As part of an ongoing search for immunomodulatory components aimed at the anti-complementary effect, ginsenosides isolated from processed ginseng were found to have inhibitory activity on complement activation through classical pathways. Activity-guided fractionation was used to isolate four ginsenosides, namely ginsenoside Rg6, F4, Rk3, and Rh4. Ginsenoside Rk3 and Rh4 had a 3 fold higher inhibition activity than rosmarinic acid which was used as a positive control while ginsenoside Rg6 and F4 showed only mild effects similar to that of the positive control. The results suggest that the activity of the corresponding ginsenosides may be increased by the glycosyl moiety at the C6 position rather than the double bond conformation at C20, and ginsenoside Rk3 and Rh4 could have a role in treating inflammatory diseases.
2011 The Pharmaceutical Society of Japan