1-1-diphenyl-2-picrylhydrazyl and gossypetin

To evaluate the protective effect of gossypetin (GTIN) against gamma (γ)-radiation-mediated DNA damage.. Increasing concentrations (10-150 μM) of GTIN were incubated with supercoiled DNA 1 h prior exposure to γ-radiation in the range of 5-Gy absorbed dose from Co(60) γ source. To establish the effective protective concentration of GTIN, supercoiled DNA was pre-incubated with 50 μM of GTIN for 1 h followed by exposure of 5, 10 and 20 Gy doses of γ-radiation. Moreover, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical, hydroxyl radical, nitric oxide (NO) scavenging, metal chelating activity and ferric reducing antioxidant power (FRAP) of GTIN were measured and compared with standards. The flowcytometric analysis and radiation-induced genomic DNA damage by comet assay were employed to estimate the level of intracellular reactive oxygen species (ROS) using isolated murine hepatocytes.. GTIN was able to effectively scavenge different free radicals in in vitro situations. It could significantly prevent radiation induced supercoiled and genomic DNA damage with reduced comet parameters. It also acted as a potent scavenger of the radiation induced ROS.. GTIN ameliorated radiation-induced oxidative stress and DNA damage by its free-radical scavenging activity.

Topics: Animals; Biological Products; Biphenyl Compounds; DNA Damage; DNA, Superhelical; Flavonoids; Free Radical Scavengers; Gamma Rays; Hydroxyl Radical; Intracellular Space; Iron Chelating Agents; Male; Mice; Nitric Oxide; Oxidation-Reduction; Picrates; Radiation-Protective Agents; Reactive Oxygen Species

Gossypetin, a flavone originally isolated from Hibiscus species, has been shown to possess antioxidant, antimicrobial, and antimutagenic activities. Here, we investigated the mechanism(s) underlying the anti-atherosclerotic potential of gossypetin. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity assay showed that the addition of >50μM of gossypetin could scavenge over 50% of DPPH radicals. The inhibitory effects of gossypetin on the lipid and protein oxidation of LDL were defined by thiobarbituric acid reactive substance (TBARS) assay, the relative electrophoretic mobility (REM) of oxidized LDL (ox-LDL), and fragmentation of apoB in the Cu(2+)-induced oxidation of LDL. Gossypetin showed potential in reducing ox-LDL-induced foam cell formation and intracellular lipid accumulation, and uptake ability of macrophages under non-cytotoxic concentrations. Molecular data showed that these influences of gossypetin might be mediated via peroxisome proliferator-activated receptor α (PPARα)/liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) and PPARγ/scavenger receptor CD36 pathways, as demonstrated by the transfection of PPARα siRNA or PPARγ expression vector. Our data implied that gossypetin regulated the PPAR signals, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that gossypetin potentially could be developed as an anti-atherosclerotic agent.

Topics: Animals; Atherosclerosis; Biphenyl Compounds; Cell Culture Techniques; Cell Line; Cell Survival; Electrophoretic Mobility Shift Assay; Flavonoids; Foam Cells; Free Radical Scavengers; Humans; Lipid Peroxidation; Lipoproteins, LDL; Mice; Picrates; Thiobarbituric Acid Reactive Substances