Vitamin C: update on physiology and pharmacology

The Protective Effects of Metformin and Vitamin C and Their Co-Administration in Bleomycin-Induced Pulmonary Fibrosis in Mice

Bleomycin, an antibacterial antibiotic, is used in chemotherapy and is effective against various forms of human carcinomas. However, its use is limited due to its tendency to cause pulmonary fibrosis. Oxidative stress and excessive expression of TGF beta occur in pulmonary fibrosis, leading to cellular death, inflammation, and additional damage to lung tissue. Metformin has the ability to reduce oxidative stress and lower the level of TGF beta by activating AMPK. Additionally, ascorbic acid possesses potent antioxidant characteristics. Consequently, we decided to investigate the effects of these two medications on pulmonary fibrosis and compare with methyl prednisolone. Thirty-six adult mice were categorized into 6 distinct groups: Control, bleomycin (bleo), bleo + methyl prednisolone, bleo + metformin, bleo + ascorbic acid, bleo + metformin + ascorbic acid. Pulmonary fibrosis was induced by the administration of bleomycin in all groups, except for the control group. Subsequently, medications were administered for a duration of 14 days. Ultimately, the mice were sacrificed and lung tissues were obtained for biochemical and histological examination. As shown by biochemical and histological analysis, all treatment groups showed a decrease in oxidative stress factors, inflammation, and lung tissue fibrosis; however, the effects of administering metformin and ascorbic acid together were noticeable. Our study found that administering metformin and ascorbic acid over a period of 14 days, either alone or in combination, may contribute to the repair of pulmonary fibrosis. However, our data indicate that the combined therapy of these drugs provided a better result.

Selenium supplementation protects cancer cells from the oxidative stress and cytotoxicity induced by the combination of ascorbate and menadione sodium bisulfite

The combination of ascorbate (vitamin C) and menadione sodium bisulfite (MSB, vitamin K3), here called VC/VK3 (also named Apatone®, or M/A), has shown selective cytotoxicity in cancer cells and is under clinical investigation as a cancer therapy. However, the mechanisms of VC/VK3-induced cell death are not fully understood. In this in vitro study using human glioblastoma and non-transformed glial cell lines, we found that VC/VK3 caused higher toxicity in cancer cells in an H2O2- and iron-dependent manner, suggesting that ferroptosis may play a role in the cell death process. Furthermore, selenium supplementation significantly protected cancer cells from VC/VK3 treatment concomitantly with enhanced expression levels and enzymatic activity of antioxidant selenoproteins, including thioredoxin reductases (TXNRDs) and glutathione reductases (GPXs). We also found that VC/VK3 competes for electrons with thioredoxin (TXN), impairing peroxiredoxin 1 (PRDX1) in cells. Finally, chemically inhibiting TXNRDs or the glutathione-dependent antioxidant systems exaggerated the toxicity of VC/VK3. Overall, this study elucidated parts of the cell death mechanisms of VC/VK3 and identified combination strategies to overcome selenium-mediated resistance, advancing the translational potential of this prooxidant treatment.

Joint and individual associations between multiple vitamins and sperm quality in adult men

Background

Several studies have suggested that a healthy diet is associated with improved male fertility outcomes. However, the joint and individual associations between the status of multiple vitamins and sperm quality remain unclear.

Objectives

This study aimed to investigate the associations between serum vitamin levels and sperm quality parameters in adult men.

Methods

A cross-sectional study was conducted among 156 adult men seeking fertility care at a reproductive center from December 2023 to June 2024. Blood and semen were collected on the same day to determine the concentrations of nine kinds of vitamins (B1, B2, B6, B9, B12, C, A, D, E) and five parameters of sperm quality [total sperm number, sperm concentration, progressive motile sperm, morphologically normal rate, and DNA fragment index (DFI)]. The joint and individual associations between vitamin levels and sperm quality were analyzed using multiple linear regression and Bayesian kernel machine regression (BKMR) models.

Results

Increased tertiles of vitamin B1 and 1,25-dihydroxyvitamin D3 [1,25-(OH)2-D3] in serum were associated with higher sperm quality (all P for trends < 0.10). Compared with the lowest tertiles, the highest tertiles of vitamin B12 had β: 3.0 (95% CI: 0.8, 5.2) increasing in DFI, and vitamin A was negatively associated with progressive sperm motility (P for trends = 0.05). We generally found null results between multiple vitamin levels and the parameters of sperm quality in the BKMR models.

Discussion

These research findings imply that vitamins could have a dose-dependent dual effect on sperm quality. More specifically, the impact of vitamins varies according to their dosage levels and types. Personalized vitamin supplementation may be more effective than taking multivitamins in improving sperm quality.

A surface chemistry perspective on SERS: revisiting the basics to push the field forward

Surfaces are well known to be complex entities that are extremely difficult to study, and any phenomenon that is related to them is consequently challenging to approach. Moving from the bulk to the nanoscale adds a further layer of complexity to the problem. Because SERS relies on surfaces at the nanoscale, a rigorous understanding of the chemical phenomena that concur in the observation of the SERS signal is still limited or disorganized at best. Specifically, the lack of understanding of the chemical properties of nanoparticle surfaces has direct consequences on the development of SERS-based devices, causing a widespread belief that SERS is an inherently unreliable and fundamentally irreproducible analytical technique. Herein, we discuss old and new literature from SERS and related fields to accompany the reader through a journey that explores the chemical nature and architecture of colloidal plasmonic nanoparticles as the most popular SERS-active surfaces. By examining the chemistry of the surface landscape of the most common SERS colloids and the thermodynamic equilibria that characterize it, we aim to paint a chemically realistic picture of what a SERS analyst deals with on a daily basis. Thus, our goal for this review is to provide a centralized compilation of key, state-of-the-art surface chemistry information that can guide the rational development of analytical protocols and contribute an additional path through which our community can continue to advance SERS as a reliable and robust analytical tool.

Unveiling the properties of ascorbic acid against M. tb through in silico approach: A comparative drug-based study

CONTEXT

Tuberculosis (TB) is a highly contagious and potentially life-threatening disease caused by Mycobacterium tuberculosis (M. tb). According to the World Health Organization (WHO), 7.5 million people were diagnosed with TB in 2022. Combating this disease requires ongoing efforts in TB drug discovery and the development of new treatment regimens. Identifying novel drug targets and inhibitory molecules is crucial in the fight against latent TB, particularly due to the rising issue of M. tb drug resistance. In modern drug discovery, the focus has shifted towards identifying new, safe natural compounds with enhanced biological activity against TB. One promising compound is ascorbic acid (Vitamin C), which possesses pro-oxidant properties that generate free radicals along with the first and second-line anti-TB drugs, aiding in the eradication of M. tb during latent infections.

METHODS

In the current research, extensive in silico studies have been conducted to investigate the potential of ascorbic acid as an inhibitor of various M. tb pathways, especially those involving protein folding (chaperone-mediated) and detoxification pathways. The proteins were analysed by various physicochemical and pharmacological parameters. Molecular docking of the selected proteins with existing first-line, second-line drugs and ascorbic acid was performed. Furthermore, the top-scoring molecular docking of ascorbic acid was subjected to Molecular Dynamics Simulation. The 500 ns Molecular Dynamics Simulation studies were carried out by GROMACS v2024.1 using CHARMM27 force field, TIP3P water model and using triclinic box for solvation. The obtained trajectories were analysed through XMGRACE tool.

Insight into the role of antioxidant in microbial lignin degradation: Ascorbic acid as a fortifier of lignin-degrading enzymes

BACKGROUND

Microbial-driven lignin depolymerization has emerged as a promising approach for lignin degradation. However, this process is hindered by the limited activity of lignin-degrading enzymes. Antioxidants are crucial for maintaining redox homeostasis in living cells, which can impact the efficiency of enzymes. Ascorbic acid (AA) is well-known for its antioxidant properties, while Trametes versicolor is a commonly used lignin-degrading fungus capable of secreting laccase (Lac) and manganese peroxidase (MnP). Thus, AA was selected as model antioxidant and added into the culture medium of T. versicolor to examine the effect of antioxidants on the activity of lignin-degrading enzymes in the fungus.

RESULTS

The presence of AA resulted in a 4.9-fold increase in the Lac activity and a 3.9-fold increase in the MnP activity, reaching 10736 U/L and 8659 U/L, respectively. This increase in enzyme activity contributed to a higher lignin degradation rate from 17.5% to 35.2%, consistent with observed morphological changes in the lignin structure. Furthermore, the addition of AA led to a reduction in the molecular weights of lignin and an increase in the content of degradation products with lower molecular weight, indicating more thorough degradation of lignin. Proteomics analysis suggested that the enhancement in enzyme activity was more likely to attributed to the reinforcement of AA on oxidative protein folding and transportation, rather than changes in enzyme expression.

CONCLUSIONS

The addition of AA enhanced the performance of enzymes responsible for lignin degradation in terms of enzyme activity, degradation rate, lignin structural change, and product mapping. This study offers a feasible strategy for enhancing the activity of lignin-degrading enzymes in the fungus and provides insights into the role of antioxidant in microbial lignin degradation.

