KRN2 or 13-(2-fluorobenzyl)-berberine is a berberine derivative that effectively blocks the invasiveness of fibroblast-like synoviocytes (FLS). It is stable and orally bioavailable. It suppresses the production of proinflammatory cytokines to ameliorate arthritis severity.
KRN2 is a specific and potent inhibitor of nuclear factor of activated T cells 5 (NFAT5) that inhibits formation of NF-κB p65-DNA complexes. KRN2 suppresses migration of Fibroblast-like synoviocytes stimulated with TGF-β. KRN2 ameliorates experimental arthritis in mice.