Vitamin C: the known and the unknown and Goldilocks

The roles of vitamin C in infectious diseases: A comprehensive review

Vitamin C is a versatile nutrient with essential antioxidant properties and roles in amino acid metabolism, collagen promotion, and hormone synthesis. It has long been regarded as benefitting infectious disease management, although its specific roles remain uncertain. The dominant view is that this efficacy not only stems from its redox regulation in the body but also from its profound impact on the immune system. This review provides a comprehensive overview of Vitamin C's effects on redox regulation and shows how the vitamin influences various immune cells and cell-intrinsic innate immunity signaling pathways, thereby updating and expanding our previous perspectives. Clinically, though some studies and case series have suggested potential benefits of Vitamin C in preventing and (or) treating respiratory tract infections and sepsis and septic shock, the evidence remains controversial. The current data is insufficient to support the routine clinical use of Vitamin C in managing these diseases and requires further rigorous evaluation to establish definitive efficacy and safety profiles. This review thoroughly examines current clinical research progress on Vitamin C, summarizes the primary controversies and their underlying causes, and proposes directions for future clinical research. Furthermore, preclinical evidence shows potential roles for Vitamin C in the supplementary treatment of the "Big Three" infectious diseases: acquired immunodeficiency syndrome (AIDS), tuberculosis, and malaria; however, systematic clinical studies in these areas are lacking. We examine related in vitro and animal studies, as well as clinical trials, and discuss potential roles for Vitamin C as a treatment and (or) adjuvant therapy.

Resetting the aging clock through epigenetic reprogramming: Insights from natural products

Epigenetic modifications play a critical role in regulating gene expression under various physiological and pathological conditions. Epigenetic modifications reprogramming is a recognized hallmark of aging and a key component of the aging clock used to differentiate between chronological and biological age. The potential for prospective diagnosis and regulatory capabilities position epigenetic modifications as an emerging drug target to extend longevity and alleviate age-related organ dysfunctions. In the past few decades, numerous preclinical studies have demonstrated the therapeutic potential of natural products in various human diseases, including aging, with some advancing to clinical trials and clinical application. This review highlights the discovery and recent advancements in the aging clock, as well as the potential use of natural products as anti-aging therapeutics by correcting disordered epigenetic reprogramming. Specifically, the focus is on the imbalance of histone modifications, alterations in DNA methylation patterns, disrupted ATP-dependent chromatin remodeling, and changes in RNA modifications. By exploring these areas, new insights can be gained into aging prediction and anti-aging interventions.

Lysine vitcylation is a vitamin C-derived protein modification that enhances STAT1-mediated immune response

Vitamin C (vitC) is essential for health and shows promise in treating diseases like cancer, yet its mechanisms remain elusive. Here, we report that vitC directly modifies lysine residues to form "vitcyl-lysine"-a process termed vitcylation. Vitcylation occurs in a dose-, pH-, and sequence-dependent manner in both cell-free systems and living cells. Mechanistically, vitC vitcylates signal transducer and activator of transcription-1 (STAT1)- lysine-298 (K298), impairing its interaction with T cell protein-tyrosine phosphatase (TCPTP) and preventing STAT1-Y701 dephosphorylation. This leads to enhanced STAT1-mediated interferon (IFN) signaling in tumor cells, increased major histocompatibility complex (MHC)/human leukocyte antigen (HLA) class I expression, and activation of anti-tumor immunity in vitro and in vivo. The discovery of vitcylation as a distinctive post-translational modification provides significant insights into vitC's cellular function and therapeutic potential, opening avenues for understanding its biological effects and applications in disease treatment.

Exploring the relationship between vitamin C deficiency and protein-energy malnutrition in adult hospitalised patients: A cross-sectional study

AIMS

To explore the prevalence of vitamin C deficiency, 'undetectable' vitamin C status, and scurvy features, in adult hospitalised patients with protein-energy malnutrition diagnosed using validated malnutrition screening and assessment tools commonly used in clinical practice.

METHODS

This study included adult inpatients from four acute hospitals within a single Australian tertiary health service, over a 3.5-year period. A medical file review activity retrospectively determined malnutrition risk and diagnosis, via Malnutrition Screening Tool, Malnutrition Universal Screening Tool, Subjective Global Assessment and Global Leadership Initiative on Malnutrition criteria. Prevalence of vitamin C deficiency and scurvy features was examined in adult patients with plasma vitamin C levels <11.4 μmol/L and <5 μmol/L ('undetectable'), respectively.

RESULTS

In the final cohort (n = 364), prevalence of vitamin C deficiency was 30.2%. Malnutrition was present in 76.1% and 79.8% of patients via Subjective Global Assessment (n = 310) and Global Leadership Initiative on Malnutrition criteria (n = 342) respectively. Patients with high nutrition risk and those diagnosed with severe malnutrition had the highest prevalence of vitamin C deficiency, reported as 32.8% for malnutrition detected via Malnutrition Screening Tool (n = 244), 32.9% via Malnutrition Universal Screening Tool (n = 222), 35.8% via Subjective Global Assessment (n = 106), and 34.2% via Global Leadership Initiative on Malnutrition (n = 152). Scurvy features were associated with severe malnutrition in patients with 'undetectable' vitamin C status.

CONCLUSIONS

Severely malnourished adult hospital patients have a high prevalence of vitamin C deficiency, and scurvy features in those with 'undetectable' vitamin C status. Leveraging existing malnutrition screening and assessment practices may support early identification of patients with vitamin C deficiency during hospitalisation.

Treatment of Herpes Zoster-Associated Neurological Complications with High-Dose Intravenous Ascorbic Acid: Two Case Reports

Background

Herpes zoster (HZ), caused by reactivation of the varicella zoster virus, can be associated with serious and difficult-to-treat neurological complications, especially in immunocompromised people. Ascorbic acid (Asc) administered intravenously in high doses has been shown to possess immunomodulatory and anti-inflammatory effects. Here, we report two cases of patients: 1) with postherpetic neuralgia (PHN) and 2) with myelitis presumably caused by HZ, who were successfully treated using this approach as adjunctive therapy. Regarding HZ-related myelitis, this is the first reported case to our knowledge.

Cases Presentation

A 72-year-old male came to the clinic with treatment-resistant postherpetic trigeminal neuralgia and cervical sympathetic ganglionitis. He rated pain intensity as 10 on the visual analogue scale (VAS). The second patient, a 34-old female, was referred with a preliminary diagnosis of cervical myelitis. She suffered from right-sided sensory-motor impairments and urinary retention. Previous treatment did not result in improvement. Neurological and MRI findings were typical of cervico-thoracic myelitis associated with right-sided hemiparesis. Two months before the onset of the first symptoms, she developed a HZ rash in the cervico-occipital region on the right, suggesting an association between HZ and myelitis. Both patients received two courses of Asc (each course consisting of 20 g administered intravenously daily for five days). The male noted a gradual pain relief from the initial 10 to 2 points on the VAS, with only a slight increase at night. In the female's case, hemiparesis regressed and bladder function was restored. Only mild neurological deficits remained.

Conclusion

This study supports the use of high-dose intravenous Asc as adjunctive therapy for HZ-associated neuralgia and myelitis, especially in treatment-resistant cases. In order to determine the optimal dosages, it is necessary to perform clinical trials. Furthermore, it would be interesting to study the potential use of Asc therapy for other HZ-related complications.

The Prevalence, Risk Factors, and Clinical Outcomes of Vitamin C Deficiency in Adult Hospitalised Patients: A Retrospective Observational Study

Background/Objectives: Assessment of vitamin C status rarely occurs in hospital patients within high-income countries on the assumption that vitamin C deficiency (VCD) is rare, and evidence on prevalence, risk factors, and clinical outcomes of VCD is limited. This study aimed to describe the prevalence of VCD, characteristics of patients with VCD, and identify risk factors and clinical outcomes associated with VCD status in adult hospitalised patients. Methods: This retrospective observational study included adult inpatients from five metropolitan hospitals within a single public health service in Australia which provides tertiary, acute, and sub-acute care, over a 3.5-year period. Non-fasting vitamin C levels were examined for the prevalence of VCD, defined as <11.4 µmol/L. Multivariate regression models were used to identify risk factors and clinical outcomes associated with VCD. Results: The prevalence of VCD was 22.9% (n = 1791), comprising 23.2% (n = 1717) and 16.2% (n = 74) within acute and sub-acute settings, respectively. VCD prevalence was high in acute setting subgroups including patients with malnutrition (30%, n = 611) and patients admitted to ICU during hospitalisation (37.3%, n = 327). Malnutrition (OR 1.50, 95% CI 1.19-1.91, p < 0.001) and male gender (OR 1.47, 95% CI 1.17-1.86, p = 0.001) were associated with VCD. VCD was not associated with clinical outcomes including in-hospital death, hospital or intensive care unit LOS, or hospital-acquired complications. Conclusions: VCD exists within adult hospital patients in high-income countries, and early, targeted detection of VCD in this setting is warranted. Further research is needed to explore the impact of VCD on hospital clinical outcomes.

