Polyphenolic fraction of virgin coconut oil inhibits the inflammatory response in oxidized LDL activated human peripheral blood mononuclear cells by modulating TLR/NF-κB signaling pathways

IntroductionOxidized low-density lipoprotein (ox-LDL) is one of the many causes of the initiation and progression of atherosclerosis, which leads to inflammation in the blood vessels.The objective of the present study was to investigate the effect of the polyphenolic fraction of virgin coconut oil (PFV) to modulate TLR/NF-κB signaling pathway in human peripheral blood mononuclear cells (hPBMCs) exposed to ox-LDL induced inflammation.MethodshPBMCs were divided into three groups, namely; Control (Group I), ox-LDL treated (50 μg/mL) (Group II) and ox-LDL+ PFV (4 μg/mL) treated (Group III).The cell cytotoxicity studies was carried out by MTT assay. RT-PCR was performed for the measurement of mRNA expressions and western blotting analysis was carried out for expressions of NF-κB, TNF-α, IL-6 and VCAM-1ResultsThe ox-LDL treated group I showed an upregulated expression of TLR4, NF-κB, pro-inflammatory cytokines and VCAM-1. When treated with PFV, TLR4 expression was inhibited at the mRNA level and inhibited the translocation of NF-κB p65 by modulating the TLR-NF-κB signaling pathway. This was evident from the down regulation in cytokine production and inflammatory mediators like LOX, NO and PGE2.ConclusionThe study demonstrated the significant anti-inflammatory effect of PFV on ox-LDL induced inflammatory condition as supported by various biochemical assays and gene/protein expression studies, indicating the potential use of virgin coconut oil polyphenols as natural anti-inflammatory agent to modulate TLR/NF-κB signaling pathway.