Vitamin C: From Self-Sufficiency to Dietary Dependence in the Framework of Its Biological Functions and Medical Implications

Vitamin C is an organic compound biosynthesized in plants and most vertebrates. Since its discovery, the benefits of vitamin C use in the cure and prevention of various pathologies have been frequently reported, including its anti-oxidant, anti-inflammatory, anticoagulant, and immune modulatory properties. Vitamin C plays an important role in collagen synthesis and subsequent scurvy prevention. It is also required in vivo as a cofactor for enzymes involved in carnitine and catecholamine norepinephrine biosynthesis, peptide amidation, and tyrosine catabolism. Moreover, as an enzymatic cofactor, vitamin C is involved in processes of gene transcription and epigenetic regulation. The absence of the synthesis of L-gulono-1,4-lactone oxidase, a key enzyme in the pathway of vitamin C synthesis, is an inborn metabolism error in some fishes and several bird and mammalian species, including humans and non-human primates; it is caused by various changes in the structure of the original GULO gene, making these affected species dependent on external sources of vitamin C. The evolutionary cause of GULO gene pseudogenization remains controversial, as either dietary supplementation or neutral selection is evoked. An evolutionary improvement in the control of redox homeostasis was also considered, as potentially toxic H2O2 is generated as a byproduct in the vitamin C biosynthesis pathway. The inactivation of the GULO gene and the subsequent reliance on dietary vitamin C may have broader implications for aging and age-related diseases, as one of the most important actions of vitamin C is as an anti-oxidant. Therefore, an important aim for medical professionals regarding human and animal health should be establishing vitamin C homeostasis in species that are unable to synthesize it themselves, preventing pathologies such as cardiovascular diseases, cognitive decline, and even cancer.

Bioactive Compounds as Alternative Approaches for Preventing Urinary Tract Infections in the Era of Antibiotic Resistance

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide. They occur in the urinary system when a microorganism, commonly present on the perineal skin or rectum, reaches the bladder through the urethra, and adheres to the luminal surface of uroepithelial cells, forming biofilms. The treatment of UTIs includes antibiotics, but their indiscriminate use has favored the development of multidrug-resistant bacteria strains, which represent a serious challenge to today's microbiology. The pathogenesis of the infection and antibiotic resistance synergistically contribute to hindering the eradication of the disease while favoring the establishment of persistent infections. The repeated requirement for antibiotic treatment and the limited therapeutic options have further contributed to the increase in antibiotic resistance and the occurrence of potential relapses by therapeutic failure. To limit antimicrobial resistance and broaden the choice of non-antibiotic preventive approaches, this review reports studies focused on the bacteriostatic/bactericidal activity, inhibition of bacterial adhesion and quorum sensing, restoration of uroepithelial integrity and immune response of molecules, vitamins, and compounds obtained from plants. To date, different supplementations are recommended by the European Association of Urology for the management of UTIs as an alternative approach to antibiotic treatment, while a variety of bioactive compounds are under investigation, mostly at the level of in vitro and preclinical studies. Although the evidence is promising, they are far from being included in the clinical practice of UTIs.

High-dose Ascorbate Exhibits Anti-proliferative and Anti-invasive Effects Dependent on PTEN/AKT/mTOR Pathway in Endometrial Cancer in vitro and in vivo

Endometrial cancer (EC) is the most common gynecological malignancy, frequently characterized by PTEN deletion, activation of the AKT/mTOR pathway, and limited effective treatment options for recurrent and advanced patients. High-dose ascorbate or combined with other chemotherapeutic agents shows potent antitumor effects in vitro and in vivo. In this study, high-dose ascorbate significantly inhibited cell proliferation and invasion, increased cellular stress and DNA damage, and induced cell cycle arrest and apoptosis in EC cells. Oral or intraperitoneal injections of high-dose ascorbate for 4 weeks effectively inhibited tumor growth in LKB1fl/flp53fl/fl -mouse model of EC, with intraperitoneal injections being more effective than oral administration. N-acetylcysteine partially reversed the antitumor effects of ascorbate in EC cells and tumor growth in LKB1fl/flp53fl/fl -mice. PTEN knockdown by shRNA reduced the antitumor sensitivity of EC cells to ascorbate, while inhibition of the AKT/mTOR pathway by Ipatasertib significantly enhanced the antitumor activity of ascorbate in EC cells. Ascorbate combined with paclitaxel synergistically inhibited tumor growth compared to either agent alone in LKB1fl/flp53fl/fl -mice. Overall, high-dose ascorbate exhibits antitumor activity partially through PTEN/AKT/mTOR and cell stress pathways, and these antitumor effects were heightened when combined with paclitaxel in EC. Clinical trials of ascorbate combined with paclitaxel deserve further investigation in EC patients.

The therapeutic potential of vitamins A, C, and D in pancreatic cancer

The pancreatic ductal adenocarcinoma (PDAC) is among the deadliest tumor diseases worldwide. While treatment options have generally become more diverse, little progress has been made in the treatment of PDAC and the median survival time for patients with locally advanced PDAC is between 8.7 and 13.7 months despite treatment. The aim of this review was to explore the therapeutic potential of complementing standard therapy with natural or synthetic forms of vitamins A, C, and D. The therapeutic use of vitamins A, C, and D could be a promising addition to the treatment of PDAC. For all three vitamins and their derivatives, tumor cell-specific cytotoxicity and growth inhibition against PDAC cells has been demonstrated in vitro and in preclinical animal models. While the antitumor effect of vitamin C is probably mainly due to its pro-oxidative effect in supraphysiological concentrations, vitamin A and vitamin D exert their effect by activating nuclear receptors and influencing gene transcription. In addition, there is increasing evidence that vitamin A and vitamin D influence the tumor stroma, making the tumor tissue more accessible to other therapeutic agents. Based on these promising findings, there is a high urgency to investigate vitamins A, C, and D in a clinical context as a supplement to standard therapy in PDAC. Further studies are needed to better understand the exact mechanism of action of the individual compounds and to develop the best possible treatment regimen. This could contribute to the long-awaited progress in the treatment of this highly lethal tumor entity.

Ascorbic acid Mitigates behavioural disturbances associated with letrozole-induced PCOS via switching-off JAK2/STAT5 and JAK2/ERK1/2 pathways in rat hippocampus

PURPOSE

Polycystic ovary syndrome (PCOS) is an endocrine disorder with the highest prevalence among other disorders in sexually-active women. It is associated with broad-spectrum hormonal and metabolic disturbances with behavioural difficulties. Experimentally, letrozole administration causes similar findings. Ascorbic acid is powerful anti-oxidant; and its cellular levels decrease with "hyperglycemic and poor anti-oxidative" status, which is, a main hallmark of PCOS. Thus, ascorbic acid administration may prevent the induction of PCOS and its consequences.

BASIC PROCEDURES

Forty female rats were divided into four groups (n = 10 in each): normal control (CTRL), ascorbic acid (ASC), letrozole (LTZ), and ascorbic acid + letrozole (ASC + LTZ) group. Behavioural tests (Y-maze spontaneous alteration, tail suspension test, forced swimming test) were performed. In serum, hormones (testosterone, estradiol, progesterone), glycemia (blood glucose, insulin and HOMA-IR) and oxidative stress (SOD activity, GSH) markers were measured. In hippocampus, inflammation and apoptosis indicators (p-JAK2, p-STAT5, p-ERK1/2, NF-κB, BAX, Bcl2, BAX/Bcl2 ratio) and neurotransmitters (DA, 5-HT, NE, BDNF) were determined. Lastly, ovary histopathological investigation was conducted to confirm PCOS induction.

PRINCIPAL RESULTS

Letrozole induced PCOS with subsequent disturbances. Testosterone levels were augmented while estradiol and progesterone were declined. Fasting blood glucose, insulin, HOMA-IR and oxidative stress markers were elevated. The expression of p-JAK2, p-STAT5, p-ERK1/2, BAX and the levels of NF-κB were increased, but Bcl2 expression, monoamines and BDNF levels were lowered. Importantly, ASC restored the last mentioned parameters markedly.

MAJOR CONCLUSIONS

Ascorbic acid mitigated the behavioural difficulties of PCOS possibly by switching-off JAK2/STAT5 and JAK2/ERK1/2 pathways in hippocampus along with its neurotransmission-improving, hormonal-normalizing, anti-hyperglycemic and anti-oxidative effects.

Pathology and Treatments of Alzheimer's Disease Based on Considering Changes in Brain Energy Metabolism Due to Type 2 Diabetes

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with cognitive dysfunction, memory decline, and behavioral disturbance, and it is pathologically characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain. Although various hypotheses have been proposed to explain the pathogenesis of AD, including the amyloid beta hypothesis, oxidative stress hypothesis, and abnormal phosphorylation of tau proteins, the exact pathogenic mechanisms underlying AD remain largely undefined. Furthermore, effective curative treatments are very limited. Epidemiologic studies provide convincing evidence for a significant association between type 2 diabetes and AD. Here, we showed energy metabolism using glucose, lactate, ketone bodies, and lipids as energy substrates in a normal brain, and changes in such energy metabolism due to type 2 diabetes. We also showed the influences of such altered energy metabolism due to type 2 diabetes on the pathology of AD. Furthermore, we comprehensively searched for risk factors related with type 2 diabetes for AD and showed possible therapeutic interventions based on considering risk factors and altered brain energy metabolism due to type 2 diabetes for the development of AD.

