A facile double moving redox boundary model for visual electrophoresis titration of ascorbic acid

In this work, we proposed a double moving redox boundary (MROB) model to realize the colorless analyte electrophoresis titration (ET) by the two steps of the redox reaction. Single MROB has been proposed for the development of ET sensing (Analyst, 2013, 138, 1137. ACS Sensor, 2019, 4, 126.), and faces great challenges in detecting the analyte without color change during redox reaction. Herein, a novel model of double-MROB electrophoresis, including its mechanisms, equations, and procedures, was developed for titration by using ascorbic acid as a model analyte. The first MROB was created with ferric iron (Fe3+) and iodide ion (I-) in which Fe3+ was reduced as Fe2+ and I- was oxidized as molecular iodine (I2) used as an indicator of visible MROB due to blue starch-iodine complex. The second boundary was then formed between the molecular iodine and model analyte of ascorbic acid. Under given conditions, there was a quantitative relationship between velocity of MROB (VMROB(ii)) and ascorbic acid concentration (CVit C) in the double-MROB system (1/VMROB(ii) = 0.6502CVit C + 4.5165, and R = 0.9939). The relevant relative standard deviation values of intraday and inter-day were less than ∼5.55% and ∼6.64%, respectively. Finally, the titration of ascorbic acid in chewable vitamin C tablets was performed by the developed method, the titration results agreed with those via the classic iodometric titration. All the results briefly demonstrated the validity of the double MROB model, in which Vit C was used as a model analyte. The developed method had potential use in quantitative analysis of redox-active species in biomedical samples.

Acquired methemoglobinemia due to nitrobenzene poisoning: An unusual acquaintance

Key Clinical Message

Nitrobenzene poisoning is a rare yet life-threatening contention. The ensuing acute methemoglobinemia has a high fatality rate, hence early prompt intervention is required. Methylene blue (intravenous or oral) and ascorbic acid are the cornerstones of management. They must be administered to suspected patients without tardiness.

Abstract

An aromatic organic chemical used in paints and the printing industry is nitrobenzene. Its poisoning causes potentially fatal methemoglobinemia. One aspect of its management involves reducing the iron moiety from its ferric to ferrous form by administering intravenous methylene blue. A 23-year-old man who had deliberately consumed nitrobenzene presented to us with a history of headache and vomiting. He was diagnosed to have methemoglobinemia on the basis of clinical grounds and was managed successfully with intravenous methylene blue and vitamin C.

Synergistic interplay of redox homeostasis and polysaccharide synthesis promotes cotton fiber elongation

Cell polarity is the foundation of cell development and tissue morphogenesis. The investigation of polarized growth provides opportunities to gain profound insights into morphogenesis and tissue functionality in organisms. Currently, there are still many mysteries surrounding the mechanisms that regulate polarized cell growth. Cotton fiber cells serve as an excellent model for studying polarized growth, and provide important clues for unraveling the molecular mechanisms, signaling pathways, and regulatory networks of polarized growth. In this study, we characterized two functional genes, GhMDHAR1AT/DT and GhDHAR2AT/DT with predominant expression during fiber elongation. Loss of function of both genes contributed to a significant increase in fiber length. Transcriptomic data revealed up-regulated expression of antioxidant genes in CRISPR mutant lines, along with delayed expression of secondary wall-related genes and temporally prolonged expression of primary wall-related genes. Experimental evidence demonstrated that the increase in GSH content and glutathione peroxidase (GPX) enzyme activity led to enhanced total antioxidant capacity (T-AOC), resulting in reduced H2O2 levels, which contributed to the extension of fiber elongation stage in CRISPR mutant lines. Moreover, the increased polysaccharide synthesis in CRISPR mutant lines was found to provide an abundant supply of raw materials for fiber cell wall elongation, suggesting that synergistic interplay between redox homeostasis and polysaccharide synthesis in fiber cells may facilitate cell wall remodeling and fiber elongation. This study provides valuable insights for deciphering the mechanisms of cell polarized growth and improving cotton fiber quality.

Assessing the Effectiveness of Stabilized Cysteamine 5% Cream Compared to Hydroquinone 4%/Ascorbic Acid 3% Combination Cream in Treating Acne-induced Post-inflammatory Hyperpigmentation: A Randomized, Controlled Study

Objective

Postinflammatory hyperpigmentation (PIH) is a common sequela of acne vulgaris. Topical treatment with hydroquinone is the standard treatment, but may be associated with complications. Cysteamine is a relatively safe depigmenting agent with an observed depigmenting effect. We designed this study to assess the efficacy of a cysteamine 5% cream in treating acne-induced PIH.

Methods

Twenty-eight out of 32 participants finalized this investigator-blind, randomized, and controlled trial (registered in Iranian Registry of Clinical Trials [IRCTID: IRCT20140212016557N5]). We randomized the patients to apply either cysteamine 5% or hydroquinone 4%/ascorbic acid 3% (HC) cream. Postacne hyperpigmentation index (PAHPI) and melanin index were the assessment measures after four months of treatment. We evaluated the quality of life by the Dermatology Life Quality Index (DLQI) questionnaire.

Results

Both cysteamine and HC cream significantly decreased the PAHPI score and melanin index of acne-induced PIH patients (p<0.05). The decrease in PAHPI score and melanin index were not significantly different in treatment groups after four months (p>0.05). Quality of life ameliorated significantly only with cysteamine treatment. However, no significant change in quality of life was observed between groups.

