title: Chinonin, a novel drug against cardiomyocyte apoptosis induced by hypoxia and reoxygenation.
abstract: The inhibitory effects of Chinonin, a natural antioxidant extracted from a Chinese medicine, on apoptotic and necrotic cell death of cardiomyocytes in hypoxia-reoxygenation process were observed in this study. The possible mechanisms of Chinonin on scavenging reactive oxygen species and regulating apoptotic related genes bcl-2 and p53 were also investigated. Neonatal rat cardiomyocytes were subjected to 24-h hypoxia and 4-h reoxygenation. Cell death was evaluated by DNA electrophoresis on agarose gel, cell death ELISA and annexin-V-FLUOS/propidium iodide (PI) double staining cytometry. Hypoxia caused the increase of apoptotic rates and the release of lactate dehydrogenase (LDH), while reoxygenation not only further increased the apoptotic rates and leakage of LDH, but also induced necrosis of cardiomyocytes. In addition, hypoxia increased the levels of NO(2)(-)/NO(3)(-) and thiobarbituric acid reacted substances (TBARS), while reoxygenation decreased NO(2)(-)/NO(3)(-), but further increased TBARS in the cultured media. Moreover, hypoxia up-regulated the expression levels of bcl-2 and p53 proteins, while reoxygenation down-regulated bcl-2 and further up-regulated p53. Chinonin significantly decreased the rates of apoptotic and necrotic cardiomyocytes, and inhibited the leakage of LDH. It also diminished NO(2)(-)/NO(3)(-) and TBARS, down-regulated the expression level of p53 protein, and up-regulated bcl-2 protein, respectively. The results suggest that Chinonin has preventive effects against apoptotic and necrotic cell death and its protective mechanisms are related to the antioxidant properties of scavenging nitric oxide and oxygen free radicals, and the modulating effects on the expression levels of bcl-2 and p53 proteins.
authors.affiliation: Institute of Chinese Medicine, First Military Medical University, Guangzhou, China.
authors.forename: J G
authors.initials: JG
authors.lastname: Shen
authors.forename: X S
authors.initials: XS
authors.lastname: Quo
authors.forename: B
authors.initials: B
authors.lastname: Jiang
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: W
authors.initials: W
authors.lastname: Xin
authors.forename: B L
authors.initials: BL
authors.lastname: Zhao
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017304:Annexin A5 / Q000032:analysis; D017209:Apoptosis / Q000187:drug effects*; D015415:Biomarkers; D015687:Cell Hypoxia; D002478:Cells, Cultured; D053938:DNA Fragmentation / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology*; D019254:Genes, bcl-2; D016158:Genes, p53; D006027:Glycosides / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D015227:Lipid Peroxidation / Q000187:drug effects; D017202:Myocardial Ischemia / Q000473:pathology*; D015428:Myocardial Reperfusion Injury / Q000473:pathology*; D009206:Myocardium / Q000473:pathology*; D009336:Necrosis; D009566:Nitrates / Q000032:analysis; D009569:Nitric Oxide / Q000378:metabolism; D009573:Nitrites / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014966:Xanthenes / Q000494:pharmacology*; D044004:Xanthones
chemical_list: D017304:Annexin A5; D015415:Biomarkers; D016166:Free Radical Scavengers; D006027:Glycosides; D009566:Nitrates; D009573:Nitrites; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D014966:Xanthenes; D044004:Xanthones; C013592:mangiferin; D009569:Nitric Oxide; D007770:L-Lactate Dehydrogenase