Effect Of Ascorbic Acid Supplementation Research Articles

Ascorbic acid deficiency affects genes for oxidation–reduction and lipid metabolism in livers from SMP30/GNL knockout mice

BackgroundWe sought to elucidate the effect of an ascorbic acid (AA) deficiency on gene expression, because the water soluble antioxidant AA is an important bioactive substance in vivo. MethodsWe performed microarray analyses of the transcriptome in the liver from senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which are unable to synthesize AA in vivo. ResultsOur microarray analysis revealed that the AA deficiency increased gene expression related to the oxidation–reduction process, i.e., the nuclear factor, erythroid derived 2, like 2 (Nrf2) gene, which is a reactive oxygen species-sensitive transcriptional factor. Moreover, this AA deficiency increased the expression of genes for lipid metabolism including the cytochrome P450, family 7, subfamily a, polypeptide 1 (Cyp7a1), which is a late-limiting enzyme of the primary bile acid biosynthesis pathway. Although an AA deficiency increased the Cyp7a1 protein level, bile acid levels in the liver and gallbladder decreased. Since Cyp7a1 has a heme iron at the active site, AA must function as a reductant of the iron required for the continuous activation of Cyp7a1. ConclusionsThis experimental evidence strongly supports a role for AA in the physiologic oxidation–reduction process and lipid metabolism including bile acid biosynthesis. General significanceAlthough many effects of AA supplementation have been reported, no microarray analysis of AA deficiency in vivo is available. Results from using this unique model of AA deficiency, the SMP30/GNL-KO mouse, now provide new information about formerly unknown AA functions that will implement further study of AA in vivo.

Effect of ascorbic acid on long-term cold exposure induced changes in thyroid activity in Sprague Dawley rats.

To determine the effect of ascorbic acid supplementation on long-term cold exposure induced changes in thyroid activity in Sprague-Dawley rats. Experimental study. Physiology Department of Islamic International Medical College, Rawalpindi, National Institute of Health, Islamabad and Railway Hospital, Rawalpindi, from January to December 2009. Ninety Sprague-Dawley rats were randomly divided into three groups of control, cold exposed and cold exposed along with ascorbic acid supplementation. After one month, their thyroid levels were analyzed by using chemiluminescent immunometric assay on Siemens Immulite 2000 Analyzer. After 4 weeks of cold exposure to experimental animals, the thyroid activity was raised significantly in the cold exposed group as compared to the control group (p-value for T3 difference = 0.004, T4 difference = 0.002 and TSH difference < 0.001). Supplementation with ascorbic acid in the third group normalized the thyroid hormone activity with p-value for difference in levels of T3 being 0.6661, T4 = 0.027 and TSH = 0.0028. Ascorbic acid prevented the cold induced changes in thyroid hormone levels in rodents.

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.

Concentration-Dependent Antioxidant/Pro-Oxidant Activity of Ascorbic Acid in Chickens

The effects of ascorbic acid supplementation on biomarkers of oxidative stress, cadmium accumulation in organs, immune system activity and kidney function in chickens were investigated. The treatment groups of chickens were fed either plain diet or diet supplemented with ascorbic acid at 100, 500, 1000 and 2000 mg/kg for four weeks. Liver and kidney tissues were assayed for cadmium concentration, and the hepatic levels of ascorbic acid and dehydroascorbic acid (DHAA; the oxidised form), malondialdehyde, glutathione, activity of glutathione peroxidase, blood serum uric acid, creatinine, lysozyme and circulating immune complexes were measured. Supplementation with a high dose of ascorbic acid (1000 and 2000 mg/kg in the diet) caused an imbalance between pro-oxidative and antioxidative activities, and induced a suppressive effect on innate immunity. The results suggest that oxidative stress compromises renal function. We observed that ascorbic acid increased cadmium accumulation in a dose-dependent manner.

