UR-1505

The aim of the present study was to evaluate the inmunomodulatory effects of UR-1505, a new salicylate derivative, on the T helper (Th)2/humoral response produced during dextran sodium sulfate (DSS)-induced rat colitis. In the in vitro studies, UR-1505 (300 microM) inhibited both the production of interleukin (IL)-10 and IL-5 in concanavalin A (Con A)-activated splenocytes and the production of immunoglobulin (Ig) G and IgA by B-lymphocytes. However, in contrast to the in vitro results, the administration of UR-1505 (10 and 30 mg/kg per day) to rats with established DSS-colitis enhanced both IL-10 and IgA production, whereas it inhibited IgG production, thus ameliorating the intestinal inflammation.

UR-1505 is a novel pentafluoropropoxy derivative of salicylic acid, selected from a series of salicylate derivatives, according to their activity as inhibitors of T-lymphocyte activation. This study describes the anti-inflammatory activity of UR-1505 on trinitrobenzenesulphonic acid-induced colitis in rat, an experimental model that resembles to Crohn's disease (CD), as well as its in vitro effects on T-cells and bone marrow-derived macrophages (BMDM) activation. UR-1505 showed intestinal anti-inflammatory effect, associated with reduced colonic levels of TNFalpha and LTB(4), inhibition of the expression of IFNgamma and iNOS, and lower colonic leukocyte infiltration. The in vitro assays revealed that UR-1505 also inhibited T-lymphocyte proliferation and IL-12/IFNgamma production, two of the main pro-inflammatory cytokines involved in the pathogenesis of CD. However, UR-1505 did not modify LPS- nor IFNgamma-induced activation in BMDM. Thus, UR-1505 specifically affects T-cells without modifying the activation of BMDM. In conclusion, the intestinal anti-inflammatory activity of UR-1505 seems to be mediated by a reduction in the recruitment of immune cells to the inflammatory foci, together with the inhibition of T-cell activation. These results suggest that UR-1505 may be an interesting candidate to be explored for the treatment of CD.