Red notoginseng: Higher ginsenoside content and stronger anticancer potential than Asian and American ginseng

A systematic comparison of the ginsenosides and anticancer activities was performed amongst white (air-dried) and red (steamed) roots of notoginseng (NG, Panax notoginseng), Asian ginseng (AG, Panax ginseng), and American ginseng (AmG, Panax quinquefolius). Chemical profiles of different ginseng species were characterised, through simultaneous quantification of 19 major ginsenosides, by HPLC–UV at 202 nm. The antiproliferative and pro-apoptotic effects on human colorectal cancer cells were determined by MTS method and flow cytometry, respectively. Chemical analysis indicated that white NG possessed the most abundant ginsenosides, i.e., 2- and 5-fold higher than white AmG and AG. During the steaming process, extensive conversion of the original polar ginsenosides in white ginseng to new, less polar, degradation compounds in red ginseng was observed. White ginsengs produced weak antiproliferative effects, while red ginsengs exhibited a significant increase in antiproliferative and pro-apoptotic effects (both p < 0.01 vs white ginseng). Amongst the three red ginsengs, red NG showed the best anticancer activity. Due to the low cost of NG and high bioactivity of red NG, the red NG is promising to be a useful botanical product in cancer chemoprevention.