Safety Test of Brown Rice Expressing Arabidopsis Calcium Transporter by Feeding Trial in Mice

Abstract

-Previously, we found that the transgenic rice plants over-expressing the Arabidopsis H + /Ca 2+ antiporter CAX 1 (accession no. U57411) gene accumulated 2.7 to 7.5-fold more calcium in the T3 rice grains as compared to those of control. To examine physiological safety of the T3 rice grains, the effect of the T3 brown rice on change in levels of body weight and white blood cells was compared with that of the control Ilpum brown rice by feeding trial in mice. During the feeding trial for one month, there was no significant difference between two mice groups, which were fed by the T3 brown rice or Ilpum brown rice. There were no detectable differences in their effects on immune functions including plaque-forming unit, peritoneal macrophage number, and NK-cell activity. In addition, biochemical analysis of the blood failed to exhibit any difference between two mice groups. Together, these results suggested that the T3 brown rice, which was produced from a genetically modified organism (GMO), might be safe and possess a potential to be applicable as calcium-fortified feed or food. Long-term safety of the T3 brown rice, however, remains to be elucidated.