Neuroprotection and neurodegeneration in submucosal VIP-IR neurons in the jejunum of ascorbic acid supplemented aging Wistar rats

The present work studied the effects of ascorbic acid supplementation (1 mg/ml in water daily) on submucosal vasoactive intestinal polypeptide-immunoreactive (VIP-IR) neurons in the jejunum of aging rats. Twenty-five male rats were divided into the following groups: Y90 (young, 90-day-old rats), A345 (aged, 345-day-old rats), A428 (aged, 428-day-old rats), AA345 (ascorbic acid-supplemented rats, 90–345-day old), and AA428 (ascorbic acid-supplemented rats, 90–428-day old). Whole mounts of the submucosal layer were subjected to immunohistochemistry for determination of VIP-IR. Morphometric analyses were carried out in 100 submucosal VIP-IR neuron cell bodies from each group. At 345 days, neurons from supplemented animals were larger than those of non-supplemented animals of the same age. These results indicate that ascorbic acid neutralized free radicals and played a neuroprotective role. At 428 days, no significant differences between cell body areas were seen with or without ascorbic acid supplementation, indicating that, from a certain age onward, the role of ascorbic acid as a VIP-IR antioxidant was reduced. This supposition is supported by the fact that both supplemented and non-supplemented animals had higher blood concentrations of ascorbic acid on Day 428 compared with Day 345. The possible neuroprotective and neurodegenerative effects of ascorbic acid appear to depend on the age of the animals, dose, and its interaction with other antioxidants.

Effect of diurnal variation and ascorbic acid administration on rectal temperature, pulse and respiratory rates in sheep during wet season in Sokoto

The research was conducted to study diurnal variation and effect of ascorbic acid supplementation on rectal temperature, pulse and respiratory rates of sheep during wet season in Sokoto. The study was conducted on ten (10) apparently healthy Oudah breed of sheep with mean age and weight of 15.9 ± 11.0 months and 24.7 ± 11.67 kg respectively. The animals were grouped into two groups of five animals each. 100mg/kg Ascorbic acid was administered daily for eight days to the experimental group while the control group was not given anything. Rectal temperature, pulse and respiratory rates were taken at 6am, 10am, 2pm and 6pm. Finding indicate that rectal temperature at 6am are significantly (P 0.03) between 2pm and 6pm temperature. At 10am the temperature was significantly lower (P< 0.05) than those of 2pm and 6pm in the control group but not in the experimental group. The pulse rate at 2pm was significantly higher (P<0.05) than those of 6am, 10am and 6pm in the experimental group. The respiratory rates at 6am were significantly lower (P<0.05) than those of 2pm and also 6pm in the experimental group. Ascorbic acid administration did not significantly cause any decrease in the rectal temperature, pulse and respiratory rates of the experimental group compared to the control group with the experimental group slightly higher than the control group.

Age-related changes in myosin-V myenteric neurons, CGRP and VIP immunoreactivity in the ileum of rats supplemented with ascorbic acid.

We examined the effects of ascorbic acid supplementation on myosin-V, calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) immunoractivities in the myenteric neurons in aging rats. Male rats were divided into groups: young 90-day-old rats (E90), 345-day-old control rats (E345), 428-day-old control rats (E428), 90- to 345-day-old rats treated with ascorbic acid (1 g/L) (EA345), and 90- to 428-day-old rats treated with ascorbic acid (1g/L) (EA428). The quantitative results showed that aging reduced the number of myosin-V-immunoreactive neurons compared with young animals (E90). Ascorbic acid supplementation in the EA345 and EA428 groups increased the average area of myosin-V neurons by 24.6% and 24.1% compared with the E345 and E428 groups, respectively. When all groups were compared, we observed significant differences for the CGRP- and VIP-immunoractive varicosities of nerve fibers from myenteric neurons. Ascorbic acid supplementation had a neurotrophic effect on all neurons studied, suggesting a neuroprotective role.

Modulatory Effect of Ascorbic Acid Supplementation on the Physiological and Behavioural Parameters in West African Dwarf Goats Confined During the Rainy Season

