title: Melatonin is protective against 6-hydroxydopamine-induced oxidative stress in a hemiparkinsonian rat model.
abstract: Melatonin is known to reduce detrimental effects of free radicals by stimulating antioxidant enzymes; however, its role has not been studied in 6-hydroxydopamine (6-OHDA)-induced rat model of Parkinson's disease (PD). Therefore, we aimed to elucidate the effects of melatonin on motor activity and oxidative stress parameters in 6-OHDA-induced rat model of PD. Three-month-old male Wistar rats were divided into 5 groups: vehicle (V), melatonin-treated (M), 6-OHDA-injected (6-OHDA), 6-OHDA-injected + melatonin-treated (6-OHDA-Mel), and melatonin-treated + 6-OHDA-injected (Mel-6-OHDA) group. Melatonin was administered intraperitoneally at a dose of 10 mg/kg/day for 30 days in M and Mel-6-OHDA groups, for 7 days in 6-OHDA-Mel group. Rats received a unilateral stereotaxic injection of 6-OHDA into the right medial forebrain bundle. The 6-OHDA-Mel group started receiving melatonin when experimental PD was created and the treatment was continued for 7 days. In the Mel-6-OHDA group, experimental PD was created on the 23rd day of melatonin treatment and continued for the remaining 7 days. Locomotor activity decreased in 6-OHDA group compared with that in vehicle group; however, melatonin treatment did not improve this impairment. 6-OHDA injection caused an obvious reduction in tyrosine-hydroxylase-positive dopaminergic neuron viability as determined by immunohistochemistry. Melatonin supplementation decreased dopaminergic neuron death in 6-OHDA-Mel and Mel-6-OHDA groups compared with that in 6-OHDA group. Biochemical analysis confirmed the beneficial effects of melatonin displaying higher superoxide dismutase, catalase, and glutathione peroxidase activities and lower lipid peroxidation in substantia nigra samples in comparison to non-treated 6-OHDA group. Starting melatonin treatment before creating experimental PD was more effective on observed changes.
authors: Department of Physiology, Faculty of Medicine, Akdeniz University , Antalya , Turkey.
authors: O
authors: O
authors: Ozsoy
authors: F B
authors: FB
authors: Yildirim
authors: E
authors: E
authors: Ogut
authors: Y
authors: Y
authors: Kaya
authors: G
authors: G
authors: Tanriover
authors: H
authors: H
authors: Parlak
authors: A
authors: A
authors: Agar
authors: M
authors: M
authors: Aslan
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000378:metabolism; D015227:Lipid Peroxidation; D008297:Male; D008474:Medial Forebrain Bundle / Q000473:pathology; D008550:Melatonin / Q000494:pharmacology*; D009043:Motor Activity; D018696:Neuroprotective Agents / Q000494:pharmacology*; D016627:Oxidopamine; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D017208:Rats, Wistar; D013378:Substantia Nigra / Q000201:enzymology; D013482:Superoxide Dismutase / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D016166:Free Radical Scavengers; D018696:Neuroprotective Agents; D016627:Oxidopamine; D002374:Catalase; D005979:Glutathione Peroxidase; D014446:Tyrosine 3-Monooxygenase; D013482:Superoxide Dismutase; D008550:Melatonin
keywords: 6-OHDA; antioxidant enzymes; lipid peroxidation; locomotor activity; melatonin