Hematein inhibits atherosclerosis by inhibition of reactive oxygen generation and NF-κB-dependent inflammatory mediators in hyperlipidemic mice

Abstract

Hematein, a natural compound, is a known antiinflammatory and antiatherogenic agent in the rabbit model. The authors investigated the effects of this compound on atherogenesis and possible mechanisms of the actions in the hyperlipidemic mice. Low-density lipoprotein receptor-deficient (Ldlr-/-) mice fed a high-cholesterol diet alone for 8 weeks developed the fatty streak lesion in the aortic sinus, whereas this lesion was significantly reduced by hematein treatment without a change in plasma lipid levels compared with control mice. Hematein treatment reduced plasma levels of lipid peroxide and superoxide generation in LPS-stimulated peritoneal macrophage. Hematein treatment inhibited NF-κB-DNA binding activity in peritoneal macrophages from Ldlr-/- mice and the activation of NF-κB in RAW264.7 macrophages. This compound suppressed plasma nitrite/nitrate levels in Ldlr-/- mice and NO production and iNOS expression in LPS+IFNγ-stimulated peritoneal macrophages. Hematein treatment also suppressed the activity of iNOS promoters in RAW264.7 macrophages, and reduced the plasma levels of TNF-α and IL-1β and the production of these cytokines in LPS+IFNγ-stimulated peritoneal macrophages. These results suggest that hematein inhibits atherosclerotic lesion formation, possibly by reducing proinflammatory mediators through a decrease in reactive oxygen species generation and NF-κB activation.