Neuroprotective effects of free radical scavengers in stroke.

Acute ischaemic stroke is a leading cause of death in the majority of industrialised countries and also in many developing countries. Free radicals are generated in the brain during ischaemic injury and these radicals are involved in the secondary injury processes. Several free radical scavengers have been developed and some of them have progressed into clinical trials. One of them, edaravone, has been approved by the regulatory authority in Japan for the treatment of stroke patients. Another scavenger, disodium 4-[(tert-butylimino)methyl] benzene-1,3-disulfonate N-oxide (NXY-059; disufenton), has demonstrated efficacy in a phase III clinical trial (SAINT [Stroke Acute Ischaemic NXY-059 Treatment study]-I) involving a large number of stroke patients. Unfortunately, SAINT II did not show efficacy in the treatment of stroke patients. The purpose of this article is to review the current development of antioxidant strategies, update recent findings for NXY-059 in the treatment of stroke patients, and discuss the future development of neuroprotective agents. Although the development of neuroprotective strategies for the treatment of stroke is challenging, progress in molecular and cellular neuroscience will uncover new information about stroke mechanisms, which should result in the realisation of neuroprotective therapy for this disease.