Morin inhibits Listeria monocytogenes virulence in vivo and in vitro by targeting listeriolysin O and inflammation

Abstract Background: Listeria monocytogenes ( L. monocytogenes ) is a global opportunistic intracellular pathogen that can cause many diseases, including meningitis and abortion in humans and animals; thus, L. monocytogenes poses a great threat to public safety and the development of the aquaculture industry. The pore-forming toxin listeriolysin O (LLO) is one of the most important virulence factors of L. monocytogenes ; LLO can promote cytosolic bacterial proliferation and aid in evading the attacks of the host immune system. In addition, L. monocytogenes infection can trigger a series of severe inflammatory reactions. Results: Here, on the basis of our previous studies, we further confirmed that morin lacking anti-Listeria activity could inhibit LLO oligomerization and found that morin could effectively alleviate the inflammation induced by Listeria in vivo and in vitro and has an obvious protective effect on infected cells and mice. Conclusions: Thus, we further prove that morin is a valuable drug precursor to be developed for the treatment of Listeria infection.