Dynamic Interference Testing-Unexpected Results Obtained with the Abbott Libre 2 and Dexcom G6 Continuous Glucose Monitoring Devices

BACKGROUND

Sensors for continuous glucose monitoring (CGM) are now commonly used by people with type 1 and type 2 diabetes. However, the response of these devices to potentially interfering nutritional, pharmaceutical, or endogenous substances is barely explored. We previously developed an in vitro test method for continuous and dynamic CGM interference testing and herein explore the sensitivity of the Abbott Libre2 (L2) and Dexcom G6 (G6) sensors to a panel of 68 individual substances.

METHODS

In each interference experiment, L2 and G6 sensors were exposed in triplicate to substance gradients from zero to supraphysiological concentrations at a stable glucose concentration of 200 mg/dL. YSI Stat 2300 Plus was used as the glucose reference method. Interference was presumed if the CGM sensors showed a mean bias of at least ±10% from baseline with a tested substance at any given substance concentration.

RESULTS

Both L2 and G6 sensors showed interference with the following substances: dithiothreitol (maximal bias from baseline: L2/G6: +46%/-18%), galactose (>+100%/+17%), mannose (>+100%/+20%), and N-acetyl-cysteine (+11%/+18%). The following substances were found to interfere with L2 sensors only: ascorbic acid (+48%), ibuprofen (+14%), icodextrin (+10%), methyldopa (+16%), red wine (+12%), and xylose (>+100%). On the other hand, the following substances were found to interfere with G6 sensors only: acetaminophen (>+100%), ethyl alcohol (+12%), gentisic acid (+18%), hydroxyurea (>+100%), l-cysteine (-25%), l-Dopa (+11%), and uric acid (+33%). Additionally, G6 sensors could subsequently not be calibrated for use after exposure to dithiothreitol, gentisic acid, l-cysteine, and mesalazine (sensor fouling).

CONCLUSIONS

Our standardized dynamic interference testing protocol identified several nutritional, pharmaceutical and endogenous substances that substantially influenced L2 and G6 sensor signals. Clinical trials are now necessary to investigate whether our findings are of relevance during routine care.

Copper(II) Cyclopeptides with High ROS-Mediated Cytotoxicity

Cu(II) coordination complexes are emerging as promising anticancer agents due to their ability to induce oxidative stress through reactive oxygen species (ROS) generation. In this study, we synthesized and characterized two novel Cu(II) metallopeptide systems, 1/Cu(II) and 2/Cu(II), derived from the oligocationic bipyridyl cyclopeptides 1 and 2, and designed to enhance the transport of Cu(II) into cells and increase ROS levels. Spectroscopic and electrochemical analyses confirmed the formation of stable metallopeptide species in aqueous media. Inductively coupled plasma mass spectrometry (ICP-MS) studies demonstrated that both metallopeptides significantly increase intracellular Cu(II) accumulation in NCI/ADR-RES cancer cells, highlighting their role as efficient Cu(II) transporters. Additionally, ROS generation assays revealed that 1/Cu(II) induces a substantial increase in intracellular ROS levels, supporting the hypothesis of oxidative stress-induced cytotoxicity. Cell-viability assays further confirmed that both 1/Cu(II) and 2/Cu(II) exhibit strong anticancer activity in a number of cancer cell lines, with IC50 values significantly lower than those of their free cyclopeptide counterparts or Cu(II) alone, showing an order of activity higher than that of cisplatin. Finally, molecular modeling studies provided further insights into the structural stability and coordination environment of Cu(II) within the metallopeptide complexes. These findings suggest that these Cu(II) cyclometallopeptide systems hold potential as novel metal-based therapeutic agents, leveraging Cu(II) transport and ROS increase as key strategies for cancer treatment.

Association between vitamin C, D, and K intake and inflammatory bowel disease risk: findings from 2009 to 2010 NHANES

BACKGROUND

Micronutrient deficiency is commonly observed in patients with inflammatory bowel disease (IBD), yet the role of certain dietary trace elements in the risk of IBD development remains unclear.

OBJECTIVES

This study aimed to investigate the relationship between vitamin C, D, and K intake and IBD risk.

METHODS

This study included 3,591 participants from the 2009-2010 National Health and Nutrition Examination Survey (NHANES). Multivariable logistic regression were conducted to assess associations between vitamin C, D, and K intake and IBD risk while controlling for multiple confounders. Subgroup analyses were employed to test the robustness of the associations across participants with various characteristics. Additionally, restricted cubic spline (RCS) analysis was conducted to investigate potential nonlinear relationships.

RESULTS

In the fully adjusted model, each 1 mcg increase in vitamin D intake was linked to an approximately 51% decrease in IBD risk (adjusted OR = 0.49, 95% CI: 0.25-0.98, p = 0.045). The benefit appeared stronger in women, individuals without hypertension, and non-smokers. No statistically significant associations were found between vitamin C or vitamin K intake and IBD risk. However, among individuals without diabetes, each 1 mcg increase in vitamin K intake was associated with an approximate 67% reduction in IBD risk (adjusted OR = 0.33, 95% CI: 0.12-0.94, p = 0.039). RCS analysis suggested a linear relationship between dietary micronutrient intake and IBD risk (vitamin D: p for nonlinearity = 0.127, p for overall = 0.015; vitamin C: p for nonlinearity = 0.984, p for overall = 0.937; vitamin K: p for nonlinearity = 0.736, p for overall = 0.434).

CONCLUSION

Increased vitamin D intake may reduce the risk of IBD, with more pronounced benefits in certain subgroups, highlighting the potential of vitamin D supplementation as a novel therapeutic approach for IBD prevention and management. Future well-designed studies should further test the therapeutic effects of vitamin D supplementation and investigate the associations of other dietary trace elements with IBD risk to better inform prevention and treatment approaches.

Reprogramming of Thyroid Cancer Metabolism: from Mechanism to Therapeutic Strategy

Thyroid cancer as one of the most prevalent malignancies of endocrine system, has raised public concern and more research on its mechanism and treatment. And metabolism-based therapies have advanced rapidly, for the exclusive metabolic profiling of thyroid cancer. In thyroid cancer cells, plenty of metabolic pathways are reprogrammed to accommodate tumor microenvironment. In this review, we initiatively summarize recent progress in the full-scale thyroid cancer metabolic rewiring and the interconnection of various metabolites. We also discuss the efficacy and prospect of metabolic targeted detection as well as therapy. Comprehending metabolic mechanism and characteristics of thyroid cancer roundly will be highly beneficial to managing individual patients.

Effects of Pharmacological Dose of Vitamin C on MDA-MB-231 Cells

Background/Objectives: In 2022, approximately 2.3 million women were diagnosed with breast cancer worldwide, resulting in 670,000 deaths, which accounted for 6.9% of all cancer-related deaths. In the United States, 1 in 8 women will be diagnosed with breast cancer during their lifetime. It was estimated that 2024 would identify about 310,720 women and 2800 men diagnosed with invasive breast cancer. The future global burden of breast cancer is projected to rise to over 3 million new cases and 1 million deaths by 2040. Approximately 20% of breast cancer diagnoses are triple-negative breast cancer (TNBC), a type of cancer that lacks receptors for estrogen (ER-negative), progesterone (PR-negative), and human epidermal growth factor receptor 2 (HER2/neu-negative). Consequently, TNBC does not respond to hormonal or targeted therapies, making it challenging to treat due to its rapid growth, metastasis, and high recurrence rate within the first three years of therapy. Alternative chemotherapies are needed to address this problem. A pharmacological dose of vitamin C (high-dose VC) has been identified as a potential treatment for some cancer cells. The present study aimed to evaluate whether VC has a therapeutic effect on TNBC, using MDA-MB-231 cells as the model. Additionally, VC's effects were trialed on other cancer cells such as MCF7 and on non-cancerous kidney HEK 293 and lung CCL205 cells. Methods: The MTT assay, Hoechst 33342 staining, nuclear-ID red/green staining, Rhodamine 123 staining, and Western blot analysis were employed to test the hypothesis that a pharmacological dose of VC can kill TNBC cells. Results: The upregulation of Apaf-1 and caspases -7, -8, and -9, the inhibition of matrix metalloproteinases (MMP-2 and MMP-9), a reduction in cell cycle protein expression, and the enhancement of tumor suppressor proteins such as p53 and p21 indicate that a pharmacological dose of VC has promising anti-cancer properties in the treatment of breast cancers. Conclusions: Pharmacological dose of VC exerts significant anti-cancer effects in MDA-MB-231 cells by promoting apoptosis, inhibiting metastasis, disrupting cell cycle progression, and enhancing tumor suppressor activity.

