Plasma Ascorbic Acid Levels Research Articles

Scurvy presenting in a homeless 32-year-old male: a case report.

Vitamin C deficiency, otherwise known as scurvy, is one the oldest known diseases. Although its prevalence has substantially diminished, certain populations such as smokers, alcoholics, elderly, and those with malabsorptive syndromes remain at risk. Deficiency presents with perifollicular hemorrhage, corkscrew hairs, and petechiae that can evolve into ecchymoses and purpura. Diagnosis starts with clinical suspicion and is confirmed with plasma and leukocyte ascorbic acid levels. Early suspicion is key. Treatment with vitamin C offers an excellent prognosis and avoids unnecessary workup for differential diagnoses. In our case, a 45-year-old male alcoholic with progressively worsening symptoms was found to have scurvy. Treatment was initiated with vitamin C supplementation, and he had remarkable improvement in his symptoms within weeks. This case demonstrates that scurvy is not a disease of history and must be considered in modern medicine, especially as homelessness with concomitant poor nutrition continues to increase.

Association between Plasma Ascorbic Acid Levels and Postoperative Delirium in Older Patients Undergoing Cardiovascular Surgery: A Prospective Observational Study.

The incidence of delirium is high in older patients undergoing cardiovascular surgery with cardiopulmonary bypass (CPB). Intraoperative tissue hypoperfusion and re-reperfusion injury, which generate reactive oxygen species (ROS), are suggested to induce delirium. Ascorbic acid is an excellent antioxidant and may reduce organ damage by inhibiting the production of ROS. This prospective observational study aimed to measure pre- and postoperative plasma ascorbic acid levels and examine their association with delirium. Patients older than 70 years of age scheduled for elective cardiovascular surgery using CPB were enrolled. From September 2020 to December 2021, we enrolled 100 patients, and the data of 98 patients were analyzed. In total, 31 patients developed delirium, while 67 did not. Preoperative plasma ascorbic acid levels did not differ between the non-delirium and delirium groups (6.0 ± 2.2 vs. 5.5 ± 2.4 µg/mL, p = 0.3). Postoperative plasma ascorbic acid levels were significantly different between the groups (2.8 [2.3-3.5] vs. 2.3 [1.6-3.3] µg/mL, p = 0.037). In patients who undergo cardiovascular surgery with CPB, lower postoperative plasma ascorbic acid levels may be associated with the development of delirium.

TO EVALUATE THE SERUM ASCORBIC ACID LEVELS IN FRESH MYOCARDIAL INFRACTION PATIENTS AND TO COMPARE THEM WITH NORMAL HEALTHY INDIVIDUALS

Objective: Decreased serum magnesium and ascorbic acid has been associated with increased risk of myocardial infarction (MI). The present study was planned to evaluate the status of ascorbic acid in patients suffering from MI and to compare them with normal healthy individuals. Methods: This retrospective study was conducted in the Department of Biochemistry in collaboration with the Department of Medicine, Government Medical College, Guru Nanak Dev Hospital, Amritsar. Fifty patients already diagnosed with MI, attending medicine OPD and IPD. Fifty healthy individuals with ages and sex-matched from the same population served as controls. Plasma acorbic acid levels and lipid profiles were also estimated. Result: In our study, we observed that the difference between the plasma ascorbic acid levels of normal individuals and the patient of MI was statistically highly significant (p<0.001). It was also seen that the maximum number of subjects was found the age of 51–70 years in MI patients. Conclusion: Decreased plasma ascorbic acid levels may be one of the causes of MI, so its supplementation may delay MI and its complications.

Interactions of Ascorbic Acid with Intermittent Preventive Treatment with Sulphadoxine Pyrimethamine in Parturients and their Controls

