Herb-drug interaction potential of Astragali Radix: a metabolic perspective

Astragali Radix (AR) is one of the most widely used herbs in Asia and has a wide range of biological activities. These activities are attributed to its various compounds like flavonoids, saponins, and polysaccharides. AR and its major components are often used in combination with other drugs for the treatment of diseases such as cancer and cerebral ischemia. With the expanding range of AR combinations, the potential for herb-drug interaction (HDI) has been raised. Key targets in HDI studies include drug-metabolizing enzymes (DMEs) and transporters. Existing studies have shown that AR and its major components have various regulatory effects on these targets, notably CYP2C9, CYP3A4, UGT1A6, and P-gp. AR may contribute to HDI when it is taken with substrates of these biomolecules, such as tolbutamide, midazolam, and digoxin. However, there are also different views in the current study, such as the effect of AR on CYP3A4. To better understand the interactions of AR with drugs, we review the metabolic pathways and pharmacokinetic parameters of the main components of AR. Meanwhile, the regulatory effects and mechanisms of AR on DMEs and transporters are summarized to provide a theoretical and technical basis for the rational use of AR in clinical practice.