Impact of high dose vitamin C on platelet function

Mucosal bleeding while on venovenous extracorporeal membrane oxygenation in the setting of vitamin C deficiency

A major complication with extracorporeal membrane oxygenation (ECMO) is bleeding which can occur in up to 40% of cases and can be life-threatening. Minor bleeding may be overlooked and under-reported. While some of the underlying mechanisms such as platelet injury and anticoagulation therapy have been identified, several other factors are still under-researched. Here, we describe a unique case of a subtle mucosal membrane bleeding that is found to be associated with vitamin C deficiency while on treatment with ECMO. Investigating vitamin C levels may be useful in understanding causes of bleeding in some patients on ECMO therapy, particularly if there are risk factors for malnutrition.

Abdominal Ecchymosis: Emergency, or Urgen-C?

Scurvy is a multisystem disease caused by vitamin C deficiency, historically associated with lethargy, gingivitis, ecchymosis, edema, and death if left untreated. Contemporary socioeconomic risk factors for scurvy include smoking, alcohol abuse, fad diets, mental health conditions, social isolation, and economic marginalization. Food insecurity is also a risk factor. This report describes a case of a man in his 70s who presented with unexplained dyspnea, abdominal pain, and abdominal ecchymosis. His plasma vitamin C level was undetectable, and he improved with vitamin C supplementation. This case highlights the significance of awareness of these risk factors and emphasizes the need for a comprehensive social and dietary history to enable the timely treatment of this rare but potentially fatal disease.

Regulation of Human Platelet Adhesion with Ascorbic Acid

Morphofunctional characteristics of human platelets in the presence of 0.1-5 mM ascorbic acid were studied. The platelet ability to form lamellae and the preservation of granules in platelets in suspension and during adhesion were evaluated. Ascorbic acid in concentrations of 0.1-1 mM induced no visible changes in platelet structure and did not affect their adhesion activity, but suppressed lamella growth and degranulation in adherent platelets in a dose-dependent manner. The maximum preservation of granules was revealed in the presence of 0.5 mM ascorbic acid (55% in 1 h from the moment of adhesion). In the presence of 2-5 mM ascorbic acid, spontaneous activation and degranulation of platelets was observed. Thus, ascorbic acid is capable of both suppressing and stimulating platelet activity. In concentrations of 0.5-1 mM ascorbic acid can be used to stabilize granules in adherent platelets.

Vitamin C and the management of diabetic foot ulcers: a literature review

OBJECTIVE

The lifetime risk of developing a diabetic foot ulcer (DFU) in people with diabetes is as high as 25%. A trio of factors constitute the diabetic foot syndrome that characterises DFUs, including neuropathy, vascular disease and infections. Vitamin C has important functions in the nervous, cardiovascular, and immune systems that are implicated in DFU development. Furthermore, vitamin C deficiency has been observed in individuals with DFUs, suggesting an important function of vitamin C in DFU management and treatment. Therefore, this literature review evaluates the role of vitamin C in the nervous, cardiovascular and immune systems in relation to wound healing and DFUs, as well as discussing vitamin C's lesser known role in depression, a condition that affects many individuals with a DFU.

METHOD

A literature search was done using PubMed, Cochrane Library, Embase, Ovid, Computer Retrieval of Information on Scientific Projects, and NIH Clinical Center. Search terms included 'diabetic foot ulcer,' 'diabetic foot,' 'vitamin C,' and 'ascorbic acid.'

RESULTS

Of the 71 studies initially identified, seven studies met the inclusion criteria, and only three were human clinical trials. Overall, the literature on this subject is limited, with mainly observational and animal studies, and few human clinical trials.

CONCLUSION

There is a need for additional human clinical trials on vitamin C supplementation in individuals with a DFU to fill the knowledge gap and guide clinical practice.

Catha edulis Forsk and Ascorbic Acid Effects on Hematological Indices in Rat

BACKGROUND

The prevalence of chewing Catha edulis Forsk and the use of ascorbic acid is increasing from time to time. Their subchronic effects on hematological indices are not well examined. The present study was aimed to investigate their subchronic effects on hematological indices in rats.

