curcumin and 2-2--azobis(2-amidinopropane)

Gold nanoparticles (AuNPs) have gained considerable attention due to their biocompatibility, customizable optical properties and ease of synthesis. In this study, an environmentally friendly method was used for synthesize curcumin-functionalized AuNPs (AuNP-C). AuNP-C exhibited a spherical shape, uniformity, and an average diameter of 6 nm. The in vitro antioxidant activity was analyzed, and cytotoxicity properties of AuNP-C were assessed in fibroblast and macrophage cells. Additionally, the effects of AuNP-C on oxidative stress in chicken embryo liver and hearts were investigated. AuNP-C demonstrated potent free radical scavenging properties without exhibiting cytotoxicity and hepatotoxicity effects. Administration of 300 µg/mL of AuNP-C in chicken embryos, subjected to oxidative damage induced by 2,2'-azobis(2-amidinopropane) dihydrochloride, significantly reduced lipid peroxidation and reactive oxygen species levels in the cardiac tissue. Moreover, the activities of cardiac superoxide dismutase, catalase, and glutathione reductase were restored, accompanied by an increase in overall antioxidant capacity. Furthermore, at higher concentrations, AuNP-C normalized the reduced glutathione content. AuNP-C preserved the normal structure of blood vessels; however, it resulted in an increase in protein carbonylation. This study provides initial evidence for the modulation of antioxidant defense mechanisms by green-synthesized AuNPs and underscores the importance of investigating the in vivo safety of phytoantioxidant-functionalized nanoparticles.

Topics: Animals; Antioxidants; Cardiotoxicity; Chick Embryo; Chickens; Curcumin; Gold; Lipid Peroxidation; Metal Nanoparticles

The purpose of this study was to compare the antioxidant capacities of seven natural pigments including the fat-soluble pigments curcumin, lycopene, lutein and β-carotene and water-soluble pigments--betalain, capsanthin and cyanidin-3-rutinoside relative to a commonly-used synthetic food antioxidant BHA. The antioxidant capacities of seven pigments and BHA were evaluated based on their ability to quench several free radicals, including DPPH, ABTS, O2(·-), H2O2 as well as using FRAP assay. Specifically, curcumin and cyanidin-3-rutinoside, which showed the highest antioxidant capacities, were further investigated using a chicken erythrocyte model. After separating pretreatments of the two pigments, AAPH was added to the erythrocyte-pigment medium to induce oxidative stress. Then the attenuation effects of the two pigments on AAPH-induced oxidative damage in chicken erythrocytes were assessed. It was found that both curcumin and cyanidin-3-rutinoside significantly attenuated apoptosis and hemolysis, decreased MDA content, and increased T-SOD activity in a time- and dose- dependent manner.

Topics: Amidines; Animals; Antioxidants; Chickens; Curcumin; Erythrocytes; Free Radical Scavengers; Hemolysis; Lipid Peroxidation; Pigments, Biological

In order to clarify the contribution of phenolic and enolic hydroxyl group to the antioxidant capacity of feruloylacetone, a model compound of half-curcumin, 6-(p-hydroxy-m-methoxyphenyl)-5-hexene-2,4-dione (FT), 6-(p-benzyloxy-m-methoxyphenyl)-5-hexene-2,4-dione (BMFT), 6-(m,p-dihydroxyphenyl)-5-hexene-2,4-dione (DDFT), 6-(p-hydroxy-m-methoxyphenyl)hexane-2,4-dione (DHFT), 6-(p-hydroxy-m-methoxyphenyl)-5-hexene-2,4-diol (THFT), and ethyl 2-(p-hydroxy-m-methoxybenzylidene)-3-oxobutanoate (EOFT) were synthesized. The radical-scavenging abilities of these compounds were tested by trapping 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+·)), 2,2'-diphenyl-1-picrylhydrazyl (DPPH), and galvinoxyl radicals. The reductive capacities were screened by quenching singlet oxygen and by inhibiting the oxidation of linoleic acid. They were also employed to inhibit the oxidation of DNA mediated by hydroxyl radical and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH). In addition, they were applied to protect erythrocytes against AAPH- and hemin-induced hemolysis. The obtained results revealed that the antioxidant capacity of half-curcumin was derived from the phenolic-OH and the conjugated linkage between phenolic and enolic-OH. The enolic-OH itself cannot trap radicals.