Limitations

Limitations of our study include the relatively small sample size and absence of follow-up.

Conclusion

Cysteamine cream is an effective treatment of post-acne PIH, with similar efficacy to the accepted treatment of PIH, i.e., hydroquinone cream.

Elevated ROS Levels Caused by Reductions in GSH and AsA Contents Lead to Grain Yield Reduction in Qingke under Continuous Cropping

Continuous spring cropping of Qingke (Hordeum viilgare L. var. nudum Hook. f.) results in a reduction in grain yield in the Xizang autonomous region. However, knowledge on the influence of continuous cropping on grain yield caused by reactive oxygen species (ROS)-induced stress remains scarce. A systematic comparison of the antioxidant defensive profile at seedling, tillering, jointing, flowering, and filling stages (T1 to T5) of Qingke was conducted based on a field experiment including 23-year continuous cropping (23y-CC) and control (the first year planted) treatments. The results reveal that the grain yield and superoxide anion (SOA) level under 23y-CC were significantly decreased (by 38.67% and 36.47%), when compared to the control. The hydrogen peroxide content under 23y-CC was 8.69% higher on average than under the control in the early growth stages. The higher ROS level under 23y-CC resulted in membrane lipid peroxidation (LPO) and accumulation of malondialdehyde (MDA) at later stages, with an average increment of 29.67% and 3.77 times higher than that in control plants. Qingke plants accumulated more hydrogen peroxide at early developmental stages due to the partial conversion of SOA by glutathione (GSH) and superoxide dismutase (SOD) and other production pathways, such as the glucose oxidase (GOD) and polyamine oxidase (PAO) pathways. The reduced regeneration ability due to the high oxidized glutathione (GSSG) to GSH ratio resulted in GSH deficiency while the reduction in L-galactono-1,4-lactone dehydrogenase (GalLDH) activity in the AsA biosynthesis pathway, higher enzymatic activities (including ascorbate peroxidase, APX; and ascorbate oxidase, AAO), and lower activities of monodehydroascorbate reductase (MDHAR) all led to a lower AsA content under continuous cropping. The lower antioxidant capacity due to lower contents of antioxidants such as flavonoids and tannins, detected through both physiological measurement and metabolomics analysis, further deteriorated the growth of Qingke through ROS stress under continuous cropping. Our results provide new insights into the manner in which ROS stress regulates grain yield in the context of continuous Qingke cropping.

Synthesis of β-Cyclodextrin@gold Nanoparticles and Its Application on Colorimetric Assays for Ascorbic Acid and Salmonella Based on Peroxidase-like Activities

The peroxidase-like behaviors of gold nanoparticles (AuNPs) have the potential to the development of rapid and sensitive colorimetric assays for specific food ingredients and contaminants. Here, using NaBH4 as a reducing agent, AuNPs with a supramolecular macrocyclic compound β-cyclodextrin (β-CD) capped were synthesized under alkaline conditions. Monodispersal of β-CD@AuNPs possessed a reduction in diameter size and performed great peroxidase-like activities toward both substrates, H2O2 and TMB. In the presence of H2O2, the color change of TMB oxidization to oxTMB was well-achieved using β-CD@AuNPs as the catalyst, which was further employed to develop colorimetric assays for ascorbic acid, with a limit of detection as low as 0.2 μM in ddH2O. With the help of the host-guest interaction between β-CD and adamantane, AuNPs conjugated with nanobodies to exhibit peroxidase-like activities and specific recognition against Salmonella Typhimurium simultaneously. Based on this bifunctional bioprobe, a selective and sensitive one-step colorimetric assay for S. Typhimurium was developed with a linear detection from 8.3 × 104 to 2.6 × 108 CFU/mL and can be provided to spiked lettuce with acceptable recoveries of 97.31% to 103.29%. The results demonstrated that the excellent peroxidase-like behaviors of β-CD@AuNPs can be applied to develop a colorimetric sensing platform in the food industry.

Physical, Chemical and Enzymatic Changes in Amla (Emblica officinalis) Fruit during Growth and Maturation

BACKGROUND

Amla (Emblica officinalis) is one of the most prominent fruits in terms of nutritional and medicinal properties and is utilized for the preparation of many traditional processed foods and in Ayurvedic formulations.

OBJECTIVE

This study aims to investigate the enzyme activity and physical and chemical quality parameters during the growth and development stages of amla fruit for the determination of proper harvesting time to get optimum nutrient contents of fruit.

METHODS

The amla fruits of the chakaiya variety were harvested at 135 to 270 days after fruit set (DAFS) in 2021 and 2022 to study the various physical, chemical and enzymatic changes during growth and maturation.

RESULTS

The geometrical and gravimetric attributes of the fruit, viz. diameter, height, weight, volume, surface area, sphericity, aspect ratio, and radius of curvature increased. However, density decreased with the growth and maturation of the fruit. Furthermore, the rolling resistance, yellowness index and firmness of the fruit increased during the entire harvesting period of 135 to 270 DAFS. Total soluble solids and titratable acidity of the fruits increased only up to 195 DAFS and after that, continuously decreased. In contrast, ascorbic acid concentration grew in the entire growth and development period. Tannic, phenolic compounds and naringin content of the fruit steadily dropped until the final stage of harvest. Pectin Methyl Esterase (PME) activity was detected very low, 0.009 unit/ml at 135 DAFS, but as the fruit grew and matured, activity increased to 0.307 unit/ml at 270 DAFS. Polygalactouronase (PG) activity was not detected until 210 DAFS and, thereforesignificantly increased with maturity.

