Investigation of the protective effects of melatonin,amifostine (WR-2721), and N-acetylcysteine onradiotherapy-induced uterine tissue injury in rats

Background: the aim of this study was to investigate the protective potencyof melatonin, amifostine (wr-2721), and n-acetylcysteine (nac) whenadministered intraperitoneally (i.p.) 15 min before 10-gy single-fractionradiotherapy. materials and methods: in this study, 35 female spraguedawley rats were divided into five groups of seven rats each. the rats in thecontrol group did not receive any treatments. rats in the radiotherapy,melatonin, amifostine, and nac groups underwent abdomino-pelvicirradiation with 10-gy single fraction gamma (γ) irradiation. melatonin 50 mg/kg, amifostine 200 mg/kg, and nac 500 mg/kg were i.p. administered to therats 15 min before irradiation. animals were sacrificed 48 h after irradiation.uterus samples were collected and, routine histopathological tissueprocessing was performed. sections from tissue samples were stained withh&e and analyzed with the terminal deoxynucleotidyl transferase dutp nickend labelling method (tunel assay). results: severe morphologicaldegenerations and increases in the apoptotic index (ai) were observed in theradiotherapy group. tissue protection and ai reduction were observed in theamifostine and nac groups. melatonin was more effective than amifostineand nac. morphological damage was almost completely repaired, and the aiof the melatonin group was quite similar to that of the control group.conclusion: this experiment failed to determine a more successfuladministration technique of amifostine. the protective effects of amifostineand nac were similar. melatonin was more successful than these two drugs,and might be an alternative to amifostine when time, dose, or adverse effectconstraints are encountered.