Anti-Inflammatory Effects of Aptamin C in Pulmonary Fibrosis Induced by Bleomycin

Background/Objectives: Vitamin C is a well-known antioxidant with antiviral, anticancer, and anti-inflammatory properties. However, its therapeutic applications are limited by rapid oxidation due to heat and light sensitivity. Aptamin C, which employs aptamers to bind vitamin C, has demonstrated enhanced stability and efficacy. This study investigates the potential of Aptamin C to inhibit the progression of pulmonary fibrosis, a prominent inflammatory lung disease with no effective treatment. Methods: Mice bearing bleomycin-induced pulmonary fibrosis were administered vitamin C or Aptamin C, and their weight changes and survival rates were monitored. Inflammatory cell infiltration was assessed in the bronchoalveolar lavage fluid (BALF), and the degree of alveolar fibrosis was measured by H&E and Masson's trichrome staining. To elucidate the mechanism of action of Aptamin C, Western blot analysis was performed in HaCaT and lung tissues from bleomycin-induced pulmonary fibrosis mice. Results: The Aptamin C-treated group showed a notably higher survival rate at 50%, whereas all subjects in the vitamin C-treated group died. Histological examination of lung tissue showed that inflammation was significantly suppressed in the Aptamin C-supplemented group compared to the vitamin C-supplemented group, with a 10% greater reduction in cell infiltrations, along with noticeably less tissue damage. Additionally, it was observed that Aptamin C increased SVCT-1 expression in the HaCaT cells and the lung tissues. Conclusions: Taken together, Aptamin C not only increases the stability of vitamin C but also induces an increase in SVCT-1 expression, facilitating greater vitamin C absorption into cells and tissues, thereby inhibiting the progression of symptoms and associated inflammatory responses in pulmonary fibrosis.

Vitamin C Alleviates Heat-Stress-Induced Damages in Pig Thoracic Vertebral Chondrocytes via the Ubiquitin-Mediated Proteolysis Pathway

Heat stress can impair organismal growth by inducing ubiquitination, proteasome-mediated degradation, and subsequent cellular damage. Vitamin C (VC) has been shown to potentially mitigate the detrimental effects of abiotic stresses on cells. Nevertheless, the impact of heat stress on growth plate chondrocytes remains unclear, and the underlying protective mechanisms of VC in these cells warrant further investigation. In this study, we focused on pig thoracic vertebral chondrocytes (PTVCs) that are crucial for promoting the body's longitudinal elongation and treated them with 41 °C heat stress for 24 h, under varying concentrations of VC. Our findings reveal that, while oxidative stress induced by heat triggers apoptosis and inhibits the ubiquitin-mediated proteolysis pathway, the addition of VC alleviates heat-stress-induced oxidative stress and apoptosis, mitigates cell cycle arrest, and promotes cellular viability. Furthermore, we demonstrate that VC enhances the ubiquitin-proteasome proteolysis pathway by promoting the expression of ubiquitin protein ligase E3A, which thereby stabilizes the ubiquitin-mediated degradation machinery, alleviates the apoptosis, and enhances cell proliferation. Our results suggest the involvement of the ubiquitin-mediated proteolysis pathway in the effects of VC on PTVCs under heat stress, and offer a potential strategy to make use of VC to ensure the skeletal growth of animals under high temperature pressures in summer or in tropical regions.

L-gulono-γ-lactone Oxidase, the Key Enzyme for L-Ascorbic Acid Biosynthesis

L-ascorbic acid (AsA, vitamin C) plays a vital role in preventing various diseases, particularly scurvy. AsA is known for its antioxidant properties, which help protect against reactive oxygen species generated from metabolic activities; however, at high doses, it may exhibit pro-oxidative effects. The final step in AsA biosynthesis is catalyzed by L-gulono-γ-lactone oxidase (GULO). This enzyme is present in many organisms, but some animals, including humans, guinea pigs, bats, and other primates, are unable to synthesize AsA due to the absence of a functional GULO gene. The GULO enzyme belongs to the family of aldonolactone oxidoreductases (AlORs) and contains two conserved domains, an N-terminal FAD-binding region and a C-terminal HWXK motif capable of binding the flavin cofactor. In this review, we explore AsA production, the biosynthetic pathways of AsA, and the localization of GULO-like enzymes in both animal and plant cells. Additionally, we compare the amino acid sequences of AlORs across different species and summarize the findings related to their enzymatic activity. Interestingly, a recombinant C-terminal rat GULO (the cytoplasmic domain of the rat GULO expressed in Escherichia coli) demonstrated enzymatic activity. This suggests that the binding of the flavin cofactor to the HWXK motif at the C-terminus is sufficient for the formation of the enzyme's active site. Another enzyme, GULLO7 from Arabidopsis thaliana, also lacks the N-terminal FAD-binding domain and is strongly expressed in mature pollen, although its activity has not been specifically measured.

Aptamin C enhances anti-cancer activity NK cells through the activation of STAT3: a comparative study with vitamin C

Vitamin C is a well-known antioxidant with antiviral, anticancer, and anti-inflammatory properties based on its antioxidative function. Aptamin C, a complex of vitamin C with its specific aptamer, has been reported to maintain or even enhance the efficacy of vitamin C while increasing its stability. To investigate in vivo distribution of Aptamin C, Gulo knockout mice, which, like humans, cannot biosynthesize vitamin C, were administered Aptamin C orally for 2 and 4 weeks. The results showed higher vitamin C accumulation in all tissues when administered Aptamin C, especially in the spleen. Next, the activity of natural killer (NK) cells were conducted. CD69, a marker known for activating for NK cells, which had decreased due to vitamin C deficiency, did not recover with vitamin C treatment but showed an increasing with Aptamin C. Furthermore, the expression of CD107a, a cell surface marker that increases during the killing process of target cells, also did not recover with vitamin C but increased with Aptamin C. Based on these results, when cultured with tumor cells to measure the extent of tumor cell death, an increase in tumor cell death was observed. To investigate the signaling mechanisms and related molecules involved in the proliferation and activation of NK cells by Aptamin C showed that Aptamin C treatment led to an increase in intracellular STAT3 activation. In conclusion, Aptamin C has a higher capability to activate NK cells and induce tumor cell death compared to vitamin C and it is mediated through the activation of STAT3.

CeO2·ZnO@biomass-derived carbon nanocomposite-based electrochemical sensor for efficient detection of ascorbic acid

Ascorbic acid (AA), a prominent antioxidant commonly found in human blood serum, serves as a biomarker for assessing oxidative stress levels. Therefore, precise detection of AA is crucial for swiftly diagnosing conditions arising from abnormal AA levels. Consequently, the primary aim of this research is to develop a sensitive and selective electrochemical sensor for accurate AA determination. To accomplish this aim, we used a novel nanocomposite comprised of CeO2-doped ZnO adorned on biomass-derived carbon (CeO2·ZnO@BC) as the active nanomaterial, effectively fabricating a glassy carbon electrode (GCE). Various analytical techniques were employed to scrutinize the structure and morphology features of the CeO2·ZnO@BC nanocomposite, ensuring its suitability as the sensing nanomaterial. This innovative sensor is capable of quantifying a wide range of AA concentrations, spanning from 0.5 to 1925 μM in a neutral phosphate buffer solution. It exhibits a remarkable sensitivity of 0.2267 μA μM-1cm-2 and a practical detection limit of 0.022 μM. Thanks to its exceptional sensitivity and selectivity, this sensor enables highly accurate determination of AA concentrations in real samples. Moreover, its superior reproducibility, repeatability, and stability underscore its reliability and robustness for AA quantification.

Employing a Toxic Aging Coin approach to assess hexavalent chromium (Cr[VI])-induced neurotoxic effects on behavior: Heads for age differences

We are facing a rapidly growing geriatric population (65+) that will live for multiple decades and are challenged with environmental pollution far exceeding that of previous generations. Consequently, we currently have a poor understanding of how environmental pollution will impact geriatric health distinctly from younger populations. Few toxicology studies have considered age differences with geriatric individuals. Critically, all top ten most prevalent age-related diseases are linked to metal exposures. Hexavalent chromium [Cr(VI)] is a metal of major environmental health concern that can induce aging phenotypes and neurotoxicity. However, there are many knowledge gaps for Cr(VI) neurotoxicity, including how Cr(VI) impacts behavior. To address this, we exposed male rats across three ages (3-, 7-, and 18-months old) to Cr(VI) in drinking water (0, 0.05, 0.1 mg/L) for 90 days. These levels reflect the maximum contaminant levels determined by the World Health Organization (WHO) and the U.S. Environmental Protection Agency (US EPA). Here, we report how these Cr(VI) drinking water levels impacted rat behaviors using a battery of behavior tests, including grip strength, open field assay, elevated plus maze, Y-maze, and 3-chamber assay. We observed adult rats were the most affected age group and memory assays (spatial and social) exhibited the most significant effects. Critically, the significant effects were surprising as rats should be particularly resistant to these Cr(VI) drinking water levels due to the adjustments applied in risk assessment from rodent studies to human safety, and because rats endogenously synthesize vitamin C in their livers (vitamin C is a primary reducer of Cr[VI] to Cr[III]). Our results emphasize the need to broaden the scope of toxicology research to consider multiple life stages and suggest the current regulations for Cr(VI) in drinking water need to be revisited.

