Effects of cinnamaldehyde on PGE2 release and TRPV4 expression in mouse cerebral microvascular endothelial cells induced by interleukin-1β

Cinnamaldehyde is a principle compound isolated from Guizhi-Tang (GZT), which is a famous traditional Chinese medical formula used to treat influenza, common cold and other pyretic conditions. Transient receptor potential vanilloid subtype 4 (TRPV4) is expressed in the anterior hypothalamus and may act as thermosensor. The purpose of the present study was to investigate the effects of cinnamaldehyde on the production of prostaglandin E-2 (PGE(2)) and the expression of TRPV4 in mouse cerebral microvascular endothelial cell strain (b.End3). In the research work, the b.End3 cells were cultured in DMEM medium containing interleukin-1 beta (IL-1 beta) in the presence or absence of ruthenium red (RR), a kind of known TRPV4 inhibitor, or different concentrations of cinnamaldehyde. The results suggested that IL-1 beta significantly increase production of PGE(2) and cinnamaldehyde evidently decrease IL-1 beta-induced PGE(2) production, while RR showed no inhibitory effect on PGE(2) production. Moreover, it was identified that TRPV4 was expressed at the mRNA and protein levels in b.End3 cells. IL-1 beta could up-regulate the expression of TRPV4, RR and cinnamaldehyde could down-regulate the high expression of mRNA and protein of TRPV4 by IL-1 beta induced in b.End3 cells. In conclusion, cinnamaldehyde decreased the production of PGE(2) and the expression of TRPV4 in b.End3 cells induced by IL-1 beta.