Preventive effects of melatonin and amifostine on irradiated rats with experimental periodontitis

The aim of this study was to investigate the preventive effects of amifostine and melatonin oxidatively, biochemically and histomorphometrically in rats with radiotherapy-induced experimental periodontitis.

40 female Sprague-Dawley rats were divided into 5 groups: Control, experimental periodontitis (Ep), Ep + radiotherapy (Ep + Rt), Ep + Rt + amifostine (Ep + Rt + Ami), Ep + Rt + melatonin (Ep + Rt + Mel). The day after induction of periodontitis by ligature, a single dose of 5 Gy radiotherapy was administered. On the same day, treatments with amifostine (200 mg/kg) for 3 days and melatonin (10 mg/kg) for 15 days were started. By after 23 days of experiment, periodontal bone loss was measured by histomorphometry. RANKL, OPG and Caspase-3 activities were analyzed immunohistochemically and inflammatory cytokine (IL-1β, IL-10, IL-6, TNF-α) levels and oxidative stress (TOS/TAS) were analyzed biochemically in tissue homogenates.

It was observed that there was a significant difference in many biochemical parameters and oxidative stress levels between the control group and Ep + Rt (p < 0.05). Alveolar bone destruction in the melatonin prophylaxis group was observed to be close to control (p > 0.05). Melatonin significantly improved biochemical, histochemical, apoptotic and bone loss levels in irradiated experimental periodontitis rats (p < 0.05). When comparing the two drug groups (Ep + Rt + Ami and Ep + Rt + Mel), no statistically significant difference was found at any parameter level (p > 0.05).

Both melatonin and amifostine can significantly limit RT-induced periodontal bone loss by suppressing inflammatory stress, apoptotic mechanisms, and RANKL-related osteoclastic activity. Given the limited side effects of melatonin, it may be an alternative to amifostine.