Topics: Acetone; Amidines; beta Carotene; Copper; Curcumin; DNA; Erythrocytes; Free Radical Scavengers; Free Radicals; Glutathione; Hemin; Hemolysis; Humans; Linoleic Acids; Oxidation-Reduction; Structure-Activity Relationship; Styrenes

The antioxidant properties of curcumin have been studied by evaluating its ability to protect RBCs from AAPH (2,2'-azobis (2-amidinopropane) hydrochloride) induced oxidative damage. RBCs are susceptible to oxidative damage, resulting in peroxidation of the membrane lipids, release of hemoglobin (hemolysis), release of intracellular K(+) ions and depletion of glutathione (GSH). In this paper, lipid peroxidation, hemolysis and K(+) ion loss in RBCs were assessed respectively by formation of thiobarbituric acid reactive substances (TBARS), absorbance of hemoglobin at 532nm and flame photometry. The treatment of RBCs with curcumin showed concentration dependant decrease in level of TBARS and hemolysis. The IC(50) values for inhibition of lipid peroxidation and hemolysis were estimated to be 23.2+/-2.5 and 43+/-5microM respectively. However in contrast to the above mentioned effects, curcumin in similar concentration range, did not prevent release of intracellular K(+) ions during the process of hemolysis, rather curcumin induced its release even in the absence of hemolysis. The ability of curcumin to prevent oxidation of intracellular GSH due to hemolysis showed mixed results. At low concentrations of curcumin (<10microM) it prevented GSH depletion and at higher concentrations, the GSH levels decreased gradually. Curcumin scavenges the peroxyl radical generated from AAPH. Based on these results, it is concluded that curcumin exhibits both antioxidant/pro-oxidant activity, in a concentration dependent manner.

Topics: Amidines; Antioxidants; Biomarkers; Curcumin; Dose-Response Relationship, Drug; Erythrocyte Membrane; Erythrocytes; Glutathione; Hemoglobins; Hemolysis; Humans; Lipid Peroxidation; Oxidants; Oxidation-Reduction; Oxidative Stress; Potassium; Reactive Oxygen Species; Thiobarbituric Acid Reactive Substances

The antioxidant activities of curcumin, its natural demethoxy derivatives (demethoxycurcumin, Dmc and bisdemethoxycurcumin, Bdmc) and metabolite hydrogenated derivatives (tetrahydrocurcumin, THC; hexahydrocurcumin, HHC; octahydrocurcumin; OHC) were comparatively studied using 2,2-diphenyl-1-picrylhydrazyl (DDPH) radical, 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) induced linoleic oxidation and AAPH induced red blood cell hemolysis assays. Hydrogenated derivatives of curcumin exhibited stronger DPPH scavenging activity compared to curcumin and a reference antioxidant, trolox. The scavenging activity significantly decreased in the order THC>HHC=OHC>trolox>curcumin>Dmc>>>Bdmc. Stronger antioxidant activities toward lipid peroxidation and red blood cell hemolysis were also demonstrated in the hydrogenated derivatives. By the model of AAPH induced linoleic oxidation, the stoichiometric number of peroxyl radical that can be trapped per molecule (n) of hydrogenated derivatives were 3.4, 3.8 and 3.1 for THC, HHC and OHC, respectively. The number (n) of curcumin and Dmc were 2.7 and 2.0, respectively, which are comparable to trolox, while it was 1.4 for Bdmc. The inhibition of AAPH induced red blood cell hemolysis significantly decreased in the order OHC>THC=HHC>trolox>curcumin=Dmc. Results in all models demonstrated the lower antioxidant activity of the demethoxy derivatives, suggesting the ortho-methoxyphenolic groups of curcumin are involved in antioxidant activities. On the other hand, hydrogenation at conjugated double bonds of the central seven carbon chain and beta diketone of curcumin to THC, HHC and OHC remarkably enhance antioxidant activity.

Topics: Amidines; Antioxidants; Biphenyl Compounds; Chromans; Curcumin; Diarylheptanoids; Erythrocyte Membrane; Free Radical Scavengers; Free Radicals; Hemolysis; Humans; Hydrogenation; In Vitro Techniques; Linoleic Acid; Lipid Peroxidation; Molecular Structure; Oxidants; Picrates; Structure-Activity Relationship; Time Factors