Radioiodination, and Biological Assessment of Olsalazine, as a Highly Selective Radiotracer for Ulcerative Colitis Imaging in Mice

Ulcerative colitis (UC) is a chronic, regressive natural disease. The use of conventional diagnostic procedures such as magnetic resonance imaging, ultrasonography, and X-rays during the dormant and early stages of the disease does not aid in diagnosing the disease. As a result, a novel design, such as labelled compounds, were used to image ulcerative colitis disease. In this study, olsalazine was labeled with [ 125/131 I] and the labelling parameters were adjusted to obtain a high radiochemical yield (98.5%). In addition, the olsalazine radiotracer gave 96.0% purity in rate serum for up to twelve hours before it started to degrade at twenty-four hours, and it was stable also, in saline for up to twenty-four hours. Molecular docking was used to assess a complex's affinity for its biological target, and the PPAR  receptor. The biological assessment was also performed in mice models of both standard and ulcerative colitis. The results demonstrated that [ 125/131 I] iodoolsalazine had a high uptake of 79.5% (ID/g) at 120 minutes post-injection and is still high to 77% at 24 hours. So, the labelled compound, [ 125/131 I] iodoolsalazine, could be considered a new potential selective radiotracer for preclinical diagnostic research of ulcerative colitis.