Fig. 10.

Effect of representative dietary bioflavonoids on the release of PGE₂ from LPS-pretreated RAW264.7 cells in culture. Cells were pretreated with 1 μg/ml LPS for 2 h to induce COX II expression, and then the culture media were removed and replaced with 300 μL serum-free medium with or with the test compound (myricetin, fisetin, quercetin, or morin) for an additional 2 h. The following concentrations of the test compounds were used: 0.01, 0.1 1, 10, and 100 μM. NS-398 (a COX II specific inhibitor, at 10 μM) and indomethacin (a nonspecific COX inhibitor, at 10 μM) were also tested for comparison. The levels of PGE₂ were measured using an EIA (Cayman, Ann Arbor, MI). Each point was the mean of duplicate determinations.