Effect of trolox, riboxin (inosine), and indralin on X-ray induced oxidative stress in A549 cells

Using dichlorofluorescein (DCF) fluorescence intensity, the oxidative stress in human lung adenocarcinoma A549 cells pretreated with trolox, riboxin (inosine), tartaric acid, and indralin was measured 2 h before, during, and 1 h after the X-ray radiation at a dose of 8 Gy. Trolox at concentrations up to 1 mM significantly reduced the oxidative stress from radiation exposure, with a less pronounced effect at 2 mM. Riboxin also suppressed the oxidative stress, though to a lesser extent, at micromolar concentrations, but showed no significant antioxidant activity at 1 and 2 mM, which can be attributed to the potential pro-oxidative impact of many antioxidants at high concentrations. Tartaric acid possessed antioxidant properties at micromolar concentrations. Of particular interest is that indralin at 1.9 mM increased the level of oxidative stress in the irradiated cells. Therefore, the effects of indralin, known for its radioprotective action due to the properties of a signaling molecule causing tissue hypoxia, can differ at cellular and organismal levels.