morphinans and Brain-Edema

Sinomenine (SIN) has been shown to have protective effects against brain damage following traumatic brain injury (TBI). However, the mechanisms and its role in these effects remain unclear. This study was conducted to investigate the potential mechanisms of the protective effects of SIN.. The weight-drop model of TBI in Institute of Cancer Research (ICR) mice were treated with SIN or a vehicle via intraperitoneal administration 30 min after TBI. All mice were euthanized 24 h after TBI and after neurological scoring, a series of tests were performed, including brain water content and neuronal cell death in the cerebral cortex.. The level of cytochrome. SIN protected neuronal cells by protecting them against apoptosis via mechanisms that involve the mitochondria following TBI.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Brain Edema; Brain Injuries, Traumatic; Cerebral Cortex; Cytochromes c; Cytoprotection; Disease Models, Animal; Dose-Response Relationship, Drug; Glutathione Peroxidase; Male; Malondialdehyde; Mice, Inbred ICR; Mitochondria; Morphinans; Nerve Degeneration; Neurons; Neuroprotective Agents; Oxidative Stress; Signal Transduction; Superoxide Dismutase-1

Astrocyte-mediated neuroinflammation plays a critical role in ischemic stroke-induced secondary cerebral injury. Previous studies have suggested that the dopamine D2 receptor (DRD2) acts as a key target in regulating the neuroinflammatory response. However, the underlying molecular mechanisms are still unknown, and effective DRD2 agonists are lacking. In the present study, we examined the anti-inflammatory and neuroprotective effects of sinomenine (Sino), a monomeric compound with potential immunoregulatory properties in nervous system.. TTC staining, apoptosis assay, evaluation of brain edema, and neurological assessment were performed in the middle cerebral artery occlusion (MCAO) mouse model. Primary astrocytes exposed to oxygen glucose deprivation (OGD) were used in the in vitro experiments. Quantitative PCR was applied to assess the levels of inflammatory cytokines. Multi-labeling immunofluorescence, Western blot, co-immunoprecipitation, and electrophoretic mobility shift assay (EMSA) were also used to investigate the molecular mechanisms underlying the Sino-mediated anti-inflammatory effects in vivo and in vitro.. Sino remarkably attenuated the cerebral infarction and neuronal apoptosis, reduced the levels of inflammatory cytokines, and alleviated neurological deficiency in MCAO mice. Sino significantly inhibited astrocytic activation and STAT3 phosphorylation as well as increased DRD2 and αB-crystallin (CRYAB) expression after MCAO. In vitro, Sino blocked OGD-induced activation of STAT3 and generation of pro-inflammatory cytokines in primary astrocytes, and these effects were significantly abolished by either DRD2 or CRYAB knockdown. Additionally, Sino induced up-regulation and nuclear translocation of CRYAB in astrocytes and enhanced the interaction between CRYAB and STAT3, which further inhibited the activation and DNA-binding activity of STAT3.. Our study demonstrates that Sino activates astrocytic DRD2 and thereby suppresses neuroinflammation via the CRYAB/STAT3 pathway, which sheds some light on a promising therapeutic strategy for ischemic stroke.

Topics: alpha-Crystallin B Chain; Animals; Animals, Newborn; Antirheumatic Agents; Astrocytes; Brain Edema; Cells, Cultured; Cerebral Infarction; Disease Models, Animal; Encephalitis; Hypoxia; Infarction, Middle Cerebral Artery; Mice; Mice, Inbred C57BL; Morphinans; Nervous System Diseases; Receptors, Dopamine D2; RNA Interference; Signal Transduction; STAT3 Transcription Factor

We studied the efficacy of systemic pre-treatment with dextrorphan (DX), a clinically tested N-methyl-D-aspartate (NMDA) antagonist, in a rabbit model of transient focal cerebral ischemia. Rabbits were treated with either a 24 mg/kg i.v. loading dose followed by 12 mg/kg/h i.v. infusion of 0.48% DX in normal saline (NS), or with an equivalent volume of NS alone. One and 1/2 h after starting the drug or NS, the rabbits underwent a 1 h occlusion of the left internal carotid and anterior cerebral arteries, followed by 4 h of reperfusion. The DX-treated rabbits had significantly less neocortical ischemic neuronal damage (7.4%) than the normal saline group (31.6%) and demonstrated a significant decrease in ischemic cortical edema. DX may prove useful in the treatment of clinical cerebrovascular disease.

Topics: Animals; Aspartic Acid; Brain; Brain Edema; Cerebral Cortex; Dextrorphan; Ischemic Attack, Transient; Magnetic Resonance Spectroscopy; Male; Morphinans; N-Methylaspartate; Neurons; Rabbits