Objective: Saponin compounds, including Glycyrrhizin, can enhance immune responses. The current investigation was conducted to study the effects of alum and Glycyrrhizin Liposomes (GL) as adjuvants on the humoral and cellular responses of the immune system in mice immunized with ovalbumin (OVA).
Materials and Methods: Male Balb/c mice were immunized with OVA adjuvant with alum, GL, or alum-GL combination twice at two-week intervals. Two weeks after the last immunization, the specific immune responses against OVA were assessed.
Results: The adjuvant formulated with alum and GL induced a Th1 cytokine pattern against OVA, while alum alone induced a Th2 cytokine pattern. The combined adjuvant increased the potential of OVA to induce a delayed- type hypersensitivity reaction and IgG2a antibody titer compared to other groups (p<0.05). OVA-specific lymphocyte proliferation did not show significant differences among the three groups receiving adjuvant (p=0.11).
Conclusion: Unlike alum, the combination of alum and GL synergistically increased the cellular and humoral immune responses after immunization with an antigen and therefore had the ability to be used as an adjuvant to induce cellular immune responses.