Effect of PY extracts on lipopolysaccharide (LPS)-induced PGE
production in RAW 264.7 cells. The cells were incubated 24 h and then pretreated with 100 μg/ml different PY extracts in 1 h. NO production was measured by PGE2 assay kit as described in the methods in the presence or absence of LPS (10 μg/ml) for 18 h. Control (Con.) cells were incubated vehicle alone. Data represent the mean ± SE of at least three independent experiments (*p < 0.05, **p < 0.01, ***p < 0.001).