Title of article :
Melatonin Ameliorates The Production of COX-2, iNOS, and The Formation of 8-OHdG in Non-Targeted Lung Tissue after Pelvic Irradiation
Author/Authors :
Fardid، Reza نويسنده Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran , , Salajegheh، Ashkan نويسنده Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran , , Mosleh-Shirazi، Mohammad Amin نويسنده , , Sharifzadeh، Sedigheh نويسنده Diagnostic Laboratory Sciences and Technology Research Center, Shiraz University of Medical Sciences , , Okhovat، Mohammad Ali نويسنده Diagnostic Laboratory Sciences and Technology Research Center, School of Paramedical Sciences, Shiraz University of Medical sciences, Shiraz, Iran , , Najafi، Masoud نويسنده , , Rezaeyan، Abolhasan نويسنده Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran , , Abaszadeh، Akbar Abaszadeh نويسنده Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran ,
Abstract :
In this study, we evaluated the bystander effect of radiation on the regulation of cyclooxygenase-
2 (COX-2), inducible nitric oxide synthase (iNOS), and 8-hydroxydeoxyguanosine
(8-OHdG) in lung tissues of Sprague-Dawley rats with and without pre-administration of
melatonin. A 2×2 cm2 area of the pelvis of male Sprague-Dawley rats with and without
pre-administration of melatonin (100 mg/kg) by oral and intraperitoneal injection was irradiated
with a 3 Gy dose of 1.25 MeV ?-rays. Alterations in the levels of COX-2, iNOS,
and 8-OHdG in the out-of-field lung areas of the animals were detected by enzyme immunoassay.
The bystander effect significantly increased COX-2, iNOS, and 8-OHdG levels
in non-targeted lung tissues (P < 0.05). Melatonin ameliorated the bystander effect of radiation
and significantly reduced the level of all examined biomarkers (P < 0.05). The results
indicated that the ameliorating effect of a pre-intraperitoneal (IP) injection of melatonin
was noticeably greater compared to oral pre-administration. Our findings revealed that
the bystander effect of radiation could induce oxidative DNA damage and increase the
levels of imperative COX-2 and iNOS in non-targeted lung tissues. Interestingly, melatonin
could modulate the indirect destructive effect of radiation and reduce DNA damage
in non-targeted cells.
