Antihistamine Effect of Supplemental Ascorbic Acid and Neutrophil Chemotaxis

Unwinding the potentials of vitamin C in COVID-19 and other diseases: An updated review

Background: The discovery of vitamin C (ascorbic acid) is related to the ancient history of persistent research on the origins of the haemorrhagic disease scurvy. Vitamin C is an important nutrient that aids in a variety of biological and physiological processes. Scientists have been researching the function of vitamin C in the prevention and ailment of sepsis and pneumonia for decades. This has created a potential platform for applying these results to individuals suffering from severe coronavirus infection (COVID-19). Vitamin C's ability to activate and enhance the immune system makes it a promising treatment in the present COVID-19 pandemic. Vitamin C also aids in the activation of vitamin B, the production of certain neurotransmitters, and the transformation of cholesterol into bile acids. Hence, vitamin C is used for the treatment of many diseases. Aim: This review highlights the Vitamin C investigations that are performed by various researchers on patients with COVID 19 infection, the clinical studies and their observations. The authors have additionally updated information on the significance of vitamin C insufficiency, as well as its relevance and involvement in diseases such as cancer, wound healing, iron deficiency anaemia, atherosclerosis and neurodegenerative disorders. Here, we discuss them with the references. Methods: The method used in order to perform literature search was done using SciFinder, PubMed and ScienceDirect. Results: There is a potential role of vitamin C in various diseases including neurodegenerative disorders, COVID-19 and other diseases and the results are highlighted in the review with the help of clinical and preclinical data. Conclusion: More research on vitamin C and the undergoing clinical trials might prove a potential role of vitamin C in protecting the population from current COVID-19 pandemic.

The Complex Interplay between Immunonutrition, Mast Cells, and Histamine Signaling in COVID-19

There is an ongoing need for new therapeutic modalities against SARS-CoV-2 infection. Mast cell histamine has been implicated in the pathophysiology of COVID-19 as a regulator of proinflammatory, fibrotic, and thrombogenic processes. Consequently, mast cell histamine and its receptors represent promising pharmacological targets. At the same time, nutritional modulation of immune system function has been proposed and is being investigated for the prevention of COVID-19 or as an adjunctive strategy combined with conventional therapy. Several studies indicate that several immunonutrients can regulate mast cell activity to reduce the de novo synthesis and/or release of histamine and other mediators that are considered to mediate, at least in part, the complex pathophysiology present in COVID-19. This review summarizes the effects on mast cell histamine of common immunonutrients that have been investigated for use in COVID-19.

Vitamin supplementation as a potential adjunctive therapeutic approach for COVID-19: biological and clinical plausibility

The recent pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus Disease 2019 (COVID-19) has introduced itself into the human population in the 21st century after the coronavirus diseases SARS-CoV and Middle East respiratory syndrome (MERS-CoV). Major investigations are underway worldwide in the search for pharmaceutical interventions for COVID-19 and many agents are administered in off-label routes. Several cases are under study to check or restrict clinical manifestations of COVID-19. According to the fact that the efficacy of some micro-nutrients like vitamins is proven to treat or prevent infectious diseases because of their antimicrobial and immunomodulatory activity, the potential role of vitamins in the COVID-19 treatment or prevention must be considered.

Common anti-oxidant vitamin C as an anti-infective agent with remedial role on SARS-CoV-2 infection. An update

Coronavirus disease -2019 (COVID-19) has led to a worldwide multifaceted crisis. The medical world agonizes to contend with the problem, but a string of tested medications has been proven unavailing. Vitamin C is well described as a salutary antioxidant and some trials conclude that it may be a potential antiviral drug. In high doses, Vitamin C can alternate crucial steps in the pathogenesis of sepsis and acute respiratory distress syndrome. This dynamic was the driving force behind trials around the world that tried immunonutrition as a weapon against clinical entities. We summarize the mechanisms of action of Vitamin C and its role against infections and the current literature referring to the potential role of Vitamin C in SARS-CoV-2 infection, also as a contingent treatment agent.

Effects of Citrus Fruit Juices and Their Bioactive Components on Inflammation and Immunity: A Narrative Review

The immune system provides defence to the host against pathogenic organisms. A weak immune system increases susceptibility to infections and allows infections to become more severe. One component of the immune response is inflammation. Where inflammation is excessive or uncontrolled it can damage host tissues and cause pathology. Limitation of oxidative stress is one means of controlling inflammation. Citrus fruit juices are a particularly good source of vitamin C and folate, which both have roles in sustaining the integrity of immunological barriers and in supporting the function of many types of immune cell including phagocytes, natural killer cells, T-cells and B-cells. Vitamin C is an antioxidant and reduces aspects of the inflammatory response. Important bioactive polyphenols in citrus fruit juices include hesperidin, narirutin and naringin. Hesperidin is a glycoside of hesperetin while narirutin and naringin are glycosides of naringenin. Hesperidin, hesperetin, naringenin, naringin and narirutin have all been found to have anti-inflammatory effects in model systems, and human trials of hesperidin report reductions in inflammatory markers. In humans, orange juice was shown to limit the post-prandial inflammation induced by a high fat-high carbohydrate meal. Consuming orange juice daily for a period of weeks has been reported to reduce markers of inflammation, including C-reactive protein, as confirmed through a recent meta-analysis. A newly emerging topic is whether polyphenols from orange juice have direct anti-viral effects. In summary, micronutrients and other bioactives present in citrus fruit juices have established roles in controlling oxidative stress and inflammation and in supporting innate and acquired immune responses. Trials in humans demonstrate that orange juice reduces inflammation; its effects on innate and acquired immunity require further exploration in well-designed trials in appropriate population sub-groups such as older people.