Background: Malaria deaths in the world have remained worrisome for many decades to centuries now. The issue of its prevention pre pregnancy, during pregnancy and post pregnancy periods needs continuous emphasis especially in our endemic areas. This will help us achieve the desired goals of eliminating malaria menace in Sub-Saharan Africa. The benefits of malaria prevention in helping to reduce the problems of malaria in pregnancy though proven needs continuous emphasis. The problems of prolonged maternal malaria illnesses especially if left untreated during pregnancy may include but not limited to preterm labours / births, pregnancy anaemias, small for date babies, high rates of admissions into special care baby units (SCBU) and intrauterine deaths. The above have been greatly reduced by concurrent practice of preventive measures like the now in use, Intermittent Preventive Treatment with Sulphadoxine Pyrimethamine (IPT-SP). It has also been noted that optimal levels of antioxidant status like Ascorbic acid (Vitamin C), Superoxide Dismutase, Glutathione Peroxidase have shown great promises in assisting our pregnant women enjoy uneventful pregnancies as well as avert most other pregnancy associated problems. Top on the list of which are maternal and neonatal anaemias, preterm labours and births, intrauterine growth restrictions (IUGR), increased admissions into special care baby units and even neonatal deaths to mention but a few. Objectives: This study made a comparative assessment of the plasma Ascorbic acid levels in parturients who judiciously received IPT-SP during their current confinements and their controls. Method: We carried out this study at the Federal Medical Centre (FMC) which is located in Owerri, the state capital of Imo state Nigeria. Owerri is noted to have a typical malaria endemic setting as with most parts of our African sub rejoin. Ethical certification was sought for and obtained from the ethics committee of the hospital enabling the commencement of a longitudinal participant recruitment after adequate counseling and informed consent. This involved both groups. The study was a laboratory based, cross-sectional descriptive study that involving 296 participants that satisfied set out inclusion criteria for one of the groups as allotted. Participants were followed up following recruitment throughout their antenatal course till delivery. This enabled a dutiful collection of blood samples for the estimation of Ascorbic acid. Vitamin C estimation was done using the Omaye, Turabull & Sanberlish method, 1979. The methodology principle is based on the fact that Ascorbic acid is oxidized by copper to form dehydroascorbic acid. The product when treated with 2, 4 dinitrophenyl hydrazine forms tris 2, 4 dinitrophenyl hydrazone which undergoes rearrangement to form a product with the absorption maximum at 520 nm in spectrophotometer. Data analysis: Computer Software Package for Social Science (SPSS) version 20.0 (SPSS, Chicago) was used to analyze obtained data. The descriptive statistics (mean, standard deviation, range, percentages etc) were determined for continuous variables, while a P-value less than (<0.05) at 95% confidence interval was considered statistically significant. Result: The mean ascorbic acid value was lower among the study group than the control. Mean ascorbic acid value for the study group was 1.75 ± 0.67 while the minimum and maximum serum ascorbic acid levels were 0.064 and 3.29 respectively. From the control group, the mean ascorbic acid level was 2.03 ± 0.68 while the minimum and maximum serum ascorbic acid levels were 0.056 and 3.75 respectively. From the results above, the mean difference of 0.28 was found to be statistically significant with (p value= 0.001) with an odds ratio of 0.54 (95% CI =0.380 – 0.771).

Effects of vitamin C supplementation on oxidative stress and serum paraoxonase/arylesterase activities in patients on long-term hemodialysis

BackgroundOxidative stress increases oxidizability of apolipoprotein-B containing lipoproteins and decreases paraoxonase (PON) activity in hemodialysis (HD) patients and plays an important part in the development of atherosclerotic cardiovascular diseases. In HD patients, plasma ascorbic acid (AA) levels are decreased either due to the loss by hemodialysis membranes or due to malnutrition and contribute to the imbalance of antioxidant defense mechanisms. We hypothesized that long-term ascorbic acid (AA) supplementation recovers oxidizability of lipoproteins in HD patients by reinforcing PON activity. MethodsTwenty-nine adult patients were treated with 100mg and 500mg AA at the end of each HD session thrice a week for two consecutive 16 weeks-periods, respectively. Blood samples were obtained before the first HD session and prior to the first HD sessions following the 100mg AA-supplemented and the 500mg AA-supplemented periods. ResultsPON activities were significantly increased after 100mg (p<0.05) and 500mg AA (p<0.001) supplementation periods compared to the basal level. Apo-B lipoprotein oxidizability (Δ-MDA) was significantly decreased after 500mg AA supplementation compared to both basal (p<0.05) and 100mg AA supplementation periods (p<0.05). Plasma AA concentrations were negatively correlated with Δ-MDA levels (R=−0.327; p<0.01). ConclusionOur results suggest that long-term parenteral 500mg AA supplementation improves PON activity alleviating apo B-containing lipoproteins oxidizability in HD patients.