This study was carried out with the aim of investigating the modulatory effect of ascorbic acid (AA) on the physiological and behavioural parameters in confined West African dwarf goats during the rainy season. A total of fourteen adult West Africa Dwarf goats, male and non-pregnant, non-nursing female were used for the study. The animals were divided into two groups of seven animals each, experimental for those in group 1 and control for group 2. The haematological parameters obtained in experimental animal pre-confinement was not significantly (P > 0.05) different from the values obtained in the control animal during the same period. The values of leukocyte (7.57 ± 0.37 x 10 3 /µl) obtained in the experimental animal post-confinement was significantly (P 0.05) difference in the recorded haemolysis between experimental and control animals at pre-confinement. The lowest percentage haemolysis of 1.58 ± 0.62 % was obtained in experimental animals post confinement at 0.85 % of Sodium Chloride concentration while the corresponding value in the control animals was significantly (P 0.05) different in both experimental and control goats. The behavioural activities of standing (71.43 %) in experimental animals was significant (P > 0.05) higher than the value of 42.86 % in control animals. Also the behavioural activities of eating and drinking with a value of 71.43 % and 57.14 % respectively was significantly (P < 0.05) greater in experimental animals than the corresponding value of 28.57 % and 14.29 % in the control animal respectively while a value of 57.14 % recorded for behavioural activities of lying down in control animals was greater than 28.57 % recorded in experimental animals during confinement. The behavioural activities of standing (85.71 %), sniffing (57.14 %), fighting (57.14 %), eating (71.43 %) and drinking (57.14 %) was significantly (P < 0.05) higher in experimental animals compared to the corresponding values in the control animals post-confinement. In conclusion, it is thus recommended that ascorbic acid should be administered to goats in confinement during rainy season to ameliorate the stress induced by confinement as this may enhance their health and productivity during this period.

The effect of ascorbic acid supplementation on endosulfan toxicity in rabbits

We investigated the endosulfan-induced alterations and the effect of vitamin C supplementation on endosulfan-induced alterations in serum biochemical markers of oxidative stress and antioxidant capacity in rabbits. Basal, 4th and 6th week serum levels of total oxidant status (TOS), thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPP), total antioxidant capacity (TAC), total protein sulfhydryl (T-SH) and glutathione-S-transferase (GST) were measured in rabbits administered endosulfan (1 mg/kg) alone or in combination with vitamin C (20 mg/kg) for 6 weeks. Control rabbits received either vehicles or vitamin C. Serum TOS, TBARS and AOPP levels at 4th and 6th week were significantly higher whereas T-SH levels were significantly lower than basal values in endosulfan-administered rabbits. GST increased significantly at 4th week but decreased below basal value at 6th week. Similarly, TAC decreased significantly at 6th week. Vitamin C supplementation increased TAC at 4th and 6th weeks in controls and increased T-SH and GST and decreased TOS, TBARS and AOPP at 4th week in endosulfan-administered rabbits. TAC increased significantly at 6th week by vitamin C supplementation in endosulfan-administered rabbits. There were significant increments in TBARS and decrements in TAC and GST levels at 6th week compared to 4th week in endosulfan-administered rabbits. Present findings indicated to an increased and progressively uncompensated oxidant stress in endosulfan-administered rabbits that was substantially ameliorated by vitamin C supplementation through an improvement in antioxidant capacity. It was suggested that vitamin C supplementation might be helpful in preventing the detrimental effects of increased oxidative stress caused by endosulfan exposure.

The Effects of Ascorbic Acid Supplementation on Muscle Blood Flow in Aged Rats

During exercise aged individuals exhibit endothelial dysfunction and decreased levels of whole-limb blood flow, both of which may be linked mechanistically to age-related increases in reactive oxygen species (ROS). Ascorbic acid (AA) reduces levels of ROS and has been shown to alleviate vascular and hyperemic dysfunction at rest and during small muscle mass exercise in humans (Kirby et al. J Physiol., 2009). However, the effect of AA on vascular function and blood flow (BF) to individual muscles during dynamic whole-body exercise is not known. PURPOSE: To test the hypothesis that a single high-dose infusion of AA would increase BF to the hindlimb musculature of old rats at rest and during treadmill running. METHODS: 18 old (∼28 months) Fischer 344 × Brown Norway rats were randomized into rest (n=9) and exercise (n=9) groups. BF to the hindlimb (28 individual muscles and muscle parts) was evaluated via radiolabeled microspheres before and after intra-arterial AA administration (76 mg/kg in 3 ml heparinized saline, 30 minute infusion) at rest and during submaximal treadmill running (20 m/min, 5% grade). Total antioxidant capacity (TAC) and thiobarbituric acid reactive species (TBARS) were measured before and after AA to determine the ability of this dose of AA to increase levels of plasma antioxidants and decrease levels of ROS, respectively. RESULTS: At rest: AA increased TAC (∼37%, P < 0.05) but did not change TBARS (Pre: 6.8 ± 0.7 vs. Post: 7.0 ± 1.0 μM, P > 0.05). AA decreased total hindlimb BF (Pre: 25 ± 3 vs Post: 16 ± 2 ml/min/100g, P < 0.05) and BF to 8 of the 28 individual muscles that were evaluated. During exercise: TAC was increased (∼35%, P < 0.05) and TBARS were decreased (Pre: 9.8 ± 2.0 vs Post: 6.1 ± 0.5 μM, P < 0.05). However, there was no effect on either total hindlimb BF (Pre: 154 ± 14 vs. Post: 162 ± 13, P > 0.05) or BF to any of the individual muscles that were evaluated. CONCLUSIONS: Increased TAC via AA infusion reduces hindlimb muscle BF at rest but not during whole-body dynamic exercise. Thus, although this specific AA dose decreased TBARS, there was no evidence that AA supplementation increases blood flow to the locomotor muscles during whole-body exercise. Whether other doses of AA or alternative antioxidants provide beneficial outcomes in other models remains unknown. Support: AHA Grant 070090Z

