Figure 1.

Effects of quercetin on Prevotella intermedia lipopolysaccharide (LPS)-induced nitric oxide (NO) production (A) and inducible NO synthase (iNOS) protein expression (B) in RAW264.7 cells. Cells were treated with different doses of quercetin (0, 0.1, 1, 10, 20, and 30 µM) in the absence or presence of P. intermedia LPS (10 µg/mL) for 24 hours. (A) NO production was assayed by measuring the accumulation of nitrite in culture supernatants. The results are mean±standard deviation of three independent experiments. ^*P<0.05 vs. P. intermedia LPS alone. ^**P<0.01 vs. P. intermedia LPS alone. (B) iNOS protein synthesis was measured by immunoblot analysis of cell lysates using an iNOS-specific antibody. A representative immunoblot from two separate experiments with similar results is shown.