Oral Bifidobacterium longum expressing alpha-melanocyte-stimulating hormone to fight experimental colitis

The oral delivery of peptides is a highly attractive treatment approach. However, the harsh environment of the gastrointestinal tract limits its application. Here, we utilize Bifidobacterium as a delivery system to orally deliver a potent anti-inflammatory but short duration peptide alpha-melanocyte-stimulating hormone (alpha-MSH) against experimental colitis. The aim of our study was to facilitate the efficient oral delivery of alpha-MSH. We designed a vector of pBDMSH and used it to construct a Bifidobacterium longum expressing alpha-MSH. We then determined the bioactivity of recombinant Bifidobacterium in lipopolysaccharide-induced inflammatory models of HT-29 cells. Finally, we used Bifidobacterium expressing alpha-MSH against dextran sulfate sodium (DSS)-induced ulcerative colitis mice. Results based on the myeloperoxidase activity, the levels of inflammatory cytokines TNF-alpha, IL-1 beta, IL-6, and IL-10 and the histological injury of colon tissue reveal recombinant Bifidobacterium was efficient in attenuating DSS-induced ulcerative colitis, suggesting an alternative way to use Bifidobacterium as a delivery system to deliver alpha-MSH for DSS-induced ulcerative colitis therapy.