Figure 2: Effect of rice hull extract on Prostaglandin E2 (PGE2) production by lipopolysaccharide (LPS)-induced macrophage cells (a) PGE2 level was determined using a competitive enzyme immunoassay kit after treatment with LPS (1 μg/ml) for 24 h in the presence or absence of rice hull extract (50, 100, or 200 μg/ml). (b) Effect of rice hull extract on cyclooxygenase-2 (COX-2) expression by RAW 264.7 cells. COX-2 protein was detected by Western blot 6 h after treatment with LPS (1 μg/ml) in the presence or absence of rice hull extract (100 or 200 μg/ml). Equal protein loading was confirmed by blotting with anti-β-actin. All data are presented as the mean ± SEM of three independent experiments. *P value less than 0.05, statistically significant differences compared to treatment with LPS alone.