title: Protection against hydrogen peroxide-induced cytotoxicity in PC12 cells by scutellarin.
abstract: The present study investigated the protective actions of the antioxidant scutellarin against the cytotoxicity produced by exposure to H2O2 in PC12 cells. This was done by assaying for MTT (3,(4,5-dimethylthiazole-2-yl)2,5-diphenyl-tetrazolium bromide) reduction and lactate dehydrogenase (LDH) release. Reactive oxygen species (ROS) and Ca2+ in cells were evaluated by fluorescent microplate reader using DCFH and Fura 2-AM, respectively, as probes. Lipid peroxidation was quantified using thiobarbituric acid-reactive substances (TBARS). Mitochondrial membrane potential (MMP) was assessed by the retention of rhodamine123 (Rh123), a specific fluorescent cationic dye that is readily sequestered by active mitochondria, depending on their transmembrane potential. The DNA content and percentage of apoptosis were monitored with flow cytometry. Vitamin E, a potent antioxidant, was employed as a comparative agent. Preincubation of PC12 cells with scutellarin prevented cytotoxicity induced by H2O2. Intracellular accumulation of ROS, Ca2+ and products of lipid peroxidation, resulting from H2O2 were significantly reduced by scutellarin. Incubation of cells with H2O2 caused a marked decrease in MMP, which was significantly inhibited by scutellarin. PC12 cells treated with H2O2 underwent apoptotic death as determined by flow cytometric assay. The percentage of this H2O2-induced apoptosis in the cells was decreased in the presence of different concentrations of scutellarin. Scutellarin exhibited significantly higher potency compared to the antioxidant vitamin E. The present findings showed that scutellarin attenuated H2O2-induced cytotoxicity, intracellular accumulation of ROS and Ca2+, lipid peroxidation, and loss of MMP and DNA, which may represent the cellular mechanisms for its neuroprotective action.
authors.affiliation: Department of Pharmacology, China Pharmaceutical University, No 24 Tong Jia Xiang, Nanjing, 210009, People's Republic of China. haohongchina@hotmail.com
authors.forename: Hao
authors.initials: H
authors.lastname: Hong
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Liu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D047310:Apigenin; D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D019610:Cytoprotection; D004273:DNA, Neoplasm / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000494:pharmacology*; D005965:Glucuronates; D006861:Hydrogen Peroxide / Q000037:antagonists & inhibitors* / Q000633:toxicity; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects; D016716:PC12 Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017382:Reactive Oxygen Species / Q000032:analysis; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D004273:DNA, Neoplasm; D005419:Flavonoids; D005965:Glucuronates; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; D014810:Vitamin E; C484876:scutellarin; D047310:Apigenin; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; C022616:thiazolyl blue; C458179:scutellarein; D002118:Calcium