) Melatonin prevents free radical formation due to the interaction between b-amyloid peptides and metal ion [Al(III), Zn(II), Cu(II), Mn(II), Fe(II)].

Alzheimer's disease, among other pathological features, is characterized by an over-accumulation of b-amyloid, metal ions, and oxidative stress protein in the brain. Amyloid-b-aggregated peptides with bound metal ions may initiate free radical generation with consequent protein and lipid oxidation, reactive oxygen species formation and eventually neuronal death. Metaltonin is able to dramatically reduce the free radical formation which follows the interaction between transition metal ions and amyloid-b. This paper reports the scavenging effect of melatonin of reactants generated by amyloid peptides in combination with some metal ions.