ascorbic-acid and zingerone

Polymeric permselective films are frequently used for amperometric biosensors to prevent electroactive interference present in the target matrix. Phenylenediamines are the most commonly used for the deposition of shielding polymeric films against interfering species; however, even phenolic monomers have been utilized in the creation of these films for microsensors and biosensors. The purpose of this paper is to evaluate the performances of electrosynthesized polymers, layered by means of constant potential amperometry (CPA), of naturally occurring compound zingerone (ZING) and its dimer dehydrozingerone (ZING DIM), which was obtained by straight oxidative coupling reaction. The polymers showed interesting shielding characteristics against the main interfering species, such as ascorbic acid (AA): actually, polyZING exhibited an AA shielding aptitude comprised between 77.6 and 99.6%, comparable to that obtained with PPD. Moreover, a marked capability of increased monitoring of hydrogen peroxide (HP), when data were compared with bare metal results, was observed. In particular, polyZING showed increases ranging between 55.6 and 85.6%. In the present work, the molecular structures of the obtained polymers have been theorized and docking analyses were performed to understand their peculiar characteristics better. The structures were docked using the Lamarckian genetic algorithm (LGA). Glutamate biosensors based on those polymers were built, and their performances were compared with biosensors based on PPD, which is the most widespread polymer for the construction of amperometric biosensors.

Topics: Ascorbic Acid; Glutamic Acid; Guaiacol; Polymers

Tetrahexyldecyl Ascorbate (THDC) is an L-ascorbic acid precursor with improved stability and ability to penetrate the epidermis. The stability and transdermal penetration of THDC, however, may be compromised by the oxidant-rich environment of human skin. In this study, we show that THDC is a poor antioxidant that degrades rapidly when exposed to singlet oxygen. This degradation, however, was prevented by combination with acetyl zingerone (AZ) as a stabilizing antioxidant. As a standalone ingredient, THDC led to unexpected activation of type I interferon signaling, but this pro-inflammatory effect was blunted in the presence of AZ. Moreover, the combination of THDC and AZ increased expression of genes associated with phospholipid homeostasis and keratinocyte differentiation, along with repression of

Topics: Antioxidants; Ascorbic Acid; Cell Line; Collagen; Fibroblasts; Guaiacol; Humans; Oxidative Stress

Parkinson's disease (PD) is characterized by progressive degeneration of dopaminergic neurons in the nigrostriatal system and dopamine (DA) depletion in the striatum. The most popular therapeutic medicine for treating PD, 3-(3,4-Dihydroxyphenyl)-L-alanine (L-DOPA), has adverse effects, such as dyskinesia and disease acceleration. As superoxide (·O(2)(-)) and hydroxyl radical (·OH) have been implicated in the pathogenesis of PD, free radical scavenging and antioxidants have attracted attention as agents to prevent disease progression. Rodents injected with 6-hydroxydopamine (6-OHDA) intracerebroventricularly are considered to be a good animal model of PD. Zingerone and eugenol, essential oils extracted from ginger and cloves, are known to have free radical scavenging and antioxidant effects. Therefore, we examined the effects of zingerone and eugenol on the behavioral problems in mouse model and on the DA concentration and antioxidant activities in the striatum after 6-OHDA administration and L-DOPA treatment. Daily oral administration of eugenol/zingerone and injection of L-DOPA intraperitoneally for 4 weeks following a single 6-OHDA injection did not improve abnormal behaviors induced by L-DOPA treatment. 6-OHDA reduced the DA level in the striatum; surprisingly, zingerone and eugenol enhanced the reduction of striatal DA and its metabolites. Zingerone decreased catalase activity, and increased glutathione peroxidase activity and the oxidized L-ascorbate level in the striatum. We previously reported that pre-treatment with zingerone or eugenol prevents 6-OHDA-induced DA depression by preventing lipid peroxidation. However, the present study shows that post-treatment with these substances enhanced the DA decrease. These substances had adverse effects dependent on the time of administration relative to model PD onset. These results suggest that we should be wary of ingesting these spice elements after the onset of PD symptoms.

Topics: Animals; Antioxidants; Ascorbic Acid; Catalase; Corpus Striatum; Disease Models, Animal; Dopamine; Eugenol; Free Radical Scavengers; Glutathione; Glutathione Peroxidase; Guaiacol; Levodopa; Male; Mice; Oxidopamine; Parkinson Disease; Parkinson Disease, Secondary; Superoxide Dismutase

Antioxidants minimize oxidation of the lipid components in foods. There is an increasing interest in the use of natural and/or synthetic antioxidants in food preservation, but it is important to evaluate such compounds fully for both antioxidant and pro-oxidant properties. The properties of thymol, carvacrol, 6-ginerol, hydroxytyrosol and zingerone were characterized in detail. Thymol, carvacrol, 6-gingerol and hydroxytyrosol decreased peroxidation of phospholipid liposomes in the presence of iron(III) and ascorbate, but zingerone had only a weak inhibitory effect on the system. The compounds were good scavengers of peroxyl radicals (CCl3O2; calculated rate constants > 10(6) M-1 sec-1) generated by pulse radiolysis. Thymol, carvacrol, 6-gingerol and zingerone were not able to accelerate DNA damage in the bleomycin-Fe(III) system. Hydroxytyrosol promoted deoxyribose damage in the deoxyribose assay and also promoted DNA damage in the bleomycin-Fe(III) system. This promotion was inhibited strongly in the deoxyribose assay by the addition of bovine serum albumin to the reaction mixtures. Our data suggest that thymol, carvacrol and 6-gingerol possess useful antioxidant properties and may become important in the search for 'natural' replacements for 'synthetic' antioxidant food additives.

Topics: Antioxidants; Ascorbic Acid; Bleomycin; Catechols; Cymenes; Deoxyribose; DNA Damage; Fatty Alcohols; Ferric Compounds; Food Preservation; Guaiacol; Hydroxyl Radical; Lipid Peroxidation; Liposomes; Monoterpenes; Phenylethyl Alcohol; Pulse Radiolysis; Terpenes; Thymol