Spices, Condiments, Extra Virgin Olive Oil and Aromas as Not Only Flavorings, but Precious Allies for Our Wellbeing

Spices, condiments and extra virgin olive oil (EVOO) are crucial components of human history and nutrition. They are substances added to foods to improve flavor and taste. Many of them are used not only to flavor foods, but also in traditional medicine and cosmetics. They have antioxidant, antiviral, antibiotic, anticoagulant and antiinflammatory properties and exciting potential for preventing chronic degenerative diseases such as cardiomyopathy and cancer when used in the daily diet. Research and development in this particular field are deeply rooted as the consumer inclination towards natural products is significant. It is essential to let consumers know the beneficial effects of the daily consumption of spices, condiments and extra virgin olive oil so that they can choose them based on effects proven by scientific works and not by the mere illusion that plant products are suitable only because they are natural and not chemicals. The study begins with the definition of spices, condiments and extra virgin olive oil. It continues by describing the pathologies that can be prevented with a spicy diet and it concludes by considering the molecules responsible for the beneficial effects on human health (phytochemical) and their eventual transformation when cooked.

Vitamin C as a Supplementary Therapy in Relieving Symptoms of the Common Cold: A Meta-Analysis of 10 Randomized Controlled Trials

Aim

To investigate whether vitamin C performs well as a supplemental treatment for common cold.

Method

After systematically searching through the National Library of Medicine (PubMed), Cochrane Library, Elsevier, China National Knowledge Infrastructure (CNKI), VIP databases, and Wanfang databases, 10 randomized controlled trials were selected for our meta-analysis with RevMan 5.3 software. Published in China, all 10 studies evaluated the effect of combined vitamin C and antiviral therapy for the treatment of common cold.

Results

The total efficacy (RR = 1.27, 95% CI (1.08, 1.48), P = 0.003), the time for symptom amelioration (MD = −15.84, 95% CI (-17.02, -14.66), P < 0.00001), and the time for healing (I, 95% CI (-14.98, -4.22), P = 0.0005) were better with vitamin C supplementation than with antiviral therapy alone.

Conclusions

Vitamin C could be used as a supplementary therapy along with antiviral regimens to relieve patients from the symptoms of common cold.

The Role of Physiological Vitamin C Concentrations on Key Functions of Neutrophils Isolated from Healthy Individuals

Vitamin C (ascorbate) is important for neutrophil function and immune health. Studies showing improved immune function have primarily used cells from scorbutic animals or from individuals with infectious conditions or immune cell disorders. Few studies have focused on the requirements of neutrophils from healthy adults. Therefore, we have investigated the role of vitamin C, at concentrations equivalent to those obtained in plasma from oral intakes (i.e., 50-200 µmol/L), on key functions of neutrophils isolated from healthy individuals. Cells were either pre-loaded with dehydroascorbic acid, which is rapidly reduced intracellularly to ascorbate, or the cells were activated in the presence of extracellular ascorbate. We measured the effects of enhanced ascorbate uptake on the essential functions of chemotaxis, oxidant production, programmed cell death and neutrophil extracellular trap (NET) formation. We found that neutrophils isolated from healthy individuals already had replete ascorbate status (0.35 nmol/10⁶ cells), therefore they did not uptake additional ascorbate. However, they readily took up dehydroascorbic acid, thus significantly increasing their intracellular ascorbate concentrations, although this was found to have no additional effect on superoxide production or chemotaxis. Interestingly, extracellular ascorbate appeared to enhance directional mobilityin the presence of the chemoattractant formyl-methionyl-leucyl-phenylalanine (fMLP). Stimulation of the cells in the presence of ascorbate significantly increased intracellular ascorbate concentrations and, although this exhibited a non-significant increase in phosphatidylserine exposure, NET formation was significantly attenuated. Our findings demonstrate the ability of neutrophils to regulate their uptake of ascorbate from the plasma of healthy humans to maintain an optimal level within the cell for proper functioning. Higher oral intakes, however, may help reduce tissue damage and inflammatory pathologies associated with NET formation.

Mechanisms underlying nickel nanoparticle induced reproductive toxicity and chemo-protective effects of vitamin C in male rats

The purpose of this research is to go a step further study on the reproductive toxicities and the underlying mechanisms induced by nickel nanoparticles (NiNPs), and the possible protective action of vitamin C. Animal experiment was designed according to the one-generation reproductive toxicity standard, and rats were exposed to NiNPs through gavage. Ultrastructural, reactive oxygen species (ROS), oxidant and antioxidant enzymes, and cell apoptosis-related factors in the testicular tissue were analyzed. In contrast with the control group, the activity of surperoxide dismutase (SOD), catalase (CAT) and gonad-stimulating hormone (GSH) was reduced, while the content of nitric oxide (NO), malondialdehyde (MDA) and ROS was increased in the NiNPs treated animals. As the doses of NiNPs increase, the mRNA of apoptotic related factor Caspase-9, Caspase-8 and Caspase-3 showed an obviously upregulation. Protein expression of Bcl-2-associated X Protein (Bax) and apoptosis inducing factor (AIF) was significantly unregulated. After addition of antioxidants-vitamin C, the toxicity was reduced. Injured testicular tissue indicated that NiNPs exposure could damage the reproductive system. Our results suggest that NiNPs induce significant reproductive toxicities. The cellular apoptosis might be induced by caspase family proteinases, but the regulator factor (factor associated suicide (Fas), B-cell lymphoma-2 (Bcl-2), Bax, BH3-interacting domain death agonist (Bid) and AIF protein) might not be involved in this process. Thus, the mechanism of reproductive toxicity of NiNPs on rat testes involves in the induction of oxidative stress, which further results in cell apoptosis. Antioxidants-vitamin C shows a significant inhibition on the reproductive toxicities induced by NiNPs.

