Nobiletin inhibits oxidized-LDL mediated expression of Tissue Factor in human endothelial cells through inhibition of NF-κB

IntroductionFlavonoids are nutrients usually included in human diet with several significant biological activities. Nobiletin is a flavonoid that, besides having anti-inflammatory and anti-tumoral activity, seems to exert protective effects on cardiovascular system. Several studies investigated nobiletin as a natural drug to antagonize the atherosclerotic disease. On the contrary, literature about its potential role in modulating the main acute complication of atherosclerosis, thrombosis, is still scanty.Several studies have indicated that Tissue Factor (TF) plays a pivotal role in the pathophysiology of cardiovascular thrombotic events by triggering the formation of intracoronary thrombi. Oxidized-LDL have an important role in promoting athero-thrombotic events. This study investigates whether nobiletin might exert protective cardiovascular effects by preventing the oxidized-LDL mediated expression of TF in human endothelial cells in vitro. Moreover, we have studied whether the nobiletin effects might be modulated by the inhibition of the NF-κB pathway.Methods and resultsIn HUVEC, ox-LDL induced TF-mRNA transcription as demonstrated by real time PCR and expression of functionally active TF as demonstrated by Western-blot, FACS analysis and pro-coagulant activity assay. Nobiletin prevented these ox-LDL-mediated effects by exerting antioxidant effects, finally leading to inhibition of the transcription factor NF-κB.ConclusionsThese data suggest that nobiletin might be a potential antithrombotic agent of dietary origin. This flavonoid, through its antioxidant proprieties, might potentially exert an antithrombotic activity by inhibiting TF expression/activity in a cell population never investigated before in this context and that is normally represented in vessel wall such as endothelial cells.

ox-LDL drive O2− production. O2− activates the transcription factor NF-κB that translocates into the nucleus where it activates the transcription of TF gene. Nobiletin, by exerting antioxidant activity, antagonizes ox-LDL effects on NF-κB finally inhibiting TF expression/activity.159