Figure 4

Carnosol and curcumin inhibit cytokine production in LPS-treated DC. DC from healthy donors (n = 4) were incubated with increasing doses of (A) carnosol (2.5–10 µM) or (B) curcumin (2.5–10 µM) for 6 hours prior to stimulation with LPS. Supernatants were collected after 24 hours and IL-12p70, IL-23p19, TNFα, and IL-10 production was measured by ELISA. Results shown are mean (±SEM) of the pooled cytokine concentrations (means of three technical replicates per donor). Statistical significance was determined by one-way ANOVA, with Dunnett’s multiple comparisons post hoc test to compare means of treatment groups to the control group. (****p < 0.0001, ***p < 0.001, ** p < 0.01, *p < 0.05). (C) DC were treated with either carnosol (10 µM), curcumin (10 µM) or a vehicle control for 6 hours prior to stimulation with LPS. Cell lysates were harvested at 3 hours and 6 hours post LPS stimulation and expression of pro-IL-1β was detected by western blotting. Representative blot of three independent experiments is shown. The blots shown are derived from the same gel; membranes were first probed for pro-IL-1β and then re-probed for β-actin. Full length blots are presented in Supplemental Fig. 3. (D) Densitometric analysis of 3 immunoblots was performed using ImageLab (Bio-Rad) software.