Intravenous vitamin C in the treatment of allergies: an interim subgroup analysis of a long-term observational study

Objective Oxidative stress appears to be a key factor in the pathogenesis of allergic diseases and a potential therapeutic target in allergy treatment. Allergic diseases are reportedly associated with reduced plasma levels of ascorbate, which is a key physiological antioxidant. Ascorbate prevents excessive inflammation without reducing the defensive capacity of the immune system. Methods An interim analysis of a multicenter, prospective, observational study was conducted to investigate the change in disease-specific and nonspecific symptoms (fatigue, sleep disorders, depression, and lack of mental concentration) during adjuvant treatment with intravenous vitamin C (Pascorbin®; Pascoe, Giessen, Germany) in 71 patients with allergy-related respiratory or cutaneous indications. Results Between the start and end of treatment, the mean sum score of three disease-specific symptoms decreased significantly by 4.71 points and that of four nonspecific symptoms decreased significantly by 4.84 points. More than 50% of patients took no other allergy-related medication besides vitamin C. Conclusions Our observations suggest that treatment with intravenous high-dose vitamin C reduces allergy-related symptoms. Our observations form a basis for planning a randomized controlled clinical trial to obtain more definitive evidence of the clinical relevance of our findings. We also obtained evidence of ascorbate deficiency in allergy-related diseases.

TRIAL REGISTRATION

Clinical Trials NCT02422901.

Ovarian Damages Produced by Aerosolized Fine Particulate Matter (PM2.5) Pollution in Mice: Possible Protective Medications and Mechanisms

Background:

Ambient aerosol fine particulate matter (PM_2.5) is associated with male reproductive toxicity in experiments and may have adverse effects in the female. However, studies evaluating the protective effects and precise mechanisms of aspirin, Vitamin C, Vitamin E, or ozone against toxic effects of PM_2.5 are sparse. This study was conducted to investigate the possible protective effects and mechanisms of aspirin, Vitamin C, Vitamin E, or ozone on fertility in female mice treated with PM_2.5.

Methods:

Eighty-four ICR mice were divided into six groups: control group, PM_2.5 group, PM_2.5 + aspirin group, PM_2.5 + Vitamin C group, PM_2.5 + Vitamin E group, and PM_2.5 + ozone group. PM_2.5 was given by intratracheal instillation every 2 days for 3 weeks. Aspirin, Vitamin C, and Vitamin E were given once a day by oral gavage for 3 weeks, and ozone was administered by intraperitoneal injection once a day for 3 weeks. The levels of anti-Müllerian hormone (AMH), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and 8-hydroxy-2’-deoxyguanosine (8-OHdG) were measured using enzyme-linked immunosorbent assay. Western blotting analysis was used to analyze the expressions of Bcl-2, Bax, and caspase-3 in ovaries. Changes in histological structure were examined by light microscope and electron microscopy was used to detect ultramicrostructure.

Results:

The results demonstrated that PM_2.5 decreased AMH levels (P < 0.001); however, aspirin (P < 0.001), Vitamin C (P < 0.001), Vitamin E (P = 0.001), and ozone (P = 0.002) alleviated the decrease. Changes of IL-6, TNF-α, 8-OHdG, Bax/Bcl-2, and caspase-3 in PM_2.5 group were increased compared to control group (P < 0.001), while in PM_2.5 + aspirin, PM_2.5 + Vitamin C, PM_2.5 + Vitamin E, and PM_2.5 + ozone groups, they were statistically decreased compared to PM_2.5 group (P < 0.001 or P < 0.05).

Conclusions:

PM_2.5 cause the damage of ovaries, and aspirin, Vitamin C, Vitamin E, and ozone antagonizes the damage. The protective mechanism is probably due to its ability to blunt the inflammatory and oxidative stress caused by PM_2.5, which subsequently suppressing the expression of apoptotic regulatory protein and reducing the incidence of ovary apoptosis.

Vitamin C and Immune Function. Nutrients. 2017;9:E1211. [PMID: 29099763 PMCID: PMC5707683 DOI: 10.3390/nu9111211]

Vitamin C is an essential micronutrient for humans, with pleiotropic functions related to its ability to donate electrons. It is a potent antioxidant and a cofactor for a family of biosynthetic and gene regulatory enzymes. Vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune system. Vitamin C supports epithelial barrier function against pathogens and promotes the oxidant scavenging activity of the skin, thereby potentially protecting against environmental oxidative stress. Vitamin C accumulates in phagocytic cells, such as neutrophils, and can enhance chemotaxis, phagocytosis, generation of reactive oxygen species, and ultimately microbial killing. It is also needed for apoptosis and clearance of the spent neutrophils from sites of infection by macrophages, thereby decreasing necrosis/NETosis and potential tissue damage. The role of vitamin C in lymphocytes is less clear, but it has been shown to enhance differentiation and proliferation of B- and T-cells, likely due to its gene regulating effects. Vitamin C deficiency results in impaired immunity and higher susceptibility to infections. In turn, infections significantly impact on vitamin C levels due to enhanced inflammation and metabolic requirements. Furthermore, supplementation with vitamin C appears to be able to both prevent and treat respiratory and systemic infections. Prophylactic prevention of infection requires dietary vitamin C intakes that provide at least adequate, if not saturating plasma levels (i.e., 100–200 mg/day), which optimize cell and tissue levels. In contrast, treatment of established infections requires significantly higher (gram) doses of the vitamin to compensate for the increased inflammatory response and metabolic demand.

Unhealthy smokers: scopes for prophylactic intervention and clinical treatment

BACKGROUND

Globally, tobacco use causes approximately 6 million deaths per year, and predictions report that with current trends; more than 8 million deaths are expected annually by 2030. Cigarette smokings is currently accountable for more than 480,000 deaths each year in United States (US) and is the leading cause of preventable death in the US. On average, smokers die 10 years earlier than nonsmokers and if smoking continues at its current proportion among adolescents, one in every 13 Americans aged 17 years or younger is expected to die prematurely from a smoking-related illness. Even though there has been a marginal smoking decline of around 5% in recent years (2005 vs 2015), smokers still account for 15% of the US adult population. What is also concerning is that 41,000 out of 480,000 deaths results from secondhand smoke (SHS) exposure. Herein, we provide a detailed review of health complications and major pathological mechanisms including mutation, inflammation, oxidative stress, and hemodynamic and plasma protein changes associated with chronic smoking. Further, we discuss prophylactic interventions and associated benefits and provide a rationale for the scope of clinical treatment.

