cytochrome-c-t and 1-1-diphenyl-2-picrylhydrazyl

The stability of solutions of fullerene C₆₀ with human serum albumin (C₆₀/HSA) has not been studied in detail. In this study, we report on the preparation of stable C₆₀/HSA solutions that are formed via the formation of C₆₀/HP-β-CyD nanoparticles, i.e. by transferring C₆₀ molecules from HP-β-CyD to HSA molecules, and an investigation of the reactive oxygen species on the behavior of the resulting C₆₀/HSA.. Structural and functional properties were examined by spectroscopic techniques, including circular dichroism (CD), fluorescent spectra (FI), and electron spin resonance spin-trapping method, and by cell viability test using A549 cells.. Aqueous C₆₀/HSA solutions with a small distribution size, excellent dispersion stability and a high dispersion concentration were obtained without the use of organic solvents. CD and FI spectra indicated that the HSA had undergone structural changes as the result of C₆₀/HSA formation. Binding experiments indicated that C₆₀/HSA had increased Site I and Site II-ligand binding capabilities. The HSA, in the form of C₆₀/HSA was, therefore, conformationally altered, and its binding capabilities were enhanced. Radical scavenging studies using the 1,1'-diphenyl-2-picrylhydrazyl radical showed that C₆₀/HSA had an increased antioxidant activity, compared to HSA alone. Further, C₆₀/HSA efficiently generated not only superoxide anion radicals O₂·- but also singlet oxygen ¹O₂ through photoirradiation. C₆₀/HSA showed cell toxicity characteristics after light irradiation, but no toxicity was observed in the absence of irradiation.. C₆₀/HSA not only has an excellent stability and antioxidant activity, but also has substantial phototoxicity properties. It thus appears that HSA can be used as a carrier of C₆₀in drug delivery systems for photodynamic therapy.

Topics: Amino Acids, Aromatic; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Biphenyl Compounds; Cell Line, Tumor; Circular Dichroism; Cyclodextrins; Cytochromes c; Dermatitis, Phototoxic; Drug Stability; Free Radical Scavengers; Fullerenes; Humans; Ketoprofen; Ligands; Nanoparticles; Picrates; Reactive Oxygen Species; Serum Albumin; Solubility; Warfarin

The bile salt, deoxycholate (DOC), can harm cells and cause disease. Hence, there is interest in identifying compounds capable of protecting cells against DOC. In HCT-116 colon epithelial cells, DOC increased generation of reactive oxygen species and caused DNA damage and apoptosis. These effects of DOC were inhibited by rottlerin, which is a phenolic compound of plant origin. In elucidating its mechansim, rottlerin prevented the release of cytochrome c from mitochondria into cytosol, and also prevented the cleavage of caspase-3. Yet, rottlerin by itself markedly decreased mitochondrial membrane potential and increased mitochondrial superoxide production, but this did not result in cytochrome c release or in caspase-3 cleavage. At a higher test concentration, two other phenolic phytochemicals, namely, quercetin and resveratrol, were each able to largely prevent the occurrence of apoptosis in cells exposed to DOC. In contrast, epigallocatechin gallate, curcumin, and genistein were ineffective.

Topics: Acetophenones; Apoptosis; Benzopyrans; Biphenyl Compounds; Caspase 3; Colon; Cytochromes c; Cytoprotection; Deoxycholic Acid; DNA Damage; DNA, Neoplasm; Epithelial Cells; HCT116 Cells; Humans; Hydrazines; Mitochondria; Phenols; Picrates; Quercetin; Resveratrol; Stilbenes; Superoxides

The phytochemical compounds oryzanols, tocopherols, tocotrienols and ferulic acid were identified in the crude methanolic extracts (CME) of defatted rice bran (DRB) by HPLC. Enrichment of antioxidants in CME was achieved by sequential extraction and fractionation resulting in three enriched fractions viz. acetone extract (AE), acetone extract-lipophilic fraction (AE-LP) and acetone extract-polar fraction (AE-PP). The scavenging effects of DRB extracts and their phytochemical constituents against DPPH and superoxide radicals were investigated. The EC(50) (g antioxidant/kg DPPH) values of CME, AE, AE-LP, AE-PP, oryzanols, ferulic acid, tocols (Tmix), tricin, beta-sitosterol, BHT and TBHQ were 1,977, 1,945, 7,985, 1,072, 972, 174, 164, 3,947, 21,416, 1,120 and 61, respectively. Tricin and beta-sitosterol isolated from CME were identified with the help of spectral data. The DRB extracts and their phytochemical constituents when assayed by cytochrome c and NBT methods showed positive superoxide radical scavenging effects. The order of efficacies of the extracts was AE-PP>AE>CME>AE-LP in both assays, but the activities were higher for the former method. The DPPH as well as superoxide scavenging activities of AE, AE-LP and AE-PP could largely be attributed to the levels of total phenols (TPC) and ferulic acid in it.

Topics: Antioxidants; Biphenyl Compounds; Chromatography, Gel; Chromatography, High Pressure Liquid; Cytochromes c; Flavonoids; Free Radical Scavengers; Oryza; Phenols; Phenylpropionates; Picrates; Plant Extracts; Polyphenols; Silica Gel; Silicon Dioxide; Tocopherols; Tocotrienols

A new flavanone Persinol (1) and the new flavanone glucosides persinosides A (2) and B (3), along with known flavonoids (4 and 5) have been isolated from the ethyl acetate soluble fraction of the whole plants of Aerva persica. Their structures were elucidated on the basis of extensive analysis of nuclear magnetic resonance (1D and 2D-NMR) spectral data. All of them showed profound antioxidative activities by DPPH and cytochrome-c-reduction assays using the HL-60 cell culture system.

Topics: Amaranthaceae; Antioxidants; Biphenyl Compounds; Cytochromes c; Flavonoids; Free Radical Scavengers; Free Radicals; Glucosides; HL-60 Cells; Humans; Hydrazines; Magnetic Resonance Spectroscopy; Molecular Structure; Pakistan; Picrates; Plant Extracts; Structure-Activity Relationship