The L-Ascorbic Acid Increases Proliferation and Differentiation of Yanbian Cattle Skeletal Muscle Satellite Cells by Activating the Akt/mTOR/P70S6K Signaling Pathway

Cell-cultured meat, as a new type of meat food, can effectively mitigate the negative effects of conventional animal husbandry on the environment, health, and animal welfare. Muscle stem cells are the main seed cells for the production of cell-cultured meat, but their weak proliferative capacity in vitro severely limits the large-scale and low-cost production of cell-cultured meat. There is growing evidence that L-ascorbic acid (AA) has the ability to increase the efficiency of muscle stem cell proliferation and differentiation in vitro. However, the role of AA in Yanbian bovine skeletal muscle satellite cells (BSCs) and its molecular mechanisms are unknown. Therefore, in the present study, the promotional effect of AA on the proliferation and differentiation of BSCs was confirmed by the Cell Counting Kit 8 (CCK-8) assay, 5-ethyl-2'-deoxyuridine (EdU) proliferation assay, real-time quantitative PCR (RT-qPCR), immunoprotein blotting (Western blotting) and immunofluorescence assay. RT-qPCR and Western blotting results showed that AA up-regulated the expression of p-Akt, p-mTOR, and p-P70S6K genes and proteins, whereas when the mTOR pathway inhibitor rapamycin was co-treated with AA in BSCs, the expression of p-Akt, p-mTOR, and p-P70S6K genes and proteins was significantly down-regulated. In summary, data suggest that AA regulates the proliferation and differentiation of BSCs by activating the AKT/mTOR/P70S6K signaling pathway. These data provide a practical approach and theoretical basis for the efficient and low-cost manufacture of cell culture meat.

The pharmacology of vitamin C

Ascorbic acid, the reduced form of vitamin C, is a ubiquitous small carbohydrate. Despite decades of focused research, new metabolic functions of this universal electron donor are still being discovered and add to the complexity of our view of vitamin C in human health. Although praised as an unsurpassed water-soluble antioxidant in plasma and cells, the most interesting functions of vitamin C seem to be its roles as specific electron donor in numerous biological reactions ranging from the well-known hydroxylation of proline to cofactor for the epigenetic master regulators ten-eleven translocation enzymes and Jumonji domain-containing histone-lysine demethylases. Some of these functions may have important implications for disease prevention and treatment and have spiked renewed interest in, eg, vitamin C's potential in cancer therapy. Moreover, some fundamental pharmacokinetic properties of vitamin C remain to be established including if other mechanisms than passive diffusion governs the efflux of ascorbate anions from the cell. Taken together, there still seems to be much to learn about the pharmacology of vitamin C and its role in health and disease. This review explores new avenues of vitamin C and integrates our present knowledge of its pharmacology. SIGNIFICANCE STATEMENT: Vitamin C is involved in multiple biological reactions of which most are essential to human health. Hundreds of millions of people are considered deficient in vitamin C according to accepted guidelines, but little is known about the long-term consequences. Although the complexity of vitamin C's physiology and pharmacology has been widely disregarded in clinical studies for decades, it seems clear that a deeper understanding of particularly its pharmacology holds the key to unravel and possibly exploit the potential of vitamin C in disease prevention and therapy.

Thiamine and Ascorbic Acid in Sepsis and Septic Shock: A Review of Evidence for their Role in Practice

Objective

To evaluate the evidence for the use of ascorbic acid, thiamine, or a combination of both agents without corticosteroids in the management of sepsis and septic shock.

Data Sources

A review of the literature was conducted through August 2023 on PubMed, MEDLINE, Web of Science, and CINAHL using the following terminology: "ascorbic acid" OR "vitamin C" OR "thiamine" OR "vitamin B" OR "vitamin B 1" AND "sepsis" OR "septic shock" NOT "steroid" OR "hydrocortisone" OR "corticosteroid."

Study Selection and Data Extraction

Trials that described patient outcomes, medication efficacy, and medication safety data were considered for inclusion, while reports describing the use of either or both thiamine and ascorbic acid for a non-sepsis indication and reports that were not readily translatable to English were excluded. Studies that allowed corticosteroid use in both the intervention and control cohorts as part of a standard-of-care protocol were eligible for inclusion.

Data Synthesis

Heterogeneity of data exists, marked by divergent quantifications for successful pharmacotherapy interventions. Whereas some data support changes in patient outcome scores or critical illness indices, others have failed to demonstrate any meaningful benefit to ICU length of stay, ventilator status, or mortality.

Conclusion

Exploring the individual and synergistic effects of ascorbic acid and thiamine on key pathways implicated in sepsis pathophysiology has not yielded unequivocal evidence supporting their use without concomitant corticosteroids.

Vitamin C: A Comprehensive Review of Its Role in Health, Disease Prevention, and Therapeutic Potential

Since Albert Szent-Györgyi discovered it and it became used in treating scurvy, vitamin C has attracted interest in many studies due to its unique properties. It is an important cofactor in the synthesis of collagen and hormones, and it is involved in immunity, iron absorption, and processes requiring antioxidants. Thus, this review aims to emphasize the importance and usefulness of vitamin C in improving quality of life and preventing various diseases (e.g., chronic diseases, cardiovascular diseases, cancer) but also for its use in treatments against infections, neurodegenerative diseases, and cancer. Although the studies presented provide essential information about the properties of VIC and its beneficial effect on health, some studies contradict these theories. In this respect, further studies on larger samples and over a longer period are needed to demonstrate the therapeutic potential of this nutrient. However, VIC remains a necessary vitamin that should be consumed daily to maintain optimal health and prevent deficiencies that can lead to scurvy and its associated complications.

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.

The association between vitamin C and breast cancer, prostate cancer and colorectal cancer: A systematic review and meta-analysis

BACKGROUND

For a comprehensive evaluation and due to the inconsistent results of previous studies, we performed this meta-analysis with the aim of vitamin C effect on breast cancer and prostate cancer and colorectal cancer.

METHODS

PubMed, Scopus and Web of Science were searched to identify studies on the association between vitamin C and breast cancer, prostate cancer and colorectal cancer through September 11, 2023. The pooled RR and the 95 % confidence intervals were used to measure the association between vitamin C and breast cancer, prostate cancer and colorectal cancer by assuming a random effects meta-analytic model. Newcastle-Ottawa scale was used for quality appraisal.

RESULTS

A total of 69 studies were included. The pooled RR for the association between vitamin C (dietary) and breast cancer in the cohort study was 0.99 [95 % CI: 0.95, 1.03], but the pooled RR in the case-control study was 0.72 [95 % CI: 0.60, 0.85]. No association was found between vitamin E (supplemental, total intake) and breast cancer in studies. The pooled RR for the association between vitamin C (dietary) and prostate cancer was 0.88 [95 % CI: 0.77, 1.00], which represents a decrease in prostate cancer. No association was found between vitamin C (supplemental) and prostate cancer in studies. The pooled RR for the association between vitamin C (dietary) and colorectal cancer was 0.55 [95 % CI: 0.42, 0.73], which represents a decrease in colorectal cancer.

CONCLUSION

Our analysis shows an inverse significant relationship between vitamin C (dietary) and breast cancer in the case-control study. Also between vitamin C (dietary) and prostate cancer and colorectal cancer in studies, which represents a decrease in cancers.

Antioxidants in Age-Related Macular Degeneration: Lights and Shadows

Age-related macular degeneration (AMD) is a leading cause of vision impairment worldwide, primarily driven by oxidative stress and inflammation. This review examines the role of antioxidants in mitigating oxidative damage, emphasizing both their therapeutic potential and limitations in AMD management. Key findings underscore the efficacy of specific antioxidants, including vitamins C and E, lutein, zeaxanthin, and Coenzyme Q10, in slowing AMD progression. Landmark studies such as AREDS and AREDS2 have shaped current antioxidant formulations, although challenges persist, including patient variability and long-term safety concerns. Emerging therapies, such as mitochondrial-targeted antioxidants and novel compounds like saffron and resveratrol, offer promising avenues for AMD treatment. Complementary lifestyle interventions, including antioxidant-rich diets and physical activity, further support holistic management approaches. This review highlights the critical role of antioxidants in AMD therapy, advocating for personalized strategies to optimize patient outcomes.

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.

Investigation of the effects of silymarin and vitamin C on kidney damage and aquaporin-2 downregulation in lithium-induced nephrogenic diabetes insipidus in rats

Although lithium (LIT) therapy is key in managing bipolar disorder long-term, prolonged use significantly contributes to acquired Nephrogenic Diabetes Insipidus (NDI). This study examined whether combining Silymarin (SIL) with Vitamin C (Vit C) enhances protection against lithium-induced nephrotoxicity in rats, comparing their individual antioxidant effects as well. Rats subjected to Li exposure were provided with a standard commercial diet supplemented with 80 mmol LiCl per kilogram for 28 days. Concurrently, SIL and Vit C were administered orally at dosages of 200 and 100 mg/kg body weight, respectively, throughout the 28 days. The study assessed levels of reactive oxygen species (ROS), glutathione (GSH), and malondialdehyde (MDA), as well as the enzyme activity of superoxide dismutase (SOD), to evaluate the protective effects of SIL and Vit C against oxidative stress. Aquaporin-2 (AQP2) levels in kidney tissues were evaluated using immunohistochemistry and ELISA. Serum and urine parameters (sodium, potassium, creatinine, blood urea nitrogen [BUN], and urea) and serum lithium levels were also measured. Lithium-induced nephrotoxicity showed increased renal toxicity markers and decreased antioxidant enzyme activity. SIL administration significantly reduced markers of kidney tissue toxicity, increased antioxidant enzyme activities, regulated the aforementioned physiological parameters in blood and urine, and downregulated AQP2 expression in the kidney. However, Vit C administration did not demonstrate a significant protective effect against lithium-induced renal toxicity. These findings indicate that SIL effectively protects against lithium-induced nephrotoxicity, whereas Vitamin C does not exhibit this protective effect.

