Cyanidin-3-O-β-glucoside, a Natural Polyphenol, Exerts Proapoptotic Effects on Activated Platelets and Enhances Megakaryocytic Proplatelet Formation

Abstract

This study investigated whether the anthocyanin cyanidin-3-O-β-glucoside (Cy-3-g) could affect platelet apoptosis and proplatelet formation in vitro. Thrombin-stimulated or resting human platelets and Meg-01 megakaryocytes were incubated with Cy-3-g (0, 0.5, 5, or 50 μM). We found that the percentage of the platelet mitochondrial membrane potential treated with 5 and 50 μM Cy-3-g was significantly higher than control (15.50% ± 3.24% and 29.77% ± 4.06% versus 2.76% ± 1.33%, respectively; P < 0.05). Treatment with 5 and 50 μM Cy-3-g significantly increased phosphatidylserine exposure compared with control (40.56% ± 10.53% and 76.62% ± 8.28% versus 15.43% ± 3.93%, respectively; P < 0.05). Moreover, Cy-3-g significantly increased the expression of Bax, Bak, and cytochrome c while markedly decreasing Bcl-xL and Bcl-2 expression as well as stimulating caspase-3, caspase-9, caspase-8, Bid, and gelsolin cleavage in thrombin-activated platelets in a dose-dependent manner ( P < 0.05). However, no significant differences were observed in the apoptosis of resting platelets when treated with Cy-3-g ( P > 0.05). Furthermore, Cy-3-g significantly ( P < 0.05) enhanced cell viability (50 μM versus control, 1.34 ± 0.01 versus 0.35 ± 0.02), the number of colony-forming unit-megakaryocytes (50 μM versus control, 38 ± 3 versus 8 ± 3), CD41 expression (50 μM versus control, 96.80% ± 2.55% versus 25.57% ± 2.86%), DNA ploidy (16N) (50 μM versus control, 19.73% ± 2.34% versus 4.42% ± 1.96%), and proplatelet formation (50 μM versus control, 27.5% ± 3.77% versus 7.67% ± 2.25%) in Meg-01 cells. In conclusion, Cy-3-g promotes activated platelet apoptosis and enhances megakaryocyte proliferation, differentiation, and proplatelet formation in vitro.

Coenzyme Q10 Upregulates Platelet cAMP/PKA Pathway and Attenuates Integrin αIIbβ3 Signaling and Thrombus Growth

“…Whole human blood was drawn into a tube containing 3.8% sodium citrate (1/9, v/v) via venipuncture from healthy volunteers and dyslipidemic patients. Platelet‐rich plasma (PRP) and gel‐filtered platelets were prepared as previously described . Briefly, PRP was obtained by centrifugation at 300 × g for 7 min at 22 °C.…”

Protocatechuic Acid Protects Platelets from Apoptosis via Inhibiting Oxidative Stress-Mediated PI3K/Akt/GSK3β Signaling

“…Whole blood was drawn into a tube containing 3.8% sodium citrate (1/9, v/v) via venipuncture from healthy subjects to prepare platelet-rich plasma and gel-filtered platelets were isolated through sepharose 2B gel filtration as we previously described. 14,17,21,22…”

“…Western blotting was performed using previously described methods. 16,17,21 To ascertain the purity of cytosolic and mitochondrial fractions, we detected the expression levels of Cox IV in the cytosolic fractions and β-actin in the mitochondrial fractions, since Cox IV is commonly used as a loading control for proteins in the mitochondrial fractions and β-actin for the cytosolic and total fractions.…”

“…10,11,14,15 Our in vitro studies also showed that Cy-3-g induced megakaryocyte apoptosis in the human megakaryoblastic Meg-01 cells 16 and promoted apo-ptosis of activated platelet. 17 However, the effective levels of Cy-3-g were determined at a range between 10 to 100 μmol/L. In vivo studies have revealed that less than 1% of the intact anthocyanins are typically absorbed, and the maximum plasma concentration of anthocyanins is usually less than 0.1 μmol/L.…”

Fruitflow attenuates human platelet granule secretion through down-regulating Src/PLCγ2/PKC signaling pathway

“…The blood sample was then centrifuged at 300 g for 7 min at 22ºC to obtain platelet-rich plasma (PRP). Gel-filtered platelets were isolated from PRP with a Sepharose 2B column in PIPES buffer(5 mM PIPES, 1.37 mM NaCl, 4 mM KCl, 0.1% (w/v) glucose, pH7.0) as we previously described [24].…”