Incorporating Ascorbic Acid into Natural Deep Eutectic Systems: A Study on Antioxidant Preservation

Reactive oxygen and nitrogen species in patients with rheumatoid arthritis as potential biomarkers for disease activity and the role of antioxidants

Ascorbic acid (AsA) treatment is expected to be a potential cancer therapy strategy with few side-effects that can be used alone or in combination with chemotherapy. However, the combination of AsA, a free radical scavenger, with radiation is not clearly understood; conflicting data are reported for cancer cell death. We conducted this study to determine the effect of AsA treatment combined with X-irradiation and the role of reactive oxygen species (ROS) in HL-60 human promyelocytic leukemia cells. Additive cytotoxic effects were observed when the cells were exposed to 2 Gy X-irradiation after 2.5 mM AsA treatment. When catalase was added to the culture with AsA alone, the cytotoxic effects of AsA disappeared. X-irradiation increased intercellular ROS levels and mitochondrial superoxide levels. By contrast, AsA alone and in combination with X-irradiation decreased ROS levels. However, in the presence of catalase neutralizing H2O2, AsA alone or in combination with X-irradiation only slightly decreased the intercellular ROS. Moreover, AsA decreased the mitochondrial membrane potential, which is commonly associated with apoptosis. These results suggest that the reduction of ROS did not result from ROS scavenging by AsA, and AsA induced apoptosis through a ROS-independent pathway. This study reports that a combination of AsA with radiation treatment is effective in cancer therapy when considering ROS in cancer cells.

Consumption of carbonated soft drinks is independently associated with the development of overactive bladder (OR 1.41, 95% Cl 1.02-1.95). We have shown previously that artificial sweeteners, present in carbonated soft drinks, enhanced detrusor muscle contraction. Other constituents of soft drinks are preservatives and antioxidants, we evaluated the effects of two of these, ascorbic acid and citric acid, on the contractile response of isolated rat bladder muscle strips. Detrusor muscle strips were suspended in a perfusion organ bath. We determined the effect of ascorbic acid and citric acid on the contractile responses to electrical field stimulation (EFS) in the absence and presence of atropine, carbachol, alpha, beta methylene ATP, potassium and calcium. Ascorbic acid and citric acid (10(-7) M to 10(-3) M) enhanced the contractile response to 10 Hz EFS compared to control (P < 0.01). The frequency and amplitude of spontaneous bladder contractions were enhanced in the presence of ascorbic acid and citric acid by 14%, 21%, 21%, and 11% respectively. Ascorbic acid 10(-4) M significantly increased the atropine resistant response to EFS 5 Hz by 37% (P < 0.01) and inhibited contraction in response to carbachol 10(-4) M by 24%, (P < 0.05). Both ascorbic acid 10(-4) M and citric acid 10(-5) M significantly enhanced maximum contractile responses to alpha, beta methylene ATP, KCI and calcium compared to control. Ascorbic acid and citric acid augmented bladder muscle contraction possibly by enhanced Ca(2+) influx. Presynaptic neurotransmitter release was enhanced by ascorbic acid. Carbonated beverages containing preservatives may aggravate symptoms of OAB.

Summary1. Ascorbic acid at 1 g/kg when administered prior to vanadium antagonizes the toxicity of vanadium as NaVO3 · H2O in mice at the LD70 and LD95 levels. Dosage levels as low as 125 mg/kg ascorbic acid showed a protective action against the LD70 of NaVO3 · H2O in mice. 2. Antidotal effects of calcium disodium ethylenediamine tetraacetate and ascorbic acid have been demonstrated in vanadium-poisoned rats and dogs, after signs of toxicity had become manifest. 3. Ascorbic acid is probably the more rapidly-acting of the 2 antidotes. Signs of vanadium toxicity were present for a longer period of time in vanadium-poisoned animals after CaNa2EDTA than after ascorbic acid administration. 4. One possible mode of detoxication of vanadium by ascorbic acid is suggested, on the basis of in vitro polarographic studies, to be reduction of the vanadium.

Follicular fluid and serum concentrations of antioxidants such as catalase, ascorbic acid (AA) and total antioxidant capacity (TAC) along with reactive oxygen species (ROS) and degree of oxidative damage to follicular cells, using protein carbonyl (PC) as marker of oxidative stress, were investigated during cystic ovarian disease in buffalo. Follicular fluid was aspirated from cystic follicles (&gt;20 mm) and also from large size (10-17 mm) of cycling buffaloes. Estradiol and progesterone were estimated to determine functional status (E: P ratio) of the follicles. Cystic follicles had greater concentrations of ROS and PC and lesser concentrations of catalase, ascorbic acid and TAC than normal follicles. An interesting finding was a simultaneous decrease of TAC and increase of ROS in serum of cystic buffaloes. Results indicated a pronounced follicular fluid oxidant-antioxidant imbalance and oxidative damage to follicular proteins during cystogenesis. In conclusion, this study provided evidence about role of oxidative stress in pathogenesis of cystic ovarian disease.

