Metabolism of 20(S)-Ginsenoside Rg₂ by Rat Liver Microsomes: Bioactivation to SIRT1-Activating Metabolites.
20(S)-Ginsenoside Rg₂ (1) has recently become a hot research topic due to its potent bioactivities and abundance in natural sources such as the roots, rhizomes and stems-leaves of Panax ginseng. However, due to the lack of studies on systematic metabolic profiles, the prospects for new drug development of 1 are still difficult to predict, which has become a huge obstacle for its safe clinical use. To solve this problem, investigation of the metabolic profiles of 1 in rat liver microsomes was first carried out. To identify metabolites, a strategy of combined analyses based on prepared metabolites by column chromatography and ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF/MS) was performed. As a result, four metabolites M1-M4, including a rare new compound named ginsenotransmetin A (M1), were isolated and the structures were confirmed by spectroscopic analyses. A series of metabolites of 1, MA-MG, were also tentatively identified by UPLC-Q-TOF/MS in rat liver microsomal incubate of 1. Partial metabolic pathways were proposed. Among them, 1 and its metabolites M1, M3 and M4 were discovered for the first time to be activators of SIRT1. The SIRT1 activating effects of the metabolite M1 was comparable to those of 1, while the most interesting SIRT1 activatory effects of M3 and M4 were higher than that of 1 and comparable with that of resveratrol, a positive SIRT1 activator. These results indicate that microsome-dependent metabolism may represent a bioactivation pathway for 1. This study is the first to report the metabolic profiles of 1 in vitro, and the results provide an experimental foundation to better understand the in vivo metabolic fate of 1.
State Key Laboratory of Natural and Biomimetic Drugs, Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University Health Science Center, Peking University, No. 38, Xueyuan Road, Haidian District, Beijing 100191, China. maliyuan0506@126.com.
Li-Yuan
LY
Ma
State Key Laboratory of Natural and Biomimetic Drugs, Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University Health Science Center, Peking University, No. 38, Xueyuan Road, Haidian District, Beijing 100191, China. zqlzdn@163.com.
Qi-Le
QL
Zhou
State Key Laboratory of Natural and Biomimetic Drugs, Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University Health Science Center, Peking University, No. 38, Xueyuan Road, Haidian District, Beijing 100191, China. xbyang0718@163.com.
Xin-Bao
XB
Yang
State Key Laboratory of Natural and Biomimetic Drugs, Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University Health Science Center, Peking University, No. 38, Xueyuan Road, Haidian District, Beijing 100191, China. sungirl9626@163.com.
Hong-Ping
HP
Wang
State Key Laboratory of Natural and Biomimetic Drugs, Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University Health Science Center, Peking University, No. 38, Xueyuan Road, Haidian District, Beijing 100191, China. xwyang@bjmu.edu.cn.
Xiu-Wei
XW
Yang
D000818:Animals; D002853:Chromatography, Liquid; D036145:Ginsenosides / Q000737:chemistry / Q000378:metabolism* / Q000627:therapeutic use; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D008862:Microsomes, Liver / Q000187:drug effects* / Q000378:metabolism; D005894:Panax / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D056564:Sirtuin 1 / Q000096:biosynthesis* / Q000235:genetics; D053719:Tandem Mass Spectrometry
D036145:Ginsenosides; C026474:ginsenoside Rg2; C488368:Sirt1 protein, rat; D056564:Sirtuin 1
20(S)-ginsenoside Rg2; SIRT1 activator; ginsenotransmetin A; liver microsomes