Atherosclerosis-related inflammation and oxidative stress are improved by rice bran enzymatic extract

Abstract

Rice bran has long been considered as a nutritional supplement in the prevention of cardiovascular diseases. ApoE−/− mice were fed high fat diet supplemented with 1 or 5% rice bran enzymatic extract (RBEE). In parallel, 100 ng/ml LPS induced human monocytes were treated with 20 µg/ml RBEE, ferulic acid (FA) or γ-oryzanol (γ-Ory). RBEE diet supplements reduced NF-κβ activation, TNF-α, COX-2 and iNOS expression and serum NO-derived metabolites. Additionally, NADPH oxidase subunits were downregulated, resulting in lower superoxide production, as evidenced by lower dihydroethidium fluorescence and oxLDL deposition in the aorta. RBEE, FA and γ-Ory reduced pro-inflammatory monocyte (CD14++ CD16+) phenotype and increased non-classical monocytes (CD14− CD16++). A shift towards M2 polarised macrophages was observed, leading to reduced IL-6 and TNF-α mRNA expressions. RBEE chronic consumption ameliorates atherosclerosis-related oxidative stress and inflammation showing its potential as nutritional supplement. FA moiety of γ-Ory was identified as the main responsible for the actions observed.

Keywords

• Inflammation
• Oxidative stress
• Rice bran enzymatic extract
• Macrophage subsets
• ApoE−/−