Immunological adjuvant effect of Japanese ginseng saponins (JGS) on specific antibody and cellular response to ovalbumin and its haemolytic activities.

In this study, the saponins (JGS) extracted from the rhizoma of Japanese ginseng were evaluated for their haemolytic activities and their potential ability as adjuvants on the immune responses to ovalbumin (OVA) in mice. The haemolytic activity of JGS was determined using 0.5% rabbit red blood cell, with its HD(50) value being 177.78+/-6.77microg/mL. ICR mice were immunized subcutaneously with OVA 100microg alone or with OVA 100microg dissolved in saline containing Alum (200microg), QuilA (10 and 20microg) or JGS (50, 100 or 200microg) on Days 1 and 15. Two weeks later (Day 28), concanavalin A (ConA)-, lipopolysaccharide (LPS)-, OVA-stimulated splenocyte proliferation and OVA-specific antibodies in serum were measured. JGS significantly enhanced the ConA-, LPS-, and OVA-induced splenocyte proliferation in the OVA-immunized mice especially at a dose of 100microg (P<0.05 or P<0.01). The OVA-specific IgG, IgG1 and IgG2b antibody levels in serum were also significantly enhanced by JGS compared with OVA control group (P<0.01). The results suggest that JGS showed a slight haemolytic effect and enhanced significantly a specific antibody and cellular response against OVA in mice.