The ethanol extracts of the root of Korean herb Angelica gigas Nakai (AGN) have promising anti-cancer, anti-nociceptive and other activities in rodent models. It is currently believed that the pyranocoumarin decursin and its structural isomer decursinol angelate (DA) in such extracts contribute to the in vitro anti-cancer activity.

We and others have demonstrated that both decursin and DA were extensively converted to decursinol (DOH) in rodents. However, our in vitro experiments using human and rodent S9 fractions suggested the hypothesis that decursin and/or DA might be metabolized differently in humans. Given the notable difference in the biological activities between decursin/DA and

DOH, we conducted a single oral dose pharmacokinetic study of these phytochemicals in healthy volunteers to address a key question for human translatability of preclinical animal studies of decursin, DA or AGN extract. Knowing that chemicals other than decursin and DA in AGN had minimal effect on their absorption and metabolism in rodents, we used an AGN-based dietary supplement as the study drug in compliance with the FDA and institutional requirements. In all, 20 healthy subjects (10 men and 10 women) had completed the study in full.

AGN product was very well tolerated by all subjects as evidenced by plasma biochemistry, complete blood cell count and physical examination. Analyzing plasma samples using UHPLC-MS/MS showed that, though humans metabolized DA slightly slower than rodents, both decursin and DA were extensively converted to DOH. Gender and racial/ethnicity do not appear to dramatically affect the PK parameters. Since we show here that humans metabolize decursin and DA in similar pattern with rodents, the anti-cancer efficacy, safety, tissue distribution and pharmacodynamic biomarker data generated in rodent models will likely be relevant for human translation. In spite of the limited number of healthy individuals in the trial, this project demonstrated feasibility for our team to consider translational research in disease-oriented populations.

Citation Format: Jinhui Zhang, Li Li, Thomas W. Hale, Wayne Chee, Chengguo Xing, Cheng Jiang, Junxuan Lü. Single oral dose pharmacokinetics of cancer chemopreventive phytochemicals from Angelica gigas Nakai in men and women. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3255. doi:10.1158/1538-7445.AM2014-3255