title: Melatonin's protective effect on the salivary gland against ionized radiation damage in rats.
abstract: OBJECTIVE
  The aim of this study was to examine the effects of melatonin on ionized radiation-induced salivary gland damage using an experimental model.
  
  
  METHODS
  Thirty-two rats were randomized into four groups: (i) the control group (C, n = 8) that received intraperitoneal (i.p.) 0.9% NaCl; (ii) the melatonin group (M, n = 8) that received i.p. 5 mg/kg melatonin; (iii) the radiotherapy group (RT, n = 8) that underwent irradiation; (iv) the melatonin plus radiotherapy group (M+RT, n = 8) that received i.p. 5 mg/kg of melatonin, followed by irradiation 30 min later; and (v) the radiotherapy plus melatonin group (RT+M, n = 8) that received irradiation followed by i.p. 5 mg/kg of melatonin 30 min later. The medications and irradiation were administered for 5 days and the salivary glands of the rats were excised 10 days later; the histopathological changes in the salivary glands were assessed and biochemical analyses were conducted (tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI)).
  
  
  RESULTS
  Regardless of whether melatonin was administered before or after radiotherapy, melatonin decreased the radiation-induced parotid and submandibular histological damage. In addition, regardless of whether administration occurred before or after radiotherapy, melatonin decreased oxidative stress markers, such as MDA, TOS, and OSI. On the contrary, levels of antioxidative markers, such as CAT and GPx, were increased by melatonin.
  
  
  CONCLUSIONS
  Melatonin may have a significant protective effect on salivary gland damage secondary to ionizing radiation.
authors.affiliation: Department of Otolaryngology, Malatya State Hospital, Malatya, Turkey.
authors.forename: Isil
authors.initials: I
authors.lastname: Cakmak Karaer
authors.affiliation: Department of ENT, School of Medicine, Kirikkale University, Kirikkale, Turkey.
authors.forename: Gokce
authors.initials: G
authors.lastname: Simsek
authors.affiliation: Department of Histology and Embryology, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Azibe
authors.initials: A
authors.lastname: Yildiz
authors.affiliation: Department of Histology and Embryology, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Nigar
authors.initials: N
authors.lastname: Vardi
authors.affiliation: Department of Physiology, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Alaadin
authors.initials: A
authors.lastname: Polat
authors.affiliation: Department of Physiology, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Kevser
authors.initials: K
authors.lastname: Tanbek
authors.affiliation: Department of Radiation Oncology, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Simay
authors.initials: S
authors.lastname: Gurocak
authors.affiliation: Department of Pharmacology, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Parlakpinar
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D005260:Female; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D008550:Melatonin / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects / Q000528:radiation effects; D020011:Protective Agents / Q000494:pharmacology*; D011833:Radiation Injuries, Experimental / Q000517:prevention & control; D011839:Radiation, Ionizing; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012469:Salivary Glands / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D012965:Sodium Chloride / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D020011:Protective Agents; D012965:Sodium Chloride; D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione; D008550:Melatonin
keywords: melatonin; oxidative stress; radiotherapy; salivary gland