Browsing by Author "Lin, Kao-Chang"

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Extracellular signal-regulated kinase 1/2 is involved in a tamoxifen neuroprotective effect in a lateral fluid percussion injury rat model
(2014-06-01)
Tsai, Yin-Tzu
;
Wang, Che-Chuan
;
Leung, Pak-On
;
Lin, Kao-Chang
;
Chio, Chung-Ching
Background: The aim of the present study was to determine whether tamoxifen (TMX) causes attenuation of traumatic brain injury (TBI) induced by fluid percussion injury. Materials and methods: Immediately after the onset of fluid percussion TBI, anesthetized male Sprague-Dawley rats were divided into three major groups and intraperitoneally administered the vehicle solution (1 mL/kg), TMX (1 mg/kg), or TMX (1 mg/kg) plus the extracellular signal-regulated kinase 1/2 antagonist SL327 (30 mg/kg). Another group of rats were used as sham-operated controls. The functional outcomes, such as motor outcomes, were evaluated using an incline plane. The cellular infarction volume was evaluated by triphenyltetrazolium chloride staining. Neuronal loss, apoptosis, and p-ERK1/2 and Bcl2 expression in neuronal cortex cells were evaluated by immunofluorescence methods. All the parameters were assessed on day 4 after injury. Results: Compared with the sham-operated controls, the TBI-induced motor deficits and cerebral infarction after TBI were significantly attenuated by TMX therapy. The TBI-induced neuronal loss and apoptosis were also significantly reduced by TMX therapy. The numbers of Bcl2- and phospho-ERK1/2-positive neuronal cells in the ischemic cortex after TBI were significantly increased by TMX therapy. These TMX effects were significantly blocked by SL327 administration. Conclusions: Our results suggest that intravenous injection of TMX may ameliorate TBI in rats by increasing neuronal p-ERK1/2 expression, which might lead to an increase in neuronal Bcl2 expression and a decrease in neuronal apoptosis and cell infarction volume, and it might represent one mechanism by which functional recovery occurred. TMX may be a promising TBI treatment strategy. (C) 2014 Elsevier Inc. All rights reserved.
Resuscitation from experimental traumatic brain injury by magnolol therapy
(2013-10-01)
Wang, Che-Chuan
;
Lin, Kao-Chang
;
Lin, Bor-Shyh
;
Chio, Chung-Ching
;
Kuo, Jinn-Rung
Background: The purpose of the present study was to determine whether magnolol, a free radical scavenger, mitigates the deleterious effects of traumatic brain injury (TBI). Material and methods: Traumatic brain injuries were induced in anesthetized male Sprague-Dawley rats using fluid percussion, and the rats were divided into groups treated with magnolol (2 mg/kg, intravenously) or vehicle. A group of rats that did not undergo TBI induction was also studied as controls. Biomarkers of TBI, including glycerol and 2,3-dihydroxybenzoic acid, were evaluated by microdialysis. Infraction volume, extent of neuronal apoptosis, and antiapoptosis factor transforming growth factor beta 1 (TGF-beta 1) were also measured. Functional outcomes were assessed by motor assays. Results: Compared with the rats without TBI, the animals with TBI exhibited higher hippocampal glycerol and 2,3-dihydroxybenzoic acid. Relative to the vehicle-treated group, the magnolol-treated group showed decreased hippocampal levels of glycerol and hydroxyl radical levels. The magnolol-treated rats also exhibited decreased cerebral infarction volume and neuronal apoptosis and increased antiapoptosis-associated factor TGF-beta 1 expression. These effects were translated into improved motor function post TBI. Conclusions: Our results suggest that intravenous magnolol injection mitigates the deleterious effects of TBI in rats based on its potent free radical scavenging capability, and the mechanism of anti-neuronal apoptosis is partly due to an increase in TGF-beta 1 expression in the ischemic cortex. (C) 2013 Elsevier Inc. All rights reserved.