Figure 1

Carnosol and curcumin are non-toxic and induce HO-1 expression in human DC. (A) Primary human DC were incubated with a vehicle control, carnosol or curcumin (2.5–10 µM). After 24 hours, cells were stained for Annexin V and PI uptake and analysed by flow cytometry. Viable cells were designated as Annexin V⁻ PI⁻ (non-apoptotic cells). Results shown are from one healthy donor and are representative of data from four donors. (B) DC from healthy donors (n = 6) were incubated with increasing doses of carnosol (2.5–10 µM) or curcumin (2.5–10 µM) for 6 hours prior to stimulation with LPS (100 ng/ml). Cells were stained with a fixable viability dye after 24 hours and analysed by flow cytometry. Pooled data (n = 6) depicting the mean (±SEM) percentage viable cells of DC (gated by scatter, see Supplemental Fig. 10) (C) Immature DC were treated with vehicle control, LPS (100 ng/ml), carnosol or curcumin (2.5–10 µM) for 24 hours or (D) treated with carnosol or curcumin for 6 hours prior to stimulation with LPS for 24 hours. HO-1 expression was detected by western blot. The blots shown are derived from the same gel; membranes were first probed for HO-1 and then re-probed for β-actin. Full length blots are presented in Supplemental Fig. 2.