Anthocyanins reduce platelet chemokines associated with atherosclerosis

Platelet chemokines contribute to the pathogenesis of atherosclerosis by recruiting leukocytes to the site of endothelial injury and by inducing the inflammatory response within atherosclerotic plaques

Furthermore, plasma levels of various platelet chemokines, such as CXCL4, CCL5, CXCL5, CXCL1, CCL2 and CXCL8, are increased in hypercholesterolemia.

Reducing platelet chemokines is therefore one feasible approach to reducing the risk of atherosclerosis.

A randomised controlled trial, published by Zhang, et al. in Nutrition & Metabolism (2016), aimed to evaluate the effects of purified anthocyanin supplementation on platelet chemokines in patients with hypercholesterolemia.

Anthocyanins, a category of phenolic flavonoids found in berries and other plant foods, have previously been shown to reduce inflammatory biomarkers, improve serum lipids and inhibit platelet activation.

A total of 146 patients with elevated cholesterol completed this trial. Participants were randomised to take purified anthocyanins (320mg/d, provided by Polyphenols AS, Norway) or a placebo for 24 weeks.

Fasting blood samples were analysed at baseline, 12 weeks and 24 weeks.

There were no significant differences in baseline levels of plasma platelet chemokine concentrations between groups.

At 12 weeks, plasma concentrations of 2 platelet chemokines (CXCL5 and CXCL8) were significantly decreased from baseline in the anthocyanin group.

At 24 weeks, when compared with the placebo, anthocyanin supplementation produced significant decreases in five platelet chemokines (CXCL5, CXCL7, CXCL8, CXCL12, and CCL2).

Decreases in certain plasma chemokines correlated with decreases in serum LDL-cholesterol, high-sensitivity C-reactive protein (hsCRP), interleukin-1ß (IL-1ß), soluble P-selectin, and tumor necrosis factor-alpha (TNF-alpha) as well as an increase in HDL-cholesterol.

The results of this controlled clinical trial suggest that anthocyanins may offer protection against atherosclerosis because of their beneficial effect on plasma platelet chemokines, serum lipids and inflammatory factors.