The cryoprotective effects of ascorbic acid supplementation on bovine semen quality

To investigate the effects of ascorbic acid supplementation on standard semen quality parameters and antioxidant activities after thawing of bovine frozen semen, antioxidant ascorbic acid was added at concentrations of 2.5, 4.5, 6.5 and 8.5 mg/ml to bovine semen cryoprotective medium. The results showed that the sperm motility and motion characteristics were improved in the presence of ascorbic acid in extender, as compared to the control. The motility and straight linear velocity (VSL), linearity index (LIN), average path velocity (VAP), wobble coefficient (WOB), lateral head displacement (ALH) values and the percentage of “grade a” sperm in the extender supplemented with 4.5 mg/ml ascorbic acid were significantly higher than that of other treatment groups ( P < 0.05). The acrosome integrity and membrane integrity were significantly improved ( P < 0.05) by supplementing with 4.5 mg/ml ascorbic acid in the extender compared with a control. The extender supplemented with ascorbic acid did not lead to any improvement in superoxide dismutase (SOD) levels. The catalase (CAT) activity was higher in the extender supplemented with ascorbic acid at 4.5 mg/ml, when compared with other groups ( P < 0.05) and the extender supplemented with ascorbic acid significantly decreased glutathione peroxidase (GSH-Px) activity, whereas reduced glutathione (GSH) activities were significantly enhanced, compared with the control ( P < 0.05). Increasing the doses level of ascorbic acid decreased GSH-Px and GSH activity, the supplementation of 8.5 mg/ml ascorbic acid produced the lowest level of GSH-Px and GSH activity among groups ( P < 0.05). The extender supplemented with ascorbic acid could reduce the oxidative stress provoked by freezing–thawing and improve bovine semen quality. The particular properties of ascorbic acid are poorly related to its effectiveness in membrane cryopreservation. Further studies are required to determine lipid peroxidation and antioxidant capacities of ascorbic acid in cryopreserved bovine semen.

Effect of ascorbic acid supplementation on nitric oxide metabolites and systolic blood pressure in rats exposed to lead

Background:Extended exposure to low levels of lead causes high blood pressure in human and laboratory animals. The mechanism is not completely recognized, but it is relatively implicated with generation of free radicals, oxidant agents such as ROS, and decrease of available nitric oxide (NO). In this study, we have demonstrated the effect of ascorbic acid as an antioxidant on nitric oxide metabolites and systolic blood pressure in rats exposed to low levels of lead.Materials and Methods:The adult male Wistar rats weighing 200-250 g were divided into four groups: control, lead acetate (receiving 100 ppm lead acetate in drinking water), lead acetate plus ascorbic acid (receiving 100 ppm lead acetate and 1 g/l ascorbic acid in drinking water), and ascorbic acid (receiving 1 g/l ascorbic acid in drinking water) groups. The animals were anesthetized with ketamin/xylazine (50 and 7 mg/kg, respectively, ip) and systolic blood pressure was then measured from the tail of the animals by a sphygmomanometer. Nitric oxide levels in serum were measured indirectly by evaluation of its stable metabolites (total nitrite and nitrate (NOχ)).Results:After 8 and 12 weeks, systolic blood pressure in the lead acetate group was significantly elevated compared to the control group. Ascorbic acid supplementation could prevent the systolic blood pressure rise in the lead acetate plus ascorbic acid group and there was no significant difference relative to the control group. The serum NOχ levels in lead acetate group significantly decreased in relation to the control group, but this reduction was not significantly different between the lead acetate plus ascorbic acid group and the control group.Conclusion:Results of this study suggest that ascorbic acid as an antioxidant prevents the lead induced hypertension. This effect may be mediated by inhibition of NOχ oxidation and thereby increasing availability of NO.

