MELATONIN PROTECTS AGAINST LIPID-PEROXIDATION INDUCED BY DELTA-AMINOLEVULINIC-ACID IN RAT CEREBELLUM, CORTEX AND HIPPOCAMPUS

The in vitro and in vivo effect of melatonin on delta-aminolevulinic a cid-induced lipid peroxidation in rat cerebellum cortex and hipppocamp us was determined. The concentration of malonaldehyde and 4-hydroxyalk enals was assayed as an index of induced membrane oxidative damage. Th e rise in malonaldehyde+4-hydroxyalkenals concentrations induced by de lta-aminolevulinic acid in cerebellar homogenates was concentration-de pendent (P<0.001) and also time-dependent in cerebellar, cortical and hippocampal homogenates (P<0.01). In vitro melatonin and vitamin E pro tected, in a concentration-dependent manner, against delta-aminolevuli nic acid-induced lipid peroxidation in cortical, cerebellar and hippoc ampal homogenates In in vivo experiments it was demonstrated that delt a-aminolevulinic acid-induced lipid peroxidation (40 mg/kg) in cerebel lum and hippocampus was reduced by acute melatonin (10 mg/kg) treatmen t (P<0.05). The results show that both in vitro and in vivo melatonin confers protection against delta-aminolevulinic acid-induced oxidative toxicity in brain regions. The findings suggest that melatonin may be useful in reducing neural damage in individuals suffering from acute intermittent porphyria. (C) 1997 IBRO. Published by Elsevier Science L td.