Objective: In vitro and animal studies suggest that purified anthocyanins have favorable effects on metabolic profiles, but clinical trials have reported inconsistent findings. Furthermore, no study has been specifically conducted among individuals with prediabetes. The aim of this study was to investigate whether purified anthocyanins could improve cardiometabolic risk factors in Chinese adults with early untreated hyperglycemia. Research Design and Methods: This was a 12-week randomized, double-blind, placebo-controlled trial. A total of 160 participants aged 40–75 years with prediabetes or early untreated diabetes were randomly allocated to receive either purified anthocyanins (320 mg/day, n = 80) or placebo (n = 80) of identical appearance. A three-hour oral glucose tolerance test (OGTT) was performed, and cardiometabolic biomarkers (glycated hemoglobin A1c (HbA1c), fasting and postprandial glucose, insulin, C-peptide, and lipids) were measured at baseline and at the end of the trial. Results: A total of 138 subjects completed the protocol. Compared with placebo, purified anthocyanins moderately reduced HbA1c (−0.14%, 95% CI: −0.23~−0.04%; p = 0.005), low-density lipoprotein-c (LDL-c) (−0.2 mmol/L, 95% CI: −0.38~−0.01, p = 0.04), apolipoprotein A-1 (apo A1) (0.09 g/L, 95% CI: 0.02~0.17; p = 0.02), and apolipoprotein B (apo B) (−0.07 g/L, 95% CI: −0.13~−0.01; p = 0.01) according to intention-to-treat analysis. Subgroup analyses suggested that purified anthocyanins were more effective at improving glycemic control, insulin sensitivity, and lipids among patients with elevated metabolic markers. Conclusions: The 12-week randomized controlled trials (RCT) in Chinese adults with prediabetes or early untreated diabetes indicated that purified anthocyanins favorably affected glycemic control and lipid profile. Future studies of a longer duration that explore the dose-response relationship among patients with cardiometabolic disorders are needed to confirm our findings.

Scope Platelet integrin αIIbβ3 is the key mediator of atherothrombosis. Supplementation of coenzyme Q10 (CoQ10), a fat‐soluble molecule that exists in various foods, exerts protective cardiovascular effects. This study aims to investigate whether and how CoQ10 acts on αIIbβ3 signaling and thrombosis, the major cause of cardiovascular diseases. Methods and results Using a series of platelet functional assays in vitro, it is demonstrated that CoQ10 reduces human platelet aggregation, granule secretion, platelet spreading, and clot retraction. It is further demonstrated that CoQ10 inhibits platelet integrin αIIbβ3 outside‐in signaling. These inhibitory effects are mainly mediated by upregulating cAMP/PKA pathway, where CoQ10 stimulates the A2A adenosine receptor and decreases phosphodiesterase 3A phosphorylation. Moreover, CoQ10 attenuates murine thrombus growth and vessel occlusion in a ferric chloride (FeCl3)‐induced thrombosis model in vivo. Importantly, the randomized, double‐blind, placebo‐controlled clinical trial in dyslipidemic patients demonstrates that 24 weeks of CoQ10 supplementation increases platelet CoQ10 concentrations, enhances the cAMP/PKA pathway, and attenuates αIIbβ3 outside‐in signaling, leading to decreased platelet aggregation and granule release. Conclusion Through upregulating the platelet cAMP/PKA pathway, and attenuating αIIbβ3 signaling and thrombus growth, CoQ10 supplementation may play an important protective role in patients with risks of cardiovascular diseases.

