Pharmacodynamics and Pharmacokinetics of Interactions Between Herbal and Clinically Used Medicines

According to the American Botanical Council, sales of herbal supplements in the U.S. rose 17.3% in 2020. In the last few years (and especially during the Covid pandemic), the number of users of herbal medicines has increased significantly. More than ever, it is believed that “natural healing powers” can improve patients’ health and protect them from various diseases. Ayurveda, aromatherapy, Chinese traditional medicine, Eastern herbal medicine, including TCM, and Japanese medicine are alternative medicines used globally. However, a more profound concern is that ingested herbal medical products (HMPs) may modulate clinically used medicine, resulting in drug pharmacokinetics and pharmacodynamic changes. Therefore, a comprehensive understanding of the interaction between HMPs and clinically used medicines from different perspectives needs to be satisfied. Despite some identified herb-drug interactions that have been shown, the limited cause-and-effect relationships in clinical case reports and animal studies are already insatiable to current needs. Therefore, the knowledge gap must be fed by scientific research.

As seen from pharmacokinetic investigations of the interaction between HMPs and clinically used medicines, certain HMPs influence gastrointestinal absorption, cytochrome P450 enzymes (CYP450), protein bonding ability, and cellular efflux proteins to affect the drug concentration in circulation. For example, St. John’s Wort (Hypericum perforatum) modulates the bioavailability of chemotherapy drugs (i.e., docetaxel, vincristine, etoposide, and irinotecan) caused by the regulation of CYP450 and P-glycoprotein activity. Furthermore, impacts on the efficacy of herbal-drug combination therapy are a primary concern. Based on the pharmacodynamic investigation, the related pharmacological networks of the herbal-drug interactions are involved in the modulation of upstream/downstream factors and share in the mechanisms of action. Traditional Chinese medicine formulations, composed of single or multiple HMPs, have been popularly prescribed for patients treated with chemotherapy, radiotherapy, or gastrointestinal diseases in Asian countries for decades. Lots of herbal-drug interaction studies focus on single HMPs and their pharmacokinetic influences. However, it rarely provides enough information to clinicians and patients. Therefore, this Research Topic aims to provide further details on the pharmacodynamics and pharmacokinetics between HMPs and other medicines are urgently needed to be investigated and then shared with societies. As herbal/food-drug interactions are not only involved in pharmacokinetic behaviors but also in pharmacodynamics, this topic welcomes research associated with the pharmacodynamic interaction between HMPs and drugs.

Based on our goals for this Research Topic, we encourage you to submit manuscripts describing recent advances in the natural products-medicine interaction to elaborate on and update the knowledge surrounding their pharmacodynamics and pharmacokinetics. We also welcome the research associated with alternative medicine and clinically used medicine. According to the general rules of this section, manuscripts investigating extracts require a description of the chemical profile. In silico studies or virtual screening studies will not be considered. It is an excellent opportunity to share your investigated outcomes with the public.

All the manuscripts submitted to the collection will need to fully comply with the Four Pillars of Best Practice in Ethnopharmacology (you can freely download the full version here).