P1536: ERYTHROCYTES’ OXIDATIVE STRESS AND ANTIOXIDANT RESPONSE IN PATIENTS WITH HEREDITARY SPHEROCYTOSIS AND Β-THALASSEMIA MINOR – A SMALL NUMBER CASE STUDY

Background: Hereditary spherocytosis (HS) and β-thalassemia (β-tal) are both associated with oxidative stress, despite their different etiologies. The pathologic red blood cells (RBC) are metabolically stressed to maintain cell integrity, accumulating oxidative stress-induced damage within the cells. To counteract the oxidative modifications, the RBC are equipped with an efficient antioxidant system, which includes several enzymes, such as catalase (CAT) and some non-enzymatic antioxidants, namely ascorbic acid (AA). In a previous work (DOI: 10.1016/j.freeradbiomed.2020.10.084) we hypothesized that AA could be an important player in the RBC antioxidant defense in patients with non-immune hemolytic anemias (NIHAs) and that its mobilization from plasma to the RBC’s cytosol could be an adaptive mechanism to face erythrocyte’s oxidative stress, in these patients. Aims: Our aim was to test that hypothesis, by studying the redox status and antioxidant system of RBC from non-splenectomized patients with HS and β-tal minor separately. Methods: In 13 healthy individuals (control group), 14 non-splenectomized patients with HS and 11 patients with β-tal minor, we evaluated the total antioxidant status (TAS), AA levels and CAT activity in both plasma and RBC’s cytosol by spectroscopy methods. Results: When compared with the control group, both HS and β-tal patients presented statistically significant increased AA levels and lower TAS values in RBC. CAT activity showed similar values in RBC from HS, β-tal and control group. No differences were found for TAS and AA levels in plasma among all groups. We observed significant negative correlations between RBC AA with plasma AA in both HS (r= -0.741, p=0.002) and β-tal (r= -0.742, p= 0.009), not observed in the control group. Additionally, RBC TAS was positively correlated with RBC AA in HS (r=0.534, p=0.049) and RBC TAS was positively correlated with RBC CAT activity in β-tal (r= 0.743, p=0.009). Summary/Conclusion: The finding of a significant increase in RBC AA levels and the significant lower RBC TAS values alongside with a significant negative correlation between RBC AA and plasma AA levels in both HS and β-tal, support the hypothesis that AA may play an important role in the erythrocyte’s adaptive response to oxidative stress and, thereby, in its antioxidant defense system. We speculate that the mobilization of AA from plasma to the RBC is an adaptive mechanism to oxidative stress that occurs in both HS and β-tal. Moreover, the RBC TAS appears to result from different antioxidant responses, as shown by the significant positive correlations found between RBC TAS and RBC AA levels or RBC TAS and RBC Cat activity for HS and β-tal, respectively. These findings might be related to the distinct etiology of the studied anemias. Further studies are needed to better explore about the role of other players in the antioxidant response, not only in HS and β-tal, but also in other oxidative stress associated congenital anemias. Acknowledgments: Financial support from FCT/MCTES through national funds to Applied Molecular Biosciences Unit (UCIBIO), UIDP/04378/2020 and UIDB/04378/2020 and the project LA/P/0140/2020 of Associate Laboratory Institute for Health and Bioeconomy (i4HB). and Daniela Melo’s PhD Grant (SFRH/BD/139622/2018).

Effects of Pumpkin (Cucurbita pepo L.) Seed Protein on Blood Pressure, Plasma Lipids, Leptin, Adiponectin, and Oxidative Stress in Rats with Fructose-Induced Metabolic Syndrome

This study evaluates the potential effects of pumpkin seeds protein on blood pressure (BP), plasma adiponectin, leptin levels, and oxidative stress in rats with fructose-induced metabolic syndrome. Twenty four male Wistar albino rats were divided into four groups and fed a 20% casein diet, 20% casein diet supplemented with pumpkin protein, 20% casein diet with 64% D-fructose, or 20% casein diet with pumpkin protein and 64% D-fructose for 8 weeks. Contin-uous fructose feeding induced an increase in plasma insulin/glucose ratio, BP, insulin and glucose, aspartate aminotrans-ferase, alanine aminotransferase (ALT), alkaline phosphatase (ALP), creatinine, urea, and uric acid levels, and a decrease in the liver and muscle glycogen stores. In addition, elevated levels of total cholesterol (TC), triglycerides (TG), and leptin and lowered adiponectin levels were observed in rats fed a fructose-enriched diet. These groups also exhibited lower plasma levels of ascorbic acid and glutathione, higher thiobarbituric acid-reactive substances, hydroperoxide, carbonyl, and nitric oxide in both the liver and kidneys than rats fed the control diet. Interestingly, pumpkin seed protein treatment significantly counteracted alterations induced by fructose improving glucose, insulin, BP, TG, TC, ALT, and ALP levels, increasing liver and muscle glycogen stores, adiponectin level, and adiponectin/leptin ratio, and reducing plasma leptin lev-els. In addition, rats fed pumpkin protein with a high-fructose diet improved oxidative stress in the liver and kidneys. In conclusion, proteins from Cucurbita pepo L. seeds effectively improve metabolic parameters and protect against oxidative stress induced by a high-fructose diet.

