RESUMO
This ex vivo study was performed to evaluate the anti-platelet and anti-thrombogenic potential of shikimic acid (SA), a plant phenolic metabolite. Fasting blood samples were collected from 22 sedentary participants to analyse the effect of varying concentrations of SA (0.1 mM, 0.2 mM, 0.5 mM, 1 mM and 2 mM) on platelet surface-marker expression, platelet aggregation and biomarkers of thrombogenesis. Monocyte-platelet aggregates (CD14/CD42b) and platelet endothelial cell adhesion molecule-1 (PECAM-1 or CD31), effective indicators of thrombus formation were evaluated. Procaspase-activating compound 1 (PAC-1) and P-selectin or CD62P were used to assess platelet activation-related thrombogenesis. Adenosine diphosphate (ADP) was used to stimulate the P2Y1/P2Y12 pathway of platelet activation to mimic the in vivo thrombogenic pathway. Platelet aggregation studies utilised both ADP and collagen as exogenous platelet agonists to target both P2Y1/P2Y12 and GPVI pathways of thrombus formation. It was observed with flow cytometry that SA produced a significant antiplatelet effect on PAC-1 (p = 0.03 at 2 mM) and CD62P (p = 0.017, p = 0.036 at 1 mM and 2 mM respectively) expression in addition to lowering monocyte-platelet aggregate formation (p = 0.013, p < 0.01 and p < 0.01 at 0.5 mM, 1 mM and 2 mM respectively). SA at 1 mM concentration reduced PECAM-1 expression (p = 0.035), signifying a reduction to endothelial leucocyte migration during thrombus growth. SA did not demonstrate a platelet aggregation inhibitory effect by targeting the GPVI collagen pathway but reduced ADP induced platelet aggregation at 2 mM concentration (p < 0.01 at 2 mM). The results suggest that SA, an active metabolite of polyphenol-rich food intake, could play an important role in reducing platelet activation, aggregation related thrombus formation and biomarkers of thrombogenesis in sedentary individuals.