Ascorbate deficiency increases quiescence and self-renewal in hematopoietic stem cells and multipotent progenitors

ABSTRACT

Ascorbate (vitamin C) limits hematopoietic stem cell (HSC) function and suppresses leukemia development, partly by promoting the function of the Tet2 tumor suppressor. In humans, ascorbate is obtained from the diet, whereas in mice, it is synthesized in the liver. In this study, we show that deletion of the Slc23a2 ascorbate transporter from hematopoietic cells depleted ascorbate to undetectable levels in HSCs and multipotent hematopoietic progenitors (MPPs) without altering the plasma ascorbate levels. Slc23a2 deficiency increased HSC reconstituting potential and self-renewal potential upon transplantation into irradiated mice. Slc23a2 deficiency also increased the reconstituting and self-renewal potentials of MPPs, conferring the ability to reconstitute irradiated mice long term. Slc23a2-deficient HSCs and MPPs divided much less frequently than control HSCs and MPPs. Increased self-renewal and reconstituting potential were observed particularly in quiescent Slc23a2-deficient HSCs and MPPs. The effect of Slc23a2 deficiency on MPP self-renewal was not mediated by reduced Tet2 function. Ascorbate thus regulates quiescence and restricts self-renewal potential in HSCs and MPPs such that ascorbate deficiency confers MPPs with long-term self-renewal potential.

Evaluation of Gingival Depigmentation Using Different Surgical Techniques and Prevention of Repigmentation With Vitamin C: A Clinical Study

Background Gingival depigmentation is a cosmetic periodontal plastic surgical procedure for removing or reducing unesthetic melanin hyperpigmentation-the reappearance of melanin pigmentation after gingival depigmentation has been reported. Vitamin C has been routinely used for the management of hyperpigmentation in dermatology. However, very few studies have been conducted on the use of Vitamin C for the management of gingival hyperpigmentation. Further, the use of Vitamin C to prevent the recurrence of pigmentation after its surgical removal has not been reported. Hence, the present study was conducted. Aim The aim of the study is to evaluate gingival depigmentation by different surgical techniques and the prevention of repigmentation using Vitamin C. Methods Sixty-four sites in subjects aged 20-45 years with chief complaints of black-looking gums were selected. Scaling and root planning were done. Gingival depigmentation was performed by scalpel at half the sites (32 sites) and by laser technique at the other half sites (32 sites) under adequate local anesthesia. The gingival pigmentation index (Dummett-Gupta oral pigmentation index (DOPI)), visual analog scale (VAS), and surface area of pigmentation were assessed. Vitamin C was administered two weeks after surgical depigmentation and then at monthly intervals for six months. Results There was a statistically significant decrease in the DOPI score, the surface area of pigmentation from baseline to one year (p < 0.000), and the VAS score at laser-treated sites as compared to scalpel-treated sites at one month (p < 0.000). Conclusion Laser depigmentation is minimally invasive and preferred. Recurrence of gingival melanin pigmentation can be minimized by the administration of Vitamin C.

Oxidative Stress in Children and Adolescents: Insights Into Human Biology

Oxidative stress (OS) is a key biological challenge and selective pressure for organisms with aerobic metabolism. The result of the imbalance between reactive oxygen species production and antioxidant defense, OS can damage proteins, lipids, and nucleic acids and plays an important role in driving variation in biological aging and health. Among humans, OS research has focused overwhelmingly on adults, with demonstrated connections between OS, inflammation, and metabolic and neurodegenerative conditions. Relatively little attention has been given to OS during childhood and adolescence. This lack of early life OS research exists despite clear implications for informing human life history evolution, subadult development, and lifelong health. Here, we review current knowledge on OS during human subadulthood. Our objectives are threefold: (1) To highlight common methods for measuring OS among children and adolescents and to establish typical measurement values; (2) To summarize the evidence linking demographic and ecological factors to variation in subadult OS; (3) To identify avenues for future OS research in human biology. Our review underscores an expanding methodological toolkit for assessing OS among children and adolescents. Subadult OS is considerably elevated compared to OS among adults, a pattern eliciting unknown consequences and likely related to increased early life metabolic demands (e.g., unique human brain development). Factors such as diet, physical activity, infectious disease, and structural neglect also appear to drive subadult OS. Current limitations for research on subadult OS are evident. Future work should emphasize evolutionary, biocultural, and energetic life course perspectives to advance this promising area of human biology.

Vitamin C and suicidal ideation: A cross-sectional and Mendelian randomization study

BACKGROUND

Studies have shown that a history of suicide attempts is associated with low levels of antioxidant vitamins. However, the specific relationship between vitamin C and suicidal ideation remains poorly understood. The purpose of this study is to investigate the effect of vitamin C on the development of suicidal ideation and to explore further the causal relationship using Mendelian randomization (MR).

METHODS

Using the 2005-2018 National Health and Nutrition Examination Survey (NHANES) dataset, a comprehensive, cross-sectional, stratified survey of 28,623 participants aged 20 years and older was conducted. Suicidal ideation was assessed using item 9 of the Patient Health Questionnaire-9 (PHQ-9) item. The relationship between vitamin C and suicidal ideation was revealed by weighted multiple linear regression, smooth curve fitting, hierarchical analysis, and interaction test. To determine causality, MR was performed on vitamin C and suicidal ideation.

RESULTS

In cross-sectional studies, all models showed a negative association between vitamin C and suicidal ideation, with a 37 % reduction in the risk of suicidal ideation for each unit increase in vitamin C in the highest quartile in the fully adjusted model. The results of the subgroup analysis showed that the association between vitamin C and suicidal ideation was stable across gender, age, education, smoking status, and marital status. In the MR study, our bivariate model showed no significant causal relationship between vitamin C and the development of suicidal ideation.

CONCLUSIONS

Dietary vitamin C intake was negatively associated with the development of suicidal ideation. However, genetic evidence does not support causation of these associations.

Succinate Regulates Endothelial Mitochondrial Function and Barrier Integrity

Endothelial dysfunction is a hallmark of several pathological conditions, including cancer, cardiovascular disease and inflammatory disorders. In these conditions, perturbed TCA cycle and subsequent succinate accumulation have been reported. The role of succinate as a regulator of immunological responses and inflammation is increasingly being recognized. Nevertheless, how endothelial cell function and phenotype are altered by elevated intracellular succinate has not been addressed yet. Thus, we employed numerous in vitro functional assays using primary HUVECs and diethyl succinate (DES), a cell membrane-permeable succinate analogue. An MTS assay 1 h post stimulation with DES suggested reduced metabolic activity in HUVECs. Concurrently, elevated production of ROS, including mitochondrial superoxide, and a reduction in mitochondrial membrane potential were observed. These findings were corroborated by Seahorse mito-stress testing, which revealed that DES acutely lowered the OCR, maximal respiration and ATP production. Given the link between mitochondrial stress and apoptosis, we examined important survival signalling pathways. DES transiently reduced ERK1/2 phosphorylation, a response that was followed by a skewed pro-apoptotic shift in the BAX to BCL2L1 gene expression ratio, which coincided with upregulating VEGF gene expression. This indicated an induction of mixed pro-apoptotic and pro-survival signals in the cell. However, the BAX/BCL-XL protein ratio was unchanged, suggesting that the cells did not commit themselves to apoptosis. An MTS assay, caspase 3/7 activity assay and annexin V/propidium iodide staining confirmed this finding. By contrast, stimulation with DES induced acute endothelial barrier permeability, forming intercellular gaps, altering cell size and associated actin filaments without affecting cell count. Notably, during overnight DES exposure gradual recovery of the endothelial barrier and cell sprouting was observed, alongside mitochondrial membrane potential restoration, albeit with sustained ROS production. COX-2 inhibition and EP4 receptor blockade hindered barrier restoration, implicating a role of COX-2/PGE2/EP4 signalling in this process. Interestingly, ascorbic acid pre-treatment prevented DES-induced acute barrier disruption independently from ROS modulation. In conclusion, succinate acts as a significant regulator of endothelial mitochondrial function and barrier integrity, a response that is counterbalanced by upregulated VEGF and prostaglandin production by the endothelial cells.

