Neuropharmacology
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Comparative Study
The radical scavenger edaravone prevents oxidative neurotoxicity induced by peroxynitrite and activated microglia.
The free radical scavenger edaravone has been used as an anti-oxidative agent in acute ischemic brain disorders. We examined the effect of edaravone on the production of nitric oxide (NO), reactive oxygen species (ROS) and proinflammatory cytokines by activated microglia, and we also examined its neuroprotective role in cortical neuronal cultures oxidatively stressed by the peroxynitrite donor N-morpholinosydnonimine (SIN-1) or activated microglia. ⋯ In addition, edaravone significantly suppressed neuronal cell death and dendrotoxicity induced by either SIN-1 or activated microglia in a dose-dependent manner. These results suggest that edaravone may function as a neuroprotective agent counteracting oxidative neurotoxicity arising from activated microglia, as occurs in either inflammatory or neurodegenerative disorders of the central nervous system.
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Comparative Study
Antinociceptive effects of the antidepressants amitriptyline, duloxetine, mirtazapine and citalopram in animal models of acute, persistent and neuropathic pain.
The effects of acute, systemic administration of amitriptyline, duloxetine and mirtazapine (antidepressant drugs that variously affect extracellular noradrenaline and serotonin levels) and the selective serotonin reuptake inhibitor (SSRI) citalopram were compared in rat models of experimental pain. None of the drugs (all 3-30 mg/kg, i.p.) affected acute nociceptive responses as measured in the tail flick test. In the hot plate test, duloxetine and mirtazapine significantly increased (P<0.05) the nociceptive response latency, whereas amitriptyline and citalopram were ineffective. ⋯ In contrast amitriptyline, duloxetine and mirtazapine significantly reduced mechanical hyperalgesia (P<0.05); citalopram was ineffective. No drug-related effects on motor performance in the rotarod test were observed. These results (a) highlight the difficulty in correlating antinociceptive effects of drugs from different antidepressant classes across a range of animal pain models and (b) suggest that antidepressants that variously affect both noradrenaline and serotonin levels have more potent and efficacious antinociceptive effects than SSRIs (as exemplified by citalopram), against a range of pain-like behaviours in an animal model of neuropathic pain.