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

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 E2 (PGE2) 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-1beta (IL-1beta) 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-1beta significantly increase production of PGE2 and cinnamaldehyde evidently decrease IL-1beta-induced PGE2 production, while RR showed no inhibitory effect on PGE2 production. Moreover, it was identified that TRPV4 was expressed at the mRNA and protein levels in b.End3 cells. IL-1beta could up-regulate the expression of TRPV4, RR and cinnamaldehyde could down-regulate the high expression of mRNA and protein of TRPV4 by IL-1beta induced in b.End3 cells. In conclusion, cinnamaldehyde decreased the production of PGE2 and the expression of TRPV4 in b.End3 cells induced by IL-1beta.