To evaluate alterations in total antioxidant capacity (TAC) and ascorbic acid (AA) levels in femtosecond laser-assisted cataract surgery (FLACS) compared with conventional cataract surgery. A prospective non-randomized study was conducted wherein 18 and 36 patients undergoing FLACS and conventional cataract surgery, respectively, with the same phacoemulsification and femtosecond laser devices were enrolled. Samples of aqueous humor were obtained via paracentesis before and 1 day after the cataract surgery, and TAC and AA concentrations were determined. The generalized linear mixed model was adopted to determine the adjusted odds ratio (aOR) and 95% confidence interval (CI) of changes in TAC and AA between groups. The TAC and AA levels significantly decreased postoperatively in both groups (p=0.05). In the multivariate analysis, the trend in decline in TAC (aOR=0.352, 95% CI=0.218-0.527, p=0.0177) and AA (aOR=0.308, 95% CI=0.156-0.488, p=0.0204) was significantly lower in the FLACS group. In the subgroup analyses, the correlation between FLACS and smaller TAC reduction was more significant in patients with high myopia, dense cataract, short anterior chamber depth, and greater axial length (p<0.05). In addition, the correlation between FLACS and smaller reduction in AA was more significant in patients with high myopia, dense cataract, greater axial length, and greater central corneal thickness (p<0.05). Patients with high myopia and dense cataract may consider FLACS to reduce the possibility of oxidative stress-related postoperative complications.

The respective and combined effects of sodium chloride, ascorbic acid, citric acid, potassium sorbate, and Thymus vulgaris extract on the growth of Aeromonas caviae and Aeromonas sobria were investigated. Sodium chloride (3%) significantly reduced the growth and 4% NaCl inhibited growth of the tested strains. Ascorbic acid (0.1%), potassium sorbate (0.05%), and citric acid (0.03%) slightly inhibited growth. T. vulgaris extract (0.3%) greatly reduced the growth. Various combinations of these compounds prevented growth of the tested strains. A combination of NaCl (3%) and ascorbic acid (0.1 %), citric acid (0.03%) and potassium sorbate (0.05%), or citric acid (0.03%) and ascorbic acid (0.1%) inhibited growth of A. caviae and A. sobria. In fish homogenates, the addition of ascorbic acid (0.1%) and citric acid (0.03%) was the most effective combination tested.

This study investigated the impact of acidification on olive paste to enhance the extraction of olive oil enriched in bioactive phenolic compounds, aiming to develop a novel functional food. Recognizing that acidic pH promotes the activity of β-glucosidase responsible for oleuropein and ligstroside hydrolysis, food-grade organic acids—citric, ascorbic, and acetic acid—were added prior to malaxation to improve the bioactive compound content in the resulting oils. A randomized experimental design was employed, using three different doses of each acid (1, 2, and 4%) with three replicates per dose, alongside control trials without acid addition. Acidification did not affect olive oil extraction efficiency or alter quality parameters for extra virgin olive oils. Treatment with 1% ascorbic acid significantly increased phenolic compound content by 37% compared to controls. Secoiridoids comprised 79.4% of the total phenolic content, with oleacein as the predominant compound (237.58 ± 9.18 mg/kg), representing over 50% of the total. This increased oleacein concentration led to up to a 67% enhancement in antioxidant capacity (428.63 ± 31.57 mg Trolox/kg) compared to controls. The antioxidant capacities of 3,4-DHPEA, 3,4-DHPEA-EDA, and 3,4-DHPEA-EA were determined to be 12.05, 5.80, and 4.91 µmol TE/mg, respectively. Furthermore, the 1% ascorbic acid treatment enhanced volatile compounds associated with the lipoxygenase (LOX) pathway while reducing ethanol levels.