MATERIALS AND METHODS

A total of 36 adult (7-8 weeks) wild-type rats weighing between 213 and 229g were used in this study. They received Catha edulis Forsk extract (Ce) (100 milligrams/kilogram, 200 milligram/kilogram and 300 milligram/kilogram b.w), Catha edulis Forsk juice (2.5 mL/kg), ascorbic acid (AA 200 milligram/kilogram), and 2% tween 80 in distilled water (T80W- v/v) for twelve weeks. Hematological indices were measured with Sysmex KX-21. Data were analyzed by SPSS version 21.0 and Microsoft Excel.

RESULTS

Neutrocytes (p < 0.01), lymphocytes (p < 0.05), plateletcrit (p < 0.05), average size of platelets (p < 0.05), platelet size variability (p < 0.01), platelet-large cell ratio (p < 0.05) and neutrocytes/lymphocytes ratio (p < 0.001) were significantly greater, while hemoglobin concentration per red blood cell (p < 0.05) and hemoglobin concentration per volume of red blood cells were significantly reduced (p < 0.05) in rats received khat. The red cell distribution width (p < 0.05), platelet size variability (p < 0.05) and platelet-large cell ratio (p < 0.01) were significantly greater in rats received ascorbic acid.

CONCLUSION

Crude Catha edulis Forsk extract and juice changed some hematological indices and increased platelet activities. The platelet activity was also increased by ascorbic acid. The mechanisms for these changes need to be investigated.

L-Ascorbic Acid Shapes Bovine Pasteurella multocida Serogroup A Infection

Bovine Pasteurella multocida serogroup A (bovine PmA) is one of the most important pathogens causing fatal pneumonia in cattle. However, it is largely unknown how nutrition shapes bovine PmA infection. Here, we discovered that the infected lung held the highest bacterial density than other tissues during infection. By screening the different metabolites between high (lung)- and low (liver)-bacterial density tissues, the present work revealed that L-ascorbic acid and L-aspartic acid directly influenced bovine P. multocida growth. Interestingly, L-ascorbic acid, which is expressed at higher levels in the infected livers, inhibited bovine PmA growth as well as virulence factor expression and promoted macrophage bactericidal activity in vitro. In addition, ascorbic acid synthesis was repressed upon bovine PmA infection, and supplementation with exogenous L-ascorbic acid significantly reduced the bacterial burden of the infected lungs and mouse mortality. Collectively, our study has profiled the metabolite difference of the murine lung and liver during bovine PmA infection. The screened L-ascorbic acid showed repression of bovine PmA growth and virulence expression in vitro and supplementation could significantly increase the survival rate of mice and reduce the bacterial load in vivo, which implied that L-ascorbic acid could serve as a potential protective agent for bovine PmA infection in clinic.

The potential of red dragon fruit peel yogurt to improve platelet levels in heparin-induced thrombocytopenia in Wistar rats

Patients infected with the dengue virus will develop thrombocytopenia which can cause bleeding and complications. One of the materials that contain antioxidants and have potential as a functional food is red dragon fruit peel. This peel can be processed into yogurt as a way to increase antioxidant function which ultimately supports the immune system of its users. This study analyzed the effect of red dragon fruit peel yogurt on the platelet levels of thrombocytopenic Wistar rats. It used a pre-post-test control group design. Male Wistar rats were randomly assigned into seven groups: K-; K+; and five treatment groups that received dragon fruit peel yogurt at doses of 5% (K1); 10% (K2); 15% (K3); 20% (K4); and 25% (K5). Thrombocytopenia was induced by 0.1 mL.100g-1 BW of heparin for 3 days. The intervention was carried out for 28 days. The result showed that all groups had significant differences before and after the intervention (p <0.05). Tukey analysis showed that there were significant differences in all groups (p <0.05). Yogurt containing 25% red dragon fruit peel provides an effective dose for improving platelet levels in thrombocytopenic rats.

