RESUMO
The serum concentrations of aluminum, a metal potentially involved in the pathogenesis of Alzheimer's disease, increase with age. Also, intense and prolonged exposure to aluminum may result in dementia. Melatonin and pinoline are two well known antioxidants that efficiently reduce lipid peroxidation due to oxidative stress. Herein, we investigated the effects of melatonin and pinoline in preventing aluminum promotion of lipid peroxidation when the metal was combined with FeCl3 and ascorbic acid in rat synaptosomal membranes. Lipid peroxidation was estimated by quantifying malondialdehyde (MDA) and 4-hydroxyalkenal (4-HDA) concentrations in the membrane suspension. Under the experimental conditions used herein, the addition of aluminum (0.0001 to 1 mmol/L) enhanced MDA + 4-HDA formation in the synaptosomes. Melatonin and pinoline reduced, in a concentration-dependent manner, lipid peroxidation due to aluminum, FeCl3 and ascorbic acid in the synaptosomal membranes. These results suggest that the indoleamine melatonin and the beta-carboline pinoline may potentially act as neuroprotectant agents in the therapy of those diseases with elevated aluminum concentrations in the tissues.
