Figure 3

Carnosol and curcumin maintenance of antigen uptake in LPS-treated DC is dependent on HO-1 but not biliverdin. DC from healthy donors (n = 8–10) were incubated with carnosol (10 µM) or curcumin (10 µM) with or without SnPP (10 µM) for 6 hours prior to stimulation with LPS for 24 hours. DC were then incubated with DQ-Ovalbumin (DQ-Ova; 500 ng/ml) for 20 minutes prior to analysis by flow cytometry. (A) Representative dot plots depicting DQ-Ova uptake by DC treated with carnosol, curcumin and SnPP are from one donor. (B) Pooled data depicting percentage DQ-Ova uptake of DC treated with carnosol and curcumin alone and (C) in the presence of SnPP. (D) DC from healthy donors (n = 5) were incubated with biliverdin (BV; 100 µM) for 6 hours prior to stimulation with LPS for 24 hours. DC were then incubated with DQ-Ova and analysed for antigen uptake as before. (E) Pooled data depicting mean (±SEM) percentage DQ-Ova uptake of DC treated with BV. (F) Pooled data depicting mean (±SEM) concentration of IL-12 in supernatants of BV treated DC as measured by ELISA (mean of three technical replicates per donor). Statistical significance was determined by one-way ANOVA, with either Tukey’s multiple comparisons post hoc test to compare means of all groups, or Sidak’s multiple comparisons post hoc test to compare means of pre-selected group pairs. (****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05).