CONCLUSIONS

Considering these premises, it is evident that much detailed translational and clinical studies are needed. Factors such as the length of smoking cessation for ex-smokers, the level of smoke exposure in case of SHS, pre-established health conditions, genetics (and epigenetics modification caused by chronic smoking) are few of the criteria that need to be evaluated to begin assessing the prophylactic and/or therapeutic impact of treatments aimed at chronic and former smokers (especially early stage ex-smokers) including those frequently subjected to second hand tobacco smoke exposure. Herein, we provide a detailed review of health complications and major pathological mechanisms including mutation, inflammation, oxidative stress, and hemodynamic and plasma protein changes associated with chronic smoking. Further, we discuss about prophylactic interventions and associated benefits and provide a rationale and scope for clinical treatment.

Pharmacological treatment options for mast cell activation disease

Mast cell activation disease (MCAD) is a term referring to a heterogeneous group of disorders characterized by aberrant release of variable subsets of mast cell (MC) mediators together with accumulation of either morphologically altered and immunohistochemically identifiable mutated MCs due to MC proliferation (systemic mastocytosis [SM] and MC leukemia [MCL]) or morphologically ordinary MCs due to decreased apoptosis (MC activation syndrome [MCAS] and well-differentiated SM). Clinical signs and symptoms in MCAD vary depending on disease subtype and result from excessive mediator release by MCs and, in aggressive forms, from organ failure related to MC infiltration. In most cases, treatment of MCAD is directed primarily at controlling the symptoms associated with MC mediator release. In advanced forms, such as aggressive SM and MCL, agents targeting MC proliferation such as kinase inhibitors may be provided. Targeted therapies aimed at blocking mutant protein variants and/or downstream signaling pathways are currently being developed. Other targets, such as specific surface antigens expressed on neoplastic MCs, might be considered for the development of future therapies. Since clinicians are often underprepared to evaluate, diagnose, and effectively treat this clinically heterogeneous disease, we seek to familiarize clinicians with MCAD and review current and future treatment approaches.

Pathobiology of tobacco smoking and neurovascular disorders: untied strings and alternative products

Tobacco smoke (TS) is the leading cause of preventable deaths worldwide. In addition to a host of well characterized diseases including chronic obstructive pulmonary disease, oral and peripheral cancers and cardiovascular complications, epidemiological evidence suggests that chronic smokers are at equal risk to develop neurological and neurovascular complications such as multiple sclerosis, Alzheimer's disease, stroke, vascular dementia and small vessel ischemic disease (SVID). Unfortunately, few direct neurotoxicology studies of tobacco smoking and its pathogenic pathways have been produced so far. A major link between TS and CNS disorders is the blood-brain barrier (BBB). In this review article, we summarize the current understanding of the toxicological impact of TS on BBB physiology and function and major compensatory mechanisms such as nrf2- ARE signaling and anti-inflammatory pathways activated by TS. In the same context, we discuss the controversial role of antioxidant supplementation as a prophylactic and/or therapeutic approach in delaying or decreasing the disease complications in smokers. Further, we cover a number of toxicological studies associated with "reduced exposure" cigarette products including electronic cigarettes. Finally, we provide insights on possible avenues for future research including mechanistic studies using direct inhalation rodent models.

Protecting the BBB endothelium against cigarette smoke-induced oxidative stress using popular antioxidants: Are they really beneficial?

Blood Brain Barrier (BBB) exposed to realistic concentrations (comparable to a chronic heavy smoker) of Cigarette Smoke Extract (CSE) triggers a strong endothelial inflammatory response which can lead to the onset of neurological disorders. The involvement of Reactive Oxygen Species (ROS) in this inflammatory cascade is evident from the up-regulation of nuclear factor erythroid 2 related factor 2 (Nrf-2), a transcription factor involved in anti-oxidant response signaling in CSE exposed endothelial cells. We have shown that pre-treatment with α-tocopherol and/or ascorbic acid is highly protective for the BBB, thus suggesting that, prophylactic administration of antioxidants can reduce CSE and/or inflammatory-dependent BBB damage. We have assessed and ranked the protective effects of 5 popular OTC antioxidants (Coenzyme Q10, melatonin, glutathione, lipoic acid and resveratrol) against CSE-induced BBB endothelial damage using hCMEC/D3 cells. The analysis of pro-inflammatory cytokines release by ELISA revealed that resveratrol, lipoic acid melatonin and Co-Q10 inhibited the BBB endothelial release of pro-inflammatory cytokines IL-6 and IL-8, reduced (not Co-Q10) CSE-induced up-regulation of Platelet Cell Adhesion Molecule-1 (PECAM-1), Vascular Cell Adhesion Molecule-1 (VCAM-1) & E-selectin and inhibited monocytes-endothelial cell adhesion. The anti-inflammatory effects correlated with the anti-oxidative protection endowed by these compounds as evidenced by upregulation of NADPH: Quinone Oxidoreductase 1 (NQO1) and reduced cellular oxidative stress. CSE-induced release of Vascular Endothelial Growth Factor (VEGF) was inhibited by all tested compounds although the effect was not strictly dose-dependent. Further in vivo studies are required to validate our results and expand our current study to include combinatorial treatments.

Ascorbic acid modulates cell migration in differentiated HL-60 cells and peripheral blood leukocytes

SCOPE

The impact of L-ascorbic acid (L-AA) on the chemokinesis (CK) and chemotaxis (CT) of HL-60 cells and polymorphonuclear cells (PMN) was investigated.

METHODS AND RESULTS

HL-60 cells were differentiated with DMSO, retinoic acid (RA), vitamin D, or L-AA. Chemokinesis and chemotaxis of differentiated HL-cells were assayed. Vitamin D3-treated HL-60 cells (dHL-60vitD3 cells) and RA-treated cells (dHL-60RA cells) acquired monocyte/macrophage-like and neutrophil-like phenotypes, respectively. DMSO induced the differentiation of an intermediate phenotype (dHL-60DMSO cells), whereas L-AA downregulated neutrophil markers (dHL-60L-AA cells). dHL-60DMSO cells had increased CK and potent CT in gradients of IL-8 and N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP). dHL-60RA cells and dHL-60L-AA cells migrated less toward IL-8 and fMLP; dHL-60vitD3 cells preferably responded to fMLP. L-AA enhanced CK of dHL-60DMSO cells and was a weak chemo-attractant. In human leukocytes, IL-8 and fMLP triggered receptor-mediated chemotaxis. CXCR2 and fMLPR were downregulated by IL-8 and fMLP, respectively. L-AA stimulated chemotaxis although significantly less than IL-8 and fMLP. IL-8 targeted chemotaxis was enhanced both in HL-60 cells and leukocytes when cells were incubated with L-AA.

