title: Antioxidant potential of melatonin enhances the response to L-dopa in 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine-parkinsonian mice.
abstract: 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 MPTP control 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.
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt. Sawsan_zaytoon@pharm.suez.edu.eg.
authors.forename: Sawsan A
authors.initials: SA
authors.lastname: Zaitone
authors.forename: Lamiaa N
authors.initials: LN
authors.lastname: Hammad
authors.forename: Noha E
authors.initials: NE
authors.lastname: Farag
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D000978:Antiparkinson Agents / Q000378:metabolism / Q000494:pharmacology*; D001479:Basal Ganglia / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D001522:Behavior, Animal / Q000187:drug effects; D002230:Carbidopa / Q000494:pharmacology; D002374:Catalase / Q000378:metabolism; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D007980:Levodopa / Q000378:metabolism / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008550:Melatonin / Q000494:pharmacology*; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D020734:Parkinsonian Disorders / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology / Q000523:psychology; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D000978:Antiparkinson Agents; D007980:Levodopa; D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione; D008550:Melatonin; D002230:Carbidopa; D004298:Dopamine