Antioxidant Properties Of Ascorbic Acid Research Articles

Development and Evaluation of an Innovative Approach Using Niosomes Based Polymeric Microneedles to Deliver Dual Antioxidant Drugs.

Ascorbic acid (AA) and caffeine (CAFF) work to protect cells from ultraviolet (UV) radiation and slow down the photoaging process of the skin. However, cosmetic application of AA and CAFF is limited due to poor penetration across the skin and rapid oxidation of AA. The aim of this study was to design and evaluate the dermal delivery of dual antioxidants utilizing microneedles (MNs) loaded with AA and CAFF niosomes. The niosomal nanovesicles were prepared using the thin film method and had particle sizes ranging from 130.6-411.2 nm and a negative Zeta potential of around -35 mV. The niosomal formulation was then combined with polyvinylpyrrolidone (PVP) and polyethylene glycol 400 (PEG 400) to create an aqueous polymer solution. The best skin deposition of AA and CAFF was achieved with the formulation containing 5% PEG 400 (M3) and PVP. Furthermore, the role of AA and CAFF as antioxidants in preventing cancer formation has been well-established. Here we validated the antioxidant properties of ascorbic acid (AA) and caffeine (CAFF) in a novel niosomal formulation referred to as M3 by testing its ability to prevent H2O2-indued cell damage and apoptosis in MCF-7 breast cancer cells. Results showed that M3 was able to shield MCF-7 cells from H2O2 induced damage at concentrations below 2.1 µg/mL for AA and 1.05 µg/mL for CAFF, and also exhibited anticancer effects at higher concentrations of 210 µg/mL for AA and 105 µg/mL. The formulations were stable for two months at room temperature in terms of moisture and drug content. The use of MNs and niosomal carriers could be a promising approach for dermal delivery of hydrophilic drugs like AA and CAFF.

Potential of Ascorbic Acid Supplements to Ameliorate the Deleterious Effects of Hyperuricemia on Albino Wistar Rats’ Hippocampus (Structural and Functional Study)

Introduction: Diet rich in purines may increase the serum level of uric acid causing hyperuricemia, contributing to learning and memory to impairments. Ascorbic acid has a potent antioxidant potential. The hippocampus is a pivotal component of human brains and other vertebrates that plays crucial roles in the consolidation of information and spatial memory. Our study was mainly designated to examine the potential palliative role of ascorbic acid supplements on harmful effects induced hyperuricemia on the hippocampus of albino Wistar rats. Methods: Forty rats were subgrouped into the control group, ascorbate-only group, hyperuricemic group, and combined hyperuricemia and ascorbate group. Results: Ascorbic acid has strongly preserved the histological architecture and maintained the normal hippocampal functions in the hyperuricemic group. Conclusion: The anti-inflammatory and antioxidant properties of ascorbic acid could protect the hippocampus of albino Wistar rats against the hazardous impact of hyperuricemia.

Exogenous Antioxidants Impact on UV-Induced Changes in Membrane Phospholipids and the Effectiveness of the Endocannabinoid System in Human Skin Cells.

Natural antioxidants effectively counteract changes caused by UV radiation in human skin cells. However, their action is limited due to their lipo/hydrophilicity. Therefore, the aim of this study was to analyze the mutual protective action of hydrophilic ascorbic acid and partially lipophilic rutin against UVA/UVB-induced changes in membranes phospholipid and endocannabinoid system in keratinocytes and fibroblasts. Obtained results clearly showed that, despite the stronger antioxidant properties of ascorbic acid, the lipid membranes were more effectively protected against UV-induced oxidation by rutin, including changes in phospholipid fatty acid levels, prevention against reactive aldehydes formation and endocannabinoids degradation. Ascorbic acid more strongly prevented UV-induced endocannabinoid receptors expression in fibroblasts, especially CB1. However, the combined action of used antioxidants resulted in the greatest cytoprotective effect, which was evident in the inflammatory marker TNFα down-regulation and increased cell viability following cell irradiation. The applied mixture of antioxidants showed a stronger protective in relation to membrane phospholipids in keratinocytes and in the endocannabinoid system in fibroblasts. In conclusion, it can be suggested that combined antioxidant capacities of ascorbic acid and rutin protects against lipid peroxidation but also decreases the UV-induced inflammation by direct interaction with the endocannabinoid system, thus increasing skin cell viability.