Objective: The associations between intake of anthocyanins and anthocyanin-rich berries and cardiovascular risks remained to be established. We aimed to quantitatively summarize the effects of purified anthocyanins and anthocyanin-rich berries on major surrogate markers of cardiovascular diseases (CVDs) and the longitudinal associations between dietary anthocyanins and CVD events.Methods: Meta-analysis of randomized controlled trials (RCTs) and prospective cohort studies.Results: We included 44 eligible RCTs and 15 prospective cohort studies in this study. Pooled analysis of RCTs showed that purified anthocyanin supplementation could significantly reduce blood LDL cholesterol (weighted mean difference (WMD): −5.43 mg/dL, 95% CI: −8.96, −1.90 mg/dL; p = 0.003) and triglyceride (WMD: −6.18 mg/dL, 95% CI: −11.67, −0.69 mg/dL; p = 0.027) while increase HDL cholesterol (WMD: 11.49 mg/dL, 95% CI: 7.43, 15.55 mg/dL; p < 0.001) concentrations. Purified anthocyanins also markedly decreased circulating tumor necrosis factor alpha (WMD: −1.62 pg/mL, 95% CI: −2.76, −0.48 pg/mL; p = 0.005) and C-reactive protein (WMD: −0.028 mg/dL, 95% CI: −0.050, −0.005 mg/dL; p = 0.014). Besides, administration of anthocyanin-rich berries could significantly lower blood total cholesterol (WMD: −4.48 mg/dL, 95% CI: −8.94, −0.02 mg/dL; p = 0.049) and C-reactive protein (WMD: −0.046 mg/dL, 95% CI: −0.070, −0.022 mg/dL; p < 0.001). Neither purified anthocyanins nor anthocyanin-rich berries could cause any substantial improvements in BMI, blood pressure, or flow-mediated dilation. In addition, meta-analysis of prospective cohort studies suggested that high dietary anthocyanins were related to lower risk of coronary heart disease (CHD) (relative risk (RR): 0.83, 95% CI: 0.72, 0.95; p = 0.009), total CVD incidence (RR: 0.73, 95% CI: 0.55, 0.97; p = 0.030), and total CVD deaths (RR: 0.91, 95% CI: 0.87, 0.96; p < 0.001).Conclusion: Habitual intake of anthocyanins and anthocyanin-rich berries could protect against CVDs possibly via improving blood lipid profiles and decreasing circulating proinflammatory cytokines.Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42020208782.

No abstract

Apoptotic-like phase is an essential step in thrombopoiesis from megakaryocytes. Anthocyanins are natural flavonoid pigments that possess a wide range of biological activities, including protection against cardiovascular diseases and induction of tumour cell apoptosis. We investigated the effects and underlying mechanisms of cyanidin-3-o-β-glucoside (Cy-3-g, the major bioactive compound in anthocyanins) on the apoptosis of human primary megakaryocytes and Meg-01 cell line in vitro We found that Cy-3-g dose-dependently increased the dissipation of the mitochondrial membrane potential, caspase-9 and caspase-3 activity in megakaryocytes from patients with newly diagnosed acute myeloid leukaemia but not in those from healthy volunteers. In Meg-01 cells, Cy-3-g regulated the distribution of Bak, Bax and Bcl-xL proteins in the mitochondria and cytosol, subsequently increasing cytochrome release and stimulating caspase-9 and caspase-3 activation and phosphatidylserine exposure. However, Cy-3-g did not exert significant effects on factor-associated suicide (Fas), Fas ligand, caspase-8 or Bid expression. Cy-3-g inhibited nuclear factor kappa B (NF-κB) p65 activation by down-regulating inhibitor of NF-κB kinase (IKK)α and IKKβ expression, followed by the inhibition of inhibitor of NF-κB (IκB)α phosphorylation and degradation and subsequent inhibition of the translocation of the p65 sub-unit into the nucleus, and finally stimulating caspase-3 activation and phosphatidylserine exposure. The inhibitory effect of Cy-3-g on NF-κB activation was mediated by the activation of extracellular signal-regulated kinases (Erk1/2) and p38 mitogen-activated protein kinase (MAPK) and the inhibition of phosphoinositide 3-kinase (PI3K)/Akt signalling. U0126 (Erk1/2 inhibitor), SB203580 (p38 MAPK inhibitor) and 740 Y-P (PI3K agonist) significantly reversed Cy-3-g-reduced phosphorylation of p65. Taken together, our data indicate that Cy-3-g induces megakaryocyte apoptosis via the inhibition of NF-κB signalling, which may play important roles in regulating thrombopoiesis.

