The ex vivo antiplatelet activation potential of fruit phenolic metabolite hippuric acid

Polyphenol-rich fruit and vegetable intake has been associated with reduction in platelet hyperactivity, a significant contributor to thrombus formation. This study was undertaken to investigate the possible role of hippuric acid, a predominant metabolite of plant cyclic polyols, phenolic acids and polyphenols, in reduction of platelet activation-related thrombogenesis. Fasting blood samples were collected from 13 healthy subjects to analyse the effect of varying concentrations of hippuric acid (100 µM, 200 µM, 500 µM, 1 mM and 2 mM) on activation-dependant platelet surface-marker expression. Procaspase activating compound-1 (PAC-1) and P-selectin/CD62P monoclonal antibodies were used to evaluate platelet activation-related conformational changes and α-granule release respectively using flow cytometry. Platelets were stimulated ex vivo via the P2Y1/P2Y12 – adenosine diphosphate (ADP) pathway of platelet activation. Hippuric acid at a concentration of 1 mM and 2 mM significantly reduced P-selectin/CD62P expression (p=0.03 and p<0.001 respectively) induced by ADP. Hippuric acid at 2 mM concentration also inhibited PAC-1 activation-dependant antibody expression (p=0.03). High ex vivo concentrations of hippuric acid can therefore significantly reduce P-selectin and PAC-1 expression thus reducing platelet activation and clotting potential. However, although up to 11 mM of hippuric acid can be excreted in the urine per day following consumption of fruit, hippuric acid is actively excreted with a recorded Cmax for hippuric acid in human plasma at 250-300 μM. This is lower than the blood concentration of 1-2 mM shown to be bioactive in this research. The contribution of hippuric acid to the protective effects of fruit and vegetable intake against vascular disorders by the pathways measured is therefore low but could be synergistic with lowered doses of antiplatelet drugs and help reduce risk of thrombosis in current antiplatelet drug sensitive populations

The potential of anthocyanin-rich Queen Garnet plum juice supplementation in alleviating thrombotic risk under induced oxidative stress conditions

Increased oxidant production in humans induces a number of thrombotic consequences; including platelet hyperactivity/aggregability, which could be countered through specifically developed functional foods. We sought to determine the antithrombotic properties of anthocyanin-rich Queen Garnet plum juice (QGPJ) supplementation with and without exercise-induced oxidative stress. Thirteen healthy participants were investigated in a randomised, double-blind, placebo controlled, cross-over trial. Participants consumed 200 mL/day of QGPJ and placebo juice for 28-days, with treatments separated by a two-week wash-out period. Blood samples were collected at baseline and after 1 h of exercise (70% peak-O2 uptake) both before and after oral supplementation and evaluated for platelet function and haemostatic activity. QGPJ supplementation inhibited adenosine diphosphate-induced platelet aggregation both without and under exercise induced oxidative stress by 10.7% (P < 0.01) and 12.7% (P < 0.001) respectively; arachidonic acid-induced aggregation under oxidative stress by 28.8% (P < 0.05); reduced platelet activation dependant P-selectin expression by 32.9% (P < 0.01) and 38.7% (P < 0.001) both without and under oxidative stress respectively; and exhibited favourable effects on coagulation parameters both with and without oxidative stress. The anti-thrombotic activity exhibited byanthocyanin-rich QGPJ suggests a potential for cardiovascular disease risk reduction and may be considered as complementary anti-platelet nutritional therapy in pro-thrombotic population

Consumption of anthocyanin-rich Queen Garnet plum juice reduces platelet activation related thrombogenesis in healthy volunteers

The anti-thrombotic properties of an anthocyanin-rich Queen Garnet plum juice (QGPJ) and anthocyanin-free prune juice (PJ) were studied in this randomised, double-blind, crossover trial. Twenty-one healthy subjects (M = 10, F = 11) consumed QGPJ, PJ or placebo, 200 mL/day for 28-days followed by a 2-week wash-out period. Only QGPJ supplementation inhibited platelet aggregation induced by ADP (2.1 s, P = 0.03); reduced plasma-fibrinogen (<7.5%, P = 0.02) and malondialdehyde levels, a plasma biomarker of oxidative stress (P = 0.016). PJ supplementation increased plasma hippuric acid content (P = 0.018). QGPJ or PJ supplementation did not affect blood cell counts, lipid profile, or inflammation markers. Our findings suggest that QGPJ but not PJ has the potential to significantly attenuate thrombosis by reducing platelet activation/hyper-coagulability and oxidative stress

Preferred learning modalities and practice for critical skills: a global survey of paediatric emergency medicine clinicians

Objective To describe senior paediatric emergency clinician perspectives on the optimal frequency of and preferred modalities for practising critical paediatric procedures. Methods Multicentre multicountry cross-sectional survey of senior paediatric emergency clinicians working in 96 EDs affiliated with the Pediatric Emergency Research Network. Results 1332/2446 (54%) clinicians provided information on suggested frequency of practice and preferred learning modalities for 18 critical procedures. Yearly practice was recommended for six procedures (bag valve mask ventilation, cardiopulmonary resuscitation (CPR), endotracheal intubation, laryngeal mask airway insertion, defibrillation/direct current (DC) cardioversion and intraosseous needle insertion) by at least 80% of respondents. 16 procedures were recommended for yearly practice by at least 50% of respondents. Two procedures (venous cutdown and ED thoracotomy) had yearly practice recommended by <40% of respondents. Simulation was the preferred learning modality for CPR, bag valve mask ventilation, DC cardioversion and transcutaneous pacing. Practice in alternative clinical settings (eg, the operating room) was the preferred learning modality for endotracheal intubation and laryngeal mask insertion. Use of models/mannequins for isolated procedural training was the preferred learning modality for all other invasive procedures. Free-text responses suggested the utility of cadaver labs and animal labs for more invasive procedures (thoracotomy, intercostal catheter insertion, open surgical airways, venous cutdown and pericardiocentesis). Conclusions Paediatric ED clinicians suggest that most paediatric critical procedures should be practised at least annually. The preferred learning modality depends on the skill practised; alternative clinical settings are thought to be most useful for standard airway manoeuvres, while simulation-based experiential learning is applicable for most other procedures