ascorbic-acid and protocatechuic-acid

This study evaluated the effect of the protocatechuic acid (PCA) as the sole antioxidant in the base medium for in vitro culture of ovine secondary follicles. Secondary follicles (200-230 μm) were isolated and cultured in α-minimal essential medium supplemented with BSA, insulin, glutamine and hypoxanthine (α-MEM: antioxidant-free medium) or α-MEM also added by transferrin, selenium and ascorbic acid (α-MEM+: with antioxidant) or α-MEM added by PCA (56.25; 112.5; 225; 450; or 900 μg/ml). Moreover, after culture, oocytes were matured and the chromatin configuration and DNA fragmentation were evaluated. After 12 days, the treatment containing 56.25 μg/ml PCA showed higher percentage of normal follicles than control medium or the other treatments (p < .05), except for 900 μg/ml PCA (p > .05). The antrum formation was significantly higher in treatments containing 56.25, 112.5 or 900 μg/ml PCA, compared to the α-MEM and similar (p > .05) to the other treatments. The rates of fully grown oocytes (≥110 μm) were similar (p > .05) among all treatments containing PCA and α-MEM+, and those were superior (p < .05) than α-MEM, except for 450 μg/ml PCA (p > .05). GSH levels and mitochondrial activity were higher (p < .05) in α-MEM+ than in α-MEM and similar (p > .05) to all PCA treatments. The rates of meiotic resumption and DNA fragmentation were similar (p > .05) among α-MEM+ and 56.25 μg/ml PCA. In conclusion, PCA at 56.25 μg/ml as the sole antioxidant added to the medium for ovine isolated secondary follicle culture maintains follicular survival, GSH and active mitochondria levels, meiotic developmental competence and DNA integrity of cultured oocytes.

Topics: Animals; Antioxidants; Ascorbic Acid; Cell Culture Techniques; Culture Media; DNA Fragmentation; Female; Glutathione; Hydroxybenzoates; Mitochondria; Oogenesis; Ovarian Follicle; Selenium; Sheep, Domestic; Transferrin

Kei-apple (Dovyalis caffra) is an evergreen tree indigenous to Southern Africa. The fruit contains high concentrations of l-malic acid, ascorbic acid, and phenolic acids. Kei-apple juice was sequentially inoculated with Schizosaccharomyces pombe and Saccharomyces cerevisiae yeasts. A reference fermentation using only S. cerevisiae was included. The fermentation was monitored by recording mass loss. At the end of fermentation, twelve untrained judges conducted free choice aroma profiling on the fruit wines. The Kei-apple juice and wines were analysed for total titratable acidity, total soluble solids, pH, alcohol, l-malic acid, and phenolic acids. Total titratable acidity was ca. 70% lower in Kei-apple wines produced with S. pombe+S. cerevisiae than in Kei-apple juice. Kei-apple wines produced with S. pombe+S. cerevisiae showed substantially lower concentrations of l-malic acid than Kei-apple wines produced with S. cerevisiae only. Wines produced with S. cerevisiae only proved higher in phenolic acid concentrations than wines produced with S. pombe+S. cerevisiae. Chlorogenic acid was the most abundant phenolic acid measured in the Kei-apple wines, followed by protocatechuic acid. Judges described the Kei-apple wines produced with S. pombe+S. cerevisiae as having noticeable off-odours, while wines produced with S. cerevisiae were described as fresh and fruity. Kei-apple wines (S. pombe+S. cerevisiae and S. cerevisiae) were of comparable vegetative and organic character. Saccharomyces cerevisiae produced Kei-apple wine with increased caffeic, chlorogenic, protocatechuic, and sinapic acids, whereas S. pombe+S. cerevisiae produced Kei-apple wines with increased ferulic, and p-coumaric acids and low l-malic acid.

Topics: Ascorbic Acid; Bioreactors; Chlorogenic Acid; Ethanol; Fermentation; Flavoring Agents; Fruit; Hydroxybenzoates; Malates; Odorants; Saccharomyces cerevisiae; Salicaceae; Schizosaccharomyces; Wine

Antioxidant and antimelanogenesis activities of protocatechuic acid (1) from Origanum vulgare (oregano) were investigated. The antioxidative capacity of 1 was confirmed from its free-radical-scavenging activities, inhibition of lipid peroxidation, and suppression of reactive oxygen species in H(2)O(2)-induced BNLCL2 cells. The inhibition by 1 of tyrosinase and DOPA oxidase activity and melanin production was possibly related to the down-regulation of melanocortin-1 receptor, microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related proteins-2, and tyrosinase-related proteins-1 expression in α-melanocyte-stimulating hormone-induced B16 cells. After a gel containing 1 was applied to mice, the values of L* slightly increased, and a* and erythema-melanin levels of skin were reduced by comparing the values of untreated control groups, indicating 1 can reduce melanin production. These results suggest that 1 may act as an effective quencher of oxidative attackers with antimelanogenesis properties.

