AbstractAtherosclerosis is associated with a haemostatic imbalance characterized by excessive activation of pro‐inflammatory and pro‐coagulant pathways. Non‐vitamin K antagonists oral anticoagulant (NOACs) may reduce the incidence of cardiovascular events, cerebral ischemia, thromboembolic events and atherosclerosis. Chronic inflammation, vascular proliferation and the development of atherosclerosis is also influenced by 25‐hydroxycholesterol (25‐OHC). The aim of the study was to assess the effect of rivaroxaban and dabigatran on the messenger RNA (mRNA) expression of anti‐inflammatory cytokines transforming growth factor β (TGF‐β), interleukin (IL)‐37, IL‐35 as well as of pro‐inflammatory cytokines IL‐18 and IL‐23, in endothelial cells damaged by 25‐OHC. Human umbilical vascular endothelial cells (HUVECs) were treated with 25‐OHC (10 μg/mL), rivaroxaban (100, 500 ng/mL), dabigatran (100, 500 ng/mL), 25‐OHC + rivaroxaban, and 25‐OHC + dabigatran. The mRNA expression of TGF‐β, IL‐37, IL‐35 subunits EBI3 and p35, IL‐18, and IL‐23 was analysed using real‐time polymerase chain reaction (PCR). The results showed that 25‐OHC decreased TGF‐β and IL‐37 mRNA expression and increased EBI3, p35, IL‐18, IL‐23 mRNA expression in endothelial cell as compared to an untreated control (P < .05). Messenger RNA expression of TGF‐β and IL‐37 significantly increased following stimulation with rivaroxaban and dabigatran as compared to an untreated control (P < .01). In HUVECs pre‐treated with oxysterol, rivaroxaban and dabigatran increased mRNA expression of TGF‐β, IL‐37 and decreased mRNA expression of EBI3, p35, IL‐23 and IL‐18 as compared to 25‐OHC (P < .01). Our finding suggests that both rivaroxaban and dabigatran inhibit the inflammatory activation caused by oxysterol in vitro.