels. The vegan group with B12 supplementation and the vegetarian group showed normal values for all parameters.

CONCLUSIONS

Vegans following a whole food diet had a borderline supply of vitamin B12. Folic acid, vitamin B6, TSH, iron metabolism, and the blood count were in the normal range. Vegans taking dietary supplements demonstrated satisfactory overall results. An ingestion of sundried mushrooms can contribute to the supply of vitamin D.