Antioxidant Diet Supplementation Starting 24 Hours after Exposure Reduces Radiation Lethality

Abstract

Antioxidants mitigate radiation-induced lethality when started soon after radiation exposure, a delivery time that may not be practical due to difficulties in distribution and because the oral administration of such agents may require a delay beyond the prodromal stage of the radiation syndrome. We report the unexpected finding that antioxidant supplementation starting 24 h after total-body irradiation resulted in better survival than antioxidant supplementation started soon after the irradiation. The antioxidant dietary supplement was L-selenomethionine, sodium ascorbate, Nacetyl cysteine, α-lipoic acid, α-tocopherol succinate, and co-enzyme Q10. Total-body irradiation with 8 Gy in the absence of antioxidant supplementation was lethal by day 16. When antioxidant supplementation was started soon after irradiation, four of 14 mice survived. In contrast, 14 of 18 mice receiving antioxidant supplementation starting 24 h after irradiation were alive and well 30 days later. The numbers of spleen colonies and blood cells were higher in mice receiving antioxidant supplementation starting 24 h after irradiation than in mice receiving radiation alone. A diet supplemented with antioxidants administered starting 24 h after total-body irradiation improved bone marrow cell survival and mitigated lethality, with a radiation protection factor of approximately 1.18.

Attenuation of oxidative damage and inflammatory responses by apigenin given to mice after irradiation

“…Currently, only a few compounds other than apigenin, e.g. l-arginine [40,41], perillic acid [42], antioxidant diet supplements [43], and Ex-Rad (ON 01210.Na) [44], have been shown to be capable of reducing the damage induced by radiation when they are given to mice after radiation exposure.…”

Short-Term Treatment with a SOD/Catalase Mimetic, EUK-207, Mitigates Pneumonitis and Fibrosis after Single-Dose Total-Body or Whole-Thoracic Irradiation

“…Continuous administration of EUK-207 via implanted subcutaneous infusion pumps from 1 h until 14 weeks after irradiation is reported to mitigate lung injuries in rats (15). Brown et al showed that continuing antioxidant diet supplementation starting 24 h after irradiation is effective at mitigating lethality (39). Furthermore, they reported that a delay of 24 h after radiation of continuous antioxidant diet supplementation is more effective than intervention initiated immediately after the exposure.…”

PROTECTION OF FEMALE C3H MICE AGAINST WHOLE-BODY gamma-IRRADIATION WITH 2,3-DIMETHYL-6-((2-DIMETHYLAMINO)ETHYL)-6H-INDOLO[2,3-b]QUINOXALINE (B220)

“…In a study on 7-8 week old C57BL/6 mice exposed to 8 Gy whole-body γ-irradiation, switching to a diet high in antioxidant supplements 24 h after the irradiation event significantly increased the survival and was considerably more efficient than when beginning the antioxidant administration 12 or 48 h after irradiation. 17 The reason for this is unclear. Also the dose and frequency of administration can play a role.…”