Undetectable triglycerides related to the combined intake of ascorbic acid and tacrolimus.

Management of triglyceride (TG) levels is essential in intensive care units (ICU), especially to manage the risk of pancreatitis induced by propofol. However, some therapeutics in ICU such as intravenous ascorbic acid protocol, especially used in the context of Covid-19 could lead to false decrease of triglycerides by analytical disruption of Trinder reaction. We report here the case of a sample with unmeasurable triglyceride levels partly due to high plasma ascorbic acid levels. However, repeated measure on the same sample four days later revealed that interference mechanism on TG was still present whereas the level of ascorbic acid was very reduced by oxidation degradation. Hence, additional interference mechanism was suspected. After clinical investigation, we found that the patient had also received high doses of tacrolimus due to a transplant. As previous studies reported that tacrolimus treatment lead to a decrease of the measured plasma activity of lipoprotein lipase (LPL), we hypothesized that tacrolimus or related metabolites could also interfere by direct inhibition of LPL involved in TG analytical method used.

Plasma Ascorbic Acid Levels in Critically Ill Pediatric Patients.

Ascorbic acid, or vitamin C, is a physiological antioxidant that has been found to be deficient in critically ill adults with sepsis and acute respiratory distress system. In adults, ascorbic acid supplementation has been shown to reduce the need for vasopressors and mechanical ventilation. This study aimed to describe the prevalence of ascorbic acid deficiency in critically ill pediatric patients. This prospective, single-centered study analyzed 34 patients aged 1 month to 18 years old with septic shock and/or acute respiratory failure requiring mechanical ventilation in a quaternary, urban, pediatric intensive care unit. Plasma ascorbic acid levels were measured by high-performance liquid chromatography within 24 hours of meeting eligibility criteria. The median level was 23.34 µM (IQR [11.45, 39.14]). Twenty-three patients had repeat samples that were collected 3 to 5 days later. The median for repeat samples was higher at 42.41 µM (IQR [13.08, 62.43]). Patients who were enterally fed had significantly higher levels than those who were not (62.4 ± 7.7 µM vs. 32.4 ± 7.1 µM; p = 0.03). Ascorbic acid levels vary widely among critically ill children with septic shock and/or respiratory failure requiring mechanical ventilation, but one-half of our patients had deficient levels that are typically seen in scurvy. Further studies are warranted to investigate the significance of low levels as well as the impact of normalizing levels through nutritional support.

Effects of vitamin C supplementation on oxidative stress and serum paraoxonase/arylesterase activities in patients on long-term hemodialysis

BackgroundOxidative stress increases oxidizability of apolipoprotein-B containing lipoproteins and decreases paraoxonase (PON) activity in hemodialysis (HD) patients and plays an important part in the development of atherosclerotic cardiovascular diseases. In HD patients, plasma ascorbic acid (AA) levels are decreased either due to the loss by hemodialysis membranes or due to malnutrition and contribute to the imbalance of antioxidant defense mechanisms. We hypothesized that long-term ascorbic acid (AA) supplementation recovers oxidizability of lipoproteins in HD patients by reinforcing PON activity. MethodsTwenty-nine adult patients were treated with 100mg and 500mg AA at the end of each HD session thrice a week for two consecutive 16 weeks-periods, respectively. Blood samples were obtained before the first HD session and prior to the first HD sessions following the 100mg AA-supplemented and the 500mg AA-supplemented periods. ResultsPON activities were significantly increased after 100mg (p<0.05) and 500mg AA (p<0.001) supplementation periods compared to the basal level. Apo-B lipoprotein oxidizability (Δ-MDA) was significantly decreased after 500mg AA supplementation compared to both basal (p<0.05) and 100mg AA supplementation periods (p<0.05). Plasma AA concentrations were negatively correlated with Δ-MDA levels (R=−0.327; p<0.01). ConclusionOur results suggest that long-term parenteral 500mg AA supplementation improves PON activity alleviating apo B-containing lipoproteins oxidizability in HD patients.