Multidimensional role of selenium nanoparticles to promote growth and resilience dynamics of Phaseolus vulgaris against sodium fluoride stress

High fluoride (F) concentrations negatively affect the seed germination, plant growth, development, and yield of crops. Phaseolus vulgaris L. is an F-sensitive crop frequently grown on marginal lands affected by F salts. Selenium (Se) is a vital elicitor of the antioxidative enzymes involved in scavenging free radicals to alleviate abiotic stress. Recent studies have demonstrated that engineered nanoparticles (NPs) have the potential to induce tolerance to abiotic stress in plants. Phytosynthesis of NPs is a novel and sustainable approach to mitigate abiotic stresses. The present study was intended to assess the role of green synthesized Se-nanoparticles (Se-NPs) in improving the physiochemical attributes, growth, and F stress tolerance of P. vulgaris growing in 200 ppm sodium fluoride (NaF) stress. NaF toxicity reduced Chl a, Chl b, and carotenoid content by 88.8%, 95.5%, and 96% compared to control with maximum improvement obtained through phyto-nano seed priming and foliar spray of 70 ppm Se-NPs. The joint treatment of NPs application through seed priming and foliar spray improved stomatal conductance (14.2%) and transpiration rate (11.7%) in plants subjected to NaF stress. The protein content (91.02%) and DPPH activity (33.72%) decreased under NaF stress, which was improved by phyto-nano seed priming and foliar spray (14.10%). Furthermore, the integrated application of Se-NPs seed priming and foliar spray increased nutritional content (P, K, Ca, Mg, and Zn), proline, ascorbic acid, and phenol yet reduced the level of NaF in plants. Se-NPs at 70 ppm were found to be more effective than 60 ppm in all modes of applications. Our results reveal a perception that Se-NPs increase P. vulgaris growth in NaF stress conditions, perhaps through a multipronged approach: improving photosynthetic content, nutrient uptake, and yield of P. vulgaris. Consequently, the findings of this study may be used for breeding and screening F-tolerant cultivars.

Mechanism of action and evaluation of ratiometric probes for uric acid using lanthanide complexes with tetraazatriphenylene sensitisers

A series of new ligands has been prepared that incorporate electron-poor aromatic moieties (dpqMe2 and dpqPh2 chromophores) into tetraazacyclododecane or triazacyclononane based complex structures, and the time-dependent photophysical properties of their Eu(iii) and Tb(iii) complexes evaluated for the selective and rapid ratiometric analysis of urate in diluted serum solution, together with mechanistic studies probing the nature of the intermediate exciplex and the excited state dynamics using transient absorption spectroscopy.

Integrated omics analysis reveals the alteration of gut microbiota and fecal metabolites in Cervus elaphus kansuensis

The gut microbiota is the largest and most complex microecosystem in animals. It is influenced by the host's dietary habits and living environment, and its composition and diversity play irreplaceable roles in animal nutrient metabolism, immunity, and adaptation to the environment. Although the gut microbiota of red deer has been studied, the composition and function of the gut microbiota in Gansu red deer (Cervus elaphus kansuensis), an endemic subspecies of red deer in China, has not been reported. In this study, the composition and diversity of the gut microbiome and fecal metabolomics of C. elaphus kansuensis were identified and compared for the first time by using 16S rDNA sequencing, metagenomic sequencing, and LC-MS/MS. There were significant differences in gut microbiota structure and diversity between wild and farmed C. elaphus kansuensis. The 16S rDNA sequencing results showed that the genus UCRD-005 was dominant in both captive red deer (CRD) and wild red deer (WRD). Metagenomic sequencing showed similar results to those of 16S rDNA sequencing for gut microbiota in CRD and WRD at the phylum and genus levels. 16S rDNA and metagenomics sequencing data suggested that Bacteroides and Bacillus might serve as marker genera for CRD and WRD, respectively. Fecal metabolomics results showed that 520 metabolites with significant differences were detected between CRD and WRD and most differential metabolites were involved in lipid metabolism. The results suggested that large differences in gut microbiota composition and fecal metabolites between CRD and WRD, indicating that different dietary habits and living environments over time have led to the development of stable gut microbiome characteristics for CRD and WRD to meet their respective survival and reproduction needs. KEY POINTS: • Environment and food affected the gut microbiota and fecal metabolites in red deer • Genera Bacteroides and Bacillus may play important roles in CRD and WRD, respectively • Flavonoids and ascorbic acid in fecal metabolites may influence health of red deer.

Epigenetic DNA modifications and vitamin C in prostate cancer and benign prostatic hyperplasia: Exploring similarities, disparities, and pathogenic implications

OBJECTIVES

Benign Prostatic Hyperplasia (BPH) and Prostate Cancer (PC) are very common pathologies among aging men. Both disorders involve aberrant cell division and differentiation within the prostate gland. However, the direct link between these two disorders still remains controversial. A plethora of works have demonstrated that inflammation is a major causative factor in both pathologies. Another key factor involved in PC development is DNA methylation and hydroxymethylation.

METHODS

A broad spectrum of parameters, including epigenetic DNA modifications and 8-oxo-7,8-dihydro-2'-deoxyguanosine, was analyzed by two-dimensional ultraperformance liquid chromatography with tandem mass spectrometry in tissues of BPH, PC, and marginal one, as well as in leukocytes of the patients and the control group. In the same material, the expression of TETs and TDG genes was measured using RT-qPCR. Additionally, vitamin C was quantified in the blood plasma and within cells (leukocytes and prostate tissues).

RESULTS

Unique patterns of DNA modifications and intracellular vitamin C (iVC) in BPH and PC tissues, as well as in leukocytes, were found in comparison with control samples. The majority of the alterations were more pronounced in leukocytes than in the prostate tissues.

CONCLUSIONS

Characteristic DNA methylation/hydroxymethylation and iVC profiles have been observed in both PC and BPH, suggesting potential shared molecular pathways between the two conditions. As a fraction of leukocytes may be recruited to the pathological tissues and can migrate back into the circulation/blood, the observed alterations in leukocytes may reflect dynamic changes associated with the PC development, suggesting their potential utility as early markers of prostate cancer development.

Dehydroascorbic acid quantification in human plasma: Simultaneous direct measurement of the ascorbic acid/dehydroascorbic acid couple by UPLC/MS-MS

Ascorbic acid (AA, vitamin C) and dehydroascorbic acid (DHA) constitute a biological couple. No technique can accurately, independently, and simultaneously quantify both members of the couple in animal and human samples, thereby constraining advances in physiology and pathophysiology. Here we describe a new UPLC/MS/MS method to measure both compounds directly and independently in human plasma. Lower limits of quantification were 16 nM, with linear coefficients >0.99 over a 100-fold concentration range. The method was stable and reproducible with <10 % injection-to-injection variation. Use of isotopic labeled internal standards for both compounds ensured precision and accuracy. Plasma preparation required only 2 steps. In plasma samples from 14 anonymized subjects who met criteria for blood donation, mean concentrations were 6±2 μmol/L (mean ± SD) and 56 ± 14 μmol/L for DHA and AA respectively, with (DHA)/(AA + DHA) ratio of 9.8 %. This method represents a pioneering approach to measuring the AA/DHA couple in human plasma.

Understanding the Genetic Architecture of Vitamin Status Biomarkers in the Genome-Wide Association Study Era: Biological Insights and Clinical Significance

Vitamins play an intrinsic role in human health and are targets for clinical intervention through dietary or pharmacological approaches. Biomarkers of vitamin status are complex traits, measurable phenotypes that arise from an interplay between dietary and other environmental factors with a genetic component that is polygenic, meaning many genes are plausibly involved. Studying these genetic influences will improve our knowledge of fundamental vitamin biochemistry, refine estimates of the effects of vitamins on human health, and may in future prove clinically actionable. Here, we evaluate genetic studies of circulating and excreted biomarkers of vitamin status in the era of hypothesis-free genome-wide association studies (GWAS) that have provided unprecedented insights into the genetic architecture of these traits. We found that the most comprehensive and well-powered GWAS currently available were for circulating status biomarkers of vitamin A, C, D, and a subset of the B vitamins (B9 and B12). The biology implicated by GWAS of measured biomarkers of each vitamin is then discussed, both in terms of key genes and higher-order processes. Across all major vitamins, there were genetic signals revealed by GWAS that could be directly linked with known vitamin biochemistry. We also outline how genetic variants associated with vitamin status biomarkers have been already extensively used to estimate causal effects of vitamins on human health outcomes, which is particularly important given the large number of randomized control trials of vitamin related interventions with null findings. Finally, we discuss the current evidence for the clinical applicability of findings from vitamin GWAS, along with future directions for the field to maximize the utility of these data.