Association between rheumatoid arthritis and serum vitamin C levels in Adults: Based on the National health and Nutrition Examination survey database

This study attempted to investigate relationship between rheumatoid arthritis and serum vitamin C levels using data from National Health and Nutrition Examination Survey (NHANES). The NHANES database aims to collect health, nutrition, biological, and behavioral data from a nationally representative sample of the population. This study utilizes NHANES data from three cycles: 2003-2004, 2005-2006, and 2017-2018, extracting data on the prevalence of rheumatoid arthritis and serum vitamin C levels. A generalized linear model is used to evaluate the association between the two. A total of 12,665 participants were included in the final analysis. Serum vitamin C levels were significantly higher in the non-rheumatoid arthritis group compared to the rheumatoid arthritis group (0.63 vs. 0.59, P = 0.042). Generalized linear model analysis showed that higher serum vitamin C levels were associated with a decreased risk of rheumatoid arthritis (OR = 0.62, 95 %CI: 0.40-0.98, P = 0.034). Stratified analysis revealed a significant interaction between non-hypertensive individuals and rheumatoid arthritis with serum vitamin C levels (P < 0.05). After adjusting for confounding factors, serum vitamin C levels remained significantly associated with rheumatoid arthritis in all models (P < 0.05). Restricted cubic spline results indicated that serum vitamin C levels above 0.95 mg/dL could help prevent rheumatoid arthritis. Increasing dietary vitamin C intake through supplementation was found to raise serum vitamin C levels. There was a significant association between rheumatoid arthritis and serum vitamin C levels, indicating that high levels of serum vitamin C may be a protective factor against rheumatoid arthritis.

Preoperative and postoperative administration of vitamin C in cardiac surgery patients - settings, dosages, duration, and clinical outcomes: a narrative review

Vitamin C or ascorbic acid is a water-soluble vitamin capable of directly donating electrons to reactive oxygen species, attenuating electrical remodeling, and cardiac dysfunction in patients undergoing cardiac surgery (CS), considered one of the most effective defenses against free radicals in the blood, thus being one of the first antioxidants consumed during oxidative stress. The aim of this review is to assess the effects of perioperative administration of vitamin C in CS patients. A comprehensive literature search was conducted in order to identify prospective cohort studies and/or randomized controlled trials reporting on the perioperative effects of vitamin C among adult patients undergoing CS. Studies published between January 1980 to December 2022 were included in our search, resulting in a total of 31 articles that met all our inclusion criteria. There seems to be a beneficial effect of vitamin C supplementation in arrhythmias such as in postoperative atrial fibrillation, reduction of ICU length of stay, and hospital length of stay, reduction in postoperative ventilation time, in inotropic demand, and in postoperative fatigue. Vitamin C can act as a scavenger of free radicals to decrease the peroxidation of the lipids present in the cell membrane, and to protect the myocardium postoperatively from ischemia/reperfusion injury, thus attenuating oxidative stress and inflammation. It represents a readily available and cost-effective strategy that could improve the outcome of patients undergoing CS, by reducing the risk of serious cardiovascular adverse events, both perioperatively and postoperatively.

High-dose ascorbate exerts anti-tumor activities and improves inhibitory effect of carboplatin through the pro-oxidant function pathway in uterine serous carcinoma cell lines

OBJECTIVE

Uterine serous carcinoma is a highly aggressive non-endometrioid subtype of endometrial cancer with poor survival rates overall, creating a strong need for new therapeutic strategies to improve outcomes. High-dose ascorbate (vitamin C) has been shown to inhibit cell proliferation and tumor growth in multiple preclinical models and has shown promising anti-tumor activity in combination with chemotherapy, with a favorable safety profile. We aimed to study the anti-tumor effects of ascorbate and its synergistic effect with carboplatin on uterine serous carcinoma cells.

METHODS

Cell proliferation was evaluated by MTT and colony formation assays in ARK1, ARK2 and SPEC2 cells. Cellular stress, antioxidant ability, cleaved caspase 3 activity and adhesion were measured by ELISA assays. Cell cycle was detected by Cellometer. Invasion was measured using a wound healing assay. Changes in protein expression were determined by Western immunoblotting.

RESULTS

High-dose ascorbate significantly inhibited cell proliferation, caused cell cycle arrest, induced cellular stress, and apoptosis, increased DNA damage, and suppressed cell invasion in ARK1 and SPEC2 cells. Treatment of both cells with 1 mM N-acetylcysteine reversed ascorbate-induced apoptosis and inhibition of cell proliferation. The combination of ascorbate and carboplatin produced significant synergistic effects in inhibiting cell proliferation and invasion, inducing cellular stress, causing DNA damage, and enhancing cleaved caspase 3 levels compared to each compound alone in both cells.

CONCLUSIONS

Ascorbate has potent antitumor activity and acts synergistically with carboplatin through its pro-oxidant effects. Clinical trials of ascorbate combined with carboplatin as adjuvant treatment of uterine serous carcinoma are worth exploring.

Vitamin C deficiency can lead to pulmonary hypertension: a systematic review of case reports

BACKGROUND

In the early literature, unintentional vitamin C deficiency in humans was associated with heart failure. Experimental vitamin C deficiency in guinea pigs caused enlargement of the heart. The purpose of this study was to collect and analyze case reports on vitamin C and pulmonary hypertension.

METHODS

We searched Pubmed and Scopus for case studies in which vitamin C deficiency was considered to be the cause of pulmonary hypertension. We selected reports in which pulmonary hypertension was diagnosed by echocardiography or catheterization, for any age, sex, or dosage of vitamin C. We extracted quantitative data for our analysis. We used the mean pulmonary artery pressure (mPAP) as the outcome of primary interest.

RESULTS

We identified 32 case reports, 21 of which were published in the last 5 years. Dyspnea was reported in 69%, edema in 53% and fatigue in 28% of the patients. Vitamin C plasma levels, measured in 27 cases, were undetectable in 24 and very low in 3 cases. Diet was poor in 30 cases and 17 cases had neuropsychiatric disorders. Right ventricular enlargement was reported in 24 cases. During periods of vitamin C deficiency, the median mPAP was 48 mmHg (range 29-77 mmHg; N = 28). After the start of vitamin C administration, the median mPAP was 20 mmHg (range 12-33 mmHg; N = 18). For the latter 18 cases, mPAP was 2.4-fold (median) higher during vitamin C deficiency. Pulmonary vascular resistance (PVR) during vitamin C deficiency was reported for 9 cases, ranging from 4.1 to 41 Wood units. PVR was 9-fold (median; N = 5) higher during vitamin C deficiency than during vitamin C administration. In 8 cases, there was direct evidence that the cases were pulmonary artery hypertension (PAH). Probably the majority of the remaining cases were also PAH.

CONCLUSIONS

The cases analyzed in our study indicate that pulmonary hypertension can be one explanation for the reported heart failure of scurvy patients in the early literature. It would seem sensible to measure plasma vitamin C levels of patients with PH and examine the effects of vitamin C administration.

Can vitamins improve periodontal wound healing/regeneration?

Periodontitis is a complex inflammatory disorder of the tooth supporting structures, associated with microbial dysbiosis, and linked to a number if systemic conditions. Untreated it can result in an irreversible damage to the periodontal structures and eventually teeth loss. Regeneration of the lost periodontium requires an orchestration of a number of biological events on cellular and molecular level. In this context, a set of vitamins have been advocated, relying their beneficial physiological effects, to endorse the biological regenerative events of the periodontium on cellular and molecular levels. The aim of the present article is to elaborate on the question whether or not vitamins improve wound healing/regeneration, summarizing the current evidence from in vitro, animal and clinical studies, thereby shedding light on the knowledge gap in this field and highlighting future research needs. Although the present review demonstrates the current heterogeneity in the available evidence and knowledge gaps, findings suggest that vitamins, especially A, B, E, and CoQ10, as well as vitamin combinations, could exert positive attributes on the periodontal outcomes in adjunct to surgical or nonsurgical periodontal therapy.

