Ulcerative colitis (UC), also known as idiopathic ulcerative colitis or chronic nonspecific ulcerative colitis, is a disease of large intestine with infiltration of the mucosa and idiopathic chronic non-specific inflammation. The main clinical symptoms are abdominal pain, diarrhea, mucus and bloody stools, and associated with optic neuritis, neuritis, and osteoporosis. It has been characterized as a hardy disease by the World Health Organization (WHO) because treatment of the disease is difficult and time-consuming and the disease relapses easily. Although currently there are a variety of drugs for curing IBD, such as amino salicylic acid, glucocorticoids and immunosuppressive agents, but they have many shortcomings, such as poor efficacy (especially to severe UC), slow onset, long course, and large side effects. Therefore, the drug with an effective, rapid onset, short course, high safety, little side effects, convenient for IBD (especially chronic nonspecific ulcer colitis) is urgently needed.
It has been shown that CBLB502, one of the flagellin derivatives from Salmonella, has a protective effect on the hematopoietic system, and can extend the survival time of mice to the high-dose radiation injury and improve the survival rates of low-dose irradiated mice (Lyudmila G. Burdelya, et al, An Agonist of Toll-Like Receptor 5 Has Radioprotective Activity in Mouse and Primate Models. Science 2008; 320 (5873): 226-230). The study found that the flagellin protein derivatives from Salmonella and other derivants containing the N- and C-terminal conserved domain have the radial protection, they can effectively improve the number of hematopoietic stem cells in the bone marrow of mice and effective preventing the death of mice caused by lethally irradiation. Its mechanism may be the anti-apoptotic role through NF-κB signal pathway. It means that this protein can be applied to development of anti-radiation drugs. There is no report on Salmonella flagellin derivatives except for the anti-radiation drug.