A narrative review of herb-induced liver injury

Abstract

: Herb and herbal product have been used for both healthy and specific ailments. Its use as medicine or dietary supplements has increased worldwide for more than a decade due to easy access, purported harmless nature, and perceived therapeutic efficacy. Herb induced liver injury which has been recognized for many years is likely to increase. Close scrutiny on herb related safety and liver toxicities is strongly advocated. Toxic ingredients, reactive metabolites, organelle stress, bile salt export inhibition and immune response have been postulated in the pathogenesis of herb-induced liver injury (HILI). HILI is in analogy to drug induced liver injury (DILI) in following aspects (I) clinical manifestations: from asymptomatic abnormal liver tests to severe liver injury and liver failure requiring liver transplantation; (II) mechanism: idiosyncratic or intrinsic; and (III) phenotypes of injury: hepatocellular, cholestatic or mixed type. The diagnosis of HILI remains a challenge. Roussel Uclaf Causality Assessment Method (RUCAM), a structured, quantitative, effective and validated tool for HILI should be reinforced in clinical use. The pathogenetic hallmarks of genome-wide association study (GWAS), human leukocyte antigen (HLA) alleles and non-HLA genetic variants may determine the risk for HILI. Diagnostic biomarkers for HILI need to be re-investigated and reliably validated in future research for their clinical implications. Global prospective HILI registry with advances in the exploration of toxic ingredients, genetic testing and new biomarkers may better explain the pathogenesis and pathogenetic mechanism of HILI which can lead to improvement in diagnosis and treatment of DILI. Pharmacovigilance and standardized regulatory surveillance on safety and efficacy of herbs and herbal products are warranted to reduce the occurrence of HILI and its associated morbidity and mortality.