Ascorbic Acid Protects Bone Marrow from Oxidative Stress and Transient Elevation of Corticosterone Caused by X-ray Exposure in Akr1a-Knockout Mice

Bone marrow cells are the most sensitive to exposure to X-rays in the body and are selectively damaged even by doses that are generally considered permissive in other organs. Ascorbic acid (Asc) is a potent antioxidant that is reported to alleviate damages caused by X-ray exposure. However, rodents can synthesize Asc, which creates difficulties in rigorously assessing its effects in such laboratory animals. To address this issue, we employed mice with defects in their ability to synthesize Asc due to a genetic ablation of aldehyde reductase (Akr1a-KO). In this study, concentrations of white blood cells (WBCs) were decreased 3 days after exposure to X-rays at 2 Gy and then gradually recovered. At approximately one month, the recovery rate of WBCs was delayed in the Akr1a-KO mouse group, which was reversed via supplementation with Asc. Following exposure to X-rays, Asc levels decreased in plasma, bone marrow cells, and the liver during an early period, and then started to increase. X-ray exposure stimulated the pituitary gland to release adrenocorticotropic hormone (ACTH), which stimulated corticosterone secretion. Asc released from the liver, which was also stimulated by ACTH, appeared to be recruited to the bone marrow. Since corticosterone in high doses is injurious, these collective results imply that Asc protects bone marrow via its antioxidant capacity against ROS produced via exposure to X-rays and the cytotoxic action of transiently elevated corticosterone.

Analysis of metabolome and transcriptome of longissimus thoracis and subcutaneous adipose tissues reveals the regulatory mechanism of meat quality in MSTN mutant castrated male finishing pigs

The underlying mechanism of myostatin (MSTN) gene mutation impact on porcine carcass and meat quality has not yet been fully understood. The meat quality trait testing of the second filial generation wild-type (WT) and homozygous MSTN mutant (MSTN-/-) castrated male finishing pigs, and RNA-seq and metabolomics on the longissimus thoracis (LT) and subcutaneous adipose tissues (SAT) were performed. Compared with WT pigs, MSTN-/- pigs had higher carcass lean percentage and lower backfat thickness (all P < 0.01), and also had lower shear force (P < 0.01) and meat redness (P < 0.05). The gene and metabolite expression profiles were different between two groups. Metabolites and genes related to purine metabolism (such as xanthine metabolite (P < 0.05), AMPD3 and XDH genes (all padj < 0.01)), PI3K/Akt/mTOR signaling pathway (such as Phe-Phe and Glu-Glu metabolites (all P < 0.05), WNT4 and AKT2 genes (all padj < 0.01)), antioxidant related pathway (such as GPX2, GPX3, and GPX7 genes (all padj < 0.01)), and extracellular matrix related pathway (such as COL1A1 and COL3A1 genes (all padj < 0.01)) were significantly altered in LT. While metabolites and genes associated to lipid metabolism (such as trans-elaidic acid and PE(18:1(9Z)/0:0) metabolites (all P < 0.05), ACOX1, ACAT1 and HADH genes (all padj < 0.01)) were significantly changed in SAT. This study revealed the biological mechanisms of homozygous MSTN mutation regulated porcine carcass and meat quality, such as lean meat percentage, fat deposition and tenderness, which provides reference for the utilization of MSTN-/- pigs.

Cerebrospinal fluid and plasma ascorbate concentrations following subarachnoid haemorrhage

Background

Ascorbate, the biologically active form of vitamin C, is the primary neural anti-oxidant. Ascorbate concentrations have never been quantified following aneurysmal subarachnoid haemorrhage (aSAH).

Objective

To quantify plasma and cerebrospinal fluid (CSF) ascorbate concentrations in patients following SAH.

Design Setting Participants Main Outcome Measures

Cohort study in which plasma and CSF ascorbate concentrations were measured longitudinally in 12 aSAH patients admitted to a quaternary referral intensive care unit and compared to one-off samples obtained from 20 pregnant women prior to delivery in a co-located obstetric hospital. Data are median [interquartile range] or median (95 % confidence intervals).

Results

Forty-eight plasma samples were obtained from the 12 aSAH patients (eight females, age 62 [53-68] years). Eight participants with extra-ventricular drains provided 31 paired CSF-plasma samples. Single plasma and CSF samples were obtained from 20 pregnant women (age 35 [31-37] years). Initial plasma and CSF ascorbate concentrations post aSAH were less than half those in pregnant controls (plasma: aSAH: 31 [25-39] μmol/L vs. comparator: 64 [59-77] μmol/L; P < 0.001 and CSF: 116 [80-142] μmol/L vs. 252 [240-288] μmol/L; P < 0.001). Post aSAH there was a gradual reduction in the CSF:plasma ascorbate ratio from ∼4:1 to ∼1:1. Six (50 %) patients developed vasospasm and CSF ascorbate concentrations were lower in these patients (vasospasm: 61 (25, 97) vs. no vasospasm: 110 (96, 125) μmol/L; P = 0.01).

Conclusion

Post aSAH there is a marked reduction in CSF ascorbate concentration that is most prominent in those who develop vasospasm.

Effects of Supplementing Growing-Finishing Crossbred Pigs with Glycerin, Vitamin C and Niacinamide on Carcass Characteristics and Meat Quality

The objective of this study was to determine the influence of supplementing the diet of growing-finishing pigs with glycerin and/or a mixture of vitamin C and niacinamide on carcass traits and pork quality. Eighty-four weaned piglets with an initial average body weight of 20.35 ± 2.14 kg were assigned, at random, to four groups for a 103-day feeding experiment: control; glycerin-supplemented group; vitamin C and niacinamide-supplemented group; and glycerin, vitamin C and niacinamide-supplemented group. At the end of the experiment, three pigs/group were randomly selected and slaughtered, and samples were collected for analysis. The results indicated that supplementing crossbred pigs with glycerin, vitamin C and niacinamide simultaneously increased the redness (a*) value (p < 0.05), glycerol content (p < 0.01) and myristoleic acid content (p < 0.01) in the longissimus dorsi and tended to increase the level of flavor amino acids, linoleic acid, linolenic acid and erucic acid, as well as the percentage and density of type I myofibers in the longissimus dorsi and the semimembranosus muscle. Glycerin had an influence (p < 0.01) on the erucic acid content in the longissimus dorsi and the semimembranosus muscle, and vitamin C and niacinamide had an interaction effect (p < 0.05) on the redness (a*) value of the longissimus dorsi. Glycerin, vitamin C and niacinamide supplementation in the diet of crossbred pigs improved the color, flavor and nutritional value of pork, which contributed to an increased intent to purchase this product.

Exploring the correlation between progression of human papillomavirus infection towards carcinogenesis and nutrition

Human papillomavirus (HPV) is a common sexually transmitted virus that can lead to the development of various types of cancer. While there are vaccines available to prevent HPV infection, there is also growing interest in the role of nutrition in reducing the risk of HPV-related cancers in HPV positive patients. Diet and nutrition play a critical role in maintaining overall health and preventing various diseases. A healthy diet can strengthen the immune system, which is essential for fighting off infections, including HPV infections, and preventing the growth and spread of cancer cells. Therefore, following a healthy diet and maintaining a healthy weight are important components of HPV and cancer prevention. This article explores the current scientific evidence on the relationship between nutrition and HPV, including the impact of specific nutrients, dietary patterns, and supplements on HPV infection toward cancer progression.

Prooxidant effects of high dose ascorbic acid administration on biochemical, haematological and histological changes in Cavia porcellus (Guinea pigs): a Guinea pig experimental model

Introduction

Ascorbic acid (AA) is a water-soluble vitamin that is well known for its antioxidant and immune-boosting properties. Owing to the wide-range application of AA in the treatment of numerous ailments and its sweet taste, it is usually abused i.e. overused. However, the effect of the abuse has rarely received attention. Therefore, this study was designed to assess the effect of oral administration of high-dose ascorbic acid on biochemical and haematological parameters as well as the effects on the kidney, liver and lungs.

Methods

adult guinea pigs were divided into four (4) groups where group 1 served as the untreated control group and groups 2-4 were dosed with 29 mg, 662 mg and 1258 mg of ascorbic acid per day, respectively for 28 days.

Results

the result revealed that administration of high dose ascorbic acid significantly (P<0.05) increased serum creatinine from 50.0 ± 7.09 (NC) to AA29- 73.8 ± 4.5, AA-662-89.7 ± 3.3 and AA1258- 79.9 ± 5.7mmol/L and urea levels in the treatment group AA-1258 -18.3 ± 0.5 µmol/L compared to the normal group (NC-2.15 ± 0.6 µmol/L). Disturbance in electrolyte balance was observed with a significant (P<0.05) increase in Na+ from NC- 131.3 ± 3.5 mmol/L to 135.7 ± 3.6 mmol/L in the AA-1258 treatment group, Cl- ( NC- 67.1 ± 1.6 mmol/L increased to AA29- 92.1 ± 0.83, AA662- 95.3 ± 1.3 and AA-1258- 95.6 ± 0.4 mmol/L), and Ca2+ (NC- 2.66 ± 0.03 to AA1258- 3.36 ± 0.03 mmol/L) and a significant (P<0.05) decrease in serum K+ in the AA29-5.0 ± 0.2, AA662-5.2 ± 0.3 and AA1258-5.6 ± 0.3 mmol/L treatment groups compared to the normal group 6.6 ± 0.3 mmol/L. There was also a significant (P<0.05) increase in the differential blood count in the animals with a significant (P<0.05) increase in red blood count ( NC-5.11 ± 0.13 ×106/µL to AA1258- 5.75 ± 0.11×106/µL ), haematocrit count (NC 39.90 ± 0.52% to AA-29-42.08 ± 0.24 and AA1258-46.13 ± 0.86%), white blood count (NC 10.15 ± 1.01 ×103/µL to AA1258- 15.18 ± 1.65×103/µL ), total lymphocytes (NC 3.5 ± 0.51×103/µL to AA29-5.28 ±0.43×103/µL), monocytes (NC 0.45 ± 0.07×103/µL to AA1258 0.80 ± 0.07×103/µL), eosinophils (NC 0.23 ± 0.03×103/µL to AA12580.40 ± 0.03×103/µL), basophils (NC0.68 ± 0.10×103/µL to AA12581.20 ± 0.10×103/µL) and neutrophil count (NC 4.73 ± 0.68×103/µL to AA1258 8.36 ± 0.71×103/µL). The histopathological indices indicate cellular necrosis in the AA662 and AA1258 treatment groups of the kidney and liver respectively compared to the normal control which has normal cells.