CONCLUSION

Considering the optimal value of all studied physical, chemical and enzymatic attributes of the fruit during the entire harvesting period of 135 to 270 DAFS, the optimal harvesting time of the fruit was 210 DAFS.

Impact of drought stress on vitamin C and anthocyanin content in cultivated lettuces (Lactuca sativa L.) and wild relatives (Lactuca spp.)

Introduction

Lettuce production and quality could be seriously affected by the increasingly limited water resources.

Methods

The effect of drought on the content of two antioxidant compounds, vitamin C and anthocyanins, in five cultivated lettuces and two wild relatives was assessed for 2 years.

Results and discusion

In leaf samples, Lactuca wild species generally had a higher content of total vitamin C than the cultivated lettuces. In contrast, the commercial varieties usually contained more total anthocyanins than the wild species. Total vitamin C decreased with the drought stress in all accessions, commercial varieties, and lettuce wild relatives, with this tendency being consistent and reproducible across the 2 years. These differences were significant in the case of the green commercial varieties 'Winter Crop' (in 2020/2021) and 'Dolomiti G12' (in 2021/2022) and very significant in the red commercial variety 'Red Sails' (in 2020/2021). However, the only group in which the effect of drought was either significant or very significant in both years was the wild species, Lactuca homblei and Lactuca dregeana, and in the latter also in both tissues (leaf and stem) analyzed. Water stress resulted in an increase of the total anthocyanin content in the leaves from all the accessions, both red commercial varieties and wild relatives, in both years. The most significant enrichment and the only one being either significant or very significant in both years was observed in one of the wild relatives assayed (L. homblei). Stems (L. dregeana) contained more anthocyanins than leaves under control conditions, and it was exactly the opposite under drought. Changes in anthocyanins in the two tissues in response to drought stress were in opposite directions, increasing in leaves and decreasing in stems. This could suggest a translocation of anthocyanins as a first quick mechanism to cope with a severe lack of water. In conclusion, anthocyanins (unlike vitamin C) could play a role in the mechanisms deployed by the plant to tolerate drought stress. The wild species with a robust significant enrichment in anthocyanins as a response to drought (L. homblei) is a promising plant material to breed more resilient lettuces.

Malaria Is Associated with Diminished Levels of Ascorbic Acid: A Systematic Review and Meta-Analysis

Background: It is still unclear how ascorbic acid levels relate to the pathogenesis of malaria. This systematic review synthesized different ascorbic acid levels in malaria patients with different severity levels of malaria and Plasmodium species. Methods: The systematic review protocol was registered in the PROSPERO database (CRD42023394849). A systematic search of PubMed, Embase, MEDLINE, Ovid, Scopus, and Google Scholar was conducted to identify studies that reported ascorbic acid and malaria. The pooled standardized mean difference (Cohen's d) with 95% confidence intervals (CIs) was calculated using the random-effects model. Results: A total of 1480 articles were obtained from the searches of the databases, and 30 studies were included for syntheses. The meta-analysis revealed that patients with malaria had lower levels of ascorbic acid than those without malaria or uninfected controls (p < 0.01, Cohen's d = -3.71, 95% CI = -4.44 to -2.98, I2 = 98.87%, 30 studies). Comparable levels of ascorbic acid were observed between patients with severe malaria and those with nonsevere malaria (p = 0.06, Cohen's d = -1.39, 95% CI = -2.85 to 0.07, I2 = 96.58%, 4 studies). Similarly, levels of ascorbic acid were comparable between patients with Plasmodium falciparum and Plasmodium vivax malaria (p = 0.34, Cohen's d = -1.06, 95% CI = -3.23 to 1.12, I2 = 97.30%, 3 studies). Conclusions: The meta-analysis reveals diminished levels of ascorbic acid in malaria cases. Manipulating the host's nutritional status, such as by supplementing it with ascorbic acid to restore reactive oxygen species balance, may alter the progression of malarial infection and prevention of disease severity. Antioxid. Redox Signal. 40, 460-469.

Fruit Quality Assessment of Novel Hybrid Pummelo × Sweet Orange and Its Molecular Characterization Using Acidity Specific Markers

Research background

There is considerable diversity in newly developed pummelo × sweet orange citrus hybrids. Most hybrids showed lower peel thickness and high juice yield but there is a lack of information on fruit quality parameters and molecular characterization. Therefore, the aim of the current study is to determine the content of antioxidants and properties of the fresh juice of 24 new pummelo × sweet orange citrus hybrids (Citrus maxima [Burm. f.] Osbeck × Citrus sinensis [L.] Osbeck) and the parental genotypes along with molecular characteristics determined using acidity specific markers.

Experimental approach

The correlation and estimate of inheritance of the fruit juice properties: ascorbic acid, total phenol, total flavonoid, total antioxidant, total soluble solid and sugar contents, pH, titratable acidity, along with sensory evaluation was performed. Molecular characterization of these hybrids was carried out using de novo generated acidity specific simple sequence repeat (SSR) markers.