Abstract PO-015: A phase Ib/II trial of high dose ascorbic acid (AA) + paclitaxel protein bound (PP) + cisplatin (C) + gemcitabine (G) in patients (pts) with previously untreated metastatic pancreatic cancer (MPC)

Abstract Background: Increasing evidence suggests that high concentrations of AA (vitamin C) can decrease the growth of aggressive tumors, including Ras-mutant tumors. Based on the unmet need in MPC, its high frequency of Ras mutations, and prior work combining PP +C +G in pts with MPC (response rate of 70.5%, median survival 16.4 mos), we explored the addition of AA to that regimen. Pre and post treatment biopsies for biomarkers and digital spacial profiling are also being performed. Methods: This pilot trial utilized a 3 + 3 design for dose escalation of AA. Eligibility criteria included untreated stage IV MPC, ECOG 0-1, and measurable disease. Excluded were pts with a G6PD deficiency, renal oxalate stones, or need of capillary blood glucose monitoring as AA causes false low readings. The primary objective of the phase 1b was to determine the maximum tolerated dose (MTD) of AA in combination with PP +C +G in pts with MPC. Exploratory objectives included analysis of tumor texture on radiologic scans as an imaging biomarker for response; correlation between peak plasma levels of AA and response to treatment; potential biomarkers in the tumor including tumor immune cell infiltration, stromal activation, stem call enumeration; change in numbers of circulating tumor stem cells and macrophage lineage changes. Results: As of 7/2021, the phase Ib enrollment in this study has been completed. Six pts were treated in the cohort of AA 25 gm/m2, 4 pts at AA 37.5 gm/m2, and 7 pts at 56.25 gm/m2. The majority of all reported AEs were grades 1-2. The most common AEs related to study treatment were: platelet count decrease (70.6%), diarrhea (70.6%), hypomagnesemia (52.9%), dysgeusia (47.1%), peripheral sensory neuropathy (47.1%), nausea (35.3%), fatigue (35.3%), neutrophil count decreased (35.3%), and hypokalemia (35.3%). Of the 17 pts enrolled, 15 were evaluable. Response by RECIST 1.1 is 11 PR (73.3%), 2 SD (13.3%), 2 PD (13.3%). Evaluation of median PFS and OS is ongoing. Conclusions: This study has a high response rate of 73%. Most pts in all AA dosing cohorts experienced a brisk response to therapy. AA did not appear to add toxicities compared to historical AE data of PP +C +G and was well tolerated in all dose cohorts. The MTD of AA was not reached in the 56.25 gm/m2 cohort. The protocol allowed for an additional dose escalation of AA to 75 gm/m2. However, all pts in the 56.25 gm/m2 cohort achieved our goal of peak plasma AA levels of &amp;gt; 20 mM so the study was closed to enrollment. Quality of life measures, tumor tissue and blood sample analyses are underway. Supported by SU2C, Cancer Research UK, Lustgarten Foundation, Destroy Pancreatic Cancer &amp; the Young family. Citation Format: Gayle S. Jameson, Erkut H. Borazanci, Daniel D. Von Hoff, Joshua D. Rabinowitz, Michael S. Gordon, Sarah D. LeGrand, Courtney Snyder, Karen Ansaldo, Denise J. Roe, Haiyong Han. A phase Ib/II trial of high dose ascorbic acid (AA) + paclitaxel protein bound (PP) + cisplatin (C) + gemcitabine (G) in patients (pts) with previously untreated metastatic pancreatic cancer (MPC) [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-015.

The relationship between vitamin C or thiamine levels and outcomes for severe sepsis patients admitted to the ICU

