Mg Of L-ascorbic Acid Research Articles

Metal–Organic Framework-Derived CuS Nanocages for Selective CO 2 Electroreduction to Formate

Electroreduction of CO2 to target products with high activity and selectivity has techno-economic importance for renewable energy storage and CO2 utilization. Herein, we report a hierarchical CuS h...

Redox-regulation of haemostasis in hypoxic exercising humans: a randomised double-blind placebo-controlled antioxidant study.

In vitro evidence has identified that coagulation is activated by increased oxidative stress, though the link and underlying mechanism in humans have yet to be established. We conducted the first randomised controlled trial in healthy participants to examine if oral antioxidant prophylaxis alters the haemostatic responses to hypoxia and exercise given their synergistic capacity to promote free radical formation. Systemic free radical formation was shown to increase during hypoxia and was further compounded by exercise, responses that were attenuated by antioxidant prophylaxis. In contrast, antioxidant prophylaxis increased thrombin generation at rest in normoxia, and this was normalised only in the face of prevailing oxidation. Collectively, these findings suggest that human free radical formation is an adaptive phenomenon that serves to maintain vascular haemostasis. In vitro evidence suggests that blood coagulation is activated by increased oxidative stress although the link and underlying mechanism in humans have yet to be established. We conducted the first randomised controlled trial to examine if oral antioxidant prophylaxis alters the haemostatic responses to hypoxia and exercise. Healthy males were randomly assigned double-blind to either an antioxidant (n=20) or placebo group (n=16). The antioxidant group ingested two capsules/day that each contained 500mg of l-ascorbic acid and 450 international units (IU) of dl-α-tocopherol acetate for 8weeks. The placebo group ingested capsules of identical external appearance, taste and smell (cellulose). Both groups were subsequently exposed to acute hypoxia and maximal physical exercise with venous blood sampled pre-supplementation (normoxia), post-supplementation at rest (normoxia and hypoxia) and following maximal exercise (hypoxia). Systemic free radical formation (electron paramagnetic resonance spectroscopic detection of the ascorbate radical (A•- )) increased during hypoxia (15,152±1193AU vs. 14,076±810AU at rest, P<0.05) and was further compounded by exercise (16,569±1616AU vs. rest, P<0.05), responses that were attenuated by antioxidant prophylaxis. In contrast, antioxidant prophylaxis increased thrombin generation as measured by thrombin-antithrombin complex, at rest in normoxia (28.7±6.4 vs. 4.3±0.2μgmL-1 pre-intervention, P<0.05) and was restored but only in the face of prevailing oxidation. Collectively, these findings are the first to suggest that human free radical formation likely reflects an adaptive response that serves to maintain vascular haemostasis.

Effect of Traditional Canning in Acetic Brine on the Antioxidants and Vitamins inBoletus edulisandSuillus luteusMushrooms

The effect of canning in traditional acetic brine on antioxidants and vitamins in Boletus edulis and Suillus luteus mushrooms was determined. Fresh mushrooms were canned in mild and strong acetic brine (containing 0.7 and 1.5% acetic acid in the final product respectively). Analysis was carried out on fresh and canned (over 12 months of storage) mushrooms; 100 g of fresh mushrooms contained 78.0–203.8 mg of total polyphenols, 18.0–33.7 mg of total flavonoids, 2.9–17.0 mg of l-ascorbic acid, 57.06–61.84 µg of total tocopherols, 139.9–238.9 µg of B1 vitamin, 171.1–418.6 µg of B2 vitamin, 2601–2648 µg of B3 vitamin, and 47.61–75.14 µg of B6 vitamin. Antioxidant activity was 36.9–132.3 mmol TE determined with ABTS, 25.6–27.2 mmol TE with DPPH and 64.4–246.4 mmol Fe2+ by FRAP assay. Canning and subsequent storage resulted in changes in all the parameters analysed: antioxidants −13 to −64%; B-group vitamins −84 to + 38%; antioxidant activity −68 to + 107%. Practical Application Wild edible mushrooms are very popular foodstuffs due to their exceptional taste and texture. Fresh mushrooms are highly perishable and processing techniques that can maintain their nutrition value as well as quality parameters are necessary. In Central Europe canning mushrooms with spices and vegetables with addition of acetic acid brine has traditionally been used for preserving mushrooms. The practical application of this research is to evaluate effect of preserving two wild mushroom species by canning in traditional acetic brine on the quality parameters of those mushrooms. The results can be used to determine whether this method of mushroom processing can be used on a larger scale by the industry to substitute currently used methods providing better quality and nutritional value.