Results and conclusions

The main constituents of the fruit juice of pummelo × sweet orange hybrids were observed in the range of w(ascorbic acid)=40.00-58.13 mg/100 g, total phenols expressed as gallic acid equivalents w(GAE)=40.67-107.33 mg/100 g, total antioxidants expressed as Trolox equivalents b(Trolox)=2.03-5.49 µmol/g, total flavonoids expressed as quercetin equivalents w(QE)=23.67-59.33 mg/100 g, along with other properties: total soluble solids=7.33-11.33 %, w(total sugar)=2.10-5.76 %, w(reducing sugar)=1.69-2.78 %, w(non-reducing sugar)=0.39-3.17 % and titratable acidity 1.00-2.11 %. The above parameters differed significantly in the fruit juice of the evaluated pummelo × sweet orange hybrids. Considering these parameters, the hybrids SCSH 17-9, SCSH 13-13, SCSH 11-15 and SCSH 3-15 had superior antioxidant properties in terms of these parameters. A higher heritability (≥80 %) was also observed for all juice properties. Molecular characterization of pummelo × sweet orange hybrids showed that >50 % of the hybrids were grouped with medium acidity parents. Both molecular and biochemical parameter-based clustering showed that interspecific hybrids exhibit transgressive segregation with increased antioxidants that help alleviate the health problems.

Novelty and scientific contribution

These newly developed pummelo × sweet orange citrus hybrids are a valuable source of high-quality antioxidants for a healthy diet. The identification of trait markers that enable selection at the seedling stage is of great benefit to citrus breeders, as the characteristic features of a mature tree are not yet visible at the juvenile stage.

Evaluating osteogenic effects associated with the incorporation of ascorbic acid in mineralized collagen scaffolds

Current treatments for craniomaxillofacial (CMF) defects motivate the design of instructive biomaterials that can promote osteogenic healing of complex bone defects. We report methods to promote in vitro osteogenesis of human mesenchymal stem cells (hMSCs) within a model mineralized collagen scaffold via the incorporation of ascorbic acid (vitamin C), a key factor in collagen biosynthesis and bone mineralization. An addition of 5 w/v% ascorbic acid into the base mineralized collagen scaffold significantly changes key morphology characteristics including porosity, macrostructure, and microstructure. This modification promotes hMSC metabolic activity, ALP activity, and hMSC-mediated deposition of calcium and phosphorous. Additionally, the incorporation of ascorbic acid influences osteogenic gene expression (BMP-2, RUNX2, COL1A2) and delays the expression of genes associated with osteoclast activity and bone resorption (OPN, CTSK), though it reduces the secretion of OPG. Together, these findings highlight ascorbic acid as a relevant component for mineralized collagen scaffold design to promote osteogenic differentiation and new bone formation for improved CMF outcomes.

Effects of Combinations of Dietary Vitamin C and Acetylsalicylic Acid on Growth Performance, Carcass Traits and, Serum and Immune Response Parameters in Broilers

This study aimed to investigate the combined effects of ascorbic acid (VC) and acetylsalicylic acid (ASA) on broiler health and performance. A total of 200 Ross 308 male broilers were divided into five groups, each receiving different dietary combinations of ASA and VC (ASA: 50 or 100 mg/kg; VC: 200 or 400 mg/kg). The 42-day trial assessed parameters such as feed intake, average daily gain (ADG), feed conversion ratio (FCR), carcass characteristics, serum parameters, immune response and cecal microbial flora. The results indicate significant treatment effects on feed intake and growth performance, with a higher feed intake of ADG and FCR in treatment groups (p < 0.05). Serum lipid parameters were unaffected, but creatine kinase increased with ASA and VC intake (p < 0.05). Changes in sheep red blood cell titers and influenza antibodies were noted (p < 0.05). The combination of ASA and VC positively influenced carcass traits, reducing abdominal fat and altering the ratio of immune response organs to body weight (p < 0.05). Additionally, the cecal E. coli count decreased with treatment (p < 0.05). This study underscores the intricate interactions between ASA and VC supplementation, growth performance and carcass composition and immune response in broilers. Further research is warranted to explore dosage nuances and variations under specific stress conditions.

Integrating Smart Greenhouse Cover, Reduced Nitrogen Dose and Biostimulant Application as a Strategy for Sustainable Cultivation of Cherry Tomato

Fruit yield and quality of greenhouse tomatoes are strongly influenced by light conditions and nitrogen (N) availability, however, the interaction between these factors is still unclear. We evaluated the effects on cherry tomatoes of two tunnel plastic covers with different optical properties and three N doses, also in combination with a biostimulant treatment. We compared a diffuse light film (Film1) and a conventional clear film (Film2), and three N levels, corresponding to 50% (N50), 75% (N75) and 100% (N100) of the optimal dose, with and without a microbial plus a protein hydrolysed biostimulant, compared to a non-treated control. The three experimental treatments significantly interacted on several yield and quality parameters. In control plants (untreated with biostimulants), the early yield was higher at reduced N doses compared to N100, with greater increments under the diffusive Film1 compared to the clear Film2 (+57.7% and +37.0% vs. +31.7% and +16.0%, in N50 and N75 respectively). Film1 boosted the total fruit production at all the N rates and with or without biostimulants, compared to Film2, with stronger effects under sub-optimal N (+29.4% in N50, +21.2% in N75, and +7.8% in N100, in plants untreated with biostimulant). Total yield decreased with decreasing N levels, while it always increased with the application of biostimulants, which counterbalanced the detrimental effects of N shortage. Quality traits were mainly affected by the cover film and the biostimulant treatment. The diffusive film increased the content of carotenoids, lycopene and total phenols compared to the clear one, and the biostimulants increased texture, soluble solids, phenols and ascorbic acid compared to the untreated control. It is worth noting that in plants fertilized at 75% of the reference N dose, the biostimulants determined higher yield than the N100 untreated control, under both the covers (+48% in Film1 and +20% in Film2). In conclusion, the diffusive film improved the fruit yield and quality of greenhouse tomatoes in the spring-summer period, presumably avoiding plant stress due to high-intensity direct light. Reduced N rates limited the plant productivity, however, the biostimulant application was effective in compensating for the detrimental effects of sub-optimal supply of N synthetic fertilizers.

