Drug development for liver diseases: focus on picroliv, ellagic acid and curcumin.

The use of herbal drugs for the treatment of liver diseases has a long tradition in many eastern countries. The easy accessibility without the need for laborious pharmaceutical synthesis has drawn increased attention towards herbal medicines. Few herbal preparations exist as standardized extracts with major known ingredients or even as pure compounds. Some of the herbals, which show promising activity, are ellagic acid for antifibrotic treatment, phyllanthin for treating chronic hepatitis B, glycyrrhizin to treat chronic viral hepatitis and picroliv for liver regeneration. These compounds, which have proven antioxidant, antiviral or anticarcinogenic properties, can serve as primary compounds for further development as hepatoprotective drugs. This review provides the chemistry, pharmacology and future aspects of picroliv, ellagic acid and curcumin with focus on hepatoprotective properties. These phytochemicals may prove to be very useful in the treatment of hepatotoxicity induced by viral agents, toxic drugs and plant poisons. The high safety profile may be an added advantage. However, poor bioavailability and temperature and light sensitivity can reduce the efficacy of drugs like curcumin. In future, the derivatives or new combinations of these drugs may prove to be useful.