A comparative study of radioprotective effect of several antioxidants on human blood lymphocytes

By means of improved fluorometric method with 2-thiobarbituric acid (TBA) as the fluorometric agent, radioprotective effects of four kinds of antioxidants on 60Co γ-ray induced lipid peroxidation (LPO) level, i.e. Malondialdehyde (MDA) content changes in human blood lymphocytes were in human blood lymphocytes were compared by using relative protective efficiency (RPE) as an indicator. The LPO level in human lymphocytes which had been treated with an antioxidant at an concentration of 5 x 10-3 g/L for 1 hr was measured 2 hr after exposure to 4 Gy of γ-rays, and the RPE values of antioxidants were calculated under these conditions: SOD, 38.23; VE, 23.75:VC, 19.32 and Se+4, 18.27, thus the anticipation that the compounds, superoxide dismutase (SOD), 2-tocopherols (VE), ascorbic acid (VC) and Na2 SeO3(Se+4) had radioprotective effects was confirmed. It was found that the radioprotective beneficial sequences of four kinds of antioxidants were arranged as SOD>VE>VC,Se+4. The results show that radioprotective effects of exogenous antioxidants on radiation induced LPO damage are dependent not only on irradiation dosage, but also especially on property of antioxidants, drug concentration, pretreatment and monitoring time, etc. The mechanism of these antioxidants effecting as radioprotectants on human lymphocytes is discussed in connection with LPO damage and radioprotection