Evaluation of the immunomodulatory properties in mice and in vitro anti-inflammatory activity of cycloartane type saponins from Astragalus species

Astragalus roots are used to treat leukemia and for their wound healing properties in Southeast Anatolia-Turkey. In vivo studies to investigate the effects of two Astragalus saponins were carried out on the immune response cytokines by using six to eight weeks old male Swiss albino mice. The production of IL-1β, TGF-1β, TNF-α, IL-2, IL-4 and IFN-γ cytokines was determined by ELISA. The spleen and lymph nodes, isolated from the mice subjects, were analyzed to realize induction of the surface antigen productions for IL-2Rα (CD25) and CD69. In addition, their effects on the targets of inflammation such as NF κB, iNOS and NAG-1 were investigated in cell-based assays. The results suggested that AST VII and Mac B had positive effect on Th1 cytokine release (IL-2 and IFN-γ), and suppression on Th2 cytokine production (IL-4). The immunohistochemical results exhibited induction of both IL-Rα (CD25) and CD69 surface receptors justifying the Th1 cytokine release. The compounds did not affect NF-κB or NAG-1 activity but iNOS activity was inhibited by Mac B with an IC50 of 156μg/ml. The results show that Ast VII and Mac B create powerful immunoregulatory effects without the stimulation of inflammatory cytokines in mice, and have no significant effect on the inflammatory cellular targets in vitro.