Multiple Physiological and Biochemical Functions of Ascorbic Acid in Plant Growth, Development, and Abiotic Stress Response

Ascorbic acid (AsA) is an important nutrient for human health and disease cures, and it is also a crucial indicator for the quality of fruit and vegetables. As a reductant, AsA plays a pivotal role in maintaining the intracellular redox balance throughout all the stages of plant growth and development, fruit ripening, and abiotic stress responses. In recent years, the de novo synthesis and regulation at the transcriptional level and post-transcriptional level of AsA in plants have been studied relatively thoroughly. However, a comprehensive and systematic summary about AsA-involved biochemical pathways, as well as AsA's physiological functions in plants, is still lacking. In this review, we summarize and discuss the multiple physiological and biochemical functions of AsA in plants, including its involvement as a cofactor, substrate, antioxidant, and pro-oxidant. This review will help to facilitate a better understanding of the multiple functions of AsA in plant cells, as well as provide information on how to utilize AsA more efficiently by using modern molecular biology methods.

Zopiclone-Induced Methemoglobinemia: A Case Report Highlighting How the Treatment Differs in Patients on Serotonergic Medication

Zopiclone is a sedative-hypnotic that is increasingly being used for insomnia, especially among patients with depression. The side effects of zopiclone include nausea, vomiting, headache, giddiness, sedation, altered mental status, and coma. Here, we describe a rare case of a patient with underlying depression who overdosed on zopiclone, resulting in a presentation of drowsiness and dyspnea. A diagnosis of methemoglobinemia was made only through astute observation of the presence of a saturation gap, poor oxygen saturation despite high flow oxygen supplementation, and the arterial blood gas sample appearing chocolate brown in color. Treatment of such patients usually includes the gold standard of methylene blue. However, in our case, there was a risk of serotonin syndrome as the patient was on a serotonergic antidepressant prior. As such, an alternative treatment with ascorbic acid was utilized instead. Methemoglobinemia, while uncommon, should always be suspected in patients who present with zopiclone overdose as it can be life-threatening and is easily treatable.

Ascorbic acid induces ferroptosis via STAT3/GPX4 signaling in oropharyngeal cancer

Ferroptosis is recognized as a new type of regulated cell death initiated by iron-dependent accumulation of lipid peroxidation. Recent studies have shown that the administration of ascorbic acid (AA) preferentially kills tumor cells by impairing iron metabolism and exerting pro-oxidant effects. Despite mounting evidence indicating the anticancer potential of AA, the underlying molecular mechanisms remain unknown. In this study, we demonstrated that AA decreased cell viability and Ki67 expression, along with its accumulation in the G0/G1 phase in FaDu and SCC-154 cell lines. Furthermore, AA exposure induced morphological changes in mitochondria associated with ferroptosis. AA-induced ferroptosis is accompanied by depletion of glutathione (GSH) and increased levels of ferrous ions (Fe2+), reactive oxygen species (ROS), and malondialdehyde (MDA). However, these ferroptotic effects were ameliorated by deferoxamine and N-acetylcysteine. Network pharmacology results showed that signal transducer and activator of transcription 3 (STAT3) is a key target of AA against oropharyngeal cancer. AA markedly downregulates the relative mRNA expression of STAT3 and glutathione peroxidase 4 (GPX4). Immunoblotting indicated that the protein levels of p-STAT3, STAT3, and GPX4 in FaDu and SCC-154 cells decreased significantly in response to AA treatment. Mechanistically, a chromatin immunoprecipitation assay confirmed that AA exposure reduced STAT3 expression in the GPX4 promoter region. Additionally, AA-induced inhibition of cell growth and ferroptosis was suppressed by STAT3 and GPX4 overexpression, respectively. In summary, AA inhibited oropharyngeal cancer cell growth in vitro by regulating STAT3/GPX4-mediated ferroptosis, which may provide a novel theoretical basis for the clinical treatment of oropharyngeal cancer with AA.

Resuscitation With Vitamin C, Hydrocortisone, and Thiamin in Children With Septic Shock: A Multicenter Randomized Pilot Study

OBJECTIVES

Adjunctive therapy with vitamin C, hydrocortisone, and thiamin has been evaluated in adults, but randomized controlled trial (RCT) data in children are lacking. We aimed to test the feasibility of vitamin C, hydrocortisone, and thiamin in PICU patients with septic shock; and to explore whether the intervention is associated with increased survival free of organ dysfunction.

DESIGN

Open-label parallel, pilot RCT multicenter study. The primary endpoint was feasibility. Clinical endpoints included survival free of organ dysfunction censored at 28 days and nine secondary outcomes, shock reversal, and two proxy measures of intervention efficacy.

SETTING

Six PICUs in Australia and New Zealand.