Effects of vitamin C and folic acid supplementation on serum paraoxonase activity and metabolites induced by heat stress in vivo

This study investigated the effects of vitamin C (L-ascorbic acid) and folic acid supplementation on the levels of enzymes activities such as paraoxonase (PON1) and arylesterase and metabolites in the plasma of heat-stressed Japanese quails ( Coturnix coturnix japonica) kept at 34°C. A total of 150 Japanese quails (10 days old) were randomly assigned to five treatment groups, with three replicates of 10 birds each. The birds, which were kept at 34°C (09.00 to 17.00; for 8 hours) were fed either a basal diet (high-temperature basal diet, HS group) or the basal diet supplemented with either 250 mg of L-ascorbic acid/kg of diet (Vit C group), 1 mg of folic acid/kg of diet (FA group), or 250 mg of L-ascorbic acid plus 1 mg of folic acid/kg of diet (Vit C + FA group), whereas birds kept at 22°C were fed a basal diet (thermo-neutral-basal diet, TN group). Supplemental vitamin C and folic acid significantly increased paraoxonase, arylesterase, creatine kinase, lactic dehydrogenase, and alkaline phosphatase activities compared with the HS group. Serum activities of aspartate aminotransferase and alanine aminotransferase were not influenced by dietary vitamin C or folic acid ( P > 0.05). Serum cholesterol, triglyceride, high density lipoprotein (HDL)–cholesterol, and glucose concentrations decreased, whereas total protein and albumin concentrations increased with dietary vitamin C and folic acid supplementation ( P < 0.05) compared with the HS group. However, the combination of vitamin C and folic acid provided the greatest results. Serum values were also greatest for PON1 and arylesterase and lowest for cholesterol, trygliceride, HDL-cholesterol and glucose ( P < 0.05) for the TN group. The results of the study show that, separately or in combination, vitamin C and folic acid supplementation improved increased PON1 and arylesterase; the results also suggest that vitamin C and folic acid, especially in combination, may offer a potential protective management practice in preventing heat-stress–related depression in the performance of broiler quails.

Efeito da vitamina C no ganho de peso e em parâmetros hematológicos de tambaqui

O objetivo deste trabalho foi avaliar o efeito da suplementação dietária com ácido L-ascórbico (vitamina C) no ganho de peso e em parâmetros hematológicos de juvenis de tambaqui, Colossoma macropomum. Após dez semanas, em que foram alimentados com dietas contendo 0, 100 e 500 mg de ácido L-ascórbico por kg de ração, os peixes foram capturados e imediatamente anestesiados para a coleta de sangue da veia caudal e determinação dos parâmetros hematológicos. Animais alimentados com maiores níveis de ascorbato mostraram pesos corpóreos maiores, melhores taxas de conversão alimentar e sobrevivência. A asência de ácido L-ascórbico na ração, além de causar redução nos valores de hematócrito e no número de eritrócitos, que caracteriza anemia, provocou aumento no volume corpuscular médio, na hemoglobina corpuscular média e na concentração de hemoglobina corpuscular média. Esses resultados revelam a importância do ácido L-ascórbico na dieta dos juvenis de tambaqui. O nível de 100 mg de ácido L-ascórbico/kg de ração é adequado, garantindo bom ganho de peso e manutenção da homeostase do organismo.

Egg production, egg quality, and lipid peroxidation status in laying hens maintained at a low ambient temperature (6°C) and fed a vitamin C and vitamin E-supplemented diet

This experiment was conducted to evaluate the effects of vitamin C (L-ascorbic acid) and vitamin E (&amp;alpha;-tocopherol acetate) on egg production, egg quality, lipid peroxidation status (measured as MDA), and some serum metabolites in laying hens (Hy-Line) maintained at a low ambient temperature (6&amp;deg;C). One hundred and twenty laying hens (18-wk-old) were divided into four groups, 30 hens per group. The laying hens were fed either a basal diet or the basal diet supplemented with either 250 mg of L-ascorbic acid/kg of diet, 250 mg of &amp;alpha;-tocopherol acetate/kg of diet or 250 mg of L-ascorbic acid plus 250 mg of &amp;alpha;-tocopherol acetate/kg of diet. Although feed consumption of the hens was similar (P &amp;gt; 0.05) among treatments, supplemental vitamin C and E significantly increased final body weight, egg production, and improved feed efficiency (P &amp;lt; 0.05). Egg weights were also greater (P &amp;lt; 0.05) in hens supplemented with the combination of vitamin C and E than that of hens supplemented either vitamin or no vitamin (control). Haugh unit did not change upon each vitamin supplementation, but the combination of the vitamin supplement yielded a higher Haugh unit (P &amp;lt; 0.05). Each dietary supplement of vitamin C and vitamin E improved the egg quality (P &amp;lt; 0.05) resulting in a greater specific gravity, thicker egg shell, and heavier egg shell weight. Separately or as a combination, supplemental vitamin C and E decreased MDA, glucose, cholesterol, and triglyceride concentrations (P &amp;lt; 0.05). Results of the present study showed that supplementing vitamin C and vitamin E, particularly as a combination, improved the performance of cold-stressed laying hens, offering a potential protective management practice in preventing cold stress-related losses in performance of laying hens. Results of the present study also indicated that the effects of vitamin C and vitamin E are additive.

