The effects of different doses (0.25, 0.5, 1 and 2 mg/kg i.p.) of cloricromene, a coumarine derivative, have been investigated on brain malondialdehyde levels, brain edema, myeloperoxidase activity, survival, locomotor hyperactivity and hippocampal neuronal loss following transient cerebral ischemia induced by temporary bilateral carotid occlusion in the Mongolian gerbil. Cloricromene reduced brain lipid peroxidation, measured through the evaluation of malondialdehyde (-82.9% with the highest dose), and the formation of post-ischemic brain edema, evaluated by water content. The increase in myeloperoxidase activity observed in the hippocampus of postischemic animals was also reduced: 0.7 +/- 0.3 U x 10(-3) vs. 3.3 +/- 0.3 U x 10(-3)/g tissue. The same treatment increased survival and reduced hyperactivity linked to neurodegeneration induced by cerebral ischemia and reperfusion. Histological observations of the pyramidal layer of CA1 showed a reduction of neuronal loss in animals that received the drug before occlusion but not in those that were treated after the occlusion. These results show that cloricromene, a drug with multiple actions, improves brain injury induced by transient cerebral ischemia.