Neuroprotective effect of acute melatonin treatment on hippocampal neurons against irradiation by inhibition of caspase-3.
Neuronal cell apoptosis is associated with various factors that induce neurological damage, including radiation exposure. When administered prior to exposure to radiation, a protective agent may prevent cellular and molecular injury. The present study aimed to investigate whether melatonin exerts a neuroprotective effect by inhibiting the caspase cell death pathway. Male Sprague-Dawley rats were administered melatonin (100 mg/kg body weight) 30 min prior to radiation exposure in red light during the evening. In order to elucidate whether melatonin has a neuroprotective role, immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick-end labeling, Nissl staining, reverse transcription-quantitative polymerase chain reaction, reactive oxygen species analysis and western blotting were performed. At 24 h post-melatonin treatment, caspase-3 mRNA and protein expression levels were significantly decreased. These results demonstrated that melatonin may protect hippocampal neurons via the inhibition of caspase-3 when exposed to irradiation. Therefore, caspase-3 inhibition serves a neuroprotective and antioxidant role in the interventional treatment of melatonin. The results of the present study suggested that melatonin may have a potential therapeutic effect against irradiation; however, further studies are required in order to elucidate the underlying antioxidant mechanisms.
Laboratory of Biomedicine, Department of Hemopathic Tumor of Mongolian Medicine, The Affiliated Hospital of Inner Mongolia University for The Nationalities, Neimenggu Tongliao, Inner Mongolia 028007, P.R. China; Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Tianjin 300192, P.R. China; Department of Human Anatomy, The School of Medicine of Inner Mongolia University for The Nationalities, Neimenggu Tongliao, Inner Mongolia 028007, P.R. China.
Jianguo
J
Li
Department of Human Anatomy, The School of Medicine of Inner Mongolia University for The Nationalities, Neimenggu Tongliao, Inner Mongolia 028007, P.R. China.
Guowei
G
Zhang
Department of Human Anatomy, The School of Medicine of Inner Mongolia University for The Nationalities, Neimenggu Tongliao, Inner Mongolia 028007, P.R. China.
Zhuangzhi
Z
Meng
Department of Human Anatomy, The School of Medicine of Inner Mongolia University for The Nationalities, Neimenggu Tongliao, Inner Mongolia 028007, P.R. China.
Lingzhan
L
Wang
Department of Human Anatomy, The School of Medicine of Inner Mongolia University for The Nationalities, Neimenggu Tongliao, Inner Mongolia 028007, P.R. China.
Haiying
H
Liu
Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Tianjin 300192, P.R. China.
Qiang
Q
Liu
Laboratory of Biomedicine, Department of Hemopathic Tumor of Mongolian Medicine, The Affiliated Hospital of Inner Mongolia University for The Nationalities, Neimenggu Tongliao, Inner Mongolia 028007, P.R. China.
Batu
B
Buren
caspase-3; hippocampus; melatonin; reactive oxygen species