A Comparison of the Efficacy of High-Dose Vitamin C Infusion and Thiamine (Vitamin B1) Infusion in Patients With Sepsis: A Prospective Randomized Controlled Trial

Background and objective Vitamin C and thiamine possess properties that may mitigate the harmful effects of sepsis. However, there is a dearth of studies in the literature comparing these two vitamins with each other and with a placebo regarding their efficacy against sepsis. This study aimed to investigate the outcomes associated with high-dose infusions of vitamin C and thiamine in septic patients, thereby seeking to contribute valuable insights into the optimal management of sepsis. The primary objective was to compare the sequential organ failure assessment (SOFA) score and C-reactive protein (CRP) level improvement on Day Six among the vitamin C, thiamine, and placebo groups after the intervention for five days. Methodology This prospective randomized comparative study involved 75 patients. Patients were randomized into three groups of 25 each. The first group received high-dose vitamin C infusion along with standard treatment for sepsis; the second group received high-dose thiamine infusion along with standard treatment for sepsis; and the third group, the placebo group, received only standard treatment for sepsis for five days. The SOFA score, CRP level, and other parameters were evaluated on Day Six. Results The SOFA score (p=0.043) and CRP level (p=0.0161) on Day Six were lower in the vitamin C group than in the placebo group. The CRP level on Day Six was significantly lower in the thiamine group than in the placebo group (p=0.016). The duration of vasopressor therapy was significantly lower in the vitamin C group than in the placebo group (p=0.0276) and the thiamine group (p=0.0236). Conclusions Based on our findings, vitamin C infusion helps improve the SOFA score and CRP level in sepsis patients. It can also decrease the duration of vasopressor therapy and serious adverse events whereas thiamine can reduce CRP levels in these patients.

Does COVID-19 Trigger the Risk for the Development of Parkinson's Disease? Therapeutic Potential of Vitamin C

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which was proclaimed a pandemic by the World Health Organization (WHO) in March 2020. There is mounting evidence that older patients with multimorbidity are more susceptible to COVID-19 complications than are younger, healthy people. Having neuroinvasive potential, SARS-CoV-2 infection may increase susceptibility toward the development of Parkinson's disease (PD), a progressive neurodegenerative disorder with extensive motor deficits. PD is characterized by the aggregation of α-synuclein in the form of Lewy bodies and the loss of dopaminergic neurons in the dorsal striatum and substantia nigra pars compacta (SNpc) of the nigrostriatal pathway in the brain. Increasing reports suggest that SARS-CoV-2 infection is linked with the worsening of motor and non-motor symptoms with high rates of hospitalization and mortality in PD patients. Common pathological changes in both diseases involve oxidative stress, mitochondrial dysfunction, neuroinflammation, and neurodegeneration. COVID-19 exacerbates the damage ensuing from the dysregulation of those processes, furthering neurological complications, and increasing the severity of PD symptomatology. Phytochemicals have antioxidant, anti-inflammatory, and anti-apoptotic properties. Vitamin C supplementation is found to ameliorate the common pathological changes in both diseases to some extent. This review aims to present the available evidence on the association between COVID-19 and PD, and discusses the therapeutic potential of vitamin C for its better management.

TET2 promotes tumor antigen presentation and T cell IFN-γ, which is enhanced by vitamin C

Immune evasion by tumors is promoted by low T cell infiltration, ineffective T cell activity directed against the tumor, and reduced tumor antigen presentation. The TET2 DNA dioxygenase gene is frequently mutated in hematopoietic malignancies and loss of TET enzymatic activity is found in a variety of solid tumors. We showed previously that vitamin C (VC), a cofactor of TET2, enhances tumor-associated T cell recruitment and checkpoint inhibitor therapy responses in a TET2-dependent manner. Using single-cell RNA sequencing (scRNA-seq) analysis performed on B16-OVA melanoma tumors, we have shown here that an additional function for TET2 in tumors is to promote expression of certain antigen presentation machinery genes, which is potently enhanced by VC. Consistently, VC promoted antigen presentation in cell-based and tumor assays in a TET2-dependent manner. Quantifying intercellular signaling from the scRNA-seq dataset showed that T cell-derived IFN-γ-induced signaling within the tumor and tumor microenvironment requires tumor-associated TET2 expression, which is enhanced by VC treatment. Analysis of patient tumor samples indicated that TET activity directly correlates with antigen presentation gene expression and with patient outcomes. Our results demonstrate the importance of tumor-associated TET2 activity as a critical mediator of tumor immunity, which is augmented by high-dose VC therapy.

Multi-Electrode Extended Gate Field Effect Transistors Based on Laser-Induced Graphene for the Detection of Vitamin C and SARS-CoV-2

Despite the clinical data showing the importance of ascorbic acid (AA or vitamin C) in managing viral respiratory infections, biosensors for their simultaneous detection are lacking. To address this need, we developed a portable and wireless device for simultaneous detection of AA and SARS-CoV-2 virus by integrating commercial transistors with printed laser-induced graphene (LIG) as the extended gate. We studied the effect of laser printing pass number and showed that with two laser printing passes (2-pass LIG), the sensor sensitivity and limit of detection (LOD) for AA improved by a factor of 1.6 and 12.8, respectively. Using complementary characterization methods, we attribute the improved response to a balanced interplay of crystallinity, defect density, surface area, surface roughness, pore density and diameter, and mechanical integrity/stability. These factors enhance analyte transport, reduce noise/variability, and ensure consistent sensor performance, making 2-pass LIG the most effective material in this work. Our sensors exhibit promising performance for detecting AA with a selective response in the presence of common salivary interfering molecules, with sensitivity and LOD of 73.67 mV/dec and 54.04 nM in 1× phosphate buffered saline and 81.05 mV/dec and 78.34 nM in artificial saliva, respectively. We also showed that functionalization of the 2-pass LIG gate with S-protein antibody enables the detection of SARS-CoV-2 protein antigens with an ultralow LOD of 52 zg/mL─an improvement of more than 10-fold compared to 1-pass LIG─and 4 particles/mL for virion mimics with a selective response against influenza virus and multiple human coronavirus strains. With low signal drift/hysteresis and wireless capabilities, the developed device holds great potential for improving at-home monitoring and clinical decision-making.

Fixed-dose combinations in pharmacotherapy of chronic venous diseases

Chronic venous diseases are the most common vascular diseases of the lower extremities, negatively affecting all components of the quality of life in the modern society. Due to their high prevalence, the prevention and treatment of chronic venous diseases are one of the priorities of national healthcare systems in industrially developed countries. In recent years, numerous experimental and clinical studies have uncovered an important role of vascular inflammation and endothelial dysfunction in the pathogenesis of chronic venous diseases, which determine not only a wide range of vein-specific symptoms, but are also the main drivers of pathological remodelling of the vein wall and its valve apparatus, followed by the development of varicose syndrome and more severe chronic venous insufficiency. Modern knowledge of the pathogenesis of chronic venous diseases enables us to identify several priority strategies aimed at managing the basic pathophysiological mechanisms of the development and progression of the disease. Pharmacotherapy with phlebotropic drugs is one of them. Some of these drugs are able to inhibit the vein-specific inflammation, improve the microcirculatory bed regulation, increase the vein tone and contractility and, as a result, have a positive effect on the clinical signs of chronic venous disease. This review presents the mechanism of action of a phlebotropic drug that is new to the Russian Federation. It is a combination of Ruscus aculeatus extract (Ruscus extract) with hesperidin methyl chalcone (HMC) and ascorbic acid. Studies showed a high level of evidence of clinical efficacy and safety of this drug for the treatment of patients with various forms of chronic venous diseases. Due to the unique features of its mechanisms of action, the optimal focus groups for its use may include patients of different age groups with early-stage disease, in which vein-specific symptoms predominate, and patients with chronic venous oedema.

Prospective and challenges of locally applied repurposed pharmaceuticals for periodontal tissue regeneration

Periodontitis is a persistent inflammatory condition that causes periodontal ligament degradation, periodontal pocket development, and alveolar bone destruction, all of which lead to the breakdown of the teeth's supporting system. Periodontitis is triggered by the accumulation of various microflora (especially anaerobes) in the pockets, which release toxic substances and digestive enzymes and stimulate the immune system. Periodontitis can be efficiently treated using a variety of techniques, both regional and systemic. Effective therapy is dependent on lowering microbial biofilm, minimizing or eradicating pockets. Nowadays, using local drug delivery systems (LDDSs) as an adjuvant therapy to phase I periodontal therapy is an attractive option since it controls drug release, resulting in improved efficacy and lesser adverse reactions. Choosing the right bioactive agent and mode of delivery is the foundation of an efficient periodontal disease management approach. The objective of this paper is to shed light on the issue of successful periodontal regeneration, the drawbacks of currently implemented interventions, and describe the potential of locally delivered repurposed drugs in periodontal tissue regeneration. Because of the multiple etiology of periodontitis, patients must get customized treatment with the primary goal of infection control. Yet, it is not always successful to replace the lost tissues, and it becomes more challenging as the defect gets worse. Pharmaceutical repurposing offers a viable, economical, and safe alternative for non-invasive, and predictable periodontal regeneration. This article clears the way in front of researchers, decision-makers, and pharmaceutical companies to explore the potential, effectiveness, and efficiency of the repurposed pharmaceuticals to generate more economical, effective, and safe topical pharmaceutical preparations for periodontal tissue regeneration.