The Emerging Role of Vitamin C as a Treatment for Sepsis

Sepsis, a life-threatening organ dysfunction due to a dysregulated host response to infection, is a leading cause of morbidity and mortality worldwide. Decades of research have failed to identify any specific therapeutic targets outside of antibiotics, infectious source elimination, and supportive care. More recently, vitamin C has emerged as a potential therapeutic agent to treat sepsis. Vitamin C has been shown to be deficient in septic patients and the administration of high dose intravenous as opposed to oral vitamin C leads to markedly improved and elevated serum levels. Its physiologic role in sepsis includes attenuating oxidative stress and inflammation, improving vasopressor synthesis, enhancing immune cell function, improving endovascular function, and epigenetic immunologic modifications. Multiple clinical trials have demonstrated the safety of vitamin C and two recent studies have shown promising data on mortality improvement. Currently, larger randomized controlled studies are underway to validate these findings. With further study, vitamin C may become standard of care for the treatment of sepsis, but given its safety profile, current treatment can be justified with compassionate use.

The impact of bilirubin ditaurate on platelet quality during storage

Bilirubin ditaurate (BRT), a conjugated bilirubin analogue, has demonstrated anti-platelet characteristics following acute ex vivo exposure. Scavenging of mitochondrial superoxide and attenuation of granule exocytosis suggested a potential benefit for including BRT for storage. With no reports of cytotoxicity following acute exposure, the impact of 35µM BRT on platelet function was investigated, in clinically suppled units, for up to seven days. Exposure to 35µM BRT significantly reduced mitochondrial membrane potential and increased glucose consumption until exhaustion after 72 hours. Platelet aggregation and activation was significantly impaired by BRT. Mitochondrial superoxide production and phosphatidylserine expression were significantly elevated following glucose exhaustion, with decreased viability observed from day five onwards. Lactate accumulation and loss of bicarbonate, support a metabolic disturbance, leading to a decline of quality following BRT inclusion. Although acute ex vivo BRT exposure reported potentially beneficial effects, translation from acute to chronic exposure failed to combat declining platelet function during storage. BRT exposure resulted in perturbations of platelet quality, with the utility of BRT during storage therefore limited. However, these are the first data of prolonged platelet exposure to analogues of conjugated bilirubin and may improve our understanding of platelet function in the context of conjugated hyperbilirubinemia.

Acute bilirubin ditaurate exposure attenuates ex vivo platelet reactive oxygen species production, granule exocytosis and activation

Background

Bilirubin, a by-product of haem catabolism, possesses potent endogenous antioxidant and platelet inhibitory properties. These properties may be useful in inhibiting inappropriate platelet activation and ROS production; for example, during storage for transfusion. Given the hydrophobicity of unconjugated bilirubin (UCB), we investigated the acute platelet inhibitory and ROS scavenging ability of a water-soluble bilirubin analogue, bilirubin ditaurate (BRT) on ex vivo platelet function to ascertain its potential suitability for inclusion during platelet storage.

Methods

The inhibitory potential of BRT (10–100 μM) was assessed using agonist induced platelet aggregation, dense granule exocytosis and flow cytometric analysis of P-selectin and GPIIb/IIIa expression. ROS production was investigated by analysis of H₂DCFDA fluorescence following agonist simulation while mitochondrial ROS production investigated using MitoSOX™ Red. Platelet mitochondrial membrane potential and viability was assessed using TMRE and Zombie Green™ respectively.

Results

Our data shows ≤35 μM BRT significantly inhibits both dense and alpha granule exocytosis as measured by ATP release and P-selectin surface expression, respectively. Significant inhibition of GPIIb/IIIa expression was also reported upon ≤35 μM BRT exposure. Furthermore, platelet exposure to ≤10 μM BRT significantly reduces platelet mitochondrial ROS production. Despite the inhibitory effect of BRT, platelet viability, mitochondrial membrane potential and agonist induced aggregation were not perturbed.

Conclusions

These data indicate, for the first time, that BRT, a water-soluble bilirubin analogue, inhibits platelet activation and reduces platelet ROS production ex vivo and may, therefore, may be of use in preserving platelet function during storage.

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The impact of conjugated bilirubin on platelet function has not been investigated to date.

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Bilirubin ditaurate (BDT) is a water-soluble analogue of conjugated bilirubin.

