Black Sorghum Phenolic Extract Modulates Platelet Activation and Platelet Microparticle Release

• Published in: Nutrients Vol. 12; no. 6; p. 1760
• Main Authors: Ed Nignpense, Borkwei, Chinkwo, Kenneth A, Blanchard, Christopher L, Santhakumar, Abishek B
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.06.2020; MDPI
• Subjects: Activation; Adenine; Adenosine diphosphate; Anticoagulants; Antioxidants; Antioxidants - pharmacology; Atherosclerosis; Biomarkers; black sorghum; Blood clots; Blood platelets; Blood Platelets - drug effects; Blood Platelets - metabolism; Cardiovascular diseases; Cell-Derived Microparticles - drug effects; Collagen; Cytotoxicity; Degranulation; Evaluation; Flow Cytometry; Gene expression; Hematology; Humans; Medical screening; Oxidative stress; Oxidative Stress - drug effects; P-selectin; PAC1 protein; Pathogenesis; Phenolic compounds; Phenols; Plant Extracts - chemistry; Plant Extracts - pharmacology; Platelet Activation - drug effects; Platelet aggregation; Platelet Aggregation - drug effects; Platelet Aggregation Inhibitors - chemistry; Platelet Aggregation Inhibitors - pharmacology; Platelet Function Tests; platelet microparticles; platelets; Polyphenols; Polyphenols - pharmacology; Quality control; Questionnaires; Signal transduction; Size distribution; Sodium; Sorghum; Sorghum - chemistry; Thrombosis; Australia; atherosclerosis; black sorghum; polyphenols; platelet microparticles; platelets
• DOI: 10.3390/nu12061760
• ISSN: 2072-6643

Platelet hyper-activation and platelet microparticles (PMPs) play a key role in the pathogenesis of cardiovascular diseases. Dietary polyphenols are believed to mimic antiplatelet agents by blunting platelet activation receptors via its antioxidant phenomenon. However, there is limited information on the anti-platelet activity of grain-derived polyphenols. The aim of the study is to evaluate the effects of sorghum extract (Shawaya short black 1 variety), an extract previously characterised for its high antioxidant activity and reduction of oxidative stress-related endothelial dysfunction, on platelet aggregation, platelet activation and PMP release. Whole blood samples collected from 18 healthy volunteers were treated with varying non-cytotoxic concentrations of polyphenol-rich black sorghum extract (BSE). Platelet aggregation study utilised 5 µg/mL collagen to target the GPVI pathway of thrombus formation whereas adenine phosphate (ADP) was used to stimulate the P2Y1/P2Y12 pathway of platelet activation assessed by flow cytometry. Procaspase-activating compound 1 (PAC-1) and P-selectin/CD62P were used to evaluate platelet activation- related conformational changes and degranulation respectively. PMPs were isolated from unstimulated platelets and quantified by size distribution and binding to CD42b. BSE treatment significantly reduced both collagen-induced platelet aggregation and circulatory PMP release at 40 µg/mL ( 0.001) when compared to control. However, there was no significant impact of BSE on ADP-induced activation-dependent conformational change and degranulation of platelets. Results of this study suggest that phenolic rich BSE may confer cardio-protection by modulating specific signalling pathways involved in platelet activation and PMP release.