Preliminary data have produced conflicting results regarding whether initial vitamin C levels in patients with severe sepsis correlate with mortality outcomes. We hypothesized that low plasma ascorbic acid or thiamine levels in severe sepsis patients admitted from the Emergency Department (ED) to the Intensive Care Unit (ICU) would be associated with increased mortality and an increased incidence of shock. Retrospective analysis of a prospective database of severe sepsis patients admitted to the ICU at an urban, academic medical center. Ascorbic acid and thiamine levels were analyzed in relation to survivors vs. non-survivors and shock vs. non-shock patients. 235 patients were included; mean age, 59.4 years ± 16.8 years; male, 128 (54.5%); in-hospital mortality, 16.6% (39/235); mean APACHE3 score, 61.8 ± 22.8; mean ascorbic acid level (reference range 0.40–2.10 mg/dL), 0.23 mg/dL (95% CI 0.07–4.02); and the mean thiamine level (reference range 14.6–29.5 nmol/L), 6.0 nmol/L (95% CI 4.0–9.5). When survivors were compared to non-survivors, survivors were more likely to be male (57.7% [113/196] vs. 38.5% [15/39]) and have lower APACHE3 scores (58.2 ± 22.6 vs. 79.9 ± 16.0). For the total cohort of 235 patients, there was no statistically significant relationship between a patient’s initial ascorbic acid or thiamine level and either survival or development of shock. In this analysis of early plasma samples from patients with severe sepsis admitted from the ED to the ICU, we found that mean ascorbic acid and thiamine levels were lower than normal range but that there was no relationship between these levels and outcomes, including 28 day mortality and development of shock.

Developmental retardation in neonates of aldehyde reductase (AKR1A)-deficient mice is associated with low ascorbic acid and high corticosterone levels

Aldehyde reductase encoded by the Akr1a gene catalyzes the NADPH-dependent reduction of a variety of aldehyde compounds, and it plays a role in the biosynthesis of ascorbic acid (AsA) by converting D-glucuronate to L-gulonate. Although supplementing drinking water with AsA (1.5 mg/mL) ameliorates the fertility of Akr1a−/− (KO) female mice, litter sizes in the KO mice are typically smaller than those for Akr1a+/+ (WT) mice, and about one-third of the neonates have a reduced stature. Half of the neonates in the smallest, developmentally retarded group died before weaning, and the remaining half (less than 6 g in weight) also barely grew to adulthood. While no difference was found in the number of fetuses between the KO and WT mice at 14.5-embryonic days, the sizes of the KO fetuses had already diverged. Among the organs of these retarded KO neonates at 30 d, the spleen and thymus were characteristically small. While an examination of spleen cells showed the normal proportion of immune cells, apoptotic cell death was increased in the thymus, which would lead to thymic atrophy in the retarded KO neonates. Plasma AsA levels were lower in the small neonates despite the fact that their mothers had received sufficient AsA supplementation, and the corticosterone levels were inversely higher compared to wild-type mice. Thus, insufficient AsA contents together with a defect in corticosterone metabolism might be the cause of the retarded growth of the AKR1A-deficient mice embryos and neonates.

Bleeding tendency and ascorbic acid requirements: systematic review and meta-analysis of clinical trials.

The World Health Organization set the recommended daily vitamin C intake, henceforth referred to as ascorbic acid (AA), on the basis of scurvy prevention. Double-blind AA depletion-repletion studies suggest that this recommended AA dose may be too low to prevent microvascular fragility. (1) To conduct a systematic review and meta-analysis of controlled clinical trials on whether AA supplementation leads to a reduced gingival bleeding tendency, a manifestation of microvascular fragility; and (2) to relate AA plasma levels to retinal hemorrhaging, another manifestation of microvascular fragility. Data were reviewed from 15 trials conducted in 6 countries with 1140 predominantly healthy participants with measures of gingival bleeding tendency, and from the National Health and Nutrition Examination Survey (NHANES) III of 8210 US residents with measures of retinal hemorrhaging. In clinical trials, AA supplementation reduced gingival bleeding tendency when estimated baseline AA plasma levels were < 28 μmol/L (standardized mean difference [SMD], -0.83; 95%CI, -1.16 to -0.49; P < 0.002). Supplementation with AA did not unequivocally reduce gingival bleeding tendency when baseline estimated AA plasma levels were >48 μmol/L or unknown (respective standardized mean differences: -0.23, 95%CI, -0.45 to -0.01, P < 0.05; and -0.56; 95%CI: -1.19 to 0.06, P < 0.08). In NHANES III, prevalence of both retinal hemorrhaging and gingival bleeding tendency increased when AA plasma levels were within the range that protects against scurvy (11-28 μmol/L; respective prevalence ratios adjusted for age and sex: 1.47; 95%CI: 1.22-1.77; and 1.64; 95%CI: 1.32-2.03; P < 0.001 for both). Consistent evidence from controlled clinical trials indicates that setting human AA requirements based on scurvy prevention leads to AA plasma levels that may be too low to prevent an increased gingival bleeding tendency. Gingival bleeding tendency and retinal hemorrhaging coincide with low AA plasma levels and thus may be reflective of a systemic microvascular pathology that is reversible with an increased daily AA intake.

