Figure 7.

Direct effect of osthole on CD4⁺ T cells. (a) The direct effect of osthole on T-cell proliferation. T cells (2 × 10⁵ cells/well) were treated with different doses (0.5, 1 and 5 μg/ml) of osthole and stimulated with anti-CD3 (1 μg/ml)/anti-CD28 (1 μg/ml) antibodies for 56 h. T cells were stimulated with anti-CD3/anti-CD28 alone as the control. Proliferative ability was determined using a [³H]-thymidine incorporation assay. (b–e) The direct effect of osthole on T-cell cytokine production. T cells (5 × 10⁵ cells/well) were cultured in 48-well plates and stimulated with anti-CD3/anti-CD28 antibodies in the presence of osthole for another 72 h. Culture supernatants were collected and analyzed by ELISA. The results from three independent experiments are shown and expressed as the mean±s.e.m. *P<0.05, **P<0.01, ***P<0.001 vs the control (anti-CD3/anti-CD28 stimulation) group.