Bioactive Ginseng Yogurts Fermented with Bifidobacteria: The Transformation of Ginsenosides to Compound K

The objective of this study was to prepare bioactive ginseng yogurts containing compound K, which is transformed from ginsenosides, and to investigate the compound's cytotoxicity against tumor cells. Milk containing ginseng was fermented by Bifidobacteria KK-I and KK-2, and their activities for transforming ginsenosides to compound K were measured. Among the tested concentrations of ginseng in the milk, compound K was effectively produced in the 3% and 6% ginseng yogurts fermented for 48 hrs. These fermented ginseng yogurts were extracted with BuOH, and their cytotoxicities against tumor cells were examined. The BuOH extract of the yogurt made from the 3% ginseng milk showed cytotoxic activity against P388 and HeLa tumor cells. However, the nonfermented ginseng milk did not exhibit cytotoxicity against these cells. Therefore, we deem that the ginseng yogurt, which contained compound K, could be developed as a potential fermented drink product.