Polycystic ovary syndrome (PCOS) affects up to 10% of women within reproductive ages and has been a cause of infertility and poor quality of life. Alteration in the oxidant-antioxidant profile occurs in PCOS. This study, therefore, investigates the contribution of ascorbic acid (AA) and alpha-tocopherol(ATE) on different PCOS parameters. The mifepristone and letrozole models were used, and young mature female mice were randomly assigned to groups of six per group. On PCOS induction with either mifepristone or letrozole, mice were administered AA and ATE at doses ranging from 10-1000mg/kg to 0.1-1000mg/kg in the respective models. Vaginal cytology, body weights, and temperature, as well as blood glucose, testosterone, and insulin levels, were measured. Total antioxidant capacity and malondialdehyde levels were analyzed. Determination of gene expression of some reactive oxygen species and histomorphological analysis on the ovaries and uteri were performed. At the end of the experiments, AA and ATE restored reproductive cycling, with AA being more effective. AA and ATE increased fasting blood glucose but had no significant effect on serum insulin levels. AA decreased testosterone levels, but ATE caused slight increases. AA and ATE both increased total antioxidant capacity and decreased malondialdehyde levels. AA and ATE also slightly upregulated the mRNA expressions of catalase, superoxide dismutase, and heme oxygenase 1 mainly. AA and ATE also decreased ovarian weight and mostly resolved cysts in the ovaries and congestion in the uterus. This study has shown that AA and ATE are beneficial in the therapy of PCOS.

The role of ascorbic acid as a key molecule antioxidant involves in biotic and abiotic stress has already been well described. Recent study indicates that it also participates in the detoxification of generated reactive oxygen species due to abiotic stresses. Thus, In order to study effects of salt stress and ascorbic acid on antioxidant enzyme activity, chlorophyll content, lipid peroxidation and abscisic acid accumulation of bean an experiment was conducted. The exogenous application of ascorbic acid in nutrition solution of bean plants indicated that later is involve in reduction of antioxidant enzyme activity and increase of resistance to salt stress. We observed that antioxidant enzyme activity increased due to salt stress and ascorbic acid via eliminating of reactive oxygen species decreased activities. Moreover, abscisic acid and lipid peroxidation were affected of salt stress. Increase of ascorbic acid concentration at 100 mM NaCl treatment prevented of lipid peroxidation and decreased generation of malondialdehyde as final product of peroxidation of membrane lipids. However, at high level of salinity, ascorbic acid did not significant effect on reduction of lipid peroxidation. Whereas, chlorophyll content decreased by reactive oxygen species. Ascorbic acid increased chlorophyll content at all of stressed and non-stressed treatments. Abscisic acid assay showed that, accumulation of this hormone increased under salt stress treatments and raise of ascorbic acid concentration in nutrition solution of stressed plants prevented of abscisic acid accumulation. Our data provide strong support to the hypothesis that exogenous of ascorbic acid reduces the harmful effects of salinity and increases resistance to salinity in bean plant.

ABSTRACTThe effect of calcium, ascorbic acid, citric acid and EDTA on texture, color and flavor of mung bean sprouts canned as a low‐acid food (pH &gt; 4.6) and the effect of acidification by acetic, citric, gluconic, lactic and malic acids on quality of mung bean sprouts canned as an acid‐food (pH &lt; 4.6) were examined. Either the addition of calcium or acidification enhanced texture. Texture of products canned as low‐acid food increased with decreasing pH. Color was markedly improved by either EDTA combined with ascorbic acid or acidification. Processing in plain (uncoated) cans or treatment with acetic acid was detrimental to flavor. Overall, the best low‐acid food product was obtained by the combination of calcium, ascorbic acid, citric acid and EDTA while the best acid‐food product was obtained by acidification with gluconic acid.

A study of oxidation reactions in buffered emulsions of linoleic acid was undertaken as a means of investigating some of the important chemical reactions associated with the production of oxidised off-flavours in dairy products. Previous investigations in this field had shown that metal, particularly copper, contamination was the most important single factor promoting lipid oxidation in milk and butter. A reducing agent, such as ascorbic acid, was found to greatly accelerate oxidation rates under some conditions. It was generally thought that the principal role of ascorbic acid was to reduce copper to the cuprous form and that cuprous copper was the active catalyst. The method adopted in this study was to systematically observe the effects of variation in ascorbic acid and copper concentration on oxidation of the emulsions at various pH's. Oxygen consumption over a 90 hour period and thiobarbituric acid test values at the end of the period were used as indices of fatty acid oxidation. Ascorbic acid at a concentration of 10-3M. was a more effective pro-oxidant in the presence of low copper concentrations (0.1 - 0.01 p.p.m.) than with high concentrations (10 p.p.m.), particularly in the initial stages of oxidation or in the lower pH range (5.5 - 4.7). This fact alone was sufficient to suggest a much more complex role for ascorbic acid than that of copper reducing agent. In fact, the ascorbic acid experiments and subsequent experiments with metal chelating agents gave strong indications that the initial oxidation state of the metal was a matter of minor importance. It was concluded that chelation of copper by ascorbic acid .and prevention of metallic termination of radical chain reactions was one important function of ascorbic acid. But this was not, in itself, sufficient to explain the pro-oxidant activity. Reaction of the ascorbic acid radical with oxygen and consequent formation of free HO• radicals was considered to be the most likely initiating reaction resulting from the oxidation of ascorbic acid to dehydro-ascorbic by copper. Dehydro-ascorbic acid was also found to be a very effective pro-oxidant in the presence of copper. The evidence suggested that this was not due to regeneration of ascorbic acid, but there was insufficient data available to offer any substantial altemative explanation. Metal chelating agents - 1,10 phenanthroline, E.D.T.A., and citric acid - on the pro-oxidant activity of copper were studied in further experiments. Citric acid had little effect. E.D.T.A. was found to inhibit the pro-oxidant effects of copper. 1,10 phenanthroline was found to be a particularly effective pro-oxidant when present in a concentration of more than three times the molar equivalent of copper concentration. Ascorbic acid was shown to have an inhibitory effect on oxidation of linoleic acid by the phenanthroline/copper complex, as well as an expected pro-oxidant effect. The predominance of one effect was dependant on the relative concentrations of the two chelating compounds. The broad conclusion reached was that the role of copper as an oxidation catalyst was dependant on the nature and concentration of groups capable of co-ordinating with the metal. Lack of information in a number of areas prevented this conclusion being extended in more specific terms. Some suggestions were made on this basis as to possible areas for future research.

