Melatonin reduces kainate‐induced lipid peroxidation in homogenates of different brain regions

Melatonin protection against in vitro kainic acid‐induced oxidative damage in homogenates from different rat brain regions is shown. Brain‐disrupted cell homogenates from cerebral cortex, cerebellum, hippocampus, hypothalamus, and corpus striatum were incubated with kainate (11.7 mM) with or without different concentrations of melatonin (0.1‐4 mM). The concentration of malonaldehyde and 4‐hydroxyalkenals was measured as an index of lipid peroxidation. Wistar and Sprague‐Dawley rats were used. When administered with kainate, melatonin markedly reduced lipid peroxidation in every brain region of both rat strains. The reduction in lipid peroxidation by melatonin was concentration‐de‐pendent and varied from 10% to 100%. The protection conferred by melatonin is likely due, at least in part, to its newly discovered, free radical scavenging ability.—Melchiorri, D., Reiter, R. J., Sewerynek, E., Chen, L. D., Nisticó, G. Melatonin reduces kainate‐induced lipid peroxidation in homogenates of different brain regions. FASEB J. 9, 1205‐1210 (1995)