For the experiments, cells were maintained in culture
medium (control) or pre-incubated with the indicated concentrations
of luteolin, luteolin 7-O-β-glucopyranoside, luteolin
6-C-β-glucopyranoside (isoorientin), luteolin 2″-O-rhamnosyl-
C-(6-deoxy-ribo-hexos-3-ulosyl) (cassiaoccidentalin B) or luteolin
8-C-β-glucopyranoside (orientin). Concentrations of luteolin derivatives
were reported to luteolin content. Then, cells were activated
with 1 g/mL LPS from E. coli (serotype 026:B6) for either
24 h, to analyze cell viability and nitrite production, or 8 h to
study cytokine expression evaluation.