Effect of Melatonin, Ascorbic Acid, and Succinic Acid on the Cumulative Toxic Effect of Repeated Treatment with Gammafos (Amifostine)

Daily treatment of outbred albino mice with gammafos in radioprotective doses of 300 and 500 mg/kg for 4 days produced a cumulative toxic effect. This effect was not observed after decreasing the dose of gammafos to 100 mg/kg. Repeated peroral administration of melatonin and ascorbic acid in a dose of 200 mg/kg 30 min before treatment with gammafos reduced its cumulative toxic effect. Succinic acid in a dose of 100 mg/kg was ineffective under these conditions. The cumulative death time for 50% animals receiving gammafos alone or in combination with melatonin, ascorbic acid, and succinic acid was 3.08, 4.29, 4.06, and 2.97 days, respectively.