Biotransformation of Ginseng Extract to Cytotoxic Compound K and Ginsenoside Rh_2 by Human Intestinal Bacteria

摘要

When saponin extracts of dried ginseng and red ginseng were anaerobically incubated with human intestinal microflora, these extracts were metabolized to compound K and ginsenoside Rh_2, respectively. However, when these extracts were incubated with commercial lactic acid bacteria, these did not metabolize these ginsenosides to compound K or ginsenoside Rh_2. Among some intestinal bacteria isolated from human feces, Bacteroides C-35 and C-36 transformed these saponin extracts to compound K and ginsenoside Rh_2, respectively. These bacteria also transformed water extracts of dried ginseng and red ginseng to compound K and ginsenoside Rh_2, respectively, similarly with that of the saponin extracts. Among transformed ginsenosides, compound K and 20(S)-ginsenoside Rh_2 exhibited the most potent cyotoxicity against tumor cells.