Effects of Dietary Chromium Picolinate and Ascorbic Acid Supplementation on Egg Production, Egg Quality and Some Serum Metabolites of Laying Hens Reared under a Low Ambient Temperature (6 °C)

This experiment was conducted to evaluate the effects of chromium (chromium picolinate, Cr Pic) and vitamin C (L-ascorbic acid) supplementation on egg production and egg quality in laying hens (Hy-Line) kept at 18 °C (at thermo-neutral zone) or 6 °C (cold stress) in temperature-controlled rooms. One hundred and fifty laying hens (32 week-old) were divided into 5 groups, 30 hens per group. The laying hens kept at 6 °C temperature were fed either a basal diet (low temperature-basal diet, LTB group) or the basal diet supplemented with either 400 µg of Cr per kg diet (Cr group), 250mg of L-ascorbic acid per kg diet (Vit C group) or 400 µg of Cr plus 250mg of L-ascorbic acid per kg diet (Vit C + Cr group) while hens kept at 18 °C fed a basal diet (thermo-neutral-basal diet, TNB group). Performance and egg quality were significantly reduced in LTB group compared with TNB group. Supplemental chromium and vitamin C significantly increased live weight change, egg production, and improved feed efficiency in cold-stressed hens compared with group fed the basal diet at 6 °C brought up to the values of the group reared under thermoneutral conditions (18 °C). Egg production and egg weight were also greater in each supplemental group compared with the LTB group. Separately or as a combination, supplemental chromium and vitamin C increased serum insulin but decreased corticosterone, glucose and cholesterol concentrations. Results of the present study show that supplementing vitamin C and chromium, particularly as a combination, improved the performance of cold-stressed hens. Such a combination of supplement can offer a potential protective management practice in preventing cold stress-related losses in performance of laying hens.

Effects of Chromium Picolinate and Ascorbic Acid Dietary Supplementation on Nitrogen and Mineral Excretion of Laying Hens Reared in a Low Ambient Temperature (7 °C)

Sahin K., N. Sahin: Effects of Chromium Picolinate and Ascorbic Acid Dietary Supplementation on Nitrogen and Mineral Excretion of Laying Hens Reared in a Low Ambient Temperature (7 o C). Acta Vet. Brno 2002, 71: 183‐189. The effects of chromium (chromium picolinate, CrPic) and ascorbic acid (L-ascorbic acid) supplementation on nitrogen (N), ash and mineral retention in laying hens (Hy-Line) reared under a low ambient temperature (7 oC) was evaluated. One hundred and twenty laying hens (32-weekold) were divided into four groups, 30 hens per group. The laying hens were fed either a basal diet or the basal diet supplemented with either 400 µg of Cr/kg of diet, 250 mg of L-ascorbic acid /kg of diet, or 400 µg of Cr plus 250 mg of L-ascorbic acid/kg of diet. Retention of N, ash, Ca, P, Zn, Fe and Cr were highest with the combination of chromium and ascorbic acid and were lowest with the control diet ( P< 0.05). Accordingly, excretion of N, ash Ca, P, Zn, Fe and Cr was lesser in chromium and ascorbic acid supplemented groups than the control ( P< 0.05), that of combination of supplemental chromium and ascorbic acid being lowest. Results of the present study show that supplementing ascorbic acid and chromium, particularly as a combination, improved retention of mineral and decreased excretion of nitrogen, ash, Ca, P, Zn, Fe, and Cr in laying hens. Such a combination of supplementation can offer a potential protective management practice in preventing the detrimental effects of cold stress in laying hens. The results of the present study also show that chromium and vitamin C had additive effects on parameters measured at the present study. Cold stress, chromium, ascorbic acid, mineral excretion, laying hen

Effects of vitamin C and vitamin E on lipid peroxidation, blood serum metabolites, and mineral concentrations of laying hens reared at high ambient temperature.

