title: Does melatonin help save dopaminergic cells in MPTP-treated mice?
abstract: This study explores whether melatonin neuroprotects dopaminergic cells of the substantia nigra pars compacta (SNc) from degeneration in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice (well-known animal model of Parkinson disease). BALB/c albino mice were divided into four experimental groups. In each, mice received three series (over a 24-h period) of two intraperitoneal injections (1h apart) in different combinations. The different groups and their combinations of injections were: (1) Saline (saline, saline); (2) Mel (melatonin, saline); (3) MPTP (saline, MPTP); (4) Mel-MPTP (melatonin, MPTP). Six days after the last injection, all mice were perfused transcardially with aldehyde fixative. Brains were processed for routine tyrosine hydroxylase (TH; rate limiting enzyme for dopamine production) immunochemistry and Nissl staining. Our results - using unbiased stereology - showed that there were more TH(+) (50%) and Nissl-stained (30%) cells in the SNc of the Mel-MPTP group compared to the MPTP group, indicating a clear saving or neuroprotection of these cells. In fact, we found no significant difference between the number of TH(+) and Nissl-stained SNc cells in the Mel-MPTP group compared to the controls, namely Saline and Mel groups. This indicated that melatonin pre-treatment potentially neuroprotected all the SNc cells from MPTP toxicity and death.
authors.affiliation: CNS Stability and Degeneration, Research School of Biological Sciences, Australian National University, Australia.
authors.forename: Jeannine
authors.initials: J
authors.lastname: Ma
authors.forename: Victoria E
authors.initials: VE
authors.lastname: Shaw
authors.forename: John
authors.initials: J
authors.lastname: Mitrofanis
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001921:Brain / Q000166:cytology / Q000187:drug effects; D002452:Cell Count / Q000379:methods; D016923:Cell Death / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D004298:Dopamine / Q000378:metabolism*; D004347:Drug Interactions; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009474:Neurons / Q000187:drug effects*; D009498:Neurotoxins / Q000494:pharmacology*; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D009498:Neurotoxins; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D014446:Tyrosine 3-Monooxygenase; D008550:Melatonin; D004298:Dopamine