Camostat monomethanesulfonate
Camostat Mesylate is the mesylate salt form of camostat, an orally bioavailable, synthetic serine protease inhibitor, with anti-inflammatory, antifibrotic, and potential antiviral activities. Upon oral administration, camostat and its metabolite 4-(4-guanidinobenzoyloxyl)phenyl acetic acid (FOY 251) inhibit the activities of a variety of proteases, including trypsin, kallikrein, thrombin and plasmin, and C1r- and C1 esterases. Although the mechanism of action of camostat is not fully understood, trypsinogen activation in the pancreas is known to be a trigger reaction in the development of pancreatitis. Camostat blocks the activation of trypsinogen to trypsin and the inflammatory cascade that follows. Camostat may also suppress the expression of the cytokines interleukin-1beta (IL-1b), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-a) and transforming growth factor-beta (TGF-beta), along with alpha-smooth muscle actin (alpha-SMA). This reduces inflammation and fibrosis of the pancreas. In addition, camostat may inhibit the activity of transmembrane protease, serine 2 (TMPRSS2), a host cell serine protease that mediates viral cell entry for influenza virus and coronavirus, thereby inhibiting viral infection and replication.