AICAR inhibits LPS- and Aβ peptide-induced cytokine production. Astrocyte-enriched glial cells (mixed glial cells) were pre-incubated with different concentrations of AICAR (as indicated) for 4 h and were stimulated with 1 ng/ml LPS ± Aβ peptide (1–42) (15 μM) as shown. After 18 h of incubation, concentrations of NO, TNF-α, IL-1β, and IL-6 released into the culture medium were measured using ELISA (left panel figs. a, c, e and g). Alternatively the cells were harvested for RNA by extraction with Trizol (see methods) and the levels of mRNA for cytokines were measured (See right panel figs. b, d, f and h) by real time-PCR (RT-PCR). Data are expressed as the mean ± SD of three different experiments. *P < 0.001 was considered significant.