Efficacy and Safety of Oltipraz in the Patients With Liver Fibrosis and Cirrhosis

Oltipraz \[5-(2-pyrazinyl)-4-methyl-1,2-dithiol-3-thione\] has been extensively studied as a cancer chemopreventive agent. Comprehensive mechanistic and phase IIa studies supported the notion that oltipraz exerts chemopreventive effects, as supported by Phase IIa human clinical studies of oltipraz on cancer chemoprevention, conducted in Qidong, China. Hepatic stellate cells cause synthesis of large quantities of extracellular matrix. Transforming growth factor beta1 (TGF-beta1), as a key fibrogenic mediator for fibrogenesis after injuries through deposition of extracellular matrix and inhibition of collagenase activity in the liver, is associated with the regulation of cell growth and differentiation and causes synthesis of extracellular matrix proteins and cellular receptors for matrix proteins. Previously, we reported the effectiveness of oltipraz in regeneration of cirrhotic liver, which includes reduction of the intensities of liver fibrotic and cirrhotic nodules, elimination of accumulated extracellular matrix, and regeneration of cirrhotic liver in animal models. Oltipraz completely resolves fibrosis in the cirrhotic liver, thereby improving viability. TGF-beta1 signaling plays an important role in liver fibrogenesis and cirrhosis as evidenced by receptor knockout experiments. No therapeutic agent that is active in interrupting TGF-beta1 signaling is available, proposing that C/EBP serve as a molecular target for the treatment of liver cirrhosis.