Dual effects of melatonin on oxidative stress after surgical brain injury in rats.
The purpose of this study was to evaluate the effect of melatonin on oxidative stress occurring in the brain after routine lobectomy neurosurgery procedures. Different concentrations of melatonin (5, 15 and 150 mg/kg) were administered 1 hr before lobectomy in a rodent surgical brain injury (SBI) model. Neurological outcomes were assessed 24 hr before the killing of the rodents, for evaluation of brain water content (brain edema) and lipid peroxidation (oxidative stress). The results showed that lower doses (5 and 15 mg/kg) failed to reduce brain edema, but the 15 mg/kg dose did lower oxidative stress and improved several neurological parameters. High concentration of melatonin (150 mg/kg) significantly increased brain edema and elevated oxidative stress when compared with the vehicle-treated group. Furthermore, high-dose melatonin also worsened neurological outcomes compared with other groups. The study suggests that melatonin has dual effects: low-dose melatonin may provide neuroprotective effects against SBI but a high dose may aggravate some parameters after SBI.
Departments of Physiology and Pharmacology, Loma Linda University Medical Center, Loma Linda, CA, USA.
Steve
S
Lee
Vikram
V
Jadhav
Robert E
RE
Ayer
Hugo
H
Rojas
Amy
A
Hyong
Tim
T
Lekic
Jiping
J
Tang
John H
JH
Zhang
D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000601:surgery; D001929:Brain Edema / Q000188:drug therapy / Q000378:metabolism*; D001930:Brain Injuries / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D009048:Motor Skills / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014738:Vibrissae
D008550:Melatonin