title: Totarol prevents neuronal injury in vitro and ameliorates brain ischemic stroke: Potential roles of Akt activation and HO-1 induction.
abstract: The natural product totarol, a phenolic diterpenoid and a major constituent isolated from the sap of Podocarpus totara, has been reported to have a potent antimicrobial activity. In this study, we determined whether totarol possessed an additional neuroprotective activity in vitro and in vivo. We found that totarol prevented glutamate- and oxygen and glucose deprivation-induced neuronal death in primary rat cerebellar granule neuronal cells and cerebral cortical neurons. Totarol increased Akt and GSK-3β phosphorylation, Nrf2 and heme oxygenase-1 (HO-1) protein expressions and suppressed oxidative stress by increasing GSH and SOD activities. The PI3K/Akt inhibitor LY294002 prevented totarol neuroprotective effect by suppressing the totarol-induced changes in HO-1 expression and the activities of GSH and SOD. The HO-1 inhibitor ZnPPIX also prevented totarol-increased GSH and SOD activities. In a model of acute cerebral ischemic injury in Sprague-Dawley rats, produced by occlusion of the middle cerebral artery for 2h followed by 22 h or 46 h of reperfusion, totarol significantly reduced infarct volume and improved the neurological deficit. In this model, totarol increased HO-1 expression and the activities of GSH and SOD. These observations suggest that totarol may be a novel activator of the Akt/HO-1 pathway protecting against ischemic stroke through reduction of oxidative stress.
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Yuanxue
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Xu
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Sai
authors.initials: S
authors.lastname: Chang
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Yunjie
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Yazhou
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Siqi
authors.initials: S
authors.lastname: Ran
authors.affiliation: Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Zhangjian
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: National Center for Drug Screening, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 189 Guo Shoujing Road, Shanghai 201203, PR China.
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors.forename: Luyong
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Saavedra
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China. Electronic address: liaohong56@hotmail.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Liao
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China; Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA. Electronic address: tpang@cpu.edu.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Pang
mesh_terms: D045784:Abietanes; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D016923:Cell Death / Q000187:drug effects; D015687:Cell Hypoxia; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004224:Diterpenes / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004790:Enzyme Induction; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity; D005947:Glucose / Q000172:deficiency; D018698:Glutamic Acid / Q000633:toxicity; D005978:Glutathione / Q000378:metabolism; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis*; D020244:Infarction, Middle Cerebral Artery / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
chemical_list: D045784:Abietanes; D000975:Antioxidants; D004224:Diterpenes; D018690:Excitatory Amino Acid Agonists; D051267:NF-E2-Related Factor 2; D018696:Neuroprotective Agents; C495637:Nfe2l2 protein, rat; D018698:Glutamic Acid; C078548:totarol; D006419:Heme Oxygenase (Decyclizing); C491523:Hmox1 protein, rat; D013482:Superoxide Dismutase; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3; D005978:Glutathione; D005947:Glucose
keywords: Akt; HO-1; Neuroprotection; Stroke; Totarol