Short-Peptide-Modified Copper Nanoclusters as a Fluorescent Probe for the Specific Detection of Ascorbic Acid

Metal nanoclusters assembled using short peptides as templates exhibit significant potential for development and application in the fields of catalysis and biomedicine, owing to their distinctive electronic structure, favorable optical properties, and biocompatibility. Among them, tripeptides exhibit a simpler structure and greater flexibility, enabling them to readily co-assemble with other functional components to create novel materials with significant application value. They can be assembled with copper ions to synthesize highly efficient luminescent nanoclusters, which can serve as an effective fluorescent probe. Here, we report a method for the synthesis of copper nanoclusters (Cu NCs) using tripeptides as templates, which also act as stabilizers and reducing agents. The synthesis conditions and properties were explored and optimized. Under optimal conditions, the Cu NCs exhibit excellent stability and are strongly fluorescent. The Cu NCs can detect 0.1-1.0 μmol/L of ascorbic acid with a low detection limit of 0.075 μmol/L, demonstrating high sensitivity and offering significant application potential for the trace of ascorbic acid in various substances. It also provides new ideas for the assembly of metal nanoclusters and the construction of fluorescent probe sensing platforms.

Transport of dehydroascorbic acid by glucose transporters GLUTs

Vitamin C is a crucial water-soluble antioxidant and an essential cofactor for enzymes like proline and lysine hydroxylases, playing a vital role in cellular physiology. While sodium-dependent ascorbate co-transporters (SVCT1 and SVCT2) are pivotal for vitamin C absorption and bioavailability, dehydroascorbic acid transporters within the facilitative glucose transporter (GLUT) family complement these functions and are relevant in various cellular, tissue-specific, or pathological contexts. This review focuses on comparing the structural and functional characteristics of GLUTs involved in glucose, dehydroascorbic acid and other substrate transport. It also presents evidence of the physiological and pathophysiological roles of dehydroascorbic acid transporters. Improved understanding of these transporters has the potential to advance strategies for preventing, diagnosing, and treating prevalent diseases such as cancer.

Hypertrophic cardiomyopathy-associated mutations drive stromal activation via EGFR-mediated paracrine signaling

Hypertrophic cardiomyopathy (HCM) is characterized by thickening of the left ventricular wall, diastolic dysfunction, and fibrosis, and is associated with mutations in genes encoding sarcomere proteins. While in vitro studies have used human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to study HCM, these models have not examined the multicellular interactions involved in fibrosis. Using engineered cardiac microtissues (CMTs) composed of HCM-causing MYH7-variant hiPSC-CMs and wild-type fibroblasts, we observed cell-cell cross-talk leading to increased collagen deposition, tissue stiffening, and decreased contractility dependent on fibroblast proliferation. hiPSC-CM conditioned media and single-nucleus RNA sequencing data suggested that fibroblast proliferation is mediated by paracrine signals from MYH7-variant cardiomyocytes. Furthermore, inhibiting epidermal growth factor receptor tyrosine kinase with erlotinib hydrochloride attenuated stromal activation. Last, HCM-causing MYBPC3-variant CMTs also demonstrated increased stromal activation and reduced contractility, but with distinct characteristics. Together, these findings establish a paracrine-mediated cross-talk potentially responsible for fibrotic changes observed in HCM.

Case report: The efficacy of adding high doses of intravenous vitamin C to the combination therapy of atezolizumab and bevacizumab in unresectable HCC

Introduction

Vitamin C (L-ascorbic acid) plays a vital role in human physiology, serving as both an antioxidant and a cofactor in enzymatic reactions. High-dose intravenous Vitamin C can achieve significantly elevated plasma concentrations, potentially enhancing its anticancer effects. This case study explores the synergistic impact of high-dose intravenous vitamin C in combination with bevacizumab and atezolizumab in the treatment of a patient with unresectable hepatocellular carcinoma (HCC).

Case presentation

A 68-year-old male was diagnosed with unresectable HCC, presenting with elevated liver enzymes and an alpha-fetoprotein (AFP) level of 2018 ng/mL. Initial treatment with atezolizumab and Bevacizumab commenced in February 2022. Although imaging indicated stable disease, AFP levels decreased modestly to 1,526 ng/mL, while liver function tests remained elevated, accompanied by further clinical deterioration and weight loss. Subsequently, intravenous vitamin C (30 grams) was introduced into the treatment regimen. This addition led to a rapid and significant reduction in AFP levels, normalization of liver function tests, and marked improvement in clinical symptoms. The patient continued on this combined regimen of vitamin c, atezolizumab, and bevacizumab. Four months later, CT scans revealed significant tumor shrinkage and necrosis. As of 30 months post-diagnosis, the patient remains on the regimen with normal liver function and an AFP level of 1.8 ng/mL, maintaining normal activities and stable weight.

Conclusion

To our knowledge, this is the first reported case of combining high-dose intravenous vitamin C with Bevacizumab and atezolizumab, which proved to be safe and resulted in significant clinical and radiological improvements in unresectable hepatocellular carcinoma (HCC). Further studies are recommended to explore the potential of this combination therapy.

Effect of orange pulp with or without zeolite on productive performance, nitrogen utilization, and antioxidative status of growing rabbits

The current study was designed to investigate the effect of dried orange pulp inclusion (OP diet), natural zeolite addition (Z diet), or both (OPZ diet) compared to control (CON diet) on digestibility, growth performance, nitrogen utilization, blood biochemical, antioxidative status, and cecum microbiota of growing rabbits. Seventy-two V-line male rabbits (6 weeks old) were divided into 4 balanced experimental groups. Results showed that administration of dried orange pulp or zeolite especially the OPZ diet significantly improved nutrient digestibility and nutritive values. Rabbits fed the experimental diets (OP, Z, or OPZ) recorded significantly higher values of average daily gain, N-retention, and N-balance compared with those fed the CON diet. Data on blood biochemical, showed non-significant differences in globulin concentrations, and significant decreases in levels of cholesterol, LDL (low-density lipoproteins), triglycerides, and MDA (malondialdehyde) as an antioxidant biomarker with OP, Z, or OPZ diets. Moreover, the incorporation of orange pulp or zeolite in diets significantly decreased the cecal count of E. coli, with no significant difference in total bacterial count among the experimental groups. It could be concluded that a combination between dried orange pulp and natural zeolite in the diet can enhance the growth performance, antioxidant and health status of rabbits.

Vitamin C as a functional enhancer in the non-specific immune defense, antioxidant capacity and resistance to low-temperature stress of juvenile mud crab, Scylla paramamosain

This experiment was conducted to explore the effects of dietary vitamin C supplementation on non-specific immune defense, antioxidant capacity and resistance to low-temperature stress of juvenile mud crab (Scylla paramamosain). Mud crabs with an initial weight of 14.67 ± 0.13 g were randomly divided into 6 treatments and fed diets with 0.86 (control), 44.79, 98.45, 133.94, 186.36 and 364.28 mg/kg vitamin C, respectively. The experiment consisted of 6 treatments, each treatment was designed with 4 replicates and each replicate was stocked with 8 crabs. After 42 days of feeding experiment, 2 crabs were randomly selected from each replicate, and a total of 8 crabs in each treatment were carried out 72 h low-temperature challenge experiment. The results showed that crabs fed diets with 186.36 and 364.28 mg/kg vitamin C significantly improved the activities of alkaline phosphatase (AKP) and acid phosphatase (ACP) in hemolymph and hepatopancreas (P < 0.05). Crabs fed diet with 133.94 mg/kg vitamin C significantly decreased the concentration of nitric oxide (NO) and the activity of nitric oxide synthase (NOS) in hemolymph (P < 0.05). Diet with 133.94 mg/kg vitamin C was improved the activity of polyphenol oxidase (PPO) and the concentration of albumin (ALB) in hemolymph. Crabs fed diet with 133.94 mg/kg vitamin C showed lower concentration of malondialdehyde (MDA) in hemolymph and hepatopancreas than those fed the other diets. Meanwhile, crabs fed diet with 98.45 mg/kg vitamin C showed higher activity of total superoxide dismutase (T-SOD) in hemolymph, and crabs fed diet with 133.94 mg/kg vitamin C showed higher activity of T-SOD in hepatopancreas. Crabs fed diet with 186.36 mg/kg vitamin C significantly decreased the concentration of reduced glutathione (GSH) and the activity of glutathione peroxidase (GSH-PX) in hepatopancreas (P < 0.05). In normal temperature, crabs fed diets with 133.94 mg/kg vitamin C significantly up-regulated the expression levels of gpx (glutathione peroxidase) and trx (thioredoxin) in hepatopancreas compared with the control treatment (P < 0.05). The highest expression levels of relish, il16 (interleukin 16), caspase 2 (caspase 2), p38 mapk (p38 mitogen-activated protein kinases) and bax (bcl-2 associated x protein) in hepatopancreas were found at crabs fed control diet (P < 0.05). Moreover, crabs fed diet with 133.94 mg/kg vitamin C showed higher expression levels of alf-3 (anti-lipopolysaccharide factor 3) and bcl-2 (B-cell lymphoma 2) in hepatopancreas than those fed the other diets (P < 0.05). Under low-temperature stress, crabs fed diet with 133.94 mg/kg vitamin C significantly improved the expression levels of hsp90 (heat shock protein 90), cat (catalase), gpx, prx (thioredoxin peroxidase) and trx in hepatopancreas (P < 0.05). In addition, dietary with 133.94 vitamin C significantly up-regulated the expression levels of alf-3 and bcl-2 (P < 0.05). Based on two slope broken-line regression analysis of activity of PPO against the dietary vitamin C level, the optimal dietary vitamin C requirement was estimated to be 144.81 mg/kg for juvenile mud crab. In conclusion, dietary 133.94-144.81 mg/kg vitamin C significantly improved the non-specific immune defense, antioxidant capacity and resistance to low-temperature stress of juvenile mud crab.

