Background: Prevention of secondary malignancy while the patient is receiving radiotherapy for the management of primary cancer has been a mammoth challenge for biological and medical safety. The risk of heart damage related to the adjuvant breast cancer radiotherapy is the issue that was considered in this study.
Aim: The aim of the study is to compare Protective Effects of Melatonin and Captopril on Early Effects of Radiation on the Heart tissue of Rats.
Method: 60 adult male Wistar rats weighing 180-220 g were used. We divided rats in 6 groups: 1 - Control group, 2 – Group Irradiated with 8 Gy and without treatment with Melatonin or Captopril, 3 - Group treated with Melatonin with no gamma radiation, 4 - Group treated with Captopril with no gamma radiation, 5 –Group irradiated with 8 Gy and treated with melatonin, 6 – Group Irradiated with 8 Gy and treated with Captopril. Rats were exposed to 8 Gy whole body dose from Co-60 sources. 30 min prior to irradiation, 6 animals received melatonin (100mg/kg body weight) and 6 animals received Captopril (50 mg/kg body weight). All groups were sacrificed 10 days post irradiation and hearts were collected. Malondialdehyde (MDA), lactate dehydrogenase (LDH) and glutathione (GSH) were measured to evaluate cellular oxidative stress induced injury.
Results: Treatment with Captopril resulted in a significant increase in LDH and MDA, although the level of GSH was decreased (P < 0.05). MDA and LDH levels were decreased after Melatonin treatment whilst GSH level was increased (P < 0.005).
Conclusions: Melatonin have protective effects following radiation, while treatment with Captopril post-irradiation is radio sensitizing and does not have protective effects against radiation.