Gut microbiota-mediated deglycosylation of ginsenoside Rb1 in rats: in vitro and in vivo insights from quantitative ultra-performance liquid chromatography-mass spectrometry analysis?

Analytical Methods Pub Date: 2015-06-18 DOI: 10.1039/C5AY01098E

Abstract

Ginsenoside Rb1, an ingredient of the herbal medicine Panax ginseng, possesses a variety of biological activities. Gut microbiota mediated deglycosylation of ginsenoside Rb1 has long been proposed to play an important role in mediating its pharmacological effects. However, the major active ginsenoside components after the gut microbial transformation have not been clearly identified. To obtain pharmacokinetic clues, we first established a rapid and sensitive ultra performance liquid chromatography (UPLC) tandem mass spectrometry method for targeted analysis of ginsenoside Rb1-related components (ginsenoside Rd, F2, Rg3, Rh2 and compound K) in biological samples. We then performed a comprehensive quantitation of ginsenoside Rb1 and its metabolites in rat plasma after oral administration of ginsenoside Rb1. In vitro microbial hydrolysis of ginsenoside Rb1 was further investigated to help elucidate the in vivo findings. The results indicated that ginsenoside Rb1 and ginsenoside Rd could be detected within 72 hours after oral administration of ginsenoside Rb1. Other metabolites, like compound K, only appeared at a very low concentration in the circulation. The in vitro hydrolysis study revealed that the formation of ginsenoside Rg3 and Rh2 was relatively low compared with the ginsenoside Rd, F2 and compound K. Ginsenoside Rb1 was rapidly hydrolyzed to ginsenoside Rd and the formation of F2 from Rd paralleled compound K from F2. Together, our work suggested that ginsenoside Rd could be the major circulating active metabolite of ginsenoside Rb1 mediated by gut microbial deglycosylation in rats.

Graphical abstract: Gut microbiota-mediated deglycosylation of ginsenoside Rb1 in rats: in vitro and in vivo insights from quantitative ultra-performance liquid chromatography-mass spectrometry analysis
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