Bioavailability Of Ascorbic Acid Research Articles

Effect of liposomal formulation of ascorbic acid on corneal permeability

Ascorbic acid (AA) has a pivotal role in corneal wound healing via stimulating the biosynthesis of highly organized extracellular matrix components, but its rapid degradation and low corneal permeability limits its therapeutic effects. In this paper, we present the pharmacokinetic properties of a liposomal-based formulation of AA in terms of corneal permeation. Chemical stability, shelf-life, and drug release rate of lyophilized liposome (AA-LLipo) formulation was determined in comparison to free-form of AA solution using high-performance liquid chromatography (HPLC) and rapid equilibrium dialysis. In vitro transcorneal permeability was studied using a parallel artificial membrane permeability assay (PAMPA). Ex vivo permeation was examined on AA-LLipo-treated porcine cornea by determining the AA content on the ocular surface, in the cornea as well as in the aqueous humor using HPLC, and by Raman-mapping visualizing the AA-distribution. Our results showed that the liposomal formulation improved the chemical stability of AA, while drug release was observed with the same kinetic efficiency as from the free-form of AA solution. Both corneal-PAMPA and porcine corneal permeability studies showed that AA-LLipo markedly improved the corneal absorption kinetics of AA, thus, increasing the AA content in the cornea and aqueous humor. AA-LLipo formulation could potentially increase the bioavailability of AA in corneal tissues.

Improvement of the Bioavailability of Amazonian Juices Rich in Bioactive Compounds Using Glow Plasma Technique

The effects of processing time (10, 20 and 30 min) and plasma flow rate (10, 20 and 30 mL min−1 of synthetic air) on the bioactive compounds of camu-camu juice (Myrciaria dubia) treated using glow plasma were evaluated herein. Plasma technology promoted the increase of the bioactive compounds’ concentration (antioxidant compounds, ascorbic acid and total monomeric anthocyanins) in the juice serum. Peroxidase and polyphenol oxidase presented the higher reduction of the enzymatic activity for treatments using plasma flow rate of 20 mL min−1. The treatments with higher air flow rate presented great color change (ΔE* > 2). Furthermore, the bioavailability of ascorbic acid was increased after using plasma technology. Therefore, the cold plasma technology may represent a useful technique to improve the bioavailability of bioactive compounds in processed fruit juices.

Ascorbic acid-cyclodextrin complex alters the expression of genes associated with lipid metabolism in bovine in vitro produced embryos.

Ascorbic acid (AC) used as antioxidant in embryo culture is very sensitive and degrades unavoidably in aqueous solution. Methyl-β-cyclodextrin (CD) improved the stability of AC in solution to elevated temperature, light, humidity and oxidation. The aim of this study was to evaluate the effect of the complex AC-CD during in vitro maturation (IVM) or in vitro culture (IVC) on oocyte developmental competence and subsequent embryo development and quality. AC-CD (100µM) was added to IVM media, and maturation level and embryo development were examined. Matured oocytes, their cumulus cells and produced blastocysts were snap-frozen for gene expression analysis by RT-qPCR. Besides, in vitro-produced zygotes were cultured with 100µM of AC-CD and blastocysts were as well snap-frozen for gene expression analysis. A group without AC-CD (control- ) and other with CD (control+ ) were included. No differences were found on maturation, cleavage or blastocyst rates. However, in matured oocytes, AC-CD downregulated BAX, GPX1 and BMP15. In cumulus cells, AC-CD downregulated BAX/BCL2 and GSTA4 while upregulated BCL2 and CYP51A1. The expression of SL2A1, FADS1, PNPLA and MTORC1 was downregulated in blastocysts derived from oocytes matured with AC-CD, while in blastocysts derived from zygote cultured with AC-CD, CYP51A1 and IGF2R were downregulated and PNPLA2 was upregulated. In conclusion, AC-CD in both IVM and IVC media may reduce accumulated fat by increasing lipolysis and suppressing lipogenesis in blastocysts derived from both oocytes and zygotes cultured with AC-CD, suggesting that CD improves the quality of embryos and bioavailability of AC during IVM and IVC.

Effect of Oral Supplementation of Vitamin C and Exercise on Plasma Vitamin C Status in Marwari Horses

The objective of the present study was to evaluate the effect of the oral supplementation with ascorbic acid on plasma levels in Marwari horses. The experiment was planned to supplement ascorbic acid @ 5 mg/kg. Body weight orally for 4 days on plasma ascorbic acid levels in horses. There was no significant difference in plasma ascorbic acid levels between day 1st and day 5th in supplemented group and control group. After that, a second trial was undertaken with supplementation of sodium ascorbate @ 20 mg/Kg body weight for 30 days in exercising horses. Exercising horses were under gallop + canter exercise of 5 km per day in sandy track. Blood samples were taken on each 10th day of the study period. There was no significant difference found in plasma ascorbic acid levels between supplemented and non-supplemented group of exercising horses. It was also found that plasma ascorbic acid levels were also significantly low in exercising non-supplemented horses than the horses which were under rest. So it was concluded that continuous 5 km gallop+ canter exercise in sandy track for a month reduces plasma ascorbic acid levels in horses but it cannot be replenished by oral supplementation of ascorbic acid because bioavailability of ascorbic acid on oral supplementation in Marwari horses is very poor.

