Melatonin prevents possible radiotherapy-induced thyroid injury

Abstract

Purpose: We aimed to investigate the protective effect of melatonin in radiotherapy-induced thyroid gland injury in an experimental rat model.

Materials and methods: Thirty-two rats were divided into four groups: the control group, melatonin treatment group, radiotherapy group and melatonin plus radiotherapy group. The neck region of each rat was defined by simulation and radiated with 2 Gray (Gy) per min with 6-MV photon beams, for a total dose of 18 Gy. Melatonin was administered at a dose of 50 mg/kg through intraperitoneal injection, 15 min prior to radiation exposure. Thirty days after the beginning of the study, rats were decapitated and analyses of blood and thyroid tissue were performed.

Results: Tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β), thiobarbituric acid reactive substances (TBARS) and nitric oxide (NO) levels in the radiotherapy group were significantly higher than those in the melatonin plus radiotherapy group (p < .05), whereas interleukin-10 (IL-10) and glutathione (GSH) values were higher in the melatonin plus radiotherapy group (p < .05). The infiltration of inflammatory cells and percentage of apoptosis in the radiotherapy group were significantly higher than those in the melatonin plus radiotherapy group (p < .05).

Conclusions: Melatonin helped protect thyroid gland structure against the undesired cytotoxic effects of radiotherapy in rats.

Keywords:

• Melatonin
• thyroid
• radiotherapy
• apoptosis
• inflammation

Acknowledgments

This research received no specific grant from any funding agency, commercial or not-for profit sectors.

Disclosure statement

The authors report no conflicts of interest.

Notes on contributors

Mitat Arıcıgil, is a assistant professor, Department of Otolaryngology and Head and Neck Surgery, Necmettin Erbakan University, Meram Medical Faculty, Konya, Turkey.

Mehmet A. Dündar, is a assistant professor, Department of Otolaryngology and Head and Neck Surgery, Necmettin Erbakan University, Meram Medical Faculty, Konya, Turkey.

Abitter Yücel, is a MD, Department of Otolaryngology, Horasan State Hospital, Erzurum, Turkey.

Mehmet A. Eryılmaz, is a assistant professor, Department of Otolaryngology and Head and Neck Surgery, Necmettin Erbakan University, Meram Medical Faculty, Konya, Turkey.

Meryem Aktan, is a assistant professor, Department of Radiation Oncology, Necmettin Erbakan University, Meram Medical Faculty, Konya, Turkey.

Mehmet A. Alan, is a MD, Department of Otolaryngology, Dinar State Hosbital, Afyon, Turkey.

Sıdıka Fındık, is a assistant professor, Department of Pathology, Necmettin Erbakan University, Meram Medical Faculty, Konya, Turkey.

İbrahim Kılınç, is a assistant professor, Department of Biochemistry, Necmettin Erbakan University, Meram Medical Faculty, Konya, Turkey.