PATIENTS

Children of age between 28 days and 18 years requiring vasoactive drugs for septic shock between August 2019 and March 2021.

INTERVENTIONS

Patients were assigned 1:1 to receive 1 mg/kg hydrocortisone every 6 hours (q6h), 30 mg/kg ascorbic acid q6h, and 4 mg/kg thiamin every 12 hours (n = 27), or standard septic shock management (n = 33).

MEASUREMENTS AND MAIN RESULTS

Sixty of 77 (78%) eligible patients consented with 91% of approached parents providing consent. The median time from randomization to intervention was 44 (interquartile range [IQR] 29-120) min. Seventy of seventy-seven (28%) patients had received IV steroids before randomization. Median survival alive and free of organ dysfunction was 20.0 (0.0-26.0) days in the intervention and 21.0 (0.0-25.0) days in the standard care group. Median PICU length of stay was 5.3 (2.5-11.3) days in the intervention group versus 6.9 (3.0-11.5) days in the control group. Shock reversal occurred at a median of 35.2 (14.6-101.2) hours in the intervention group versus 47.3 (22.4-106.8) hours in the standard care group (median difference -12 hr; 95% CI, -56.8 to 32.7 hr).

CONCLUSIONS

In children requiring vasopressors for septic shock, a protocol comparing adjunctive treatment with high-dose vitamin C, hydrocortisone, and thiamin versus standard care was feasible. These findings assist in making modifications to the trial protocol to enable a better-designed larger RCT.

Effect of a multinutrient supplement as an adjunct to nonsurgical treatment of periodontitis: A randomized placebo-controlled clinical trial

BACKGROUND

The aim of this double-blind randomized placebo-controlled clinical trial was to evaluate the efficacy of a multinutrient supplement as an add-on therapy to scaling and root planing for patients with periodontitis.

METHODS

Forty-two patients with stage III or IV periodontitis were randomly allocated to a 2-month treatment of either a multinutrient supplement containing vitamin C, vitamin E, zinc, selenium, alpha-lipoic-acid, cranberry extract, grapeseed extract, and coenzyme Q10 or placebo capsules as an adjunct to conservative periodontal therapy. Periodontal parameters, including probing pocket depth, gingival recession, bleeding on probing, approximal plaque index, and papillary bleeding index, were assessed. Clinical attachment loss, periodontal inflamed surface area, periodontal epithelial surface area, and percentages of pocket sites with ≤3, ≤4, ≥5, ≥6, ≥7, and ≥4 mm with bleeding on probing were calculated.

RESULTS

All clinical parameters significantly improved from baseline to reevaluation within each group (p < 0.05). Multinutrient intake resulted in a significantly higher reduction of probing-pocket-depth (-0.75 ± 0.42 mm) and bleeding-on-probing (-21.9 ± 16.1%) from baseline to reevaluation compared with placebo (-0.51 ± 0.30 mm, p = 0.040 and -12.5 ± 9.8%, p = 0.046, respectively). All periodontal parameters showed insignificantly higher improvements in patients receiving the supplement compared with those receiving the placebo (p > 0.05).

CONCLUSIONS

Multinutrient supplementation as an adjunct to nonsurgical treatment of periodontitis showed some additional benefit regarding probing-pocket-depth and bleeding-on-probing. However, the clinical relevance needs to be further explored.

Serum Levels of Vitamin C and Thiamin in Children With Suspected Sepsis: A Prospective Observational Cohort Study

OBJECTIVES

Vitamin C and thiamin have been trialed as adjunctive therapies in adults with septic shock but their role in critically ill children is unclear. We assessed serum levels of vitamin C and thiamin in children evaluated for sepsis.

DESIGN

Single-center prospective observational study. Serum levels of vitamin C and thiamin were measured on admission and association with multiple organ dysfunction syndrome (MODS) was explored using logistic regression.

SETTING

Emergency department and PICU in a tertiary children's hospital, Queensland, Australia.

PATIENTS

Children greater than 1 month and less than 17 years evaluated for sepsis.

INTERVENTIONS

Not applicable.

MEASUREMENTS AND MAIN RESULTS

Vitamin levels were determined in 221 children with a median age of 3.5 (interquartile range [IQR] 1.6, 8.3) years. Vitamin C levels were inversely correlated with severity as measured by pediatric Sequential Organ Failure Assessment (Spearman's rho = -0.16, p = 0.018). Median (IQR) vitamin C levels on admission were 35.7 (17.9, 54.1) µmol/L, 36.1 (21.4, 53.7) µmol/L, and 17.9 (6.6, 43.0) µmol/L in children without organ dysfunction, single organ dysfunction, and MODS, respectively (p = 0.017). In multivariable analyses, low levels of vitamin C at the time of sampling were associated with greater odds of MODS (adjusted odds ratio [aOR] 3.04; 95% CI, 1.51-6.12), and vitamin C deficiency was associated with greater odds of MODS at 24 hours after sampling (aOR 3.38; 95% CI, 1.53-7.47). Median (IQR) thiamin levels were 162 (138, 192) nmol/L, 185 (143, 200) nmol/L, and 136 (110, 179) nmol/L in children without organ dysfunction, single organ dysfunction, and MODS, respectively (p = 0.061). We failed to identify an association between thiamin deficiency and either MODS at sampling (OR 2.52; 95% CI, 0.15-40.86) or MODS at 24 hours (OR 2.96; 95% CI, 0.18-48.18).

