title: Protective effect of vitexin compound B-1 against hypoxia/reoxygenation-induced injury in differentiated PC12 cells via NADPH oxidase inhibition.
abstract: Vitexin compound B-1 (VB-1) is a novel member of the vitexins family isolated from the seeds of the Chinese herb Vitex negundo. This study aims to investigate whether VB-1 is able to protect nerve cells against oxidative injury and whether the antioxidative effects of VB-1 occur through a mechanism involving the inhibition of NADPH oxidase (NOX) in a manner of hypoxia-inducible factor 1α (HIF-1α)-dependent. To establish a neuronal in vitro model of oxidative stress, the differentiated PC12 cells were subjected to 5 h of hypoxia followed by 20 h of reoxygenation (H/R). Three dosages of VB-1 (10(-8), 10(-7), and 10(-6) M) were chosen to evaluate the effect of VB-1 on H/R-induced injury and the underlying mechanisms. At the end of the experiments, culture mediums and cells were collected for analysis of cellular apoptosis, lactate dehydrogenase (LDH) and caspase 3/7-like activities, reactive oxygen species (ROS) levels, 4-hydroxynonenal (4-HNE) and malondialdehye (MDA) contents, and HIF-1α and NOX expression, respectively. Our results showed that cell injury (indicated by apoptosis ratio, caspase 3/7-like activity, and LDH release), oxidative stress (indicated by ROS production, 4-HNE, and MDA contents), NOX activity, and NOX expression (NOX2 and NOX4 isoforms) were dramatically increased in PC12 cells following H/R, which were attenuated in the presence of VB-1 at dosage of 10(-7) or 10(-6) M. There was no significant change in HIF-1α expression in all experimental groups. These results provide evidence that VB-1 is able to protect the PC12 cells against H/R-induced injury through a mechanism involving the suppression of NOX expression and subsequent reduction of ROS production. The effect of VB-1 on H/R-induced NOX expression is independent on HIF-1α inhibition.
authors.affiliation: Department of Pharmacology, School of Pharmaceutical Sciences, Central South University, No. 110 Xiang-Ya Road, Changsha, 410078, China.
authors.forename: Zhong-Bao
authors.initials: ZB
authors.lastname: Yang
authors.forename: Bin
authors.initials: B
authors.lastname: Tan
authors.forename: Ting-Bo
authors.initials: TB
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Lou
authors.forename: Jun-Lin
authors.initials: JL
authors.lastname: Jiang
authors.forename: Ying-Jun
authors.initials: YJ
authors.lastname: Zhou
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Xiu-Ju
authors.initials: XJ
authors.lastname: Luo
authors.forename: Jun
authors.initials: J
authors.lastname: Peng
mesh_terms: D000447:Aldehydes / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002454:Cell Differentiation; D000860:Hypoxia / Q000378:metabolism*; D017705:Lignans / Q000494:pharmacology*; D008315:Malondialdehyde / Q000378:metabolism; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D016716:PC12 Cells; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: C000596986:6-hydroxy-4-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxy-3,4-dihydro-2-naphthaldehyde; D000447:Aldehydes; D017705:Lignans; D018696:Neuroprotective Agents; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D019255:NADPH Oxidases; C505410:Casp3 protein, rat; D053148:Caspase 3; D053179:Caspase 7; C027576:4-hydroxy-2-nonenal