Botanicals as medicinal food and their effects on drug metabolizing enzymes

Botanicals fall under different regulations in different countries and are mostly consumed without the consultation of the healthcare professional. Over the last decade, utilization of herbal therapies has been extensively documented. The findings indicate the possibility of potential herb-drug interactions due to the concomitant administration of herbal extracts and prescription/over-the-counter drugs. Simultaneously, with the increasing public awareness and search for safer herbal remedies, the study on herbal-drug interactions has gained momentum through the study of drug metabolizing enzymes. Cytochrome P450 (CYP) inhibition or induction is probably the most common mechanism for the pharmacokinetic interactions of herbs and drugs. Any inhibition of CYP enzymes by herbal extracts may result in enhanced plasma and tissue concentration of drugs, leading to toxicity, while induction results in reduced drug concentration leading to decreased drug efficacy and treatment failure. Considering the rapidly growing herbal markets, these types of clinical interactions remain under-reported and unclear. With the increasing consumption of herbal extracts along with prescription medicines, the safety of herbs has become a concern. This article reviews the potential for drug interactions by herbal extracts through drug metabolizing enzymes.