Curcumin reduced microglial activation and inflammatory mediator release induced by lipopolysaccharide (LPS) in the transwell co-culture of neurons and microglia. (A) Colocalization of CD11b and TLR4 was evident. Treatment with curcumin after LPS stimulation resulted in a less reactive state of the microglia, as shown. (B) TLR4 immunofluorescence intensity in microglia was also reduced after curcumin treatment. ELISA showed that curcumin-treated cells had a change in the release of IL-1β, IL-6, TNF-α, MCP-1 and RANTES (C, D, E, F, G) at 24 hours after LPS administration. Values (mean ± SD) are representative of three independent experiments. *P < 0.05, **P < 0.01. Bar = 50 μm.