Topics: alpha-MSH; Animals; Antioxidants; Benzothiazoles; Biphenyl Compounds; Drugs, Chinese Herbal; Free Radical Scavengers; Hydroxybenzoates; Melanins; Melanocytes; Mice; Molecular Structure; Monophenol Monooxygenase; Origanum; Picrates; Reactive Oxygen Species; Skin Pigmentation; Sulfonic Acids

Oxidative stress in diabetes co-exists with a reduction in the antioxidant status, which can further increase the deleterious effects of free radicals. Hyperlipidaemia is one of the major risk factors of cardiovascular complications in diabetes. A study was undertaken to evaluate the antioxidant and antihyperlipidaemic activity of protocatechuic acid (PCA) on streptozotocin (STZ)-induced diabetic rats. The levels of thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were increased and the level of enzymatic and non-enzymatic antioxidants decreased except vitamin E. Lipid profile increased in diabetic rats, whereas HDL-C level decreased. These alterations reverted to near control levels after the diabetic rats were treated with PCA. Histopathological studies also revealed the protective effects of PCA on liver and kidney. These findings suggest that PCA treatment exerts a therapeutic property by decreasing the oxidative stress and lipid profile. The effect of PCA was comparable to glibenclamide, a well-known hypoglycaemic drug.

Topics: Animals; Antioxidants; Ascorbic Acid; Diabetes Mellitus, Experimental; Glutathione; Hydroxybenzoates; Hypolipidemic Agents; Kidney; Lipid Peroxides; Liver; Male; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances; Vitamin E

The application of single-molecule fluorescence techniques to complex biological systems places demands on the performance of single fluorophores. We present an enzymatic oxygen scavenging system for improved dye stability in single-molecule experiments. We compared the previously described protocatechuic acid/protocatechuate-3,4-dioxygenase system to the currently employed glucose oxidase/catalase system. Under standardized conditions, we observed lower dissolved oxygen concentrations with the protocatechuic acid/protocatechuate-3,4-dioxygenase system. Furthermore, we observed increased initial lifetimes of single Cy3, Cy5, and Alexa488 fluorophores. We further tested the effects of chemical additives in this system. We found that biological reducing agents increase both the frequency and duration of blinking events of Cy5, an effect that scales with reducing potential. We observed increased stability of Cy3 and Alexa488 in the presence of the antioxidants ascorbic acid and n-propyl gallate. This new O(2)-scavenging system should have wide application for single-molecule fluorescence experiments.

Topics: Ascorbic Acid; Carbocyanines; Catalase; Enzyme Stability; Fluorescent Dyes; Free Radical Scavengers; Glucose Oxidase; Hydroxybenzoates; Microscopy, Fluorescence; Nanotechnology; Oxygen; Photobleaching; Propyl Gallate; Protocatechuate-3,4-Dioxygenase; Reactive Oxygen Species

A xanthine oxidase hydroxyl radical (.OH)-generating system was created for sustained in vitro production of *OH. This assay was coupled with microdialysis sampling to elucidate the factors that influence microdialysis calibration during radical trapping. A *OH trapping agent, 4-hydroxybenzoic acid, was included either in the microdialysis perfusion fluid or in the medium external to the microdialysis probe. Xanthine oxidase enzymatic activity was reproducible and had an average activity measured by UV absorbance of produced uric acid of 0.037 +/- 0.005 deltaAU/min (n = 5). A considerable amount of variance in the rate and amount of the product, 3,4-dihydroxybenzoic acid (3,4-DHBA), was observed when one microdialysis probe was placed in the reaction mixture. When two microdialysis probes were placed in the reaction mixture, a greater rate and amount of 3,4-DHBA was observed. Different concentrations of 3,4-DHBA were obtained between quiescent and stirred systems.

Topics: Ascorbic Acid; Calibration; Chromatography, High Pressure Liquid; Hydroxybenzoates; Hydroxyl Radical; Hypoxanthine; Microdialysis; Uric Acid; Xanthine; Xanthine Oxidase