NASA - Radiation Proection and Leukemia-gene Studies

PMC Antioxidant Micronutrient Program for Biological Protection Against Ionizing Radiation Damage – National Aeronautic and Space Administration (NASA), Johnson Space Center, Houston, TX

NASA has identified oxidative damage as a risk to astronaut health, and has explored countermeasures to mitigate this risk. The potential health injuries to crewmembers during space flight include muscle fatigue, hearing damage, and chronic diseases such as cancer, cataracts and cognitive dysfunction. Oxidative damage due to increased production of free radicals plays a critical role in initiating these injuries. Astronauts, particularly those who perform extravehicular activity (EVA), are at increased risk for these effects since they are exposed to may different sources of oxidative stress including cosmic radiation. Astronauts’ exposure to oxidative stress is expected to increase in the future because of longer space missions, and the amount of EVA work required for the completion and maintenance of the International Space Station, as well as for planetary and solar system exploration. Some studies have been performed on astronauts in Low Earth Orbit, on in-vitro cell and tissue culture models in NASA-designed microgravity-analog bioreactors and on small animals in space analogs.

At present, there are no effective countermeasures against damage produced by cosmic radiation. Developing countermeasures against radiation –induced damage is essential for successful exploration of space and planetary environments. PMC in collaboration with NASA and the Russian Academy of Sciences, has completed a pilot study in which a PMC formulation containing both dietary and endogenous antioxidants increased the survival time, by 5-6 fold in irradiated sheep receiving a lethal dose of whole-body radiation. The irradiated animals not receiving antioxidants died in 7 days after irradiation. Rabbits receiving a lethal dose of whole body radiation died in 4 hours exhibiting CNS syndromes with or without antioxidant treatment; however, the damage to the lung in rabbits receiving antioxidants before irradiation was markedly reduced in comparison to those who received no antioxidants. The large animal studies performed in Russia are appropriate since radiation experiments cannot be performed directly in humans.

PMC Antioxidant Micronutrient Program for Biological Protection Against Proton- Radiation Damage – National Aeronautic and Space Administration (NASA), Ames Research Center, Moffett Field, CA

A pilot study was carried out with female Fruit flies ( Drosophila) carrying a leukemia-type gene that increases their sensitivity for the development of tumors. Proton irradiation increased the incidence of tumors in a dose-dependent manner. The PMC antioxidant micronutrient formulation mixed with the diet (100 µg/gram of diet) before proton irradiation completely protected Drosophila against radiation-induced tumor formation (in collaboration with Dr Sharmila Bhattacharya of Ames Research Center, NASA, Moffett Field, CA).