A: Representative photomicrographs showing RT-PCR products of COX-1, COX-2, mPGES-1, and β-actin mRNAs. Microglial cells were treated with LPS (10 ng/ml) in the absence or presence of different concentrations of resveratrol. The mRNA expression levels were tested for each condition. There is a constitutive COX-1 mRNA expression that is observed under all conditions. However, COX-2 and mPGES-1 are undetectable in untreated microglial cells, while their expression is dramatically increased in the presence of LPS. Resveratrol treatment significantly reduced mPGES-1, but not COX-2 expression. RT-PCR analysis was performed after 4 h of incubation with LPS. Resveratrol was added to the cultures 30 min before LPS. B: Semi-quantitative analysis of the effect of resveratrol on mPGES-1 expression. This analysis was done with results from 4 different RT-PCR experiments performed independently. Relative expression of rat β-actin was used for normalization. The amplicon size of the PCR product appears below the name of each transcript. *p < 0.05 and **p < 0.01 with respect to untreated LPS control.