Immunomodulatory studies of a bioactive fraction from the fruit of Prunus cerasus in BALB/c mice

In order to evaluate the role of ethyl acetate fraction (PNRS-EtOAC) obtained from the Prunus cerasus fruit in the modulation of immune responses, detailed studies were carried out using a panel of in vivo assays. Oral administration of PNRS-EtOAC (25–100mg/kg) stimulated the IgM and IgG titre expressed in the form of hemagglutination antibody (HA) titre. Further, it elicited a dose related increase in the delayed type hypersensitivity reaction (DTH) after 24 and 48h in BALB/c mice. Besides augmenting the humoral and cell mediated immune response, the concentration of cytokines (IFN-γ, IL-4, and TNF-α) in serum with respect to T cell interactions, i.e. the proliferation of lymphocytes were significantly increased at 50mg/kg compared with the control. The results in these studies demonstrated the immunostimulatory effect of PNRS-EtOAC in a dose-dependent manner with respect to the macrophage activation possibly expressing the phagocytosis and nitrite production by the enhancement of TNF-α production as a mode of action. ► Immunostimulatory potential of PNRS-EtOAC fraction (Prunus cerasus) investigated. ► Augmentation of HA titre and DTH response to sheep red blood cells (SRBC) revealed. ► A significant enhancement of Th1 (IFN-γ and TNF-α) and Th2 (IL-4) immune response. ► Significant enhancement in CD4, CD8, CD80 and CD86 cell populations revealed. ► Important role of PNRS-EtOAC in the modulation of the immune response highlighted.