This study was conducted to determine the effects of vitamin C (L-ascorbic acid) and vitamin E (alpha-tocopherol acetate) on serum concentrations of lipid peroxidation (MDA) and triiodothyronine (T3), thyroxine (T4), adrenocorticotropic hormone (ACTH), and some metabolite and mineral in laying hens reared at high ambient temperatures ranging from 25 degrees C to 35 degrees C. One hundred twenty laying hens (18 wk old; Hy-Line) were divided into 4 groups, 30 hens per group. The laying hens were fed either a basal diet (control) or the basal diet supplemented with either 250 mg of L-ascorbic acid/kg of diet (vitamin C), 250 mg of alpha-tocopherol acetate/kg of diet (vitamin E), or 250 mg of L-ascorbic acid plus 250 mg alpha-tocopherol acetate/kg of diet (combination). Separately or as a combination vitamins C and E increased serum vitamin C and vitamin E concentrations (p < 0.001) but decreased serum MDA concentration (p < 0.05). Serum concentrations of vitamin E and vitamin C were found highest but serum MDA concentration was lowest in the combination group. Supplemental vitamins C and E either separately or in a combination increased serum T3 and T4 concentrations (p < 0.05), whereas decreased serum ACTH concentration (p < 0.01). Serum glucose and cholesterol concentrations decreased, whereas serum protein concentration increased (p < 0.05) when vitamins C and E singly or together were added to the diet. Vitamin C and vitamin E supplementation resulted in an increase in serum concentrations of Ca, P, and K (p < 0.01) but a decrease in serum concentration of Na (p < 0.05). The results of the present study suggest that supplemental vitamin C and vitamin E alter serum lipid peroxidation, vitamin C, vitamin E and metabolite status, and diets supplemented with a combination of these two vitamins offer a good management practice in laying hens reared at high temperatures. In addition, the results suggest that dietary vitamin C and vitamin E act synergistically.

Isolation and Characterization of a New Vitamin C Producing Enzyme (L-Gulono-γ-lactone Dehydrogenase) of Bacterial Origin

For the first time we found that the bacterial strain Gluconobacter oxydans DSM 4025 produced L-ascorbic acid from L-gulono-γ-lactone and therefore we isolated and purified the enzyme L-gulono-γ-lactone dehydrogenase catalyzing the oxidation reaction. G. oxydans DSM 4025 produced 8.57 and 13.9 mg of L-ascorbic acid per ml from 70.3 and 89.3 mg of L-gulono-γ-lactone per ml in the growing and resting cell systems, respectively. The enzyme was isolated from the soluble fraction of the cells of G. oxydans DSM 4025 by DEAE-cellulose, Q-Sepharose, hydroxylapatite, and Sephacryl S-300 column chromatographies. The molecular weight of the enzyme was 110, 000 and it consisted of three kinds of subunits of 61, 000, 32, 500, and 16, 5000. L-Gulono-γ-lactone was oxidized to L-ascorbic acid very rapidly in the presence of dyes, such as 2, 6-dichlorophenolindophenol or phenazine methosulfate, but oxygen was not available as an electron acceptor. The absorption spectrum of the reduced form of the native enzyme showed maxima at 416, 521, and 552 nm in the visible region, indicating the presence of cytochrome c. The enzyme isolated from G. oxydans DSM 4025 was entirely different from isofunctional enzymes of eucaryotic organisms.

Effect of water temperature on the skeletal deformity in ascorbic acid-deficient rainbow trout.

The effect of rearing water temperature on the skeletal deformity in ascorbic acid-deficient rainbow trout, weighing 0.17g on average, was investigated. Three groups of fish were fed a diet at one of three ascorbic acid levels, i.e., 0, 2, and 200mg of L-ascorbic acid per 100g of diet, and were maintained either at 16°C or at 20°C for 20 weeks. Two other groups were given a diet at one of two ascorbic acid levels, i.e., 0 and 200mg of L-ascorbic acid per 100g of diet, and maintained at 16°C for the first 10 weeks and at 20°C for the last 10 weeks. Lower growth was observed in the groups maintained at 20°C irrespective of dietary ascorbic acid levels. The skeletal deformity was observed only in the ascorbic acid-deficient groups. The rate of development of skeletal deformity increased markedly in the group which was maintained initially at 16°C with subsequent rise of water temperature to 20°C. These results indicate that underhydroxylated collagen in the tissues of ascorbic acid-deficient fish is denatured and digested quickly at higher water temperature, resulting in the low collagen content of the connective tissues, and finally developing a fragile bone structure.

