Attenuation of atherosclerotic complications by modulating inflammatory responses in hypercholesterolemic rats with dietary Njavara rice bran oil.

Atherosclerosis is a chronic inflammatory disease. The role of inflammation in atherosclerosis is well established, with all stages of disease progression being assessed as inflammatory response to injury. Preventive treatments and drugs identified so far are based on lipid lowering strategies which also involves functional foods and dietary supplementation. The present study investigated the effect of supplementation of Njavara rice bran oil (NjRBO), extracted from a medicinal rice variety, to high cholesterol diet (HCD) fed rats on atherosclerosis by attenuating the inflammatory responses in PBMCs, aortic endothelial cells and macrophages. Adult male rats (Sprague-Dawley strain, weighing 100-120g) were grouped into 3 of six rats each. Group I served as control, Group II were fed high cholesterol diet (HCD) and Group III were fed a HCD and NjRBO (100mg/kg body weight). The experimental duration was 60days. Activities of cyclooxygenase, lipoxygenase, nitric oxide synthase, and myeloperoxidase, expression of Tumor necrosis factor-α, Interleukin-6, Interferon γ, monocyte chemoattractant protein-1, and cytosolic phospholipase A were found to be decreased on NjRBO supplementation which were increased in HCD fed rats. Expression of ICAM-1 and VCAM-1 in aortic endothelial cells was decreased significantly in NjRBO treatment than HCD fed rats. This attenuations were mainly due to inhibition in translocation of NF-κB into nucleus in aortic endothelial cells. Also, NjRBO treatment significantly decreased the gene expressions of TLR-2, TLR-4, and CD36 in both macrophages and endothelial cells than HCD fed rats indicates its anti-inflammatory effect via TLR - NF-κB signaling pathway. NjRBO has thereby shown to possess anti-atherogenic property by effectively modulating inflammatory mechanisms.