The effect of ascorbic acid supplementation on brain oxidative events in experimental diabetes

Increased oxidant stress plays an important role in the etiopathogenesis of chronic complications of diabetes. This study aimed to examine the effects of ascorbic acid (vitamin C, AA) supplementation on the oxidant and antioxidant processes in the brain of diabetic rats. Wistar albino rats were divided into four groups: group 1 (control), group 2 (ascorbic acid, AA, vitamin C), group 3 (diabetes), and group 4 (diabetes + AA). The rats were treated with a single dose of streptozotocin (45 mg/kg, intraperitoneal) to induce diabetes. After 48 h, the rats whose fasting blood glucose levels exceeded 200 mg/100 mL were included in the diabetes groups. The rats in the AA and diabetes + AA groups were treated with AA (20 mg/kg/day), administered intragastrically for 21 days. At the end of the experiment, malondialdehyde (MDA), glutathione (GSH), AA, and total nitric oxide (NOx) levels in the liver tissues were determined. Analysis of variance (ANOVA) and Mann–Whitney U tests were used for statistical analyses. Whereas the MDA levels increased in the diabetes group, the NOx levels decreased. The NOx levels increased in the diabetes + AA group compared with the control subjects. There were no significant differences in the diabetes + AA group in terms of GSH levels. In conclusion, vitamin C or vitamin C preparations may be beneficial in the treatment of diabetic patients for maintenance of the brain cells against oxidative damage.

Effects of ascorbic acid supplementation in ileum myenteric neurons of streptozotocin-induced diabetic rats

The exacerbation of the oxidative stress and of the polyol pathway which impair damage myenteric plexus are metabolic characteristics of diabetes. The ascorbic acid (AA) is an antioxidant and an aldose reductase inhibitor, which may act as neuroprotector. The effects of AA supplementation on the density and cellular body profile area (CP) of myenteric neurons in STZ-induced diabetes in rats were assessed. Four groups with five animals each were formed: normoglycemic (C); diabetic (D); AA-treated diabetic (DS) and AA-treated normoglycemic (CS). Dosagen of 50mg of AA were given, three times a week, for each animal (group DS and CS). Ninety days later and after euthanasia, the ileum was collected and processed for the NADPH-diaphorase technique. There were no differences (P&gt;0.05) in the neuronal density among the groups. The CP area was lower (P&lt;0.05) in the DS and CS groups, with a higher incidence of neurons with a CP area exceeding 200µm² for groups C and D. The AA had no influence on the neuronal density in the ileum but had a neuroprotective effect, preventing the increase in the CP area and allowing a higher number of neurons with a CP area with less than 200µm².

Influence of maternal nicotine exposure on neonatal rat oxidant–antioxidant system and effect of ascorbic acid supplementation

There have been a few studies that examined the oxidative stress effects of nicotine during pregnancy and lactation. We aimed to determine the adverse effects of maternal nicotine exposure during pregnancy and lactation on oxidant-antioxidant system, and to determine a protective effect of ascorbic acid (Asc). Gravid rats were assigned into four groups. In Group 1, pregnant rats received 6-mg/kg/day nicotine subcutaneously during pregnancy from 1 to 21 days of gestation and lactation (until postnatal day 21). Group 2 received nicotine and Asc for the same period. In Group 3, the rats received nicotine during lactation. Control pregnant rats (Group 4) received only saline subcutaneously. Serum malondialdehyde (MDA), myeloperoxidase (MPO), and superoxide dismutase (SOD) levels were determined at 21 days of age. Nicotine exposure decreased birth weight and pregnancy weight gain. MDA values of the rat pups exposed to nicotine in both Groups 1 and 2 were higher than those of control and Group 3. SOD and MPO values of the groups were similar. Mean birth weight and serum MDA levels of Groups 1 and 2 were similar. Nicotine exposure via placental transfer increases oxidative stress as manifested by an increase in MDA level. Asc supplementation does not prevent the adverse effects of maternal nicotine exposure.

