New Insights into Herb-Induced Liver Injury

Abstract
Significance: Herbs are widely used worldwide. However, inappropriate use of some of the herbs can lead to herb-induced liver injury (HILI). Intriguingly, HILI incidents are on the rise and our understanding of the underlying etiologies is in progress, and hence an update on the current status of incidents as well as our understanding on the etiologies of HILI is appropriate. Recent Advances: HILI reports due to the use of some herbs that are traditionally considered to be safe are also on the rise. Furthermore, HILI due to the use of certain herbs in combination with other herbs (herb-herb interaction, HHI)) or non-herb components (herb-drug interaction, HDI) have also been reported, suggesting a potentially important new type of inappropriate use of herbs. Critical Issues: Updated overviews focusing on the epidemiology, etiology, phenotypes, and risk factors of HILI, as well as HDI and HHI; and analysis on several types of newly reported “toxic” effects of herbs based on types of hepatotoxicity and the HILI mechanisms. Future Direction: HILI will continue to be a significant public health challenge in the near future. In the light of the lack of broadly available guidelines and regulations for proper and safe uses of herbs worldwide, raising the public awareness of HILI will remain one of the most effective measures. In particular, it should include a better understanding of the contributing factors; a more detail sub-classification and description of HILI, better characterization of the components/substances that could induce HILI; and development of HILI diagnosis based on RUCAM.