Effects of steaming on saponin compositions and antiproliferative activity of Vietnamese ginseng

Background: Steaming of ginseng is known to change its chemical composition and biological activity. This study was carried out to investigate the effect of different steaming time-scales on chemical constituents and antiproliferative activity of Vietnamese ginseng (VG). Methods: VG was steamed at 105 degrees C for 2-20 h. Its saponin constituents and antiproliferative activity were studied. The similarity of chemical compositions between steamed samples at 105 degrees C and 120 degrees C were compared. Results: Most protopanaxadiol and protopanaxatriol ginsenosides lost the sugar moiety at the C-20 position with 10-14 h steaming at 105 degrees C and changed to their less polar analogues. However, ocotillol (OCT) ginsenosides were reasonably stable to steaming process. Antiproliferative activity against A549 lung cancer cells was increased on steaming and reached its plateau after 12 h steaming. Conclusion: Steaming VG at 105 degrees C showed a similar tendency of chemical degradation to the steaming VG at 120 degrees C except the slower rate of reaction. Its rate was about one-third of the steaming at 120 degrees C. Copyright (C) 2015, The Korean Society of Ginseng, Published by Elsevier. All rights reserved.