title: Protective effects of melatonin and caffeic acid phenethyl ester against retinal oxidative stress in long-term use of mobile phone: a comparative study.
abstract: There are numerous reports on the effects of electromagnetic radiation (EMR) in various cellular systems. Melatonin and caffeic acid phenethyl ester (CAPE), a component of honeybee propolis, were recently found to be potent free radical scavengers and antioxidants. Mechanisms of adverse effects of EMR indicate that reactive oxygen species may play a role in the biological effects of this radiation. The present study was carried out to compare the efficacy of the protective effects of melatonin and CAPE against retinal oxidative stress due to long-term exposure to 900 MHz EMR emitting mobile phones. Melatonin and CAPE were administered daily for 60 days to the rats prior to their EMR exposure during our study. Nitric oxide (NO, an oxidant product) levels and malondialdehyde (MDA, an index of lipid peroxidation), were used as markers of retinal oxidative stress in rats following to use of EMR. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were studied to evaluate the changes of antioxidant status in retinal tissue. Retinal levels of NO and MDA increased in EMR exposed rats while both melatonin and CAPE caused a significant reduction in the levels of NO and MDA. Likewise, retinal SOD, GSH-Px and CAT activities decreased in EMR exposed animals while melatonin and CAPE caused a significant increase in the activities of these antioxidant enzymes. Treatment of EMR exposed rats with melatonin or CAPE increased the activities of SOD, GSH-Px and CAT to higher levels than those of control rats. In conclusion, melatonin and CAPE reduce retinal oxidative stress after long-term exposure to 900 MHz emitting mobile phone. Nevertheless, there was no statistically significant difference between the efficacies of these two antioxidants against to EMR induced oxidative stress in rat retina. The difference was in only GSH-Px activity in rat retina. Melatonin stimulated the retinal GSH-Px activity more efficiently than CAPE did.
authors.affiliation: Department of Physiology, School of Medicine, Suleyman Demirel University, P. K. 13, 32100 Isparta, Turkey. drmfehmi@yahoo.com
authors.forename: Fehmi
authors.initials: F
authors.lastname: Ozguner
authors.forename: Yavuz
authors.initials: Y
authors.lastname: Bardak
authors.forename: Selcuk
authors.initials: S
authors.lastname: Comlekci
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002109:Caffeic Acids / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D040421:Cell Phone; D004574:Electromagnetic Fields / Q000009:adverse effects*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000378:metabolism; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008550:Melatonin / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects* / Q000528:radiation effects; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002109:Caffeic Acids; D016166:Free Radical Scavengers; D009569:Nitric Oxide; D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; C055494:caffeic acid phenethyl ester; D008550:Melatonin; D010626:Phenylethyl Alcohol