Anti-tumor activity of three novel derivatives of ginsenoside on colorectal cancer cells.

25-Hydroxyprotopanaxadiol (25-OH-PPD) is a natural compound isolated from Panax ginseng, and its anti-tumor activity has been studied in previous publication. In the current study, we investigated the anti-tumor activity of three novel derivatives synthesized from 25-OH-PPD, namely (20R)-12β-O-(l-chloracetyl)-dammarane-3β, 20, 25-triol (xl), (20R)-3β-O-(l-alanyl)-dammarane-12β, 20, 25-triol (1c), and (20R)-3β-O-(Boc-l-arginyl)-dammarane-12β, 20, 25-triol (8b). All three compounds significantly inhibited the growths of human colorectal cancer cells, while having lesser effect on the growth of normal primary muscle cells and spleno-lymphocytes. Further mechanistic study demonstrated that these compounds could induce apoptosis by activating the components of caspase-signaling pathways in HCT116 cells, but not in spleno-lymphocytes. Taken together, the results suggested that 25-OH-PPD derivatives exerted promising anti-tumor activity that is specific to human colorectal cancer cells, and may therefore represent a potential chemotherapeutic strategy for the treatment of colorectal cancer.