Inhibitory Effect of Orientin on Secretory Group IIA Phospholipase A^sub 2

It is well known that the expression level of secretory group IIA phospholipase A^sub 2^ (sPLA^sub 2^-IIA) is elevated in inflammatory diseases and lipopolysaccharide (LPS) upregulates the expression of sPLA^sub 2^-IIA in human umbilical vein endothelial cells (HUVECs). Orientin, a C-glycosyl flavonoid, is known to have anxiolytic, anti-oxidative, and anti-inflammatory activity. Here, orientin was examined for its effects on the expression and activity of sPLA^sub 2^-IIA in HUVECs and mouse. Prior treatment of cells or mouse with orientin inhibited LPS-induced expression and activity of sPLA^sub 2^-IIA. And orientin suppressed the activation of cytosolic phospholipase A^sub 2^ (cPLA^sub 2^) and extracellular signal-regulated kinase (ERK) 1/2 by LPS. Therefore, these results suggest that orientin may inhibit LPS-mediated expression of sPLA^sub 2^-IIA by suppression of cPLA^sub 2^ and ERK 1/2.