A Comparative Study on the Life-Saving Radioprotective Effects of Vitamins A, E, C and Over-the-Counter Multivitamins

Introduction: Oral intake of vitamins which present antioxidant characteristics can protect living organisms against oxidative damage caused by exposure to ionizing radiation. It was previously reported that administration of high levels of vitamin C can lead to increased DNA damage through production of hydroxyl radicals from hydrogen peroxide by the Fenton reaction. However, our early experiments did not confirm this hypothesis. The main goal of this study was to determine if high doses of Vit C can show life-saving radioprotective effects.Materials and Methods: Phase I: Seventy two male Balb/c mice weighing ۲۰-۲۵g were randomly divided into six groups of ۱۲ animals each. Group I; Vit E for five days, Groups II and III; Vit C and Vit A. Group ۴; all three vitamins. Group V; an over-the-counter multivitamin. Group VI; none of the above. Phase II: ۱۲۰ male BALB/c mice weighing ۲۰-۲۵g were randomly divided into ۱۲ groups of ۱۰ each. Group I; Vit A for five days. Groups II-IV; Vit C ۲۰۰ mg/kg, ۴۰۰ mg/kg, ۸۰۰ mg/kg, respectively. Group V-VII; Vit E at daily doses of ۲۰۰ iu/kg, ۴۰۰ iu/kg, ۸۰۰ iu/kg, respectively. Group VIII and IX; all three vitamins at low and high doses, respectively. Group X; an over-the-counter multivitamin. Group XI; controls group and Group XII; received pure olive oil. All animals (Phases I and II) were exposed to a lethal dose of gamma rays and the survival rates of the animals were monitored and recorded continuously for ۱۶ days after exposure. Results: Phase I: ۱۴ days after irradiation the survival rate for control group was ۳۳.۳۳%, while the survival rates for the ۱st to ۵th groups were ۴۵.۴۵%, ۸۱.۸۱%, ۵۰%, ۵۷.۱۴%, and ۹.۰۹% , respectively. Phase II: The survival rates in the control group and the group that only received pure olive oil, were ۵۰% and ۶۰%, respectively. Survival rate in the animals received Vit C at daily doses of ۲۰۰ mg/kg, ۴۰۰ mg/kg, ۸۰۰ mg/kg, were ۹۰%, ۹۰% and ۹۰%, respectively. Log rank (Mantel-Cox) test showed statistically significant differences between the survival rates in control irradiated mice (no vitamins) and mice received Vit C at daily doses of ۲۰۰ mg/kg (P=۰.۰۴۲), ۴۰۰ mg/kg (P=۰.۰۴۲) and ۸۰۰ mg/kg (P=۰.۰۴۲). Conclusion: Altogether, findings of this study showed that even high doses of Vit C can show life-saving radioprotective effects. The significant radioprotective effect of Vit C at doses used in this study, opens new horizons in developing non-toxic, cost effective, easily available radioprotectors in life-threatening situations such as exposure to lethal doses of ionizing radiation.  The radioprotective effect of Vit A and Vit E seem to be less efficient compared to that of Vit C.Â

کلیدواژه ها:

Radioprotective Effects ، Vitamin C ، Ascorbic Acid ، Radiation ، Survival