Protection And Mechanisms Of Selenium On Spirulina Platensis And Human Red Blood Cells Against Oxidative Stress

The aims of this study are to investigate the protective effects and the underlying mechanisms of two selenium (Se) species, sodium selenite (Na2SeO3/Se(â…£)) and Se-containing allophycocyanin (Se-APC), on Spirulina platensis and human red blood cells against oxidative stress. Many interesting results have been obtained, which included:1. Treatments with H2O2 induced decrease in growth and biomass concentrations of S. platensis. The algal filament was found to be fragmented and the level of MDA increased significantly after exposure to H2O2. These results indicate that the lipids of alge cells membrane were damaged, and the physiological and biochemical metabolism was disordered.2. To investigate the possibility and the underlying mechanisms of these two compounds as protective agents against oxidative stress, the effects of various concentrations of Se(â…£) on the growth, biomass, morphology, contents of malondialdehyde (MDA), antioxidant enzymes in S. platensis exposed to H2O2 were examined in this study. The results showed that pretreatments of Se(â…£) significantly enhanced the activities of antioxidant enzymes and elevated the contents of water-soluble proteins and photosynthetic pigments. Taken together, these results suggest that Se(â…£) could stimulate the antioxidant activities and alleviate the cell membrane lipid peroxidation, thus maintain the physiological and biochemical balance of S. platensis.3. The results of spectroscopic investigation showed that the photosynthesis ability of S. platensis was decreased under H2O2 stress. Se(â…£) could effectively recover the cell photosynthesis, thus protect S. platensis from oxidative stress.4. Hemolysis, the contents of MDA, levels of ROS and morphology of human RBCs treated with t-BOOH were examined, while Se-APC was used as a preprotective agent. The results showed that Se-APC could effectively protect the RBCs through reduction of MDA contents and ROS accumulation. In conclusion, the two selenium (Se) species, Se(â…£) and Se-APC, could protect the S. platensis and the human RBCs against oxidative damage to a certain extent respectively, and then maintain their physiological functions.