title: Standardized extracts of flavonoids increase the viability of PC12 cells treated with hydrogen peroxide: effects on oxidative injury.
abstract: Oxidative stress plays an important role in cell death associated with many diseases. In the present study, concentration-dependence of hydrogen peroxide on rat pheochromocytoma (PC12) cell viability was studied. Preventive effects of antioxidants on the viability of these cells treated with 2 mM hydrogen peroxide were compared. Trolox and Stobadine, as chain-breaking antioxidants were studied in comparison with standardized extracts of flavonoids of Ginkgo biloba and Pycnogenol, known as agents effective in several diseases. All antioxidants increased the viability of hydrogen peroxide-treated PC12 cells. Flavonoid extracts were more effective than Trolox and Stobadine. Antioxidants were most effective if present after the oxidative treatment. As expected, the preloading with antioxidants was without effect on cell viability. Correlations between viability increase induced by antioxidants, and content of oxidation products of proteins and lipids were studied at concentrations of antioxidants mostly effective in preventing cell death: Trolox (10 microM), Stobadine (30 microM), Ginkgo biloba (160 microg/ml), Pycnogenol (100 microg/ml). In these concentrations, antioxidants did not statistically significantly decrease the content of protein carbonyls, with exception of Stobadine, which had no effect. Ginkgo biloba, Trolox and Stobadine intensively decreased the content of malondialdehyde, a product of lipid peroxidation. Pycnogenol was without any preventive effect. Concentrations of antioxidants with a large effect on viability of PC12 cells were not effective in preventing oxygen radical-induced injury of proteins. Antioxidants prevented the oxidative injury of lipids more effectively than that of proteins.
authors.affiliation: Neuroscience Research Center, Medical Faculty (Charité), Humboldt University Berlin, Schumannstr. 20/21, 10098 Berlin, Germany.
authors.forename: Lubica
authors.initials: L
authors.lastname: Horáková
authors.forename: Anke
authors.initials: A
authors.lastname: Licht
authors.forename: Grit
authors.initials: G
authors.lastname: Sandig
authors.forename: Manuela
authors.initials: M
authors.lastname: Jakstadt
authors.forename: Zdena
authors.initials: Z
authors.lastname: Duracková
authors.forename: Tilman
authors.initials: T
authors.lastname: Grune
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002243:Carbolines / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002839:Chromans / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004336:Drug Antagonism; D005419:Flavonoids / Q000494:pharmacology*; D020441:Ginkgo biloba / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000633:toxicity*; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D016716:PC12 Cells / Q000187:drug effects* / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D011506:Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D051381:Rats
chemical_list: D000975:Antioxidants; D002243:Carbolines; D002839:Chromans; D005419:Flavonoids; D006834:Hydrazines; D010936:Plant Extracts; D011506:Proteins; C029424:hydrazine; D008315:Malondialdehyde; C024070:pycnogenols; D006861:Hydrogen Peroxide; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; C100106:dicarbine