Effect of ascorbic acid supplementation on nitric oxide metabolites and systolic blood pressure in rats exposed to lead

Effect of ascorbic acid supplementation on nitric oxide metabolites and systolic blood pressure in rats exposed to lead

Effect of ascorbic acid supplementation on growth performance, carcass traits, some physiological parameters and some blood constituents of growing lambs under the summer Egyptian conditions.

Effect of ascorbic acid supplementation on growth performance, carcass traits, some physiological parameters and some blood constituents of growing lambs under the summer Egyptian conditions.

Effect of Time of Initiation of Feeding after Hatching and Influence of Dietary Ascorbic Acid Supplementation on Productivity, Mortality and Carcass Characteristics of Ross 308 Broiler Chickens in South Africa

An experiment was conducted to evaluate the effect of time of initiation of feeding after hatching and influence of dietary ascorbic supplementation during realimentation on productivity, carcass characteristics and mortality of Ross 308 broiler chickens. The study was a factorial arrangement in a complete randomized design. Six hundred and seventy five unsexed Ross 308 broiler chickens with an initial weight of 32±2 g per bird were assigned to 15 treatments in a 3 (times of initiation of feeding) x 5 (ascorbic acid supplemental levels) factorial arrangement with three replications, each having 15 birds each. The experimental diets were isocaloric and isonitrogenous but with different ascorbic acid supplementation levels. Ascorbic acid supplementation started three days after hatching. More than 50% of the birds died between one and three days of age when initiation of feeding after hatching was above 36 hours. Time of initiation of feeding above 36 hours of hatching resulted in lower (p 0.05) on feed intake of the bird's irrespective of time of initiation of feeding after hatching. It is concluded that time of initiation of feeding above 36 hours after hatching is not desirable, mainly because of its effect on mortality. However, the beneficial effect of ascorbic acid supplementation could be exploited in reducing mortality rate and improving growth rates in broiler chickens subjected to delayed initiation of feeding after hatching.

Ascorbic acid supplementation attenuates exercise-induced bronchoconstriction in patients with asthma

Previous research has shown that diet can modify the bronchoconstrictor response to exercise in asthmatic subjects. Determine the effect of ascorbic acid supplementation on pulmonary function and several urinary markers of airway inflammation in asthmatic subjects with exercise-induced bronchoconstriction (EIB). Eight asthmatic subjects with documented EIB participated in a randomized, placebo controlled double-blind crossover trial. Subjects entered the study on their usual diet and were placed on either 2 weeks of ascorbic acid supplementation (1500 mg/day) or placebo, followed by a 1-week washout period, before crossing over to the alternative diet. Pre- and post-exercise pulmonary function, asthma symptom scores, fraction of exhaled nitric oxide (FENO), and urinary leukotriene (LT) C4-E4 and 9alpha, 11beta-prostagladin (PG) F2] were assessed at the beginning of the trial (usual diet) and at the end of each treatment period. The ascorbic acid diet significantly reduced (p < 0.05) the maximum fall in post-exercise FEV1 (-6.4 +/- 2.4%) compared to usual (-14.3 +/- 1.6%) and placebo diet (-12.9 +/- 2.4%). Asthma symptoms scores significantly improved (p<0.05) on the ascorbic acid diet compared to the placebo and usual diet. Post-exercise FENO, LTC4-E4 and 9alpha, 11beta-PGF2 concentration was significantly lower (p<0.05) on the ascorbic acid diet compared to the placebo and usual diet. Ascorbic acid supplementation provides a protective effect against exercise-induced airway narrowing in asthmatic subjects.

Effect of Ascorbic Acid Supplementation on Certain Oxidative Stress Parameters in the Post Reperfusion Patients of Myocardial Infarction

Reperfusion injury causes oxidative stress thereby resulting in an imbalance between oxidant-antioxidant systems. In the present communication, the effect of ascorbic acid supplementation has been studied on certain oxidant and antioxidant parameters in the blood of the patients with myocardial infarction before and after thrombolysis. In patients after thrombolysis, the activity of antioxidant enzyme, superoxide dismutase, in the blood was found to be significantly reduced where as the activity of the oxidant enzyme, xanthine oxidase, was found to be significantly increased. Malondialdehyde levels, the index of free radical mediated damage, was also found to be significantly elevated in thrombolysed patients compared to the patients before thrombolysis. Supplementation of vitamin C to the post reperfusion patients restored these parameters back to normal or near normal levels.