Oxidative stress plays crucial roles in initiating platelet apoptosis that facilitates the progression of cardiovascular diseases (CVDs). Protocatechuic acid (PCA), a major metabolite of anthocyanin cyanidin-3-O-β-glucoside (Cy-3-g), exerts cardioprotective effects. However, underlying mechanisms responsible for such effects remain unclear. Here, we investigate the effect of PCA on platelet apoptosis and the underlying mechanisms in vitro. Isolated human platelets were treated with hydrogen peroxide (H2O2) to induce apoptosis with or without pretreatment with PCA. We found that PCA dose-dependently inhibited H2O2-induced platelet apoptosis by decreasing the dissipation of mitochondrial membrane potential, activation of caspase-9 and caspase-3, and decreasing phosphatidylserine exposure. Additionally, the distributions of Bax, Bcl-xL, and cytochrome c mediated by H2O2 in the mitochondria and the cytosol were also modulated by PCA treatment. Moreover, the inhibitory effects of PCA on platelet caspase-3 cleavage and phosphatidylserine exposure were mainly mediated by downregulating PI3K/Akt/GSK3β signaling. Furthermore, PCA dose-dependently decreased reactive oxygen species (ROS) generation and the intracellular Ca2+ concentration in platelets in response to H2O2. N-Acetyl cysteine (NAC), a ROS scavenger, markedly abolished H2O2-stimulated PI3K/Akt/GSK3β signaling, caspase-3 activation, and phosphatidylserine exposure. The combination of NAC and PCA did not show significant additive inhibitory effects on PI3K/Akt/GSK3β signaling and platelet apoptosis. Thus, our results suggest that PCA protects platelets from oxidative stress-induced apoptosis through downregulating ROS-mediated PI3K/Akt/GSK3β signaling, which may be responsible for cardioprotective roles of PCA in CVDs.

CoQ10 supplementation in ApoE−/− mice attenuates high-fat diet-induced platelet hyper-reactivity via down-regulating platelet αIIbβ3 signaling, and thus protecting against atherothrombosis.

Background: Dyslipidemia induces platelet hyperactivation and hyper-aggregation, which are linked to thrombosis. Anthocyanins could inhibit platelet function in vitro and in mice fed high-fat diets with their effects on platelet function in subjects with dyslipidemia remained unknown. This study aimed to investigate the effects of different doses of anthocyanins on platelet function in individuals with dyslipidemia. Methods: A double-blind, randomized, controlled trial was conducted. Ninety-three individuals who were initially diagnosed with dyslipidemia were randomly assigned to placebo or 40, 80, 160 or 320 mg/day anthocyanin groups. The supplementations were anthocyanin capsules (Medox, Norway). Platelet aggregation by light aggregometry of platelet-rich plasma, P-selectin, activated GPⅡbⅢa, reactive oxygen species (ROS), and mitochondrial membrane potential were tested at baseline, 6 weeks and 12 weeks. Findings: Compared to placebo group, anthocyanins at 80 mg/day for 12 weeks reduced collagen-induced platelet aggregation (-3.39 §2.36%) and activated GPⅡbⅢa (-8.25 §2.45%) (P < 0.05). Moreover, compared to placebo group, anthocyanins at 320 mg/day inhibited collagen-induced platelet aggregation (-7.05 §2.38%), ADP-induced platelet aggregation (-7.14 §2.00%), platelet ROS levels (-14.55 §1.86%), and mitochondrial membrane potential (7.40 §1.56%) (P < 0.05). There were dose-response relationships between anthocyanins and the attenuation of platelet aggregation, mitochondrial membrane potential and ROS levels (P for trend <0.05). Furthermore, significantly positive correlations were observed between changes in collagen-induced (r = 0.473) or ADP-induced (r = 0.551) platelet aggregation and ROS levels in subjects with dyslipidemia after the 12-week intervention (P < 0.05). Interpretation: Anthocyanin supplementation dose-dependently attenuates platelet function, and 12-week supplementation with 80 mg/day or more of anthocyanins can reduce platelet function in individuals with dyslipidemia.