Effects of Artemisia Absinthium L. Extract on the Maturation and Function of Dendritic Cells

Background: Artemisia absinthium L. (known as wormwood) is used as an antihelminthical, antimalarial, antiseptic, anti-inflammatory agent, and also in the treatment of gastric pain, in traditional medicine. Objectives: In the present study, we have evaluated the effects of the ethanolic extract of A. absinthium L. on the maturation and function of dendritic cells (DCs). Materials and Methods: The immunomodulatory effects of A. absinthium L. extract on DCs phenotypic maturation were determined by flow cytometry. The ability of the treated DCs to stimulate allogenic T cells proliferation and cytokines secretion was examined by mixed lymphocyte reaction (MLR) and enzyme-linked immuosorbent assay (ELISA), respectively. Results: A. absinthium L. extract showed that it could promote DCs phenotypic maturation by increasing the level of surface expression of CD40 as an important costimulatory marker on the DCs, compared to the control. Extract with concentration below 100 μg/mL significantly increased the production of interleukin (IL)-12 cytokine by DCs. The same 100 μg/mL concentration A. absinthium L. inhibited the proliferation of allogenic T cells and also significantly increased the level of IL-10 (P < 0.001). Moreover, the extract with concentrations below 100 μg/mL significantly increased production of interferon-γ (IFN-γ). Nevertheless, these changes were not significant for IL-4 production. Conclusions: Artemisia absinthium L. extract, at concentrations below 100 μg/mL, can modulate the immune response toward a Th1 pattern, by induction of CD40 expression on DCs and cytokine production. Also, it can inhibit DCs T cell stimulating activity, at high concentrations. Therefore, the traditional use of this plant possibly modulates immune-mediated disorders. However, future studies are needed to confirm these results.