Absorption of Folic Acid and Ascorbic Acid from Nutrient Comparable Beverages

One hundred percent fruit juices can help consumers increase the nutrient content of the diet since these beverages can be naturally rich in micronutrients. Micronutrient-fortified low-calorie beverages are an important alternative to those wishing to minimize their calorie intakes. However, little is known about the bioavailability of nutrients from fortified beverages relative to 100% fruit juices. The present study examined the bioavailability of ascorbic acid (AA) and folic acid (FA) in 100% orange juice (OJ) and a low-calorie beverage fortified with these nutrients. In a within-subjects, cross-over design, 12 adult men consumed a 591 mL serving of OJ, a low-calorie beverage fortified with AA and FA, and 1% low fat milk. Participants were aged 20 to 35 y, with body mass indexes between 20 and 30 kg/m(2). Blood plasma concentrations of AA and serum concentrations of FA were assayed by serial blood draws, made at 30 min intervals for 4.5 h. Blood plasma concentration of AA was significantly greater after ingestion of the fortified beverage compared to after OJ ingestion. However, the bioavailability of AA did not significantly differ from that of OJ. Analyses of FA indicated no significant difference between fortified beverage and OJ. Consumption of both vitamin containing beverages led to higher concentrations of AA and FA than the milk control. This study showed that similar levels of AA and FA bioavailability can be attained through ingestion of 100% OJ and a fortified beverage.

Ascorbic acid bioavailability in foods and supplements.

The bioavailability of ascorbic acid from food has been assumed to be high, but little quantitative information has been available to substantiate this assumption because of the limited precision and low statistical power of previous studies. A recent depletion-repletion study with a more effective experimental design has shown clearly that ascorbic acid bioavailability is equivalent in ascorbic acid tablets (with and without iron), orange juice, whole orange sections, and cooked broccoli. The bioavailability of ascorbic acid in raw broccoli was 20% lower, although this difference would probably have little nutritional significance in typical mixed diets.

Influence of oral dosing with D-isoascorbic acid on L-ascorbic acid content in guinea pig tissues

The effect of graded doses of D-isoascorbic acid (IAA) on the tissue content of ascorbic acid (AA) in guinea pigs administered a marginal intake of ascorbic acid was studied. Thirty guinea pigs (inbred Hartley-strain) were randomly assigned to three equally sized treatment groups: 1) 1 mg AA (only); 2) 1 mg AA + 20 mg IAA, or 3) 1 mg AA + 100 mg IAA. Ascorbic acid alone or in combination with IAA was orally administered daily to all animals over 42 consecutive days, after which time the animals were sacrificed. Over the study period, animals dosed with 1 mg AA plus 100 mg IAA had a higher rate of weight gain than those dosed with 1 mg AA or 1 mg AA + 20 mg IAA. Tissue concentrations of AA, IAA, and their oxidized forms, dehydroascorbic acid (DHAA) and dehydroisoascorbic acid (DHIAA) were determined by high-pressure liquid chromatography equipped with an electrochemical detector. In guinea pigs dosed with either 20 or 100 mg IAA, AA levels in the plasma, brain, liver, adrenals, lungs, kidneys, spleen, and heart were significantly decreased (P < 0.05) compared with the nonsupplemented group. IAA content in the guinea pig tissues increased progressively after incremental dosing with IAA. DHAA levels decreased significantly in guinea pigs dosed with 20 mg IAA or 100 mg IAA compared with the corresponding controls in all tissues examined. Thus, in guinea pigs, the co-administration of graded levels of IAA with a marginal AA intake resulted in a decreased bioavailability of AA.

Bioavailability of vitamin C from two ascorbyl monophosphate esters in rainbow trout, Oncorhynchus mykiss (Walbaum)

The relative bioavailability of ascorbic acid (AA) from several sources was compared in juvenile rainbow trout, Oncorhynchus mykiss (Walbaum). Fingerling trout were offered AA, and equimolar amounts of ascorbyl monophosphate Ca salt (CaAMP) or ascorbyl monophosphate-K, Mg salt (K/MgAMP) at graded levels of 20, 40, 80 and 320 mg kg−1. A control group was fed the same formula diet devoid of AA. During the 12 week long experiment, dietary concentrations of CaAMP and K/MgAMP remained unchanged while AA concentration decreased by 62.5%. No significant growth differences were found over a 12 week growout period, during which body weights increased 8–9 fold. No mortality or acute scurvy signs were observed in fish. Lysozyme activities tended to decrease in fingerlings supplemented with the highest AA level from all sources, although the difference was significant only in the case of the CaAMP diets. Blood plasma alkaline phosphatase showed no significant differences between treatments. However, phosphatase activity toward ascorbyl monophosphate (AMP) extracted from the intestine showed a gradual increase as the dietary AMP source was increased from 20 to 80 mg kg−1. Significant differences were found in AA concentration in the liver after 3 weeks of feeding graded levels of different sources of ascorbic acid. The differences in tissue AA concentrations among groups fed different dietary supplements increased with the duration of feeding. The bioavailability of AA and AA esters as measured by AA concentrations in the liver, kidney, intestine and blood plasma were equal. Despite the decrease in AA concentration in feeds supplemented with unprotected ascorbic acid after several weeks of storage, relationships between concentrations of ascorbic acid in the liver and those actually measured in feeds were not significantly different between treatments.

