Figure 9.
Hops and XH inhibition of iNOS. RAW 264.7 cells were plated at a density of 12 × 104 cells/mL in 96-well plates and incubated at 37 °C for 24 h. Cells were treated with LPS (1 μg/mL) and (A) the standardized spent hop extract or (B) XH and incubated at 37 °C for 24 h. Griess reagent (150 μL of 0.5% sulfanilamide and 0.05% (N-1-naphthyl) ethylenediamine dihydrochloride in 2.5% w/w H3PO4) was added to a 96-well plate containing media collected from cells (50 μL). Nitrite levels were detected after the plate was incubated at RT for 30 min. Absorbance was measured at 530 nm, and concentrations were calculated using a NaNO2 standard curve. Results represent the mean ± SD of three independent experiments and are analyzed by one-way ANOVA with Dunnett’s multiple comparison post-test; *p < 0.001.