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 20-25g were randomly divided into six groups of 12 animals each. Group I; Vit E for five days, Groups II and III; Vit C and Vit A. Group 4; all three vitamins. Group V; an over-the-counter multivitamin. Group VI; none of the above. Phase II: 120 male BALB/c mice weighing 20-25g were randomly divided into 12 groups of 10 each. Group I; Vit A for five days. Groups II-IV; Vit C 200 mg/kg, 400 mg/kg, 800 mg/kg, respectively. Group V-VII; Vit E at daily doses of 200 iu/kg, 400 iu/kg, 800 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 16 days after exposure.

RESULTS:Phase I: 14 days after irradiation the survival rate for control group was 33.33%, while the survival rates for the 1st to 5th groups were 45.45%, 81.81%, 50%, 57.14%, and 9.09% , respectively. Phase II: The survival rates in the control group and the group that only received pure olive oil, were 50% and 60%, respectively. Survival rate in the animals received Vit C at daily doses of 200 mg/kg, 400 mg/kg, 800 mg/kg, were 90%, 90% and 90%, 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 200 mg/kg (P=0.042), 400 mg/kg (P=0.042) and 800 mg/kg (P=0.042).

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.

OBJECTIVES:Sleep disturbances and fatigue are common in prostate cancer patients undergoing radiotherapy. Prior research suggests mind-body techniques may improve these outcomes. We conducted a randomized-controlled trial of qigong/tai chi (QGTC) in men with prostate cancer undergoing radiotherapy.

METHODS:Men with prostate cancer starting definitive radiation were randomized to one of three groups: (1) QGTC; (2) light exercise (LE); or (3) wait list control (WLC). Sleep disturbances (PSQI) and fatigue (BFI) were assessed at baseline, mid-radiotherapy (T2), during the last week of radiotherapy (T3) and at 1 (T4) and 3 months (T5) after the end of radiotherapy. Patients in the QGTC and LE groups attended three 40-minute classes per week throughout radiotherapy.

RESULTS:Ninety patients were randomized to the three groups (QGTC = 26; LE = 26; WLC = 24). QGTC group reported longer sleep duration at mid-XRT (QGTC = 7.01 hours; LE = 6.42; WL = 6.50; p = 0.05) but this difference did not persist over time. There were no group differences in other domains of sleep or fatigue. Exploratory analyses conducted to examine the effect of health-related QOL (EPIC and AUA score) on sleep and fatigue showed significant correlations across multiple domains.

CONCLUSIONS:QGTC during radiation for prostate cancer resulted in superior sleep duration midway through radiation, but this effect was not durable and there were no differences in other domains of sleep or fatigue. Exploratory analysis demonstrated that both sleep and fatigue were highly correlated with prostate cancer related physical symptoms. Future mind-body intervention studies should incorporate multi-modal therapy focused on improving physical symptoms in this population.