Figure 2.

Effect of ethyl gallate, 5,4′-dihydroxyflavone, and 7,4′-dihydroxyflavone on prostaglandin E₂ (PGE₂) release from lipopolysaccharide (LPS)-pretreated RAW264.7 cells. Cells were pretreated with 1 μg/mL of LPS for 2 h to induce Cyclooxygenase 2 (COX-2) expression, and then, the culture media were removed and replaced with 300 μL of serum-free medium containing the test compound ethyl gallate for another 2 h. The following concentrations of ethyl gallate were used: 0.01, 0.1, 1, and 10 μM. The levels of PGE₂ were measured using an enzymatic immunoassay (EIA) kit (Cayman Chemical). The PGE₂ level in the control group is 1.5 ng/mL. Each point was the mean ± standard deviation (SD) of triplet determinations.