Conclusion

high dose of ascorbic acid can therefore be suggested to cause damage to the cells by causing cellular necrosis as observed in the histopathology results and has effect on the blood cells as observed in the increase compared to the normal control, and the consequences are possibly triggered through inflammatory responses.

Exogenous 2-keto-L-gulonic Acid Supplementation as a Novel Approach to Enhancing L-ascorbic Acid Biosynthesis in Zebrafish (Danio rerio)

L-ascorbic acid (ASA) is a micronutrient that is essential for reproduction, growth, and immunity in animals. Due to the loss of enzyme L-gulono-1,4-lactone oxidase (GLO), most aquatic animals lack the capacity for ASA biosynthesis and therefore require supplementation with exogenous ASA. Recent studies have shown that 2-keto-L-gulonic acid (2KGA), a novel potential precursor of ASA, can enhance plant growth and improve stress resistance by promoting the synthesis and accumulation of ASA. Our hypothesis is that 2-keto-L-gulonic acid (2KGA) plays a similar role in aquatic animals. To investigate this, we conducted an in vivo trial to examine the effects of exogenous 2KGA supplementation on ASA metabolism and growth of zebrafish (Danio rerio). Zebrafish were categorized into groups based on their dietary intake, including a basal diet (CK group), a basal diet supplemented with 800 mg/kg ASA (ASA group), and 800 mg/kg 2KGA-Na (2KGA group) for a duration of three weeks. The results demonstrated a significant increase in ASA content in zebrafish treated with 2KGA (34.82% increase, p < 0.05) compared to the CK group, reaching a consistent level with the ASA group (39.61% increase, p < 0.05). Furthermore, the supplementation of 2KGA significantly improved growth parameters relevant to zebrafish (specific growth rate increased by 129.04%, p < 0.05) and enhanced feed utilization (feed intake increased by 15.65%, p < 0.05). Positive correlations were observed between growth parameters, feed utilization, whole-body chemical composition, and ASA content. Our findings suggest that supplementation with exogenous 2KGA can serve as a novel approach for elevating ASA synthesis in aquatic animals, and further investigation of its underlying mechanism is required.

Endogenous and Exogenous Antioxidants as Agents Preventing the Negative Effects of Contrast Media (Contrast-Induced Nephropathy)

The use of conventional contrast media for diagnostic purposes (in particular, Gd-containing and iodinated agents) causes a large number of complications, the most common of which is contrast-induced nephropathy. It has been shown that after exposure to contrast agents, oxidative stress often occurs in patients, especially in people suffering from various diseases. Antioxidants in the human body can diminish the pathological consequences of the use of contrast media by suppressing oxidative stress. This review considers the research studies on the role of antioxidants in preventing the negative consequences of the use of contrast agents in diagnostics (mainly contrast-induced nephropathy) and the clinical trials of different antioxidant drugs against contrast-induced nephropathy. Composite antioxidant/contrast systems as theranostic agents are also considered.

A comprehensive metabolic map reveals major quality regulations in red-flesh kiwifruit (Actinidia chinensis)

Kiwifruit (Actinidia chinensis) is one of the popular fruits world-wide, and its quality is mainly determined by key metabolites (sugars, flavonoids, and vitamins). Previous works on kiwifruit are mostly done via a single omics approach or involve only limited metabolites. Consequently, the dynamic metabolomes during kiwifruit development and ripening and the underlying regulatory mechanisms are poorly understood. In this study, using high-resolution metabolomic and transcriptomic analyses, we investigated kiwifruit metabolic landscapes at 11 different developmental and ripening stages and revealed a parallel classification of 515 metabolites and their co-expressed genes into 10 distinct metabolic vs gene modules (MM vs GM). Through integrative bioinformatics coupled with functional genomic assays, we constructed a global map and uncovered essential transcriptomic and transcriptional regulatory networks for all major metabolic changes that occurred throughout the kiwifruit growth cycle. Apart from known MM vs GM for metabolites such as soluble sugars, we identified novel transcription factors that regulate the accumulation of procyanidins, vitamin C, and other important metabolites. Our findings thus shed light on the kiwifruit metabolic regulatory network and provide a valuable resource for the designed improvement of kiwifruit quality.

Low Overpotential Amperometric Sensor Using Yb2O3.CuO@rGO Nanocomposite for Sensitive Detection of Ascorbic Acid in Real Samples

The ultimate objective of this research work is to design a sensitive and selective electrochemical sensor for the efficient detection of ascorbic acid (AA), a vital antioxidant found in blood serum that may serve as a biomarker for oxidative stress. To achieve this, we utilized a novel Yb₂O₃.CuO@rGO nanocomposite (NC) as the active material to modify the glassy carbon working electrode (GCE). The structural properties and morphological characteristics of the Yb₂O₃.CuO@rGO NC were investigated using various techniques to ensure their suitability for the sensor. The resulting sensor electrode was able to detect a broad range of AA concentrations (0.5-1571 µM) in neutral phosphate buffer solution, with a high sensitivity of 0.4341 µAµM^-1cm^-2 and a reasonable detection limit of 0.062 µM. The sensor's great sensitivity and selectivity allowed it to accurately determine the levels of AA in human blood serum and commercial vitamin C tablets. It demonstrated high levels of reproducibility, repeatability, and stability, making it a reliable and robust sensor for the measurement of AA at low overpotential. Overall, the Yb₂O₃.CuO@rGO/GCE sensor showed great potential in detecting AA from real samples.

Difficult to think about but easy to treat: scurvy

OBJECTIVES

Severe vitamin C deficiency, or scurvy, presents as a syndrome of multisystem abnormalities associated with defective collagen synthesis and antioxidative functions. The many clinical features of scurvy lead to frequent misdiagnoses, as they can often point to other diseases, such as vasculitis, venous thrombosis and musculoskeletal disorders. As such, an extensive workup is recommended in cases in which scurvy is suspected.

CASE PRESENTATION

A 21-month-old male patient and a 36-month-old female patient presented with difficulty in walking, painful joint movements, irritability, gingival hypertrophy and bleeding. After exhaustive investigations and risky invasive procedures, vitamin C deficiency was diagnosed in both cases, and the symptoms improved dramatically with vitamin C treatment.

CONCLUSIONS

The importance of taking a dietary history in pediatric patients is highly recommended. In cases where scurvy is considered, serum ascorbic acid levels should be checked to confirm the diagnosis prior to conducting invasive tests.

A New Ultra-Performance Liquid Chromatographic Method for the Quantification of Vitamin C in Fresh and Dried Goji Berries (Lycium barbarum L.) Cultivated in Turkey

BACKGROUND

The potential background of the study is related to comprehensive detection of the content of vitamin C with an actual chromatographic method.

OBJECTIVE

Vitamin C is of vital importance in terms of human life and health due to its polyfunctional activity such as antioxidant activity and antiviral effect with other biological functions. In this regard, it may be necessary to update analytical methods or develop up-to-date analytical methods to accurately estimate the amount of vitamin C in natural samples. In this study, a new ultra-performance liquid chromatography with photodiode array detection (UPLC-PDA) method has been developed for the determination of vitamin C content in fresh and dried goji berries (Lycium barbarum L.), which are cultivated in Turkey.

METHOD

The chromatographic elution of vitamin C in natural fruit samples was achieved on an ACQUITY UPLC BEH C18 (1.7 µm, 2.1 mm × 100 mm) column using methanol and 0.1 M H3PO4 pH 2.15 (20:80, v/v), which are mobile phase. UPLC determination was done at the 242.8 nm. Flow rate was 0.20 mL/min at a column temperature of 30°C. Linearity range of the calibration graph was found to be at 5-30 µg/mL. The validity of the newly developed UPLC method was tested by analyzing individual test samples and added samples.

RESULTS

Applicability of the validated UPLC method was verified by the quantitative analysis of vitamin C content in both fresh and dried goji berries.

CONCLUSIONS

We believe that the newly developed and validated UPLC method would be a useful and promising approach for simple quantitative analysis of goji berry samples for vitamin C.

