Radioprotective effect of melatonin against radiotherapy-induced cerebral cortex and cerebellum damage in rat

Abstract

Purpose

The present study aims to investigate the radioprotective effect of melatonin (MEL) against early period brain damage caused by different dose rate beams in the experimental rat model.

Materials and methods

Forty-eight Sprague Dawley rats were randomly divided into six groups; the control, only melatonin, low dose rate-radiotherapy (LDR-RT), high dose rate-radiotherapy (HDR-RT) groups and (LDR-RT) + MEL and (HDR-RT) + MEL radiotherapy plus melatonin groups. Each rat administered melatonin was given a dose of 10 mg/kg through intraperitoneal injection, 15 minutes before radiation exposure. The head and neck region of each rat in only radiotherapy and radiotherapy plus melatonin groups was irradiated with a single dose of 16 Gy in LDR-RT and HDR-RT beams. Rats in all groups were examined for histopathology and biochemistry analysis 10 days after radiotherapy.

Results

Comparing the findings for LDR-RT and HDR-RT only radiotherapy groups and the control group, there was a statistically significant difference in histopathological and biochemical parameters, however, melatonin administered in radiotherapy plus melatonin groups contributed improving these parameters (p < .05). There was no statistically significant difference between LDR-RT and HDR-RT beams (p > .05).

Conclusions

It was concluded that melatonin applied before LDR-RT and HDR-RT radiotherapy protected early period radiotherapy-induced brain damage. The effects of clinically low and high dose beams on the cerebral cortex and cerebellum were investigated histopathologically for the first time. HDR beams can be safely applied in brain radiotherapy. However, more experimental rat and clinical studies are needed to explain the radiobiological uncertainties about the clinic dose rate on different cancerous and healthy tissues.

Keywords:

• Radiotherapy
• flattening filter free
• melatonin
• brain
• histopathology
• biochemistry

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. This manuscript has not been published before and it is not under consideration for publication anywhere else.

Additional information

Funding

This study was supported by the Scientific Research Projects Grants Unit, University of Health Sciences Turkey, Istanbul, Turkey [Grant Number: 2019/055].

Notes on contributors

Serhat Aras

Serhat Aras, PhD is an Assistant Professor of Medical Imaging Techniques and a Senior Researcher in University of Health Sciences in Istanbul, Turkey.

Mustafa Efendioğlu

Mustafa Efendioğlu, MD is with Department of Neurosurgery and a Senior Researcher in Haydarpaşa Numune Training and Research Hospital, University of Health Sciences Turkey, Istanbul, Turkey.

Aini Wulamujiang

Aini Wulamujiang, MD is an Assistant Professor of Pathology Laboratory Techniques and a Senior Researcher in University of Health Sciences in Istanbul, Turkey.

Sidika Seyma Ozkanli

Sıdıka Şeyma Özkanlı, MD is an Associate Professor of Department of Pathology and a Senior Researcher in Göztepe Training and Research Hospital, Medeniyet University, Istanbul, Turkey.

Mevlüt Sait Keleş

Mevlüt Sait Keleş, MD is a Professor of Department of Medical Biochemistry and a Senior Researcher in Faculty of Medicine, Ataturk University, Erzurum, Turkey.

İhsan Oğuz Tanzer

İhsan Oguz Tanzer, PhD is an Assistant Professor of Biomedical Engineering and a Senior Researcher in University of Health Sciences in Istanbul, Turkey and visiting scientist in Department of Neuroscience and Biomedical Engineering, Aalto University, Finland.