Effect of OR on the expression of (A – C) cytokines and (D) mRNAs. Cells were pretreated with OR for 30 min before being incubated with LPS for (A–C) 24 h and (D) 6 h. Cytokine production was measured by ELISA and mRNA level was analyzed by RT-PCR. RNA value was quantitated using an i-MAXTM Gel Image Analysis System (Core Bio, Seoul, Korea). Data represent the mean ± SE values of duplicate determinations from three independent experiments. *p < 0.01 and **p < 0.001 were calculated by comparison with the LPS-stimulation value.