Exploring the potential of selenium nanoparticles and fabricated selenium nanoparticles @vitamin C nanocomposite in mitigating nicotine-induced testicular toxicity in rats

Background

The tobacco epidemic signifies a major public health threat. Nicotine (NIC), a major active constituent in tobacco, impedes male fertility and semen quality. This work is implemented to explore the potential of selenium nanoparticles (SeNPs) and the newly fabricated SeNPs @vitamin C (SeNPs@VITC) nanocomposite in mitigating testicular toxicity induced by NIC.

Materials and methods

The six groups of 48 adult Wistar rats were designed as follows: the control group injected intraperitoneally with normal saline, the SeNPs group treated orally with 2 mg/kg of SeNPs, the SeNPs@VITC nanocomposite group treated orally with 2 mg/kg of SeNPs@VITC nanocomposite, the NIC group injected intraperitoneally with 1.25 mL/kg of NIC, the NIC+ SeNPs group received SeNPs plus NIC, and the NIC+ SeNPs@VITC nanocomposite group received SeNPs@VITC nanocomposite plus NIC. Treatments were administered over a 28-day period.

Results

NIC treatment significantly caused poor sperm quality, decreased serum testosterone, increased follicle-stimulating hormone (FSH), luteinizing hormone (LH) concentrations, reduced hemoglobin levels, leukocytosis, disrupted testicular oxidant/antioxidant balance, and disorganized testicular structure. The construction of the novel SeNPs@VITC nanocomposite, compared to NIC plus SeNPs alone, demonstrated a more potent ameliorative effect on NIC-induced reproductive toxicity in adult rats. The SeNPs@VITC nanocomposite significantly increased sperm count, reduced the percentage of sperm head abnormalities, lowered both serum FSH and LH concentrations, and improved the hemoglobin response.

Conclusions

Both SeNPs and SeNPs@VITC nanocomposite alleviated the testicular toxicity induced by NIC, but the SeNPs@VITC nanocomposite exhibited superior efficacy. The SeNPs@VITC nanocomposite could be employed to advance enhanced therapeutic strategies for addressing male infertility.

New randomized controlled trials on micronutrients in critical care nutrition: A narrative review

There has been increasing interest in the role of micronutrient supplementation in critical care. This narrative review summarizes the recent studies on micronutrients in critically ill patients. We searched two databases for primary randomized controlled trials that investigated the effects of micronutrient supplementation in patients with critical illness published from January 2021 to August 2023. Personal files, reference lists of included studies, and previous reviews were also screened. Twelve studies reported on vitamin C, four studies on vitamin D, three studies on thiamin, two studies on multivitamins, and one study on cobalamin. The therapeutic effects of vitamin C appear mixed, although vitamin C monotherapy appears more promising than vitamin C combination therapy. Intramuscular administration of vitamin D appeared to lower mortality, mechanical ventilation duration, and intensive care unit stay, whereas enteral administration showed limited clinical benefits. Intravenous thiamin was not associated with improved outcomes in patients with septic shock or hypophosphatemia. Preliminary evidence suggests reduced vasopressor dose with cobalamin. Decreased disease severity and hospital stay in patients with COVID-19 with vitamins A-E requires further investigation, whereas providing solely B-group vitamins did not demonstrate therapeutic effects. It is currently premature to endorse the provision of high-dose micronutrients in critical illness to improve clinical outcomes. This review may help to inform the design of future trials that will help better elucidate the optimal dosage and form of micronutrients, methods of administration, and subgroups of patients with critical illness who may most benefit.

Is Micronutrient Supplementation Helpful in Supporting the Immune System during Prolonged, High-Intensity Physical Training?

It is well known that during prolonged, high-intensity physical training, athletes experience a state of immunosuppression and that balanced nutrition can help maintain immunity. This review summarizes the effects (amplified by virus infection) of high-intensity, long-term exercise on immunity, critically presenting key micronutrients and supplementation strategies that can influence athletes' performance and their immune system. The main conclusion is that micronutrient supplementation with diet could help to protect the immune system from the stress effects induced by intense physical activities. The importance of personalized supplementation has been also recommended.

Vitamin C deficiency after kidney transplantation: a cohort and cross-sectional study of the TransplantLines biobank

PURPOSE

Vitamin C deficiency is associated with excess mortality in kidney transplant recipients (KTR). We aim to evaluate plasma vitamin C status at different post-transplantation moments and assess the main characteristics associated with vitamin C deficiency in KTR.

METHODS

Plasma vitamin C was assessed in 598 KTR at 3-, 6-, 12-, 24-, and 60-months post-transplantation, 374 late KTR with a functioning graft ≥ 1 year, and 395 potential donors. Vitamin C deficiency was defined as plasma vitamin C ≤ 28 µmol/L. Diet was assessed by a 177-item food frequency questionnaire. Data on vitamin C-containing supplements use were extracted from patient records and verified with the patients.

RESULTS

Vitamin C deficiency ranged from 46% (6-months post-transplantation) to 30% (≥ 1 year post-transplantation). At all time points, KTR had lower plasma vitamin C than potential donors (30-41 µmol/L vs 58 µmol/L). In cross-sectional analyses of the 953 KTR at their first visit ≥ 12 months after transplantation (55 ± 14 years, 62% male, eGFR 55 ± 19 mL/min/1.73 m2), the characteristics with the strongest association with vitamin C deficiency were diabetes and smoking (OR 2.67 [95% CI 1.84-3.87] and OR 1.84 [95% CI 1.16-2.91], respectively). Dietary vitamin C intake and vitamin C supplementation were associated with lower odds (OR per 100 mg/day 0.38, 95% CI 0.24-0.61 and OR 0.21, 95% CI 0.09-0.44, respectively).

CONCLUSION

Vitamin C deficiency is frequent among KTR regardless of the time after transplantation, especially among those with diabetes and active smokers. The prevalence of vitamin C deficiency was lower among KTR with higher vitamin C intake, both dietary and supplemented. Further research is warranted to assess whether correcting this modifiable risk factor could improve survival in KTR.

Protected biofactors and antioxidants reduce the negative consequences of virus and cold challenge by modulating immunometabolism via changes in the interleukin-6 receptor signaling cascade in the liver

Protected biofactors and antioxidants (PBA), and protected biofactors and antioxidants with protected organic acids and essential oils (PBA+POAEO) have been shown to have benefits in stressed or challenged birds. Here, we describe the immunometabolic changes observed in the liver of Ross 308 broilers during feed supplementation and brief physiological stress. These studied additives contain protected essential oils, organic acids, and vitamins which may have protective effects on the liver. Thus, we aimed to determine the signaling changes induced by these supplements and the resultant immunometabolic effects in the liver. All birds received a 2X dose of live bronchitis vaccine at d 0 and a 48-h cold challenge by reducing the temperature from 30 to 32°C, to 20 to 23°C on d 3 to 5. Control birds were fed a standard diet without supplementation. Liver samples were collected to evaluate the effects of these treatments on cytokine gene expression and protein phosphorylation via kinome peptide array. ANOVA was used for statistical analysis of the gene expression data (significance at a p-value of 0.05), and PIIKA2 was used for statistical evaluation and comparative analysis of the kinome peptide array data. At d 15, the kinome peptide array analysis and gene expression data showed stimulation of the interleukin 6 receptor (IL-6R) signal transduction for host protection via heightened immune response while inducing immune modulation and reducing inflammation in both supplement treated groups. Significant changes were observed via IL-6R signaling in the metabolic profiles of both groups compared to control and no significant differences when compared to each other. In the liver, these 2 feed additives induced immunometabolic changes predominantly via the IL-6 receptor family signaling cascade. Differences between the 2 treated groups were predominantly in the metabolic pathways, centered around the mTOR pathway and the proteins AMPK, mTOR and S6K, with a more anabolic phenotype following the addition of essential oils.