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BDT attenuates ex vivo platelet activation and ROS generation.

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Conjugated forms of bilirubin might inhibit platelet activation during storage.

Potential Role of Vitamin C Intracoronary Administration in Preventing Cardiac Injury After Primary Percutaneous Coronary Intervention in Patients with ST-Elevation Myocardial Infarction

Objective:

The aim of the present study was to determine the effects of intravenous (IV) and intracoronary administration of Vitamin C on the incidence of periprocedural myocardial injury in patients undergoing primary percutaneous coronary intervention (PCI).

Methods:

In this prospective, double-blind, randomized clinical trial, that was conducted in Tehran Heart Center, Iran, between October 2016 and March 2017, 252 patients undergoing primary PCI were enrolled to receive either 3 g of IV Vitamin C before PCI and 100 mg of intracoronary Vitamin C during PCI in addition to the routine treatment (n = 126) or just the routine treatment (n = 126). Cardiac biomarkers were measured before and then 6 and 12 h postprocedurally. We determined the occurrence of contrast-induced acute kidney injury (CI-AKI), according to the levels of serum creatinine, neutrophil gelatinase-associated lipocalin, and platelet activation biomarker (P-selectin) in a subset of 119 patients before and 6 h after PCI.

Findings:

In the patients who received Vitamin C, the serum levels of troponin T after 12 h and creatine kinase-MB after 6 h were significantly lower than those in the placebo group (P = 0.003 andP = 0.00, respectively). CI-AKI occurred in 6 (4.7%) patients in the study group and 8 (6.3%) patients in the control group; there was no significant reduction in CI-AKI in the study group. In addition, the two groups were statically similar as regards the changes in the level of P-selectin.

Conclusion:

In primary PCI patients, the prophylactic use of IV and intracoronary Vitamin C can confer additional clinical benefits such as cardioprotection.

Lipidomics in translational research and the clinical significance of lipid-based biomarkers

Lipidomics is a rapidly developing field of study that focuses on the identification and quantitation of various lipid species in the lipidome. Lipidomics has now emerged in the forefront of scientific research due to the importance of lipids in metabolism, cancer, and disease. Using both targeted and untargeted mass spectrometry as a tool for analysis, progress in the field has rapidly progressed in the last decade. Having the ability to assess these small molecules in vivo has led to better understanding of several lipid-driven mechanisms and the identification of lipid-based biomarkers in neurodegenerative disease, cancer, sepsis, wound healing, and pre-eclampsia. Biomarker identification and mechanistic understanding of specific lipid pathways linked to a disease's pathologies can form the foundation in the development of novel therapeutics in hopes of curing human disease.

Reductive Stress in Inflammation-Associated Diseases and the Pro-Oxidant Effect of Antioxidant Agents

Abstract: Reductive stress (RS) is the counterpart oxidative stress (OS), and can occur in response to conditions that shift the redox balance of important biological redox couples, such as the NAD⁺/NADH, NADP⁺/NADPH, and GSH/GSSG, to a more reducing state. Overexpression of antioxidant enzymatic systems leads to excess reducing equivalents that can deplete reactive oxidative species, driving the cells to RS. A feedback regulation is established in which chronic RS induces OS, which in turn, stimulates again RS. Excess reducing equivalents may regulate cellular signaling pathways, modify transcriptional activity, induce alterations in the formation of disulfide bonds in proteins, reduce mitochondrial function, decrease cellular metabolism, and thus, contribute to the development of some diseases in which NF-κB, a redox-sensitive transcription factor, participates. Here, we described the diseases in which an inflammatory condition is associated to RS, and where delayed folding, disordered transport, failed oxidation, and aggregation are found. Some of these diseases are aggregation protein cardiomyopathy, hypertrophic cardiomyopathy, muscular dystrophy, pulmonary hypertension, rheumatoid arthritis, Alzheimer's disease, and metabolic syndrome, among others. Moreover, chronic consumption of antioxidant supplements, such as vitamins and/or flavonoids, may have pro-oxidant effects that may alter the redox cellular equilibrium and contribute to RS, even diminishing life expectancy.