We next measured mRNA levels of the pro-inflammatory molecules in the brains after LPS injection. LPS elevated TNFα, IL-1β, IL-6, iNOS, and COX-2 at 6 hours (Figs. 3B–F). The levels of TNFα, IL-1β, IL-6, and iNOS were returned toward the basal at 3 days after LPS (Figs. 3B–E); however, they remained significantly higher compared to saline injection. Wy-14643 and fenofibrate inhibited the LPS-induced elevations of TNFα, IL-1β, IL-6, and COX-2. Wy-14643, but not fenofibrate, also attenuated iNOS at 6 hours (Fig. 3E). At 3 days after LPS, Wy-14643 and fenofibrate showed similar inhibitory patterns in TNFα, IL-1β, and IL-6 (Figs. 3B–D). iNOS was attenuated by fenofibrate but not by Wy-14643 (Fig. 3E). Both drugs rather elevated COX-2 (Fig. 3F).