HIGHLIGHTS

In previous studies, no UPLC-PDA method was reported for the analysis of vitamin C in goji berries. The method provided a good repeatability for the analysis of real samples.

Demand for Water-Soluble Vitamins in a Group of Patients with CKD versus Interventions and Supplementation-A Systematic Review

BACKGROUND

Increasingly, chronic kidney disease (CKD) is becoming an inevitable consequence of obesity, metabolic syndrome, and diabetes. As the disease progresses, and through dialysis, the need for and loss of water-soluble vitamins both increase. This review article looks at the benefits and possible risks of supplementing these vitamins with the treatment of CKD.

METHODS

Data in the PubMed and Embase databases were analyzed. The keywords "chronic kidney disease", in various combinations, are associated with thiamin, riboflavin, pyridoxine, pantothenic acid, folates, niacin, cobalamin, and vitamin C. This review focuses on the possible use of water-soluble vitamin supplementation to improve pharmacological responses and the overall clinical condition of patients.

RESULTS

The mechanism of supportive supplementation is based on reducing oxidative stress, covering the increased demand and losses resulting from the treatment method. In the initial period of failure (G2-G3a), it does not require intervention, but later, especially in the case of inadequate nutrition, the inclusion of supplementation with folate and cobalamin may bring benefits. Such supplementation seems to be a necessity in patients with stage G4 or G5 (uremia). Conversely, the inclusion of additional B6 supplementation to reduce CV risk may be considered. At stage 3b and beyond (stages 4-5), the inclusion of niacin at a dose of 400-1000 mg, depending on the patient's tolerance, is required to lower the phosphate level. The inclusion of supplementation with thiamine and other water-soluble vitamins, especially in peritoneal dialysis and hemodialysis patients, is necessary for reducing dialysis losses. Allowing hemodialysis patients to take low doses of oral vitamin C effectively reduces erythropoietin dose requirements and improves anemia in functional iron-deficient patients. However, it should be considered that doses of B vitamins that are several times higher than the recommended dietary allowance of consumption may exacerbate left ventricular diastolic dysfunction in CKD patients.

CONCLUSIONS

Taking into account the research conducted so far, it seems that the use of vitamin supplementation in CKD patients may have a positive impact on the treatment process and maintaining a disease-free condition.

Vitamin C Modes of Action in Calcium-Involved Signaling in the Brain

Vitamin C (ascorbic acid) is well known for its potent antioxidant properties, as it can neutralize ROS and free radicals, thereby protecting cellular elements from oxidative stress. It predominantly exists as an ascorbate anion and after oxidation to dehydroascorbic acid and further breakdown, is removed from the cells. In nervous tissue, a progressive decrease in vitamin C level or its prolonged deficiency have been associated with an increased risk of disturbances in neurotransmission, leading to dysregulation in brain function. Therefore, understanding the regulatory function of vitamin C in antioxidant defence and identification of its molecular targets deserves more attention. One of the key signalling ions is calcium and a transient rise in its concentration is crucial for all neuronal processes. Extracellular Ca²⁺ influx (through specific ion channels) or Ca²⁺ release from intracellular stores (endoplasmic reticulum, mitochondria) are precisely controlled. Ca²⁺ regulates the functioning of the CNS, including growth, development, myelin formation, synthesis of catecholamines, modulation of neurotransmission and antioxidant protection. A growing body of evidence indicates a unique role for vitamin C in these processes. In this short review, we focus on vitamin C in the regulation of calcium-involved pathways under physiological and stress conditions in the brain.

The Effect of Ascorbic Acid and Nicotinamide on Panton-Valentine Leukocidin Cytotoxicity: An Ex Vivo Study

Background: Panton−Valentine Leukocidin sustains a strong cytotoxic activity, targeting immune cells and, consequently, perforating the plasma membrane and inducing cell death. The present study is aimed to examine the individual effect of ascorbic acid and nicotinamide on PVL cytotoxicity ex vivo, as well as their effect on granulocytes viability when treated with PVL. Materials and Methods: The PVL cytotoxicity assay was performed in triplicates using the commercial Cytotoxicity Detection Kit PLUS (LDH). LDH release was measured to determine cell damage and cell viability was measured via flow cytometry. Results and discussion: A clear reduction in PVL cytotoxicity was demonstrated (p < 0.001). Treatment with ascorbic acid at 5 mg/mL has shown a 3-fold reduction in PVL cytotoxicity; likewise, nicotinamide illustrated a 4-fold reduction in PVL cytotoxicity. Moreover, granulocytes’ viability after PVL treatment was maintained when incubated with 5 mg/mL of ascorbic acid and nicotinamide. Conclusions: our findings illustrated that ascorbic acid and nicotinamide exhibit an inhibitory effect on PVL cytotoxicity and promote cell viability, as the cytotoxic effect of the toxin is postulated to be neutralized by antioxidant incubation. Further investigations are needed to assess whether these antioxidants may be viable options in PVL cytotoxicity attenuation in PVL-associated diseases.

Chloroplastic ascorbate peroxidases targeted to stroma or thylakoid membrane: The chicken or egg dilemma

Ascorbate peroxidases (APXs) are heme peroxidases that remove hydrogen peroxide in different subcellular compartments with concomitant ascorbate cycling. Here, we analysed and discussed phylogenetic and molecular features of the APX family. Ancient APX originated as a soluble stromal enzyme, and early during plant evolution, acquired both chloroplast-targeting and mitochondrion-targeting sequences and an alternative splicing mechanism whereby it could be expressed as a soluble or thylakoid membrane-bound enzyme. Later, independent duplication and neofunctionalization events in some angiosperm groups resulted in individual genes encoding stromal, thylakoidal and mitochondrial isoforms. These data reaffirm the complexity of plant antioxidant defenses that allow diverse plant species to acquire new means to adapt to changing environmental conditions.

Harnessing Escherichia coli's Native Machinery for Detection of Vitamin C (Ascorbate) Deficiency

Vitamin C (l-ascorbate) deficiency is a global public health issue most prevalent in resource-limited regions, creating a need for an inexpensive detection platform. Here, we describe efforts to engineer whole-cell and cell-free ascorbate biosensors. Both sensors used the protein UlaR, which binds to a metabolite of ascorbate and regulates transcription. The whole-cell sensor could detect lower, physiologically relevant concentrations of ascorbate, which we attributed to intact functionality of a phosphotransferase system (PTS) that transports ascorbate across the cell membrane and phosphorylates it to form UlaR's ligand. We used multiple strategies to enhance cell-free PTS functionality (which has received little previous attention), improving the cell-free sensor's performance, but the whole-cell sensor remained more sensitive. These efforts demonstrated an advantage of whole-cell sensors for detection of molecules─like ascorbate─transformed by a PTS, but also proof of principle for cell-free sensors requiring membrane-bound components like the PTS. In addition, the cell-free sensor was functional in plasma, setting the stage for future implementation of ascorbate sensors for clinically relevant biofluids in field-deployable formats.

Prospective Role of Indigenous Leafy Vegetables as Functional Food Ingredients

Indigenous leafy vegetables (ILVs) play a pivotal role in sustaining the lives of many people of low socio-economic status who reside in rural areas of most developing countries. Such ILVs contribute to food security since they withstand harsher weather and soil conditions than their commercial counterparts and supply important nutrients such as dietary fibre, vitamins and minerals. Furthermore, ILVs contain bioactive components such as phenolic compounds, flavonoids, dietary fibre, carotene content and vitamin C that confer health benefits on consumers. Several studies have demonstrated that regular and adequate consumption of vegetables reduces risks of chronic conditions such as diabetes, cancer, metabolic disorders such as obesity in children and adults, as well as cardiovascular disease. However, consumption of ILVs is very low globally as they are associated with unbalanced and poor diets, with being food for the poor and with possibly containing toxic heavy metals. Therefore, this paper reviews the role of ILVs as food security crops, the biodiversity of ILVs, the effects of processing on the bioactivity of ILVs, consumer acceptability of food derived from ILVs, potential toxicity of some ILVs and the potential role ILVs play in the future of eating.

Association between serum vitamin C and HPV infection in American women: a cross-sectional study

Background

Evidence regarding the relationship between serum vitamin C levels and human papillomavirus (HPV) infection is limited. Therefore, this study aimed to investigate whether serum vitamin C levels are independently associated with HPV infection.

Methods

Data for this cross-sectional study were obtained from the National Health and Nutrition Examination Survey 2003–2006. A total of 2174 women, 18–59 years of age, were enrolled in this study. The associations between serum vitamin C levels (continuous and categorical forms) and cervicovaginal HPV infection were estimated using weighted logistic regression.

