Anti-inflammatory effect of novel analogs of natural enkephalinase inhibitors in a mouse model of experimental colitis

The pharmacotherapy of inflammatory bowel disease is difficult and currently available treatments bring mostly poor and unsatisfactory results. The purpose of this work was the synthesis of opiorphin, sialorphin, spinorphin and a series of their analogs and the characterization of their effect on degradation of enkephalin by neutral endopeptidase and aminopeptidase N. Consequently, we investigated the anti-inflammatory effect of the most active inhibitors selected in the studies (Pal-KKQRFSR & Pal-KKQHNPR). Putative inhibitor - enzyme (neutral endopeptidase or aminopeptidase N) complexes are also presented and their binding interfaces are identified. Our results suggest that Pal-KKQHNPR has the potential to become a valuable template for anti-inflammatory therapeutics for the treatment of GI tract inflammation.