CONCLUSION

L-AA modulated chemokinesis and had significant chemo-attractant properties, which were independent on fMLP or IL-8 receptors. The results suggest that L-AA improves leukocyte function in innate immune responses.

Effect of antioxidants on histamine receptor activation and sustained postexercise vasodilatation in humans

NEW FINDINGS

What is the central question of this study? Is exercise-induced oxidative stress the upstream exercise-related signalling mechanism that leads to sustained postexercise vasodilatation via activation of H1 and H2 histamine receptors? What is the main finding and its importance? Systemic administration of the antioxidant ascorbate inhibits sustained postexercise vasodilatation to the same extent as seen previously with H1 and H2 histamine receptor blockade following small muscle-mass exercise. However, ascorbate has a unique ability to catalyse the degradation of histamine. We also found that systemic infusion of the antioxidant N-acetylcysteine had no effect on sustained postexercise vasodilatation, suggesting that exercise-induced oxidative stress does not contribute to sustained postexercise vasodilatation. An acute bout of aerobic exercise elicits a sustained postexercise vasodilatation that is mediated by histamine H1 and H2 receptor activation. However, the upstream signalling pathway that leads to postexercise histamine receptor activation is unknown. We tested the hypothesis that the potent antioxidant ascorbate would inhibit this histaminergic vasodilatation following exercise. Subjects performed 1 h of unilateral dynamic knee extension at 60% of peak power in three conditions: (i) control; (ii) i.v. ascorbate infusion; and (iii) ascorbate infusion plus oral H1 /H2 histamine receptor blockade. Femoral artery blood flow was measured (using Doppler ultrasound) before exercise and for 2 h postexercise. Femoral vascular conductance was calculated as flow/pressure. Postexercise vascular conductance was greater for control conditions (3.4 ± 0.1 ml min(-1) mmHg(-1) ) compared with ascorbate (2.7 ± 0.1 ml min(-1) mmHg(-1) ; P < 0.05) and ascorbate plus H1 /H2 blockade (2.8 ± 0.1 ml min(-1) mmHg(-1) ; P < 0.05), which did not differ from one another (P = 0.9). Given that ascorbate may catalyse the degradation of histamine in vivo, we conducted a follow-up study, in which subjects performed exercise in two conditions: (i) control; and (ii) i.v. N-acetylcysteine infusion. Postexercise vascular conductance was similar for control (4.0 ± 0.1 ml min(-1) mmHg(-1) ) and N-acetylcysteine conditions (4.0 ± 0.1 ml min(-1) mmHg(-1) ; P = 0.8). Thus, the results in the initial study were due to the degradation of histamine in skeletal muscle by ascorbate, because the histaminergic vasodilatation was unaffected by N-acetylcysteine. Overall, exercise-induced oxidative stress does not appear to contribute to sustained postexercise vasodilatation.

Vitamin C supplementation modulates gene expression in peripheral blood mononuclear cells specifically upon an inflammatory stimulus: a pilot study in healthy subjects

In order to study the effects of vitamin C supplementation on gene expression and compare its action between physiological and inflammatory conditions, a pilot study was set up utilizing microarray and qPCR technologies. Five healthy volunteers were supplemented with 1 g vitamin C (Redoxon^®) per day for five consecutive days. Peripheral blood mononuclear cells (PBMNC) were isolated before and just after the last supplementation, and RNA was isolated for the Affymetrix gene 1.0 ST chip analysis. PBMNC were also, ex vivo, treated with LPS, and gene expression was quantified by means of a “Human NFkB Signaling” qPCR array. Only a very moderate effect on the baseline gene expression modulation was associated with vitamin C supplementation. However, in spite of the limited number of subjects analyzed, vitamin C supplementation resulted in a markedly different modulation of gene expression upon the inflammatory stimulus, specifically at the level of the MyD88-dependent pathway and of the anti-inflammatory cytokine IL-10 synthesis. This study suggests that vitamin C supplementation in healthy subjects, not selected according to a specific genetic profile, consuming an adequate amount of vitamin C, and having a satisfactory vitamin C plasma concentration at the baseline, does not result in a significant modification of gene expression profile. Under this satisfactory micronutrient status, supplementation of vitamin C is “buffered” within a homeostatic physiological equilibrium. Differently, following a second “hit” constituted of an inflammatory stimulus such as LPS, able to trigger a critical burst to the normal physiological state, the higher availability of ascorbic acid emerges, and results in a significant modulation of cell response.

Effects of hyperoxia on the permeability of 16HBE14o- cell monolayers--the protective role of antioxidant vitamins E and C

The use of hyperoxia for critically ill patients is associated with adverse impacts resulting in lung injury accompanied by inflammation. The aim of this study was to evaluate aspects of mechanisms that contribute to hyperoxia-induced disruption of the epithelial permeability barrier, and also the protective effects of the antioxidants α-tocopherol and ascorbate. 16HBE14o- cells were cultured as monolayers at an air-liquid interface for 6 days, after which transepithelial electrical resistance reached 251.2 ± 4.1 Ω.cm(2) (mean ± standard error of the mean). They were then exposed for 24 h to normoxia (21% O2, 5% CO2), hyperoxia (95% O2, 5% CO2), hyperoxia with 10(-7) M α-tocopherol, hyperoxia with 10(-7) M ascorbate, hyperoxia with 10(-6) M ascorbate, and hyperoxia with a combination of α-tocopherol and ascorbate (10(-7) M and 10(-6) M, respectively). Significant reductions (P < 0.05) in transepithelial electrical resistance seen after hyperoxia (with or without antioxidants) were associated with reductions in the levels of zona occludens-1 (ZO-1) observed by immunohistochemistry, and downregulation of ZO-1 expression (P < 0.01) as compared with normoxia. In contrast, the expression levels of interleukin (IL)-8, IL-6 and tumour necrosis factor-α (TNF-α) were increased after hyperoxia (P < 0.01), and marked increases in the levels of these cytokines (ELISA) were seen in the medium (P < 0.001) as compared with normoxia. The antioxidant vitamins E and C had a partial protective effect against the hyperoxia-induced reduction in ZO-1 levels and the increase in levels of the proinflammatory cytokines IL-8, IL-6, and TNF-α. In conclusion, hyperoxia-induced epithelial disruption is associated with tight junction weakening, and induction of a proinflammatory environment.

