Figure 6.

Effect of each component of EJE on LPS-induced NO production and iNOS, COX-2, and HO-1 expression in BV2 cells. EJE was fractionally extracted using the following succession of organic solvents: hexane (HX), chloroform (CF), ethyl acetate (EA), butanol (BT), and residual water (DW) fractions. In this Figure, the unfractionated hot water extract of Erythronium japonicum is expressed as unfractionated extract (UE). (A) The butanol extracted fraction of EJE was most active among organic solvent extracted fractions in reducing LPS-induced NO production in BV2 cells. NO contents were confirmed by the Griess reagent, as indicated in the Materials and Methods section. (B) No fraction of EJE induced any cell toxicity at concentrations ranging from 25 to 100 μg/mL. (C) The butanol fraction of EJE decreased LPS-induced iNOS and COX-2 and distinctly induced HO-1 expression in BV2 cells. Expression levels were confirmed by each antibody, as described in Materials and Methods. Hash symbols (#) indicate a significant difference (p < 0.001) between the control group and the group exposed to LPS alone; asterisks (***) indicate significant differences (p < 0.001, respectively) between the groups co-treated with LPS and samples and the group exposed to LPS alone. In cell viability test, dollar signs ($, $$ and $$$) indicate significant differences (p <0.05, p < 0.01 and p < 0.001, respectively) between the control groups and the groups treated samples. In this and all the following Figures, data are presented as the mean ± SEM of three independent experiments.