Herbal medicine hepatotoxicity: A new step with development of specific biomarkers

Abstract

Hepatic impairment resulting from the use of conventional drugs is widely acknowledged, but there is less awareness of the potential hepatotoxicity of alternative medicines such as herbal preparations [1]. The increasing attraction for herbals medicines is partly explained by the return to natural products occurring along with the ecological movement in industrialized countries [1]. It is also related to the limited efficacy or the important side effects of treatments of various chronic diseases [1–5]. Several recent studies that focused on the use of herbal medicines in chronic hepatitis C are particularly demonstrative in Western countries [6,7]. A prospective inquiry carried out in France, based on outpatients seen for chronic liver diseases, has revealed that there was a herbal medicine intake for at least 1 month in 30% of included patients with hepatitis C [6]. Similarly, the hepatitis C antiviral long-term treatment against cirrhosis (HALT-C) trial conducted in the USA showed that 21% of enrolled patients had taken herbal medicines before and 23% at the time of inclusion [7]. In both studies, the most commonly used herbal compounds were sylimarin and valerian [6,7]. The use of herbal medicines does not require any medical prescription. Patients may find these products in various stores, some of them being specialized in herbal products but also in pharmacy stores. Furthermore, the possibility to get herbal products via the internet has markedly contributed to the increase in their sales [4]. In several areas of the world, particularly in Asia, Africa, and central and South America, the use of herbal medicines is an important part of a traditional medicine exhibiting several advantages, in particular, easy availability and low cost [1–5]. Over the last decades it has become apparent that herbal medicines may cause a very large spectrum of liver injury, affecting all cells present in the liver and biliary tree, and ranging from mild asymptomatic liver enzyme elevation to acute hepatitis, chronic hepatitis, cirrhosis, liver failure, acute and chronic cholangitis, macroand micro-vesicular steatosis, and vascular lesions [1–5]. Furthermore, herbal medicines may produce interactions with liver drug metabolizing enzymes [2]. A representative instance is St. John’s Wort (Hypericum perforatum L.) which