A: Resveratrol dose-dependently inhibits LPS-induced PGE2 production in primary rat microglial cells. B: Effects of Trolox C and α-tocopherol on PGE2 production by microglia challenged with LPS. The amounts of PGE2 in the culture medium were determined using an enzyme immunoassay after 24 h incubation with LPS. Substances were added 30 min before stimulating the cells with LPS. Each column and error bar represents the mean ± S.E.M. of 4 independent experiments. Asterisks indicate significant difference between the treatments. *p < 0.05, **p < 0.01 and ***p < 0.001 with respect to LPS control (One-way ANOVA followed by the Student-Newman-Keuls post-hoc test).