CONCLUSIONS

Critically ill children evaluated for sepsis frequently manifest decreased levels of vitamin C, with lower levels associated with higher severity.

Ascorbic acid deficiency amongst spondylodiscitis patients

BACKGROUND

Spondylodiscitis can be a disabling and life-threatening infection. Ascorbic Acid is crucial for neutrophil function and collagen formation. Its association and clinical relevance in spondylodiscitis has not been previously examined.

AIMS

To determine the prevalence, characteristics, and clinical outcomes of spondylodiscitis patients with Ascorbic Acid deficiency.

METHODS

Sixty-eight consecutive patients admitted with spondylodiscitis, between December 2021 and August 2023 were included. Clinical characteristics, Ascorbic Acid levels and clinical outcomes were evaluated.

RESULTS

Thirty-seven patients had Ascorbic Acid levels taken during admission. The median initial Ascorbic Acid level was 15 μmol/L with an IQR 6.5-27 μmol/L. Depletion defined as <28 μmol/L was present in 78% of patients. Deficiency defined as ≤11 μmol/L was present in and 46% of patients. Patients with depletion were more likely to require Intensive Care Admission (absolute risk increase = 24.1%; 2.6%-45.7%). Fifteen patients had repeat serum levels taken during admission with median increase of 17 μmol/L and an IQR 0-26 μmol/L. Patients that received supplementation had a significantly greater increase in Ascorbic Acid levels compared with those that did not receive supplementation (P = 0.002).

CONCLUSION

Ascorbic acid deficiency is highly prevalent amongst spondylodiscitis patients. Depletion was associated with worse outcomes. Replacement significantly increased serum levels in comparison to standard hospital diet. The clinical significance of replacement remains to be evaluated.

A Sorghum F-Box Protein Induces an Oxidative Burst in the Defense Against Colletotrichum sublineola

The hemibiotrophic fungal pathogen Colletotrichum sublineola is the causal agent of anthracnose in sorghum (Sorghum bicolor), resulting in leaf blight, stalk rot, and head blight in susceptible genotypes, with yield losses of up to 50%. The development of anthracnose-resistant cultivars can reduce reliance on fungicides and provide a more sustainable and economical means for disease management. A previous genome-wide association study of the sorghum association panel identified the candidate resistance gene Sobic.005G172300 encoding an F-box protein. To better understand the role of this gene in the defense against C. sublineola, gene expression following infection with C. sublineola was monitored by RNA sequencing in seedlings of sorghum accession SC110, which harbored the resistance allele, and three accessions that harbored a susceptible allele. Only in SC110 did the expression of Sobic.005G172300 increase during the biotrophic phase of infection. Subsequent transcriptome analysis, gene co-expression networks, and gene regulatory networks of inoculated and mock-inoculated seedlings of resistant and susceptible accessions suggest that the increase in expression of Sobic.005G172300 induces an oxidative burst by lowering the concentration of ascorbic acid during the biotrophic phase of infection. Based on gene regulatory network analysis, the protein encoded by Sobic.005G172300 is proposed to target proteins involved in the biosynthesis of ascorbic acid for polyubiquitination through the SCF E3 ubiquitin ligase, causing their degradation via the proteasome.

Ascorbic Acid Treatments as Effective and Safe Anti-Aging Therapies for Sensitive Skin

The most common signs of aging skin include a decrease in firmness and density, uneven skin tone, and a tendency to erythema. There is an ever-increasing interest in aesthetic treatments that maintain the skin's favorable appearance. However, such therapies are difficult in the case of sensitive skin, defined as a set of stimuli-triggered symptoms (stinging, erythema, burning, and itching) that would not appear in healthy skin. Sensitive skin is common and affects, to varying degrees, about half of the European population. This study was aimed at evaluating the effects of ascorbic acid-a known antioxidant-applied with sonophoresis and microneedling on the signs of photoaging in reactive and erythematous skin. A significant improvement in skin elasticity was observed after a series of tests. A significant reduction in erythema was observed after both therapies. The greatest reduction was observed on the cheeks after applying vitamin C combined with microneedling. At the same time, the results showed an excellent tolerance of both treatments, which proved them to be safe and effective.

Vitamin C Inhibits Lipopolysaccharide-Induced Hyperinflammatory State of Chronic Myeloid Leukemia Cells through Purinergic Signaling and Autophagy

Background: Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the overproduction of white blood cells, leading to symptoms such as fatigue, infections, and other complications. CML patients must take measures to prevent infections to mitigate the exacerbation of cancer cell proliferation and comorbidities. Methods: This study investigated whether vitamin C can suppress the hyperinflammatory activation of K-562 cells induced by lipopolysaccharide (LPS) and whether purinergic signaling (ATP and P2X7 receptor) and autophagy play a role in it. Two different doses of vitamin C (5 µg/mL and 10 µg/mL) were employed, along with the lysosome inhibitor chloroquine (CQ; 100 µM), administered 2 h prior to LPS stimulation (10 ng/mL) for a duration of 22 h in K-562 cells (3 × 105 cells/mL/well). Results: Both doses of vitamin C reduced the release of interleukin-6 (IL-6) (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01) and tumor necrosis factor (TNF) (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01) induced by LPS. Furthermore, in LPS + CQ-stimulated cells, vitamin C at a concentration of 10 µg/mL inhibited the expression of LC3-II (p < 0.05). Conversely, both doses of vitamin C led to the release of the anti-inflammatory cytokine interleukin-10 (IL-10) (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01), while only the 10 µg/mL dose of vitamin C induced the release of Klotho (10 µg/mL, p < 0.01). In addition, both doses of vitamin C reduced the accumulation of ATP (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01) and decreased the expression of the P2X7 receptor at the mRNA level. Conclusions: Vitamin C inhibits the hyperinflammatory state induced by LPS in K-562 cells, primarily by inhibiting the ATP accumulation, P2X7 receptor expression, and autophagy signaling.

