Epidemiologic evidence has demonstrated significant associations between atherosclerosis and Porphyromonas gingivalis (Pg). We had investigated the effect of andrographolide (AND) on atherosclerosis induced by Pg in rabbits. For experimental purpose, we separated thirty male white New Zealand rabbits into 5 groups. Group 1 received standard food pellets; Groups 2-5 were orally challenged with Pg; Group 3 received atorvastatin (AV, 5 mg/kg), and Groups 4-5 received 10 and 20 mg/kg of AND, respectively, over 12 weeks. Groups treated with AND showed significant decrease in TC, TG, and LDL levels (P<0.05) and significant increase in HDL level in the serum of rabbits. Furthermore, the treated groups (G3-G5) exhibited reductions in interleukins (IL-1β and IL-6) and C-reactive protein (CRP) as compared to atherogenicgroup (G2). The histological results showed that the thickening of atherosclerotic plaques were less significant in treated groups (G3-G5) compared with atherogenicgroup (G2). Also, alpha-smooth muscle actin (α-SMA) staining decreased within the plaques of atherogenicgroup (G2), while it was increased in treated groups (G3-G5). Lastly, groups treated with AV and AND (G3-G5) showed significant reduction of CD36 expression (P<0.05) compared to atherogenicgroup (G2). These results substantially proved that AND contain antiatherogenic activity.
Hypercholesterolemia causes endothelial dysfunction, an early feature of atherosclerosis, leading to increased production of adhesion molecules and cytokines. The aim of this study was to investigate the effects of three months of treatment with low dose atorvastatin on serum levels of adhesion molecules, interleukin-6 (IL-6) and highly sensitive C-reactive protein (hs-CRP) in patients with non-familial hypercholesterolemia. Fifty-five patients with non-familial hypercholesterolemia were randomized to treatment with atorvastatin 10 mg/day or placebo for 3 months. Soluble intercellular adhesion molecules-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, IL-6 and hs-CRP levels were measured to assess the inflammatory activity of the endothelium. There was a significant reduction in ICAM-1 at 2 weeks (p<0.0001) with further reduction at 3 months (p<0.0001). At 3 months, there were significant reductions in VCAM-1 (p<0.02), IL-6 (p<0.0001) and hs-CRP (p<0.01), but an increase in E-selectin levels (p<0.002). Treatment with statin was an independent determinant of change in ICAM-1 (p<0.05) and IL-6 levels (p<0.05) after correcting for anthropometric indices, blood pressure and lipid profile. Low-dose atorvastatin treatment leads to reduction in proinflammatory markers of endothelial function, suggesting an attenuation of endothelial activation and improvement in endothelial function, independent of lipid lowering. This may lead to a reduction in the progression of atherosclerosis.
Adhesion molecules and cytokines are involved in the pathogenesis of intimal injury in atherosclerosis but their relationship with endothelial function remains unclear. The objectives of this study were to examine the effects of atorvastatin on soluble adhesion molecules, interleukin-6 (IL-6) and brachial artery endothelial-dependent flow mediated dilatation (FMD) in patients with familial (FH) and non-familial hypercholesterolaemia (NFH). A total of 74 patients (27 FH and 47 NFH) were recruited. Fasting lipid profiles, soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular-cellular adhesion molecule-1 (sVCAM-1), E-selectin, IL-6 and FMD were measured at baseline, 2 weeks, 3 and 9 months post-atorvastatin treatment (FH--80 mg/day, NFH--10 mg/day). In both groups, compared to baseline, sICAM-1 levels were significantly reduced at 2 weeks, further reduced at 3 months and maintained at 9 months (P<0.0001). The IL-6 levels were significantly reduced at 3 months and 9 months compared to baseline for FH (P<0.005) and NFH (P<0.0001). In both groups, the FMD at 2 weeks was higher than baseline (P<0.005), with progressive improvement up to 9 months. FMD was negatively correlated with sICAM-1 and IL-6. In conclusion, both low and high doses of atorvastatin lead to early progressive improvement in endothelial function in patients with primary hypercholesterolaemia. sICAM-1 and IL-6 levels reflect endothelial dysfunction in these patients.