Fig. 2. Avicularin significantly attenuated LPS-induced overproduction of NO (A) and PGE₂ (B) in RAW 264.7 macrophage cells. RAW 264.7 cells were pretreated with various concentrations of avicularin for 1 hr before incubation with LPS (200 ng/ml) for 24 hr. (A) The amount of nitrite in the supernatants was measured using Griess reagent. Avicularin exhibited a significant suppression of LPS-induced NO production in a concentration-dependent manner. (B) To measure the amount of PGE₂ secretion, culture media were subjected to PGE₂ ELISA. PGE₂ secretion was significantly suppressed with avicularin in a concentration-dependent manner. (C) Effect of avicularin on the viability of RAW 264.7 cells. No noticeable cell death was observed with avicularin concentrations used in the present study. The data are expressed as mean ± S.D. (n=3), and are representative of three or more independent experiments. *p<0.05 and **p<0.01 indicate statistically significant differences from treatment with LPS alone. ^##p<0.01 indicates statistically significant difference between indicated groups.