Biological and Pharmaceutical Bulletin
Online ISSN : 1347-5215
Print ISSN : 0918-6158
ISSN-L : 0918-6158
Regular Articles
The Effect of Yokukansan, a Traditional Herbal Preparation Used for the Behavioral and Psychological Symptoms of Dementia, on the Drug–Metabolizing Enzyme Activities in Healthy Male Volunteers
Hiromi SoraokaKentaro OnikiKazuki MatsudaTatsumasa OnoKosuke TaharazakoYoshihiro UchiyashikiRyoko KamihashiAyana KitaAyaka TakashimaKazuko NakagawaNorio Yasui-FurukoriDaisuke KadowakiKeishi MiyataJunji Saruwatari
Author information
JOURNAL FREE ACCESS FULL-TEXT HTML
Supplementary material

2016 Volume 39 Issue 9 Pages 1468-1474

Details
Abstract

The concomitant use of herb and prescription medications is increasing globally. Herb–drug interactions are therefore a clinically important problem. Yokukansan (YKS), a Japanese traditional herbal medicine, is one of the most frequently used herbal medicines. It is effective for treating the behavioral and psychological symptoms of dementia. We investigated the potential effects of YKS on drug–metabolizing enzyme activities in humans. An open-label repeat-dose study was conducted in 26 healthy Japanese male volunteers (age: 22.7±2.3 years) with no history of smoking. An 8-h urine sample was collected after a 150-mg dose of caffeine and a 30-mg dose of dextromethorphan before and after the administration of YKS (2.5 g, twice a day for 1 week). The activities of cytochrome P450 (CYP) 1A2, CYP2D6, CYP3A, xanthine oxidase (XO) and N-acetyltransferase 2 (NAT2) were assessed based on the urinary metabolic indices of caffeine and dextromethorphan, and the urinary excretion ratio of 6β-hydroxycortisol to cortisol. There were no statistically significant differences in the activities of the examined enzymes before or after the 7-d administration of YKS. Although further studies assessing the influence of YKS on the pharmacokinetics and pharmacodynamics of the substrates of the drug–metabolizing enzymes are needed to verify the present results, YKS is unlikely that a pharmacokinetic interaction will occur with concomitantly administered medications that are predominantly metabolized by the CYP1A2, CYP2D6, CYP3A, XO and NAT2.

Graphical Abstract Fullsize Image
Content from these authors
© 2016 The Pharmaceutical Society of Japan
Previous article Next article
feedback
Top