The effects of postharvest treatment and chemical interactions on the bioavailability of ascorbic acid, thiamin, vitamin a, carotenoids, and minerals

All recent health recommendations include admonitions to reduce calories, maintain desirable weight, reduce fat, increase complex carbohydrates, and ensure an adequate intake of nutrients. Such recommendations require that we know not only nutrient composition of foods, but also potential losses and decreased bioavailability due to postharvest treatment and chemical interactions. This article discusses in some detail the reactions of concern that cause such changes and their potential alleviation with several key nutrients. The nutrients discussed were chosen as a result of the conclusions of the Joint Nutrition Monitoring Report of the Department of Health and Human Services and the U.S. Department of Agriculture. Obviously other choices could have been made, but the authors felt that the nutrients chosen--ascorbic acid, thiamin, vitamin A, carotenoids, calcium, and iron--were representative of a key profile of nutrients whose reactivity makes them vulnerable to losses in bioavailability, as well as being noted in the Joint Nutrition Monitoring Report.

Bioavailability of Synthetic Ascorbic Acid and a Citrus Extract

Introduction There is now considerable general interest in Vitamin C supplementation due to recent popular books on the treatment of the common cold and cancer by ascorbic acid (AA). Also, certain populations such as smokers and the elderly are known to be deficient in AA [1, 2] and would benefit from supplementation. Although natural and synthetic AA are chemically identical, citrus fruits contain bioflavonoids that might affect the bioavailability of AA.

Impairment of absorption of ascorbic acid following ingestion of aspirin in guinea pigs

A study was undertaken to investigate the interactions between aspirin and ascorbic acid in guinea pigs. Animals received by gastric intubation either a single dose of radiolabelled ascorbic acid alone or ascorbic acid with aspirin and the exhalation of CO 2 was monitored for 400 min following administration. Animals receiving the vitamin only reached plasma peak levels within 90 min following administration while coadministration of the vitamin with aspirin, not only resulted in lower plasma peak levels, but also delayed their attainment until after 160 min. The bioavailability of ascorbic acid during the first 400 min was reduced by half following simultaneous administration of aspirin. The initial rate of exhalation of CO 2 was decreased by 70% following coadministration of aspirin. These observations indicate that aspirin impairs the gastrointestinal absorption of ascorbic acid in guinea pigs, possibly by interfering with its active transport.

Maternal hyperglycemia and its effect on the placental transport of ascorbic acid.

Summary: This report explored the possibility that maternal hyperglycemia during pregnancy might produce a competition between glucose (G) and ascorbic acid (AA) and reduce the transfer of AA to the fetus using an in vivo single-pass placental perfusion technique in the guinea pig. Levels of G in maternal plasma increased from 104 ± 4 mg/dl (x ± S.E.) before AA + G infusion to 370 ± 19 mg/dl at the end of each study (P < 0.001). Preinfusion levels of AA in maternal and fetal plasma were 0.29 ± 0.02 mg/dl and 0.46 ± 0.03 mg/dl, respectively. Maternal infusion of AA or AA + G produced significant increases in maternal plasma AA (P < 0.025) and fetal plasma AA (P < 0.001); however, fetal plasma AA from dams infused with AA + G were significantly below fetal plasma values obtained when only AA was infused (P < 0.005) suggesting that when maternal plasma G is increased, the placental transport of AA to the fetus is reduced. Preinfusion levels of AA in placental tissue were 10.8 ± 0.5 mg/dl and infusion of AA or AA + G produced significant increases in AA in this organ (P < 0.001). Comparison of the AA in placental tissue from fetuses of dams infused with either solution demonstrates that significantly less AA was present after AA + G infusion (P < 0.005). Additionally, when AA + G was infused a significant decrease in AA transferred across the placenta was found (P < 0.001) as maternal plasma G increased beyond 200 mg/dl. The data suggest that in the guinea pig glucose may compete with ascorbic acid transfer across the placenta and that maternal hyperglycemia may reduce the bioavailability of AA to the fetus.Speculation: An acute episode of maternal hyperglycemia interferes with the placental transfer of ascorbic acid. Therefore, maternal hyperglycemia during gestational diabetes may result in a decreased supply of ascorbic acid to the fetus.