Nitration products (nitroalkenes) of linoleic acid (LNO(2)) and oleic acid (OA-NO(2)) can act as endogenous PPARgamma ligands with electrophilic properties to exert anti-inflammatory effects on atherosclerotic plaques in the vasculature. Here, we show that OA-NO(2) and LNO(2) prevent tumor necrosis factor alpha (TNFalpha)-stimulated inflammatory and atherogenic responses in human umbilical vein endothelial cells (HUVECs). Both OA-NO(2) and LNO(2) prevented TNFalpha-stimulated release of the cytokines, IL-6, IL-8, IL-12/p40, IFNgamma, MCP-1, and IP-10, and inhibited NF-kappaB activation. OA-NO(2) and LNO(2) also blocked TNFalpha-induced expression of the adhesion molecules, ICAM-1, VCAM-1, and E-selectin, and suppressed monocyte adhesion to HUVECs. In each case, OA-NO(2) was more potent and efficacious than was LNO(2), possibly due to increased stability in aqueous media. Collectively, these results substantiate a new functional role for nitrated fatty acids, demonstrating that OA-NO(2) and LNO(2) exert an anti-inflammatory function against the inflammatory cascade initiated by the representative pro-inflammatory cytokine, TNFalpha.