A new masking reagent, maleonitrildithiolate ion, for the spectrophotometric determination of aluminum (III) by 8-quinolinol extraction method

A new masking reagent, maleonitrildithiolate (MNT) ion, was proposed for the spectrophotometric deter-mination of Al(III) by 8-quinolinol extraction method. Meleonitrildithiolate ion reacts with various heavy metal ions to form water-soluble and stable anionic complexes, but hardly reacts with Al(III). As these MNT complexes were not extracted into chloroform, only Al(III) was able to be extracted into chloroform as a neutral 8-quinolinolato complex. Diverse heavy metal ions, such as 1900 fold amount (μg/cm3) of Cu (II) for 0.54 μg/cm3 of Al(III), 220 fold of Co (II), 210 fold of Ni(II) and 130 fold of Fe (II) for 2.16 μg/cm3 of Al(III) were quantitatively masked in the extraction of Al (III), by shaking for one minute using 60 mg of MNT (sodium salt) and 20 mg of L-ascorbic acid.

The antiscorbutic action of l-ascorbic acid and d-isoascorbic acid (erythorbic acid) in the guinea pig

Female guinea pigs were fed a scorbutigenic diet supplemented with either L-ascorbic acid or D-isoascorbic acid or combinations of these. Their responses were judged by changes in body weight, serum alkaline phosphatase levels, wound healing, and tooth structure. Large additions (100 mg daily) of D-isoascorbic acid to the scorbutigenic diet resulted in normal growth over a 7-wk period and normal serum alkaline phosphatase levels, tooth structure development, and collagen formation after wounding. The addition of 0.5 or 5.0 mg of L-ascorbic acid to this high D-isoascorbic diet improved neither growth rate nor collagen deposition during wound healing. On the basis of changes in tooth structure, D-isoascorbic acid has 1/20 the potency of L-ascorbic acid. Its effect is additive to subminimal maintenance levels of L-ascorbic acid implying that there is no competitive inhibition in the utilization of the two compounds. The relatively weak activity of D-isoascorbic acid is probably due to poor transport to the tissues and ineffective binding to functional sites. This explains why the onset of scurvy is much more rapid after withdrawal of D-isoascorbic acid from the diet when it had been the sole antiscorbutic dietary constituent. It is concluded that D-isoascorbic acid is a "weakly" antiscorbutic agent on the basis that it is both poorly absorbed and retained by the tissue; that in fact it may, to the degree that it is taken up by the tissues and retained, be equal in antiscorbutic potency to L-ascorbic acid.

Synergistic effect of vitamin C and aspirin on gastric lesions in the rat

The effects of varying levels of dietary vitamin C on the incidence of aspirin-induced gastric hemorrhagic lesions were studied in young, male rats. Rats fed diets containing either 20, 40, or 60 mg of l-ascorbic acid per gram of diet did not exhibit focal gastric lesions. Administering a single oral dose of aspirin (30 mg aspirin/100 g of body weight) to rats fed control diets produced gastric lesions. When the rats were given aspirin plus a diet containing either 40 or 60 mg ascorbic acid per gram of diet, there was a significant increase in number of gastric lesions. Since vitamin C and aspirin seem to act synergistically in producing hemorrhagic lesions in the stomach, it is recommended that all individuals taking megadoses of vitamin C be cautioned against taking aspirin concurrently.

Action of l-Ascorbic Acid upon the Isolated Frog Heart.

It was recently reported that hydrogen peroxide is the cause of the positive inotropic and of the irreversible systolic effect upon the frog heart of ascorbic acid solutions.1 The evidence available in the literature indicates that the hydrogen peroxide formation in ascorbic acid solutions is related to the dehydrogenation of the molecule, and, more specifically, to the catalytic action of copper in this process.2 It is known that the catalytic action of copper can be prevented by the formation of complexes between the metal and suitable substances like protein3 or diethyl-dithiocarbamate.4 Serum globulin and sodium diethyldithiocarbamate were therefore used to determine whether copper inhibitors were able to diminish or prevent the action of l-ascorbic acid solutions upon the frog heart.Method. 50 to 100 mg of l-ascorbic acid were dissolved in one cc of distilled water; and this solution, after neutralization with sodium bicarbonate, was diluted to an initial concentration of approximately 1:10,000 with ...