Plant antioxidants in the protection against radiation damage

The scientific community agrees to recognize a link between oxidative stress, mainly due to hyperaccumulation of free radicals, and many serious diseases, such as cancer, atherosclerosis, hypertension, Parkinson's disease, Alzheimer's disease, diabetes mellitus, colitis and rheumatoid arthritis (1). It is known that the levels of oxidative stress may decrease considerably following the introduction of antioxidant molecules, contained in foods, dietary supplements or drugs (2). The molecules able to decrease the levels of oxidative stress belong particularly to the phenols and carotenoids. This research is aimed to develop food supplements containing mixtures of antioxidant plant compounds, with proven non-toxicity, to be used in the prevention of damage from oxidative stress to which are subjected the astronauts during space missions, as a result of exposure to cosmic radiation and to numerous not optimal environmental factors. The obtained formulations can also be used in other fields where there is an increase in oxidative stress in the h uman body, such as exposure to ionizing radiation at radiodiagnostic purpose or radiotherapy (3). This study is part of the project PAPARD (2014-034 R.0 financed by ASI). For the preparation of the formulations will be used a pool of bioactive molecules most widely studied by our research group (4). It will be evaluated the effectiveness of different mixtures consisting of: catechins and procyanidins, resveratrol and its oligomers (viniferins), hydroxytyrosol free and/or linked to secoiridoidic molecules, anthocyanins obtained from red grapes and red fruits and ascorbic acid (vitamin C). All the molecules selected for this study are already present as components of food and/or food supplements and known for their antioxidant properties. The different formulations will be evaluated for their antioxidant capacity and prevention from oxidative damage in two model systems (e.g. erythrocytes and human intestinal tissue); it will be also investigated the stability of the molecules in time, when subjected to irradiation with ionizing radiation. The doses used will be from 0.01 to 1 Sv, so as to cover both the simulation of exposure radiodiagnosis and radiotherapy (up to 0.07 Sv), it is the one that characterizes the space missions of long duration (up to 1 Sv). The research group coordinated by Prof. Gabriella Pasqua performed chemical extraction on the seeds from grapes cvs. Michele Palieri (red), Italia (white), and Pinot. Preliminary observations have shown that the most effective solvent for the extraction of the proanthocyanidins is mixture of ethanol and water at 70:30. The extracts were added with maltodextrin and inulin, due to the its use as fiber and its antioxidant properties (5) at a concentration equal to 5% to obtain a fine powder. In collaboration with the group coordinated by Prof. Nadia Mulinacci have been carried out the HPLC/DAD/MS analysis. The chromatographic profiles showed that the cvs. M. Palieri and Italia were the richest in proanthocyanidins both oligomers and polymers. The group coordinated by Prof. De Gara conducted a preliminary analysis of the total antioxidant capacity of a first preparation of extracts of Vitis vinifera cv Michele Palieri (without excipients and added with 5% inulin and maltodextrin). The results of the preliminary ex periment showed a very high antioxidant activity of the extracts, comparable to the range of ascorbic acid or vitamin C (ASC) and glutathione (GSH), two potent biological antioxidants.