Therapeutic Role of HAT Therapy in Sepsis: A Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis aimed to determine whether the combination of hydrocortisone, vitamin C (ascorbic acid), and thiamine (HAT therapy) diminishes the mortality and is effective in expediting the resolution of sepsis and septic shock or not.

METHODS

The following databases of PubMed, Scopus, ISI Web of Science, and Google Scholar were explored until March 2021 for all existing literature related to this field. An automatic alert for all databases was also activated to update our search. Meta-analysis was performed on clinical trials and cohorts separately as well as on all the pooled populations.

RESULTS

This study evaluated nine clinical trials (1358 participants) and nine cohorts (339,437 participants) and is the most comprehensive systematic review in this field. The results of our meta-analysis demonstrated a significant difference in the reduction of Sepsis-Related Organ Failure Assessment (SOFA) score changes (Δ-SOFA) over 72 h (Standard Mean Difference (SMD) = -0.429; 95% CI: -0.737, 0.120; P = 0.006), duration of vasopressor (VP) (SMD = -0.373; 95% CI: -0.619, -0.128; P = 0.003), and procalcitonin (PCT) clearance (SMD = 0.496; 95% CI: 0.061, 0.931%; P = 0.026). Considering the results of cohorts, HAT therapy was effective in the survival of intensive care units (ICUs) patients (OR = 0.641; 95% CI: 0.423-0.970, P = 0.035). However, no significant difference was observed between the intervention and control groups in hospital mortality (Odds Ratio (OR) = 0.811, 95% CI: 0.544-1.209, P = 0.304), 28- to 30-day mortality (OR = 1.000; 95% CI: 0.782-1.279, P = 0.998), new onset acute kidney injury requiring renal replacement therapy ((OR = 0.856, 95% CI: 0.526, 1.391; P = 0.529), in-hospital length of stay (LOS) (SMD = 0.090; 95% CI: -0.036, 0.216 days; P = 0.162), LOS in ICU (SMD = 0.016, 95% CI: -0.138, 0.170 days; P = 0.838), and mechanical ventilation-free days (SMD = 0.004; 95% CI: -0.154, 0.163 days; P = 0.956).

CONCLUSION

Supplementation of septic and septic shock patients with HAT therapy has significant beneficial effects on SOFA score over 72 hours, duration of exogenous vasopressor infusion and procalcitonin clearance. Considering the results of cohort studies, supplementation with HAT is efficacious in reducing ICU mortality.

Influence of Pasteurisation (Conventional vs. Radiofrequency) and Chill Storage on Retention of Ascorbic Acid, Tocopherol and Carotenoids in Salmorejo

Salmorejo, a Mediterranean tomato-oil puree, is considered a dietary source of antioxidant vitamins C and E and carotenoids lycopene and β-carotene, the latter endowed with provitamin A activity. However, these antioxidants can be degraded in oxidation reactions catalysed or not by enzymes during pasteurisation and storage treatments used to stabilise the salmorejo before consumption. Due to its better penetration, the use of dielectric heating by radiofrequency (RF) may improve results of pasteurisation in this product. The objective was to assess the effects of pasteurisation temperature (70-100 °C, at 5 °C intervals) and storage time (0-5 months, at one-month intervals) on levels of ascorbic acid, α-tocopherol and carotenoids and antioxidant capacity (AC) in salmorejo pasteurised (over 10 s) by conventional (CH) or RF continuous heating. Two successive experiments were conducted to select an adequate pasteurisation temperature for use in the shelf-life study. Pasteurisation upon tested conditions allows a good retention of salmorejo antioxidants. Either CH or RF pasteurisers can be used with similar results. Vitamin C (L-ascorbic + dehydroascorbic acids) was more abundant (15-19 mg 100 g-1) than carotenoids (0.9-2.6 mg 100 g-1) (all-trans + cis lycopene and β-carotene) and α-tocopherol (0.8-1.2 mg 100 g-1) in the pasteurised product. Using excessively low temperatures (70 °C) resulted in partial losses of the three antioxidants, possibly due to oxidase residual activities. Intensifying thermal treatment improved this issue with minor losses of the thermolabile vitamin C and increased carotenoid content. Using a suitable temperature (80 °C) did not prevent most vitamin C from being degraded by the first month, while α-tocopherol, and, to a lesser extent, carotenoids, showed good retention levels during shelf life under refrigeration. Vitamins C and E and carotenoids, either by degradation, regeneration or releasing, likely contribute to the AC in salmorejo. Phenolic antioxidant response, radical-scavenging activities and redox potential values confirmed this finding. The pasteurised-chilled salmorejo shows good antioxidant properties with potential health implications, a positive nutritional aspect for consumers of this tomato-oil homogenate. The losses of antioxidants and AC due to pasteurization would be of little relevance compared to the losses accumulated during shelf life.