Anti-inflammatory effects of Artemisia princeps in antigen-stimulated T cells and regulatory T cells

Objectives The aim was to investigate the anti‐inflammatory effects of Artemisia princeps extract on the activity of anti‐CD3/CD28‐stimulated CD4+CD25‐ T cells and antigen‐expanded regulatory T cells. Methods CD4+CD25‐ T cells were activated with coated anti‐CD3 and anti‐CD28 and cultured in the presence or absence of various concentrations of A. princeps extract. The cultures were pulsed on Day 6 with [3H]thymidine and, after harvesting the cells, [3H] thymidine incorporation was measured. For analysis of interleukin‐2 and interferon‐γ secreted from CD4+CD25‐ T cells, culture supernatants were collected on Days 2 and 6. For the analysis of interleukin‐10 secreted from the CD4+CD25‐ T cells and expanded regulatory T cells, supernatants were collected after 2 and 7 days, respectively. Cytokine levels were determined using an enzyme‐linked immunosorbent assay. Potential medicinal components of the A. princeps extract were determined using gas chromatography–mass spectrometry. Key findings A. princeps (30 μg/ml) effectively suppressed proliferation of CD4+CD25‐ T cells that were stimulated with anti‐CD3/CD28 without causing cytotoxicity in spleen cells incubated under conditions lacking antigen stimulation. A. princeps inhibited production of the pro‐inflammatory cytokines interleukin‐2 and interferon‐γ in anti‐CD3/CD28‐stimulated CD4+CD25‐ T cells. Also, the extract slightly increased production of the anti‐inflammatory cytokine interleukin‐10 in these cells. In regulatory T cells expanded by anti‐CD3/CD28, A. princeps increased production of interleukin‐10 and Foxp3. Conclusions The results suggest that A. princeps may be useful in the treatment of autoimmune diseases and organ transplantation rejection by inhibiting proliferation of inflammatory T cells, suppressing inflammatory processes in antigen‐stimulated CD4+CD25‐ T cells and increasing activity of expanded regulatory T cells.