Mechanism and enhancement of Cr(VI) contaminated groundwater remediation by molasses.

The remediation of Cr(VI)-contaminated groundwater with molasses has many advantages compared with traditional in-situ chemical methods, including high cost-effectiveness and negligible secondary contamination. Hence, the reaction conditions and mechanisms of molasses were investigated in this study. The results showed that Cr(VI) was chemically reduced by molasses at acidic pH (3.0), wherein the dominant active components were the hydroxyl and carbonyl groups of molasses. At neutral pH (7.0), molasses mainly acted as an electron donor for direct or indirect reduction of Cr(VI) by microorganisms. The main functional microorganisms were Bacillus and Clostridium Sensu Stricto. Compared with chemical reduction, bio-reduction could completely reduce higher concentrations of Cr(VI) when molasses was added at a concentration of 3g/L. Ascorbic acid was added to promote the removal rate of bioremediation. Owing to the antioxidant properties of ascorbic acid, the reaction rate increased by 9.3% and 37.5% when 0.05g/L of ascorbic acid was added to the 50 and 100mg/L Cr(VI) bioremediation systems, respectively. Due to the decrease in pH during bioremediation, NaHCO3 was added to buffer the pH changes and promote Cr(III) precipitation. Compared with the addition of NaHCO3 and molasses simultaneously, separate additions were more effective for precipitation. Furthermore, X-ray absorption near-edge structure analysis revealed that after chemical reduction and biological reduction, Cr was attached to the solid medium in the form of Cr(III).

An ascorbic acid delivery system based on (W1/O/W2) double emulsions encapsulated by Ca-alginate hydrogel beads

The aim of the present study was to develop ascorbic acid (AA)-loaded (W1/O/W2) double emulsions encapsulated by Ca-alginate hydrogel beads system (AA-HB) for efficient topical delivery. Some factors related to the stability and encapsulation efficiency of AA-HB were investigated. In addition, AA-HB were evaluated for storage stability, antioxidant activity, release characteristics, and skin permeation properties. The results showed that AA-HB had good stability when stored at 4 °C and 25 °C for 60 d. Compared with AA-loaded (W1/O/W2) double emulsions (AA-DE) and AA-water solution (AA-WS), the AA-HB had a more significant sustained-release effect on AA, while the antioxidant properties of AA in AA-HB were not affected. In vitro permeation study showed that the skin permeation of AA was promoted by the synergistic effect of double emulsions and hydrogel beads. Hence, the (W1/O/W2) double emulsions encapsulated by Ca-alginate hydrogel beads might be a promising delivery system for topical applications of AA.

Lipoic acid: physiological role and prospects for clinical application

α-Lipoic acid (also known as thioctic acid) is a natural vitamin-like compound. Lipoic acid contains asymmetrical carbon, which causes the presence of two possible optical isomers (enantiomers): R-lipoic acid (levogyrate isomer) and S-lipoic acid (rightspinning isomer). Lipoic acid functions as a cofactor for several important mitochondrial multienzyme complexes, enhances the uptake of glucose by the cells, and modulates the activity of various signaling molecules and transcription factors. It was shown that α-lipoic acid and its derivative, dihydrolipoic acid, have a direct antioxidant effect due to the neutralization of reactive oxygen species that are destructive to DNA, proteins and lipids of cells. Dihydrolipoic acid enhances the antioxidant properties of ascorbic acid, glutathione and ubiquinone. Available evidence suggests that supplementation with lipoic acid reduces the symptoms of peripheral diabetic neuropathy. Results from randomized controlled trials show that high doses of lipoic acid can improve the glycemic profile of subjects with metabolic disorders. Lipoic acid can be used to control body weight in people with obesity. R-Lipoic acid is synthesized in the human body and is contained in foods in a form covalently associated with lysine (lipoyllysine). Its dose in dietary supplements significantly exceeds the amount in the diet. Most dietary supplements contain a racemic mixture of R- and S-lipoic acid.