Intravenous infusion of ascorbic acid decreases serum histamine concentrations in patients with allergic and non-allergic diseases

Histamine plays an important role in the development of symptoms in allergic, infectious, neoplastic and other diseases. Empirical findings have suggested beneficial effects of ascorbic acid supplementation in those diseases, and these effects are assumed to be related to a possible decrease in systemic histamine concentration. In the present study, we systematically investigated for the first time the effect of 7.5 g of intravenously administered ascorbic acid on serum histamine levels (as detected by ELISA) in 89 patients (19 with allergic and 70 with infectious diseases). When all patients were grouped together, there was a significant decline in histamine concentration from 0.83 to 0.57 ng/ml×m2 body surface area (BSA, p<0.0001). The decrease in serum histamine concentration in patients with allergic diseases (1.36 to 0.69 ng/ml×m2 BSA, p=0.0007) was greater than that in patients with infectious diseases (0.73 to 0.56 ng/ml×m2 BSA, p=0.01). Furthermore, the decline in histamine concentration after ascorbic acid administration was positively correlated with the basal, i.e. pre-therapeutic, histamine concentration. Intravenous infusion of ascorbic acid clearly reduced histamine concentrations in serum, and may represent a therapeutic option in patients presenting with symptoms and diseases associated with pathologically increased histamine concentration.

In vitro assessment of tobacco smoke toxicity at the BBB: do antioxidant supplements have a protective role?

BACKGROUND

Tobacco smoke (TS) contains highly reactive oxygen species (such as hydrogen peroxide, peroxynitrite, etc), which cause oxidative damage in vascular tissue and may exacerbate inflammatory events leading to the blood-brain barrier damage (BBBD) which accompanies the development of a variety of neurological disorders. Smokers often have elevated leukocyte counts (primarily neutrophils and monocytes), and significant decreases in plasma alpha-tocopherol (vitamin E) and ascorbic acid (vitamin C) levels due to increased anti-oxidative mobilization in response to oxidative stress evoked by TS. For this purpose, using static culture systems and a well-established dynamic in vitro BBB model (DIV-BBB) we tested the hypothesis that antioxidant vitamin supplementation (E and/or C) can protect the BBB during exposure to whole soluble TS.

RESULTS

TS exacerbates inflammatory events and leads to endothelial overexpression of vascular adhesion molecules (VCAM-1, P-selectin and E-selectin), release of pro-inflammatory cytokines (TNF-α and IL-6) and nitric oxide (NO), release and activation of matrix metalloproteinases (MMP-2 and MMP-9), monocytic maturation into macrophages, and adhesion to the vascular endothelium. Furthermore, TS altered the normal glucose metabolic behaviour of in vitro BBB capillaries and caused a period of transient anaerobic respiration to meet the cellular bioenergetic demand. Pre-treatment with antioxidant vitamins (C and/or E) effectively reduced the pro-inflammatory activity associated with TS, protecting the viability and functions of the BBB.

CONCLUSION

Our results have shown that loss of endothelial viability as well as BBB function and integrity caused by TS exposure can be prevented or at least reduced by normal physiologic concentrations of antioxidant vitamins in vitro.

Essential role of vitamin C and zinc in child immunity and health

With the progressive elimination of dietary protein-energy deficits, deficiencies of micronutrients are emerging as the limiting factors in ensuring children's optimal health. Data from several countries in Asia and Latin America indicate that deficiencies of vitamin C and zinc continue to be at alarming levels. This article reviews the roles of vitamin C and zinc in supporting children's growth and development, with a particular focus on the complementary roles they play in supporting immune functions and combating infections. The contemporary relevance of vitamin C and zinc deficiency in the Asian and Latin American regions, both undergoing a rapid nutritional transition, are also discussed. Overall, there is increasing evidence that deficiency of vitamin C and zinc adversely affects the physical and mental growth of children and can impair their immune defences. Nutrition should be the main vehicle for providing these essential nutrients; however, supplementation can represent a valid support method, especially in developing regions.

Assessment of stage of change, decisional balance, self-efficacy, and use of processes of change of low-income parents for increasing servings of fruits and vegetables to preschool-aged children

OBJECTIVE

Use the Transtheoretical Model of Behavior Change (TTM) to determine the proportionate stage of change of low-income parents and primary caregivers (PPC) for increasing accessibility, measured as servings served, of fruits and vegetables (FV) to their preschool-aged children and evaluate response differences for theoretical constructs.

DESIGN

Cross-sectional, quantitative survey design consisting of staging algorithm, construct scales, and food frequency questionnaire.

SETTING

Rural and urban communities in a southwestern state of the United States.

PARTICIPANTS

238 low-income PPC enrolled in federal nutrition education programs were recruited from group nutrition education sessions.

MAIN OUTCOME MEASURES

Stage of change using a staging algorithm, TTM constructs of processes of change, decisional balance, and self-efficacy measured by multiple-item scales using Likert response, and fruit and vegetable servings served using a food frequency questionnaire.

ANALYSIS

Descriptive analysis, Pearson's chi-square, analyses of variance with Tukey's Honestly Significant Difference post hoc test, and principal component function analysis.

