Platycodin D2 Improves Specific Cellular and Humoral Responses to Hepatitis B Surface Antigen in Mice

Abstract

Platycodin D2 (1), a less hemolytic saponin from the root of Platycodon grandiflorum than platycodin D (2), was evaluated for the potential to enhance specific cellular and humoral immune responses to hepatitis B surface antigen (HBsAg) in mice. It significantly increased the concanavalin A (Con A)-, lipopolysaccharide (LPS)-, and HBsAg-induced splenocyte proliferation in HBsAg-immunized mice (PPPPPγ) and Th2 (IL-4 and IL-10) cytokines from splenocytes in the HBsAg-immunized mice (P<0.001). The adjuvant potential of 1 on splenocyte proliferation, serum HBsAg-specific IgG2a and IgG2b antibody response, as well as Th1-cytokine secretion from splenocytes in the HBsAg-immunized mice was higher than that of Alum. The results suggest that 1 could improve both cellular and humoral immune responses to HBsAg in mice. Hence, 1 might be a promising adjuvant for hepatitis B vaccine with dual Th1- and Th2-potentiating activity.