Therapeutic Management of Pulmonary Tuberculosis by Mannosylated Chitosan Ascorbate Microspheres: Preparation and Characterization

Objective: In this study, biodegradable Chitosan Ascorbate Microsphere (CAMs) and mannosylated chitosan ascorbate microsphere (m-CAMs) prepared for targeting towards alveolar macrophages to treatment of pulmonary tuberculosis. 
 Significance: Ascorbic acid is an antioxidant and reported killing effect on mycobacterium by induces fenton reaction. This study enlightens the possible benefits of adding antioxidant properties of ascorbic acid with chitosan microsphere to an anti-tuberculosis regimen and mannosylation of microsphere significantly induce the targetability of antitubercular drug to alveolar macrophages.
 Methods: CAMs prepared by firstly salification of chitosan by ascorbic acid then ionic gelation with STPP and m-CAMs prepared by incubation method and purified for further studies. The physicochemical, in vitro and in vivo characterizations of both formulations were carried out.
 Results: The size of microspheres (both CAMs and m-CAMs) were found to be in range of 3.40-4.81µm. Evident changes were observed in crystallinity and structure of both carrier systems and depicted by Fourier transform infrared (FTIR), Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. In vitro lung deposition study of microspheres showed favourable aerodynamic properties for deep lung delivery (MMAD 2.0- 3.8 μm) and, thus, show potential for an application as inhalable tuberculosis therapy. The drug release showed the biphasic pattern of release, i.e., initial burst (30-45% up to 8 h) followed by a slower sustained release pattern (more than 80% up to 72 h) in both simulated lung fluids. Optimized formulations exhibited lower cytotoxicity and bio distribution studies demonstrated the efficiency of m-CAMs for spatial delivery of INH to alveolar tissues. CAMs and m-CAMs evidenced minor cytotoxicity on lung epithelial cells (A549 cell lines).
 Conclusion: m-CAMs thus has a promising potential to be explore as an effective carrier system for delivery of antitubercular drugs regimen.
 Key words: Targetability, alveolar macrophage, lung cancer A549 cells

Design of Functional Therapeutic Deep Eutectic Solvents Based on Choline Chloride and Ascorbic Acid

In this work, we report the preparation of novel therapeutic deep eutectic solvents (THEDES) based on choline chloride (CC) and ascorbic acid (AA), in which dexamethasone (DEX) was successfully solubilized. THEDES were synthesized and characterized for thermal behavior and polarized optic microscopy to confirm the formation of a eutectic mixture. The solubility profile of DEX solubilized in THEDES was greatly improved when compared with DEX in powder form. Additionally, the diffusion and permeability of DEX were also slightly increased. The antioxidant properties of AA were maintained up to 6 months when the compound is in THEDES form. Biological tests were also performed, and the results indicate that cell viability varies in a dose-dependent manner. After the half maximal effective concentration (EC50) was determined, a controlled drug delivery system was successfully developed by supercritical fluid sintering of a starch:poly-e-caprolactone blend doped with THEDES containing solubilized DEX. The presen...

Antioxidant properties of ascorbic acid in bulk oils at different relative humidity

The effects of relative humidity (RH) on the antioxidant properties of ascorbic acid (10, 20, 42, and 84ppm) were investigated in stripped corn oils stored at 60°C. The degree of oxidation in oils was determined by analysing headspace oxygen content and conjugated dienoic acids. The oxidative stability of bulk oils without addition of ascorbic acid was significantly different depending on the RH. As the concentration of ascorbic acid increased from 10 to 84ppm, oxidative stability increased significantly irrespective of RH (p<0.05). Generally, oils containing ascorbic acid at low RH had higher oxidative stability after storage at 60°C than those at high RH. The antioxidant properties of ascorbic acid were greatly influenced by both the moisture content in the oil and the ascorbic acid concentration.

Final Report of the Safety Assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate as Used in Cosmetics1

Final Report of the Safety Assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate as Used in Cosmetics1

A mechanism of inhibition of short-wavelength ultraviolet light-induced deamination of pyrimidine bases by ascorbic acid

The relation of ascorbic acid to the ultraviolet light-induced deamination of cytosine (to uracil) and 5-methylcytosine (to thymine) was examined using gas chromatography-mass spectrometry. There was an inverse relation between the uracil content measured in solutions of cytosine after exposure to short wavelength (254 nm) ultraviolet light and the ascorbic acid concentration of the solution indicating inhibition of deamination of cytosine by ascorbic acid. Ascorbic acid also inhibited ultraviolet light-induced deamination of 5-methylcytosine. The ascorbic acid was only partially consumed during the exposure suggesting that protection from deamination was not due entirely to the antioxidant properties of ascorbic acid. Mercaptoethanol did not prevent ultraviolet light-induced deamination of either cytosine or 5-methylcytosine. However, near identical protection from ultraviolet light-induced deamination was provided by 4-aminobenzoic acid and ascorbic acid at equivalent ultraviolet light absorbing concentrations. This observation suggests that ascorbic acid prevents short wavelength ultraviolet light-induced deamination through absorbance of ultraviolet light rather than through antioxidant mechanisms.