Results

The adjusted binary logistic regression showed that serum vitamin C was not associated with the risk of HPV infection after adjusting for age, race, poverty income ratio, alcohol consumption, smoking, body mass index, education, and health condition (odds ratio [OR] 0.998, 95% confidence interval [CI] 0.994–1.001). Serum vitamin C levels were converted from a continuous variable to a categorical variable for the analysis. Compared with the vitamin C deficiency and hypovitaminosis groups, there was a negative correlation between vitamin C and HPV infection when vitamin C was adequate (OR 0.7, 95% CI: 0.52–0.94); however, when the serum vitamin C level was inadequate and saturated, this negative correlation was weaker or nonexistent (OR 0.76, 95% CI 0.56–1.03 and OR 0.76, 95% CI 0.55–1.04, respectively). A nonlinear relationship was detected between vitamin C level and HPV infection. Furthermore, we performed subgroup analysis of different models and found that serum vitamin C concentration was negatively associated with HPV infection in women ≥ 25 years of age; however, in women < 25 years of age, serum vitamin C levels were not associated with HPV infection.

Conclusion

The results from this United States nationally representative sample supported the hypothesis that there was a U-shaped relationship between serum vitamin C levels and HPV infection. Future studies are warranted to assess the association between vitamin C and HPV persistence and clarify the underlying mechanisms of these associations.

Immunomodulator Vitamin C: An Adjuvant Therapy in Second Wave of Coronavirus Disease 2019

Since its sudden outbreak in December 2019 in Wuhan, A pandemic of SARS-CoV-2 has been announced. Vitamin C is a water-soluble vitamin with anti-oxidant and immunity-boosting properties. Vitamin C acts as a nutritional supplement profoundly impacting the immune response to the second or third wave of the coronavirus disease (COVID-19). Vitamin C efficacy as an adjuvant treatment for inflammation and symptoms associated with COVID-19 infection should be investigated further. This report sheds light on the available information on the current clinical trials and pharmacotherapy related to COVID-19. Information available on Pubmed, EMBASE, Scopus, Web of Science databases and EU clinical trials regarding the use of therapeutic agents in patients with COVID-19 was used to perform analysis. Data was taken from 18 clinical trials available in the U.S. National Library of Medicine. All trials that are active, completed, or in the process of recruiting are included in data. Because of majority of clinical trials are still ongoing, specific results and high-quality clinical evidence are lacking. Before being standardised for use, the protocol must undergo large randomised clinical studies using a variety of existing medications and potential therapies. The pivotal role played by vitamins C in maintaining our immune system, is quite apparent. This review is an attempt to summarize the available information regarding the use of vitamin C as an adjuvant therapy in COVID-19 patients.

Development, Validation, and Use of 1H-NMR Spectroscopy for Evaluating the Quality of Acerola-Based Food Supplements and Quantifying Ascorbic Acid

Acerola (Malpighia emarginata D.C.) is an exotic fruit with high agro-industrial potential due to its high content of ascorbic acid (AA), phenolic compounds, and carotenoid pigments. Acerola fruit is processed into concentrated juice or powder to be incorporated into food supplements. The ascorbic acid content of concentrated juice or powders must be controlled and well assessed. Therefore, the development of optimal methods and procedures for the rapid and accurate determination of the ascorbic acid content in juice concentrate and juice powder remains of considerable commercial interest. NMR spectroscopy is currently a powerful spectroscopic tool for the qualitative and quantitative analysis of molecules of all types and sizes. Firstly, this article presents the NMR-based metabolomic profiling of acerola juice and concentrate powder to describe and compare their composition. Thirty-six metabolites were identified. The AA over choline ratio and the NMR metabolomic profiles could be used for authentication in the future. Secondly, a rapid (8 min), reliable, and non-destructive method for the quantification of ascorbic acid by 1D ¹H-NMR spectroscopy was developed and validated. The LOD and LOQ were 0.05 and 0.15 mg/mL, respectively. These two approaches could be combined to better characterize ingredients derived from acerola and incorporated into food supplements.

The Anti-Leukemia Effect of Ascorbic Acid: From the Pro-Oxidant Potential to the Epigenetic Role in Acute Myeloid Leukemia

Data derived from high-throughput sequencing technologies have allowed a deeper understanding of the molecular landscape of Acute Myeloid Leukemia (AML), paving the way for the development of novel therapeutic options, with a higher efficacy and a lower toxicity than conventional chemotherapy. In the antileukemia drug development scenario, ascorbic acid, a natural compound also known as Vitamin C, has emerged for its potential anti-proliferative and pro-apoptotic activities on leukemic cells. However, the role of ascorbic acid (vitamin C) in the treatment of AML has been debated for decades. Mechanistic insight into its role in many biological processes and, especially, in epigenetic regulation has provided the rationale for the use of this agent as a novel anti-leukemia therapy in AML. Acting as a co-factor for 2-oxoglutarate-dependent dioxygenases (2-OGDDs), ascorbic acid is involved in the epigenetic regulations through the control of TET (ten-eleven translocation) enzymes, epigenetic master regulators with a critical role in aberrant hematopoiesis and leukemogenesis. In line with this discovery, great interest has been emerging for the clinical testing of this drug targeting leukemia epigenome. Besides its role in epigenetics, ascorbic acid is also a pivotal regulator of many physiological processes in human, particularly in the antioxidant cellular response, being able to scavenge reactive oxygen species (ROS) to prevent DNA damage and other effects involved in cancer transformation. Thus, for this wide spectrum of biological activities, ascorbic acid possesses some pharmacologic properties attractive for anti-leukemia therapy. The present review outlines the evidence and mechanism of ascorbic acid in leukemogenesis and its therapeutic potential in AML. With the growing evidence derived from the literature on situations in which the use of ascorbate may be beneficial in vitro and in vivo, we will finally discuss how these insights could be included into the rational design of future clinical trials.

Development and Optimization of Electrochemical Method for Determination of Vitamin C

The focus of this work was to develop a simple electrochemical method for the determination of vitamin C (VitC) by using a specially constructed microelectrode made from pyrolytic graphite sheet (PGS). A procedure for quantifying VitC in a real sample was established. VitC shows a single quasi-reversible reaction. The method was optimized, and analytical determination was performed by using cyclic voltammetry and square wave voltammetry for electroanalytical purposes. The obtained results show a linear response of the PGS electrode in a wide concentrations range. For the lower concentration range, 0.18–7.04 µg L−1, the sensitivity is 11.7 µAcm−2/mgL−1, while for the higher concentration range, 10.6–70.4 µg L−1, the sensitivity is 134 µAcm−2/mgL−1, preserving the linearity of 0.998 and 0.999. The second objective was to determine the effect of the addition of five different types of “green” biowaste on plant growth, VitC content, and antioxidant activity in arugula (Eruca sativa L.) using the developed method. After three weeks of cultivation, small differences in growth and large differences in certain nutritional characteristics were observed. The addition of black coffee makes the soil slightly alkaline and causes a significant increase in VitC content and antioxidant activity.

Opioids and Vitamin C: Known Interactions and Potential for Redox-Signaling Crosstalk

Opioids are among the most widely used classes of pharmacologically active compounds both clinically and recreationally. Beyond their analgesic efficacy via μ opioid receptor (MOR) agonism, a prominent side effect is central respiratory depression, leading to systemic hypoxia and free radical generation. Vitamin C (ascorbic acid; AA) is an essential antioxidant vitamin and is involved in the recycling of redox cofactors associated with inflammation. While AA has been shown to reduce some of the negative side effects of opioids, the underlying mechanisms have not been explored. The present review seeks to provide a signaling framework under which MOR activation and AA may interact. AA can directly quench reactive oxygen and nitrogen species induced by opioids, yet this activity alone does not sufficiently describe observations. Downstream of MOR activation, confounding effects from AA with STAT3, HIF1α, and NF-κB have the potential to block production of antioxidant proteins such as nitric oxide synthase and superoxide dismutase. Further mechanistic research is necessary to understand the underlying signaling crosstalk of MOR activation and AA in the amelioration of the negative, potentially fatal side effects of opioids.

A pilot study on the effect of formulation and individual muscle mass on vitamin C absorption in randomized clinical study

The current study investigated that the vitamin C absorption in plasma depends on the individual muscle mass and the formulation including drinks (Vita 500), capsules, and tablets by using a randomized and double-blind clinical study. The volunteers were divided into two groups that depended on their muscle mass, including those whose muscle mass was greater than 40% ( ≥ $ \ge $ 40%) and less than 40% muscle mass (<40%). Levels of vitamin C in blood plasma was analyzed by high-performance liquid chromatography by ultraviolet detection (HPLC-UV). The existing HPLC method was modified according to lab conditions but maintained a constantly low pH sample reduction procedure. The analytical method validated stability, linearity, recovery, reliability, and accuracy. The vitamin C absorption was the highest at 120 min after ingesting Vita 500 (21.47 ± 15.99 µmol/L). It was higher in the group that has more than 40% muscle mass compared to other formulations, such as tablets and capsules. The results from the current study indicate that vitamin C formulations differently affect the vitamin C absorption, and its effect depends on the muscle mass. As the results, liquid type vitamin C formulations could enhance vitamin C absorption, which resulted in an improvement of vitamin C absorption according to muscle mass. PRACTICAL APPLICATION: The results of this study may recommend using vitamin C supplementation as liquid type. It may also provide evidence that people with higher muscle mass can absorb vitamin C more efficiently.