title: Honokiol, a neuroprotectant against mouse cerebral ischaemia, mediated by preserving Na+, K+-ATPase activity and mitochondrial functions.
abstract: Honokiol, a component of the herb Magnolia officinalis, exhibits antioxidant, anti-inflammatory and anxiolytic properties, increases seizure threshold, and promotes neurite outgrowth. Because stroke has become the second leading cause of death in industrialized countries, an effective neuroprotectant is urgently required. In this study, we attempted to elucidate in a mouse cerebral ischaemia model whether honokiol could be a neuroprotectant. Adult male Institute of Cancer Research (ICR) mice were subjected to middle cerebral artery occlusion for 45 min. Honokiol (10 microg/kg in 0.2 ml of saline) or control vehicle was intraperitoneally administered twice, 15 min. before and 60 min. after the induction of ischaemia. Cerebral ischaemia induced by this method was associated with an increase in synaptosomal production of reactive oxygen species, with decreases in synaptosomal mitochondrial membrane potential (DeltaPsim) and synaptosomal mitochondrial metabolic function, and with reductions in Na(+), K(+)-ATPase activities of tissues isolated from selected brain regions. Administration of honokiol resulted in significant reductions in brain infarct volume and in synaptosomal production of reactive oxygen species. The decreases in synaptosomal mitochondrial membrane potential, synaptosomal mitochondrial metabolic function and tissue Na(+), K(+)-ATPase activities observed in the ischaemic brains were also attenuated by honokiol treatments. It is concluded that honokiol can protect brain against ischaemic reperfusion injury and preserve mitochondrial function from oxidative stress. Regarding therapeutic application, further studies are needed to assess the efficacy and safety of honokiol in clinical situations.
authors.affiliation: Division of Neurosurgery, Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, and Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Chang-Mu
authors.initials: CM
authors.lastname: Chen
authors.forename: Shing-Hwa
authors.initials: SH
authors.lastname: Liu
authors.forename: Shoei-Yn
authors.initials: SY
authors.lastname: Lin-Shiau
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000627:therapeutic use*; D001713:Biphenyl Compounds / Q000627:therapeutic use*; D002545:Brain Ischemia / Q000201:enzymology / Q000517:prevention & control*; D017705:Lignans / Q000627:therapeutic use*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D051379:Mice; D008813:Mice, Inbred ICR; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D017382:Reactive Oxygen Species / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects / Q000201:enzymology; D000498:Allyl Compounds; D010636:Phenols
chemical_list: D014151:Anti-Anxiety Agents; D001713:Biphenyl Compounds; D017705:Lignans; D018696:Neuroprotective Agents; D017382:Reactive Oxygen Species; D000254:Sodium-Potassium-Exchanging ATPase; C005499:honokiol; D000498:Allyl Compounds; D010636:Phenols