Discovery of 6‐Acylamino/Sulfonamido Benzoxazolone with IL‐6 Inhibitory Activity as Promising Therapeutic Agents for Ulcerative Colitis

Abstract Ulcerative colitis has been widely concerned for its persistent upward trend, and the sustained overproduction of pro‐inflammatory cytokines such as IL‐6 remains a crucial factor in the development of UC. Therefore, the identification of new effective drugs to block inflammatory responses is an urgent and viable therapeutic strategy for UC. In our research, twenty‐three 6‐acylamino/sulfonamido benzoxazolone derivatives were synthesized, characterized, and evaluated for anti‐inflammatory activity against NO and IL‐6 production in LPS‐induced RAW264.7 cells. The results demonstrated that most of the target compounds were capable of reducing the overexpression of NO and IL‐6 to a certain degree. For the most active compounds 3i, 3j and 3 l , the inhibitory activities were superior or equivalent to those of the positive drug celecoxib with a dose‐dependent relationship. Furthermore, animal experiments revealed that active derivatives 3i, 3j and 3 l exhibited definitive therapeutical effect on DSS induced ulcerative colitis in mice by mitigating weight loss and DAI score while decreasing levels of pro‐inflammatory cytokines such as IL‐6 and IFN‐γ, simultaneously increasing production of anti‐inflammatory cytokines IL‐10. In addition, compounds 3i , 3j and 3 l could also inhibit the oxidative stress to alleviate ulcerative colitis by decreasing MDA and MPO levels. These finding demonstrated that compounds 3i, 3j and 3 l hold significant potential as novel therapeutic agents for ulcerative colitis.