Effects of ascorbic acid supplementation on immune status in healthy women following a single bout of exercise

This study was designed to determine the effects of ascorbic acid (AA) supplementation on immune status following a single bout of exercise. In a crossover design, 20 healthy sedentary women performed 30 min moderate-intensity cycling with (1000AA) or without (0AA) ingesting 1000 mg of AA daily for 1 week. Blood samples were taken immediately before, immediately after and 24 h post-exercise to determine the oxidative stress markers, immunophenotyping of peripheral blood lymphocytes and neutrophil phagocytic function. Moderate-intensity exercise in participants ranged in age from 21 to 23 years, showed no significant changes in oxidative stress markers in both cohorts. Plasma total creatine kinase was increased immediately after exercise and returned to baseline at 24 h post-exercise in both cohorts. Participants ingesting 1000 mg AA demonstrated significant higher level of plasma AA at pre-exercise and post-exercise as compared with the same time point in 0AA group. White blood cell and absolute neutrophil counts were increased immediately after exercise in both cohorts. Exercise resulted in increased lymphocyte count, CD4 + and CD8 + T cell counts immediately after exercise (p < 0.05) in 0AA group. AA supplement mitigated effects of exercise on CD4 + T cells. No significant change in neutrophil phagocytic function were observed when incubated with low or high concentrations of Candida albicans in both cohorts. These results suggested that a single bout of moderate-intensity exercise caused muscle injury with increased absolute CD4 + and CD8 + T cell counts, accompanied by a transient increase in neutrophil count, while their phagocytic function was not changed. However, a short-term AA supplementation does not show beneficial effects on exercise-induced changes in leukocyte subpopulations.

Collagen remodelling and plasma ascorbic acid levels in patients suspected of inherited bleeding disorders harbouring germline variants in collagen-related genes.

IntroductionVariants in collagen‐related genes COL1A1, COL3A1, COL5A1 and COL5A2 are associated with Ehlers‐Danlos syndrome (EDS), a heterogeneous group of connective tissue disorders strongly associated with increased bleeding. Of patients with incompletely explained bleeding diathesis, a relatively high proportion were shown to harbour at least one heterozygous variant of unknown significance (VUS) in one of these genes, the vast majority without meeting the clinical criteria for EDS.AimTo investigate the functional consequences of the identified variants by assessing the formation and degradation of types I, III and V collagen, in addition to plasma levels of ascorbic acid (AA).MethodsA total of 31 patients harbouring at least one heterozygous VUS in COL1A1, COL3A1, COL5A1 or COL5A2 and 20 healthy controls were assessed using monoclonal antibodies targeting neo‐epitopes specific for collagen formation and degradation. Plasma AA levels were measured in patients using high‐performance liquid chromatography.ResultsSerum levels of C5 M (degradation of type V collagen) were decreased in patients compared with healthy controls (p = .033). No significant differences were found in biomarkers for remodelling of types I and III collagen. A significant negative correlation between bleeding (ISTH‐BAT score) and plasma AA levels was shown (r = −.42; r2 = .17; p = .020). Suboptimal or marginally deficient AA status was found in 8/31 patients (26%).ConclusionFunctional investigations of collagen remodelling were not able to identify any clear associations between the identified variants and increased bleeding. The negative correlation between plasma AA levels and ISTH‐BAT score motivates further investigations.

Study of vitamin C therapy in allergic rhinitis

&lt;p&gt;&lt;strong&gt;Background:&lt;/strong&gt; Vitamin C has a therapeutic role in allergic rhinitis by reduction of oxidative stress and inflammation. The present study has been undertaken to evaluate the improvement or otherwise in the clinical manifestations of allergic rhinitis, following supplementation of this vitamin.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;40 subjects of allergic rhinitis were selected from the allergy clinics of Dayanand medical college and hospital. The study period was one and a half year. Vitamin C in the dose of 1 gm per day was administered in the case group and in the placebo group a sugar tablet was administered by the oral route. Plasma levels of ascorbic acid and its effect on the symptoms and signs of rhinitis were recorded.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; The mean duration of illness in the patients with allergic rhinitis was 10.15±3.4 years, with 25 patients having duration of less than 10 years, 10 patients were with of illness between 10 to 20 years and 5 having duration more than 20 years. The most common complaint in patients with allergic rhinitis was of nasal obstruction (57.5%).&lt;/p&gt;&lt;p&gt;All the patients who showed improvement had increase in plasma ascorbic after the respective treatment but not all the patients showing increase in plasma ascorbic acid post-treatment showed improvement.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;Vitamin C ameliorates the signs and symptoms of allergic rhinitis by raising the plasma ascorbic acid levels.&lt;/p&gt;