Interrelationships among selenium status, antioxidant capacity and oxidative stress in the horse

Ascorbic acid induces apoptosis, autophagy, and necrotic cell death in cancer cells. We investigated the mechanisms by which ascorbic acid induces death in laryngeal squamous cell carcinoma Hep2 cells. Ascorbic acid markedly reduced cell viability and induced death without caspase activation and an increase in cytochrome c. Hep2 cells exposed to ascorbic acid exhibited membrane rupture and swelling, the morphological characteristics of necrotic cell death. The generation of reactive oxygen species (ROS) was increased in Hep2 cells treated with ascorbic acid, and pretreatment with N-acetylcysteine blocked ascorbic acid-induced cell death. Ascorbic acid also stimulated protein kinase C (PKC) signaling, especially PKC α/β activation, and subsequently increased cytosolic calcium levels. However, ascorbic acid-induced necrotic cell death was inhibited by Ro-31-8425 (PKC inhibitor) and BAPTA-AM (cytosolic calcium-selective chelator). ROS scavenger NAC inhibited PKC activation induced by ascorbic acid and Ro-31-8425 suppressed the level of cytosolic calcium increased by ascorbic acid, indicating that ROS is represented as an upstream signal of PKC pathway and PKC activation leads to the release of calcium into the cytosol, which ultimately regulates the induction of necrosis in ascorbic acid-treated Hep2 cells. These data demonstrate that ascorbic acid induces necrotic cell death through ROS generation, PKC activation, and cytosolic calcium signaling in Hep2 cells. J. Cell. Physiol. 232: 417-425, 2017. © 2016 Wiley Periodicals, Inc.

Ascorbic acid (AA) is an antioxidant that might be beneficial for adjunctive treatment of sepsis in horses. The optimal dose and effects on oxidative status are unknown. Ascorbic acid administration will increase plasma AA concentrations and decrease determinants of reactive oxygen metabolites (dROM), basal and stimulant-induced intraerythrocytic reactive oxygen species (ROS) concentrations, and stimulant-induced neutrophil ROS production, and increase plasma antioxidant capacity (PAC) in a dose-dependent manner. Eight healthy horses. Randomized placebo-controlled crossover study. Each horse received 4 single-dose IV treatments including AA at 25, 50, and 100 mg/kg and saline (placebo) with each treatment separated by ≥1 week. Blood was collected at baseline, 2 and 6 hours for assessment of plasma dROM and PAC via photometer, intraerythrocytic ROS by flow cytometry, and stimulant-induced neutrophil ROS by a fluorometric assay. Plasma AA concentrations were measured by high-performance liquid chromatography/electrochemical detection. Ascorbic acid at 100 mg/kg resulted in decreased dROM 2 hours after treatment (P = .03, 95% CI 5.51-121.2, point estimate 63.3). There was no effect of AA on basal or stimulant-induced intraerythrocytic ROS (P = .88, 95% CI -0.156 to 0.081, point estimate -0.037; P = .93, 95% CI -0.123 to 0.112, point estimate -0.006, respectively), basal or stimulant-induced neutrophil ROS (P ≥ .12, 95% CI -644.9 to 56.2, point estimate -294.4), or PAC (P ≥ .64, 95% CI -1567 to 463.4, point estimate -552.0) at any dose or timepoint. Plasma AA concentrations increased in a dose-dependent manner. High-dose administration of AA might provide antioxidant benefits in horses.