Melatonin affords protection against kainate-induced in vitro lipid peroxidation in brain.

Melatonin protection against in vitro kainic acid-induced oxidative damage in rat brain is shown. Brain disrupted cell homogenates were incubated with different concentrations of kainate and with or without different concentrations of melatonin. The concentration of malonaldehyde and 4-hydroxyalkenals was measured as an index of lipid peroxidation. When administered together with kainate, melatonin produced a concentration-dependent decrease in kainate-induced lipid peroxidation ranging from 20% to 100%. Moreover, when added to the reaction mixture alone, melatonin decreased the basal level of lipid peroxidation compared to controls.