Increased serum bile acid level is associated with high-risk coronary artery plaques in an asymptomatic population detected by coronary computed tomography angiography.

BACKGROUND: There are limited data on the association between serum total bile acid level and coronary plaque characteristics. This study investigated the relationship between serum total bile acid level and the severity of coronary stenosis and coronary plaque features in an asymptomatic population using coronary computed tomography angiography (CTA). METHODS: A total of 1,137 consecutive participants with no known coronary artery disease (CAD) undergoing CTA as part of a general routine health evaluation were recruited. Serum total bile acid level and clinical parameters were assayed. Coronary stenosis and high-risk plaques features (napkin-ring sign, low-attenuation plaque, spotty calcification, positive remodelling) were evaluated. Associations between serum total bile acid concentration and high-risk coronary plaques was tested through univariate and multivariate analyses. RESULTS: A total of 101 high-risk coronary plaques subjects and 93 controls were eligible for study inclusion. The severity of coronary artery stenosis and high-risk coronary plaques increased with serum total bile acid level quartiles (all P<0.001). The independent predictor of high-risk coronary plaques in multivariate analysis was serum total bile acid level (P<0.001). Receiver operating characteristic (ROC) confirmed that serum total bile acid concentration significantly differentiated high-risk coronary plaques [the area under the curve (AUC) =0.876; P<0.001, with a sensitivity of 87.13% and a specificity of 86.02%]. CONCLUSIONS: Higher serum total bile acid level was associated with the severity of coronary artery stenosis and high-risk coronary artery plaques detected by CTA in asymptomatic populations.

Luteolin alleviates NLRP3 inflammasome activation and directs macrophage polarization in lipopolysaccharide-stimulated RAW264.7 cells.

Pure plant extract luteolin has been demonstrated to possess numerous biological effects. However, the specific effect of luteolin on macrophage polarization and NOD-like receptor protein 3 (NLRP3) inflammasome activation has not been documented. In this study, Cultured RAW264.7 cells were treated with or without luteolin in the presence or absence of LPS. Subsequently, cell viability was tested by CCK-8 assay. Total reactive oxygen species (ROS) were measured by flow cytometry. NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), caspase-1, inducible nitric oxide synthase (iNOS) and Arginase (Arg-1) protein expression was detected using western blotting. Enzyme-linked immunosorbent assay (ELISA) kits were used to detect the level of TNF-α, IL-18, and Interleukin-1ß (IL-1ß). Increased production of ROS and expression of NLRP3, ASC, caspase-1, IL-18 and IL-1ß proteins were observed in RAW264.7 cells incubated with LPS and were effectively inhibited by 2 µM luteolin. Furthermore, 2 µM luteolin pretreatment enhanced the expression of M2 macrophage markers (Arg-1 and IL-10), and decreased the expression of markers associated with M1 macrophage polarization (TNF-α, IL-6 and iNOS). These results indicated that low-dose luteolin inhibits NLRP3 inflammasomes activation and promotes macrophage polarization toward an M2 phenotype, which provides new evidence for the anti-inflammation activity of luteolin.