title: Andrographolide inhibits PI3K/AKT-dependent NOX2 and iNOS expression protecting mice against hypoxia/ischemia-induced oxidative brain injury.
abstract: This study aimed to explore the mechanisms by which andrographolide protects against hypoxia-induced oxidative/nitrosative brain injury provoked by cerebral ischemic/reperfusion (CI/R) injury in mice. Hypoxia  IN VITRO was modeled using oxygen-glucose deprivation (OGD) followed by reoxygenation of BV-2 microglial cells. Our results showed that treatment of mice that have undergone CI/R injury with andrographolide (10-100 µg/kg, i. v.) at 1 h after hypoxia ameliorated CI/R-induced oxidative/nitrosative stress, brain infarction, and neurological deficits in the mice, and enhanced their survival rate. CI/R induced a remarkable production in the mouse brains of reactive oxygen species (ROS) and a significant increase in protein nitrosylation; this primarily resulted from enhanced expression of NADPH oxidase 2 (NOX2), inducible nitric oxide synthase (iNOS), and the infiltration of CD11b cells due to activation of nuclear factor-kappa B (NF- κB) and hypoxia-inducible factor 1-alpha (HIF-1 α). All these changes were significantly diminished by andrographolide. In BV-2 cells, OGD induced ROS and nitric oxide production by upregulating NOX2 and iNOS via the phosphatidylinositol-3-kinase (PI3K)/AKT-dependent NF- κB and HIF-1 α pathways, and these changes were suppressed by andrographolide and LY294002. Our results indicate that andrographolide reduces NOX2 and iNOS expression possibly by impairing PI3K/AKT-dependent NF- κB and HIF-1 α activation. This compromises microglial activation, which then, in turn, mediates andrographolide's protective effect in the CI/R mice.
authors.affiliation: Department of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chang-Ming
authors.initials: CM
authors.lastname: Chern
authors.forename: Kuo-Tong
authors.initials: KT
authors.lastname: Liou
authors.forename: Yea-Hwey
authors.initials: YH
authors.lastname: Wang
authors.forename: Jyh-Fei
authors.initials: JF
authors.lastname: Liao
authors.forename: Jiin-Cherng
authors.initials: JC
authors.lastname: Yen
authors.forename: Yuh-Chiang
authors.initials: YC
authors.lastname: Shen
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use*; D002460:Cell Line; D002544:Cerebral Infarction / Q000150:complications / Q000517:prevention & control; D004195:Disease Models, Animal; D004224:Diterpenes / Q000494:pharmacology / Q000627:therapeutic use*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D020925:Hypoxia-Ischemia, Brain / Q000150:complications / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D017628:Microglia / Q000378:metabolism; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015538:Nitrosation / Q000187:drug effects; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D020521:Stroke / Q000150:complications / Q000517:prevention & control*; D013481:Superoxides / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004224:Diterpenes; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D013481:Superoxides; C002744:3-nitrotyrosine; C030419:andrographolide; D014443:Tyrosine; D052247:Nitric Oxide Synthase Type II; D019255:NADPH Oxidases; D058539:Phosphatidylinositol 3-Kinase