title: Involvement of activation of the Nrf2/ARE pathway in protection against 6-OHDA-induced SH-SY5Y cell death by α-iso-cubebenol.
abstract: Free radical-mediated neurodegeneration is one of the many causes of Parkinson's disease (PD). As part of our ongoing studies on the identification of biologically active Schisandra chinensis components, we have isolated and structurally elucidated α-iso-cubebenol. This study was carried out in an attempt to clarify the neuroprotective effect of α-iso-cubebenol on toxin-insulted dopaminergic neuronal death using 6-hydroxy-dopamine (6-OHDA)-induced dopaminergic SH-SY5Y cells. α-iso-cubebenol significantly attenuated the loss of mitochondrial function (MTT assay) and membrane integrity (lactate dehydrogenase assay) associated with 6-OHDA-induced neurotoxicity. Pretreatment of the cells with α-iso-cubebenol diminished the intracellular accumulation of reactive oxygen species (ROS) and calcium in response to 6-OHDA. Moreover, α-iso-cubebenol protected against 6-OHDA-induced neurotoxicity through inhibition of SH-SY5Y cell apoptosis. In addition, JC-1 staining, which is a well-established measure of mitochondrial damage, was decreased after treatment with α-iso-cubebenol. Notably, α-iso-cubebenol inhibited the release of mitochondrial flavoprotein apoptosis inducing factor (AIF) from the mitochondria to the cytosol and nucleus following 6-OHDA treatment. In addition, α-iso-cubebenol reduced the 6-OHDA-induced phosphorylation of ERK and induced the phosphorylation of PKA, PKB, and CREB in a dose-dependent manner. Moreover, α-iso-cubebenol stimulated the activation of Nrf2, a downstream target of CREB. Furthermore, α-iso-cubebenol stimulated the expression of multiple antioxidant response genes (NQO-1 and HO-1). Finally, CREB and Nrf2 siRNA transfection diminished α-iso-cubebenol-mediated neuroprotection.
authors.affiliation: Bio-IT Fusion Technology Research Institute, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Horticultural Bioscience, Pusan National University, Miryang 627-706, Republic of Korea.
authors.forename: Do Yeon
authors.initials: DY
authors.lastname: Kim
authors.affiliation: College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors.forename: Jong-Koo
authors.initials: JK
authors.lastname: Kang
authors.affiliation: Bio-IT Fusion Technology Research Institute, Pusan National University, Busan 609-735, Republic of Korea; Institute for Research &Industry Cooperation, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Geuntae
authors.initials: G
authors.lastname: Park
authors.affiliation: College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, Republic of Korea; Life and Industry Convergence Research Institute, Pusan National University, Miryang 627-706, Republic of Korea. Electronic address: ywchoi@pusan.ac.kr.
authors.forename: Young-Whan
authors.initials: YW
authors.lastname: Choi
mesh_terms: D061745:Antioxidant Response Elements; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D059290:Dopaminergic Neurons / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D009447:Neuroblastoma; D018696:Neuroprotective Agents / Q000494:pharmacology*; D016627:Oxidopamine / Q000633:toxicity; D017382:Reactive Oxygen Species / Q000378:metabolism; D012717:Sesquiterpenes / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D018696:Neuroprotective Agents; D017382:Reactive Oxygen Species; D012717:Sesquiterpenes; C571662:alpha-iso-cubebenol; D016627:Oxidopamine
keywords: 6-OHDA; Apoptosis; CREB; Oxidative stress; α-iso-cubebenol