Protective effects of melatonin and caffeic acid phenethyl ester against retinal oxidative stress in long-term use of mobile phone: A comparative study
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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.
Key wordscaffeic acid phenethyl ester melatonin mobile phone oxidative stress retina
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- 1.Knave B: Electromagnetic fields and health outcomes. Ann Academ Med 30(5): 489–493, 2001Google Scholar
- 6.Bardak Y, Ozguner F, Comlekci S, Yilmaz HR, Mollaoglu, Uz E: Mobile phone-induced retinal impairment in rats: Protection by melatonin. Bioelectromagnetics (in press) 2005Google Scholar
- 8.Hepsen IF, Bayramlar H, Gultek A, Ozen S, Tilgen F, Evereklioglu CJ: Caffeic acid phenethyl ester to inhibit posterior capsule opacification in rabbits. Cataract Refract Surg 23(10): 1572–1576, 1997Google Scholar
- 10.Michaluart P, Masferrer JL, Carothers AM, Subbaramaiah K, Zweifel BS, Koboldt C, Mestre JR, Grunberger D, Sacks PG, Tanabe T, Dannenberg AJ: Inhibitory effects of caffeic acid phenethyl ester on the activity and expression of cyclooxygenase-2 in human oral epithelial cells and in rat model of inflammation. Cancer Res 59: 2347– 2352, 1999PubMedGoogle Scholar
- 17.Siu AW, Reiter RJ, To CH: The efficacy of vitamin E and melatonin as an oxidant against lipid peroxidation in rat retinal homogenates. J Pineal Res 24: 229–244, 1998Google Scholar
- 22.Ozguner F, Oktem F, Armagan A, Ramazan Yilmaz HR, Koyu A, Demirel R, Huseyin Vural H, Uz E: Comparative analysis of the protective effects of melatonin and caffeic acid phenethyl ester (CAPE) on 900 MHz emitted mobile phone-induced renal impairment in rat. Mol Cell Biochem 276(1–2): 31–37, 2005PubMedGoogle Scholar
- 23.Tan DX, Poeggeler B, Reiter RJ, Chen LD, Chen S: Melatonin: A potent, endogenous hydroxyl radical scavenger. Endocr J 1: 57–60, 1993Google Scholar