[Effect of apigenin on dendritic cells maturation and function in murine splenocytes]

This study was designed to explore the effect of apigenin (Api) on dendritic cell (DCs) maturation and function in murine spleen cells. The single spleen cell was isolated, and then cultured with lipopolysaccharide (LPS) in the present and absence of apigenin. After 24 h, the toxicity of Api and the T cell proliferation were determined by CCK8 kit. In addition, we collected the cell-free supernatants to measure cytokine production using ELISA, collected the cells to determine the DC maturation using flow cytometry. Finally, we purified Api and/or LPS-treated CD11c+ DCs which were pulsed with ovalbumin (OVA)323−339 and then were adoptive transferred into C57BL/6 mice to detect the OVA323−339-specific T cell proliferation and T helper (Th1) and Th2 cell secreting IFN-γ and IL-4 production, respectively. We found that Api did not affect splenocyte viability, but inhibited the production of pro-inflammatory cytokine IL-1β, IL-6 and TNF-α, not anti-inflammatory cytokine IL-10. In addition, Api inhibited the expression of co-stimulatory CD80, CD86 and MHCII of CD11c + DCs. Finally, compared to LPS+OVA DCs group, DCs from Api and LPS co-treated splenocytes (Api+LPS+DCs) impaired OVA323−339-specific T cell proliferation and the production of IFN-γ and IL-4 in CD4+ T cells, which had the similar responses with OVA+DCs. These data suggest that Api exhibits anti-inflammatory properties via inhibiting DC activation and function, as a new immune-modulator, which may induce immune-tolerance with a benefit to those with chronic inflammation.