Protective effects of phytochemicals from cosmic radiations

During long-term space missions, crew is subjected to potentially dangerous environmental factors, among which cosmic radiations that generate elevated oxidative stress levels. This physiological condition, caused by redox homeostasis disequilibrium with resulting hyper-accumulation of Reactive Oxygen Species (ROS) and others free radicals, is very dangerous for human organism and it is a common characteristic of several pathologies. It is well known that oxidative damages can be considerably reduced by increasing the intake of antioxidant compounds. Current technology is not able to totally protect astronauts from absorbed radiations. To date few studies have been focused on this topic. This research is aimed to identify dietary supplements, containing plant-deriving bioactive natural molecules having ROS-scavenging properties and proven non-toxicity , which do not lose their antioxidant capability when are exposed to cosmic radiation. These mix of phytochemicals could offer an appropriate protection to astronauts during long-term space missions. The ability of different natural plant extracts to counteract oxidative damage was evaluated. Particular interest was focused on green bioactive molecules extractable from food waste matrices. All samples were analyzed and compared for their ROS-scavenging properties before and after the treatment with ionizing radiations (140 cSv, calculated as the amount of radiations absorbed by astronauts after an hypothetical stay of three years in the space). In parallel, a metabolomics characterization of extracts, with particular attention to polyphenolic component, was effectuated by HPLC/DAD analysis coupled to HPLC-MS-TOF to identify possible variations of samples chemical profile. The vitamin C content and redox state was also analyzed in the plants extracts before and after treatment with ionizing radiation. Matrices selected for highest antioxidant properties will be also analyzed in ex vivo biological essays using blood red cell membranes in order to test the in vivo protective effects on a biological system. In vitro results so far obtained showed that the treatment with a high dose of radiation induced only little modifications in the phenol composition and total antioxidant capability of the extracts, while it slightly altered their vitamin C content. Overall, for the first time, the findings of this research allow to know the chemical stability of several natural phenols and the related antioxidant potency of the related extracts after a strong irradiation treatment (140 cSv). These results could have relevant impacts for space mission, but they also could have interesting output in biomedicine: the intake of food supplements or pharmaceutical formulations rich in ROS-scavenging bioactive molecule could help to protect citizens/patients from induced by medical therapies, as imaging and diagnostics technologies and radiotherapy, that involve exposure to ionic radiations.