How to Characterize a Biological Antioxidant

An antioxidant is a substance that, when present at low concentrations compared to those of an oxidizable substrate, significantly delays or prevents oxidation of that substrate. Many substances have been suggested to act as antioxidants in vivo, but few have been proved to do so. The present review addresses the criteria necessary to evaluate a proposed antioxidant activity. Simple methods for assessing the possibility of physiologically-feasible scavenging of important biological oxidants (superoxide, hydrogen peroxide, hydroxyl radical, hypochlorous acid, haem-associated ferryl species, radicals derived from activated phagocytes, and peroxyl radicals, both lipid-soluble and water-soluble) are presented, and the appropriate control experiments are described. Methods that may be used to gain evidence that a compound actually does function as an antioxidant in vivo are discussed. A review of the pro-oxidant and anti-oxidant properties of ascorbic acid that have been reported in the literature leads to the conclusion that this compound acts as an antioxidant in vivo under most circumstances.

Effect of Ascorbic Acid on Antioxidant Defense Systems and Lipid Peroxidation in Guinea Pig

In view of the antioxidant properties of ascorbic acid (AA), effects of inadequate and excessive doses of AA on hepatic and pulmonary antioxidant enzymes and NADPH-dependent lipid peroxidation were investigated in the present study. Male guinea pigs, dosed daily with 0.2mg AA/100g b wt (inadequate) or 50mg AA/100g b wt (excessive) for 8 weeks, demonstrated no difference in body growth, liver and lung weights, and post-10, 000×g supernatant protein contents as compared with the control group, which was daily fed with 2mg AA/ 100g b wt. Inadequacy of AA decreased the hepatic and pulmonary contents of catalase, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD), but it significantly increased glutathione reductase (GR) activity (p<0.005) in lung. However, levels of hepatic and pulmonary NADPH-dependent lipid peroxidation remained unaltered when the supply of AA was inadequate. Excessive doses of AA did not influence any pulmonary antioxidant enzyme, level of NADPH-dependent lipid peroxidation and content of reduced glutathione (GSH), but increased the hepatic GSH-Px and GR activities. Hepatic SOD activity showed a significant decrease (p<0.01), whereas NADPH-dependent lipid peroxidation and GSH contents remained unchanged. It appears that the changes in antioxidant enzymes may be a nonspecific response to AA or these changes may not be sufficient to bring about any shift in the levels of NADPH-dependent lipid peroxidation in the presence of unaltered GSH contents or other biomolecules which may act as antioxidants or free radical scavengers in the cell system.

The cooperative interaction between vitamin E and vitamin C in suppression of peroxidation of membrane phospholipids

The time course of peroxidation of rat liver microsomes by FeSO 4 in the presence of ascorbate showed a delay in the onset of peroxidation compared to the time course when NADPH replaced ascorbate as the electron donor. The delay was consistent with an antioxidant function of ascorbate, possibly mediated through endogenous vitamin E. In order to further investigate the cooperation between ascorbate and vitamin E in suppressing lipid peroxidation, a liposomal system containing polyunsaturated phospholipids was used. Peroxidation was initiated by ferrous iron at pH 5, where spontaneous oxidation of Fe 2+ did not occur and the antioxidant properties of ascorbic acid could be characterized independently of its pro-oxidant properties as a reducer of Fe 3+. Ascorbic acid alone at concentrations of 30–100 μM delayed peroxidation by 20 min and at higher concentrations prevented peroxidation for 60 min. Physiological levels of vitamin E decreased peroxidation at early time points but the vitamin was apparently consumed during the course of the incubation. The presence of both vitamin C and vitamin E produced suppression of peroxidation at early time points (0–20 min) which was approximately the sum of the individual inhibitions. At longer time points, however, the mixture of anti-oxidants was much more effective than the sum of both vitamins alone. This suggests that interaction between these antioxidants yields an enhanced delivery of antioxidant protection.