Fig. 2.

Vitamin E forms differentially inhibited PGE₂ in IL-1β-treated A549 cells and the presence of sesamin partially decreased the inhibitory potency (A and B). Vitamin E forms did not affect IL-1β-induced COX-2 expression (C). A549 cells were preincubated with different concentrations of tocopherols (A) and tocotrienols (B) in the presence or absence of 1 μM sesamin (S1) for 15 h and then stimulated with IL-1β (2 ng/ml) for 24 h. PGE₂ accumulated in cell culture media was measured by ELISA assays. Results are the averages of three independent experiments and expressed as mean ± SEM. *, P < 0.05 and **, P < 0.01 indicate significant differences of PGE₂ in the presence and absence of sesamin. Western blotting (C) showed the effect of vitamin E forms on COX-2 induction with actin as the loading control. Cells were treated with vehicle (lane 1); IL-1β at 2 ng/ml (lane 2); IL-1β and γ-T at 40 μM (lane 3); or δ-T at 40 μM (lane 4), α-TE at 10 μM (lane 5), or γ-TE at 10 μM (lane 6) for 24 h.