Fever, an elevation in body temperature, is thought to be terminally mediated by prostaglandin E(2) (PGE(2)). Both Guizhi Tang (GZT) and its active fraction A (Fr.A) showed an antipyretic effect in rats. 3-Phenyl-2-propene-1-ol was one of the active compounds isolated from Fr.A. In the present study, we examined the influence of interleukin-1beta (IL-1beta) on prostaglandin E(2) (PGE(2)) release, and the effect of 3-phenyl-2-propene-1-ol on IL-1beta-induced PGE(2) release from rat cerebral endothelial cells (rCMEC). Cultured rCMEC were used in the study. In vitro, cells express typical phenotypic markers of brain endothelium. Using a monoclonal antibody against von Willebrand factor, immunocytochemical analysis revealed positive immunoreactivity in the cytoplasm of cultured cells. rCMEC were incubated in M199 medium containing IL-1beta in the presence or absence of 3-phenyl-2-propene-1-ol. After incubation, the conditioned media were collected and the amount of PGE(2) was measured by enzyme-linked immunosorbent assay (ELISA). IL-1beta increased the production of PGE(2) in a dose- and time-dependent manner. 3-Phenyl-2-propene-1-ol significantly decreased IL-1beta-induced PGE(2) release in a dose-dependent manner. Our results indicate that 3-phenyl-2-propene-1-ol inhibits the PGE(2) release from rCMEC stimulated by IL-1beta, and may have an antipyretic effect.