RESULTS

Of the surveyed PPC, 43% were in precontemplation/contemplation stages, and 29% were in the preparation stage for increasing FV accessibility (measured by servings served) to their preschool-aged children. PPC in the action/maintenance stages evidenced greater use of behavioral processes and had higher self-efficacy scores compared to PPC in precontemplation/contemplation and preparation stages.

CONCLUSIONS AND IMPLICATIONS

Interventions aimed at increasing FV accessibility for preschool-aged children should be tailored to meet PPCs' stage of change. Interventions targeting PPC in precontemplation/contemplation stages should use methods to share ideas for planning meals and snacks to include FV. Interventions for PPC in the preparation stage should aim to build skills in quick preparation of economical FV, address parental role modeling of FV consumption, and encourage goal setting. Learning formats providing social support may prove effective in prevention of behavior relapse for PPC in action/maintenance stages.

Clinical and biochemical effects of a combination botanical product (ClearGuard) for allergy: a pilot randomized double-blind placebo-controlled trial

Background

Botanical products are frequently used for treatment of nasal allergy. Three of these substances, Cinnamomum zeylanicum, Malpighia glabra, and Bidens pilosa, have been shown to have a number of anti-allergic properties in-vitro. The current study was conducted to determine the effects of these combined ingredients upon the nasal response to allergen challenge in patients with seasonal allergic rhinitis.

Methods

Twenty subjects were randomized to receive the combination botanical product, (CBP) 2 tablets three times a day, loratadine, 10 mg once a day in the morning, or placebo, using a randomized, double-blinded crossover design. Following 2 days of each treatment and during the third day of treatment, subjects underwent a nasal allergen challenge (NAC), in which nasal symptoms were assessed after each challenge dose and every 2 hours for 8 hours. Nasal lavage fluid was assessed for tryptase, prostaglandin D2, and leukotriene E4 concentrations and inflammatory cells.

Results

Loratadine significantly reduced the total nasal symptom score during the NAC compared with placebo (P = 0.04) while the CBP did not. During the 8 hour period following NAC, loratadine and the CBP both reduced NSS compared with placebo (P = 0.034 and P = 0.029, respectively). Analysis of nasal lavage fluid demonstrated that the CBP prevented the increase in prostaglandin D2 release following NAC, while neither loratadine nor placebo had this effect. None of the treatments significantly affected tryptase or leukotriene E4 release or inflammatory cell infiltration.

Conclusion

The CBP significantly reduced NSS during the 8 hours following NAC and marginally inhibited the release of prostaglandin D2 into nasal lavage fluid, suggesting potential clinical utility in patients with allergic rhinitis.

Short and long term treatment of asthma with intravenous nutrients

Background

Asthma is an increasing problem in this country and others. Although medications for the treatment of asthma abound and are improving, there are inherent risks and side effects with all of them. Intravenous magnesium has been employed in the treatment of acute asthma, but its use has not become universal, nor has it been studied for the treatment of chronic asthma. It is known to be a safe drug with minimal side effects. In this study, the author investigates the use of magnesium and other nutrients in the treatment of both acute and chronic asthma.

Methods

In this non-blinded outcome study, following informed consent, forty-three (43) randomly selected volunteer patients with both acute and chronic asthma were treated with IV infusions described herein. All patients were observed with spirometry 10 minutes post-infusion; two sub-groups of patients were also observed after multiple infusions over a short period of time (less than one month) and a longer period of time (average 5.8 months). Pulmonary function was analyzed by spirometric testing with pre- and post-infusion spirometric measurements with the pre/post group. For longer term (Trend) patients, baseline spirometry measurements were compared to spirometry measurements after patients had received multiple infusions over a period of time. Eight (8) patients were measured for both pre/post and Trend data.

Results

The 38 pre-infusion/post-infusion patients with acute and chronic asthma demonstrated an overall average improvement (percentage improvement in percent predicted) of 45%. The 13 patients measured for improvement over time (Trend data, average duration 5.82 months), demonstrated an overall average improvement (percentage improvement in percent predicted) of 57%. Of the 13 patients in the multiple infusion group, 9 patients who received longer-term therapy (average duration of 12.58 months) for chronic asthma demonstrated an overall average improvement of 95% (percentage improvement in percent predicted).

Conclusion

The use of intravenous treatment with multiple nutrients, including magnesium, for acute and chronic asthma may be of considerable benefit. Pulmonary function improved progressively the longer patients received treatment.

Measurement of ascorbic acid in single human neutrophils by capillary zone electrophoresis with electrochemical detection

A method has been developed for the determination of ascorbic acid (AA) in individual human neutrophils by capillary zone electrophoresis with electrochemical detection at a carbon fiber microdisk bundle electrode. The natively easily oxidized substances such as glutathione, dopa, dopamine, serotonin, epinephrine do not interfere with the determination of ascorbic acid. A procedure of treating capillaries, which can overcome the influence of the adsorption of the substances in cells on the inner surface wall of the capillary on the migration time and the number of theoretical plates of interests, has been described. The average amount of AA in an individual neutrophil is 0.557 fmol, which is consistent with the literature value.

The effect of vitamin C on the non-specific immune response of the juvenile soft-shelled turtle (Trionyx sinensis)

The study was conducted to determine the effect of supplementation vitamin C in dietary non-specific immunity in juvenile soft-shelled turtles. The soft-shelled turtles were fed with vitamin C supplementation at dosages of 0, 250, 500, 2500, 5000 and 10000 mg/kg diets, respectively, for 4 weeks. The results showed that there were no differences in the phagocytosis of blood cells, serum bacteriolytic activity and bactericidal activity among soft-shelled turtles fed with vitamin C supplementation in 0-500 mg/kg diets. However, firm indicators were significantly enhanced in soft-shelled turtles fed with vitamin C supplementation at 2500 mg/kg diets compared with those fed at 0 and 250 mg/kg diets. The soft-shelled turtles fed with 5000 mg/kg diets had only significantly higher bactericidal activity than those fed vitamin C-deficient diets. The vitamin C supplementation in 10000 mg/kg diets had no notable effects on the phagocytosis, bacteriolytic activity and bactericidal activity. These results suggest that vitamin C seems have an upper and lower threshold for improving non-specific immune function, and the optimum dose was 2500 mg/kg.

Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans

The current recommended dietary allowance (RDA) for vitamin C for adult nonsmoking men and women is 60 mg/d, which is based on a mean requirement of 46 mg/d to prevent the deficiency disease scurvy. However, recent scientific evidence indicates that an increased intake of vitamin C is associated with a reduced risk of chronic diseases such as cancer, cardiovascular disease, and cataract, probably through antioxidant mechanisms. It is likely that the amount of vitamin C required to prevent scurvy is not sufficient to optimally protect against these diseases. Because the RDA is defined as "the average daily dietary intake level that is sufficient to meet the nutrient requirement of nearly all healthy individuals in a group," it is appropriate to reevaluate the RDA for vitamin C. Therefore, we reviewed the biochemical, clinical, and epidemiologic evidence to date for a role of vitamin C in chronic disease prevention. The totality of the reviewed data suggests that an intake of 90-100 mg vitamin C/d is required for optimum reduction of chronic disease risk in nonsmoking men and women. This amount is about twice the amount on which the current RDA for vitamin C is based, suggesting a new RDA of 120 mg vitamin C/d.

Vitamin C depletion is associated with alterations in blood histamine and plasma free carnitine in adults

OBJECTIVE

The purpose of this study was to determine whether carnitine metabolism or histamine degradation would be useful parameters for investigating the optimal requirement for vitamin C.

METHODS

Twenty-two non-scorbutic subjects with subnormal vitamin C status (plasma vitamin C < 28 mumol/L) were placed on a metabolic diet low in vitamin C for 3 weeks and repleted with graded doses of vitamin C: 10, 30 and 60 mg vitamin C daily (group 1) or 10,125 and 250 mg vitamin C daily (group 2) for weeks 1, 2 and 3, respectively. Fasting blood samples were collected weekly and analyzed for plasma vitamin C, plasma free carnitine and blood histamine.

RESULTS

Group 1 subjects remained in a subnormal vitamin C state throughout the 3-week study, and blood histamine and plasma free carnitine were not impacted by the experimental treatment. Plasma vitamin C in group 2 subjects rose significantly during the study, and these subjects finished the study with an ample vitamin C status indicative of vitamin C intakes above the recommended dietary allowance. Both blood histamine and plasma free carnitine were inversely related to vitamin C status in group 2 subjects.

CONCLUSIONS

These data indicate that blood histamine and plasma free carnitine are altered in individuals with subnormal, non-scorbutic vitamin C status and provide evidence that metabolic changes independent of collagen metabolism occur prior to the manifestation of scurvy. Thus utilizing scurvy as an end-point to determine vitamin C requirements may not provide adequate vitamin C to promote optimal health and well-being.

Nutrition and the immune system

Malnutrition frequently contributes to the immunocompromise seen in hospitalized patients. Nutritional support corrects malnutrition and can reverse the associated immunocompromise. Developing an understanding of nutritional needs and the role of nutrition in immune function is essential to prevention and treatment of nutrition-related immunocompromise. Current research is defining the role of specific nutrients in immune function. Recent evidence also suggests that the route (enteral versus parenteral) of providing nutritional support can affect immune competence. Intervention trials may show a role of key nutrients in not only maintaining normal immune competence, but also in modulating immunologic outcomes in critically ill patients.

Asthma and oxidant stress: nutritional, environmental, and genetic risk factors

A considerable body of evidence suggests that oxidant stress results in inflammation and tissue damage in the respiratory system, and later in immune damage, and that individuals with lowered cellular reducing capacity are at increased risk to develop asthma. Reducing capacity in the erythrocyte is generated through the pentose phosphate pathway and this pathway also generates a major portion of the reducing capacity in all cells of the body. Therefore, dietary, environmental, and genetic factors which diminish cellular reducing capacity will increase tissue vulnerability to oxidant stress and are likely to increase asthma risk. Dietary selenium deficiency lowers red cell glutathione peroxidase activity and is associated with an increased risk for asthma, and low dietary intakes of vitamins C and E also appear to increase asthma risk. High body iron stores increase free radical production and may also elevate asthma risk. Environmental lead exposure depresses the activities of a several enzyme systems that influence cellular reducing capacity (glucose-6-phosphate dehydrogenase, NAD synthetase, glutathione peroxidase, superoxide dismutase, catalase) and consequently may increase asthma risk. Genetically-determined low activity of glucose-6-phosphate dehydrogenase lowers cellular reducing capacity and may also heighten asthma risk. Simple dietary and environmental interventions may significantly reduce oxidant stress and prevent or minimize the development of asthmatic symptoms and should prove to be a cost effective approach to asthma management in addition to current pharmacological strategies.

Vitamin C (ascorbic acid): new roles, new requirements?

There is an enormous amount of literature on vitamin C intake and health in animals, cell cultures, and humans. Beyond its function in collagen formation, ascorbic acid is known to increase absorption of inorganic iron, to have essential roles in the metabolism of folic acid and of some amino acids and hormones, and to act as an antioxidant. In recent years, research has increasingly focused on this latter function, stimulated by suggestions that "oxidative stress" may be a causal factor in the etiology of such diverse and important disorders of aging as cancer, cardiovascular disease, and cataract formation. The present evidence is strong enough to have convinced nutritionists that daily vitamin C intake should be many times higher than the amount needed to protect against scurvy, and this is reflected in the present Recommended Dietary Allowances. Suggestions that the recommended levels should be higher still are largely based on extrapolations from results of animal and tissue culture studies. How much ascorbic acid is necessary to achieve in humans the effects seen in animal studies is not clear. In general, the limited human studies have not been persuasive. The data are incomplete, and many of the studies have serious flaws. There are no toxicity studies of the type done for new compounds being considered for approval as therapy for major disease conditions. Intervention studies will be difficult, but are essential, and methods for tissue saturation measurement must be defined before new recommendations for the public are designed.