Antioxidant potential of melatonin enhances the response to L-dopa in 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine-parkinsonian mice

Background: parkinson's disease is a neurodegenerative disorder of uncertain pathogenesis characterized by a loss of dopaminergic neurons in substantia nigra pars compacta,and can be modeled by the neurotoxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (mptp). the current research was directed to investigate the role of melatonin in preventing the gradual decrease in the response to l-dopa in mptp-induced parkinsonism in mice. methods: eighty four male swiss mice were divided into seven groups. group i is the saline group. the other six groups were injected with mptp(20 mg/kg/2 h). group ii is the mptpcontrol group. group iii was treated with l-dopa/carbidopa (100/10 mg/kg,po). group iv and v were treated with melatonin (5 or 10 mg/kg,po),respectively. group vi and vii received l-dopa/carbidopa in combination with melatonin in the same above-mentioned doses,respectively. results: results showed that mptp-treated mice exhibited low striatal dopamine level accompanied by motor impairment and increased oxidative stress. treatment with l-dopa improved the motor performance of mice. addition of melatonin to l-dopa therapy improved the motor response to l-dopa and increased striatal dopamine level. this combination reduced lipid peroxidation,ameliorated reduced glutathione and improved antioxidant enzyme activities (p ≤ 0.05). conclusions: overall,our study suggests that the antioxidant potential of melatonin makes it a promising candidate to l-dopa in treating parkinson's disease.copyright © 2013 by institute of pharmacology polish academy of sciences.