Neuroprotective effect of NXP031 in the MPTP-induced Parkinson's disease model

Parkinson’s disease (PD) is a neurodegenerative disease characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra (SN). Oxidative stress has been identified as one of the major causes of nigrostriatal degeneration in PD. Ascorbic acid plays a role as an efficient antioxidant to protect cells from free radical damage, but it is easily oxidized and loses its antioxidant activity. To overcome this limitation, we have recently developed NXP031, a single-stranded DNA aptamer that binds to ascorbic acid with excellent specificity, reducing its oxidation and increasing its efficacy. This study investigated the neuroprotective effects of NXP031 in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD model. Acute degeneration of nigral dopaminergic neurons was induced by four consecutive treatments of MPTP (20 mg/kg) in male C57BL/6 J mice. NXP031 (Vitamin C/Aptamin C 200 mg/4 mg/kg) was administered intraperitoneally for 5 days following MPTP. We observed that the administration of NXP031 ameliorated MPTP-induced loss of dopaminergic neurons in the SN and exhibited improvement of MPTP-mediated motor impairment. We further found that NXP031 increased plasma ascorbic acid levels and inhibited microglia activation-induced neuroinflammation in the SN, which might contribute to the protective effects of NXP031 on nigrostriatal degeneration. Our findings suggest that NXP031 could be a potential therapeutic intervention in PD.

Can vitamin C and interleukin 6 levels predict preterm premature rupture of membranes: evaluating possibilities in North Indian population.

ObjectiveWe aimed to evaluate the relation between plasma ascorbic acid levels and the occurrence of preterm premature rupture of membranes (PPROM) and whether patients with ascorbic acid deficiency have predisposition to microbial invasion, as revealed by serum interleukin-6 (IL-6) levels and confirmed by placental culture sensitivity evaluation.MethodsThis controlled study involved 50 women with PPROM at gestational age between 28 and 36.6 weeks. Fifty patients with uncomplicated pregnancy and intact membranes were observed as control group. Serum ascorbic acid and IL-6 levels were evaluated for PPROM group subjects and controls, matched by their gestational age and body mass index. Repeat samples for IL-6 were taken after 48 hours of admission in PROM group subjects and at the onset of labor in controls. Placental membranes were sent for culture sensitivity evaluation after delivery.ResultsThe mean plasma level of ascorbic acid was 0.60±0.35 mg/dL and 1.18±0.43 mg/dL in the PPROM and control groups, respectively, showing significant difference. Plasma IL-6 level rose from 18.18±5.94 pg/mL to 34.32±7.31 pg/mL after 48 hours of admission in the PPROM group (P=0.000). Plasma IL-6 level in controls rose from 5.59±4.36 pg/mL at admission to 7.36±3.67 pg/mL at the onset of labor. Membrane culture test results were positive in a total of 40 samples, of which 37 samples were from the PPROM group subjects.ConclusionVitamin C deficiency, when complemented with elevated serum IL-6 level, can predict susceptibility to PPROM in the third trimester; the risk increases in women with prior history of similar pathology.

Association of Plasma and Aqueous Humor Ascorbic Acid Level with Morphology Pattern of Age-Related Cataract

Background: Age-related cataract is one of the most important causes of preventable blindness among elderly population in the world. Among various causes of cataract, the level of ascorbic acid in the plasma and aqueous humor is an important parameter that can prevent cataract formation. The level of ascorbic acid in the plasma and aqueous humor is also an indicator of various morphological pattern of cataract.&#x0D; Materials and Methods: A hospital-based cross-sectional study was conducted among 136 patients with immature age-related cataract (≥50 years) who underwent Manual Small Incision Cataract Surgery in the Ophthalmology Department of BPKIHS for the duration of 1 year. Plasma and aqueous humor ascorbic acid levels were determined by standard competitive ELISA test.&#x0D; Results: Ascorbic acid concentrations in aqueous humor as well as plasma were statistically significant with the nuclear type of cataract (p&lt;0.001). There was a positive correlation between plasma and aqueous ascorbic acid level with r = 0.532 and p&lt;0.001.&#x0D; Conclusion: The finding of the study concludes that nuclear type of cataract has a strong association with both aqueous humor and plasma ascorbic acid level.