macrostachyols a-d, oligostilbenes from gnetum macrostachyum inhibited in vitro human platelet aggregation

Introduction: gnetum macrostachyum is a known thai medicinal plant as a source of bioactive oligostilbenes, which possess platelet inhibitory activities. the study aimed to evaluate the in vitro human platelet aggregation inhibitory activities of macrostachyols a-d (compounds 1-4) isolated from the roots of g. macrostachyum. methods: the in vitro human platelet aggregation assay was assayed with a 96-well microtiter plate format. the well-known aggregating agents were used to investigate the possible mechanism of inhibition, including adenosine diphosphate (adp), arachidonic acid (aa), thromboxane a2 analog (u-46619), collagen, thrombin, and thrombin receptor-activating peptide-6 (trap-6). results: compound 1 was more potent than ibuprofen (positive control) on the adenosine diphosphate- induced platelet aggregation assay (p < 0.05). compound 3 was more potent than 1, 2, and 4 (p < 0.05), but all active oligostilbenes were less potent than the positive control (p < 0.05) on the arachidonic acid-induced platelet aggregation assay. the oligostilbenes 1, 2, 3, and 4 also displayed the inhibitory effects on the u-46619-induced platelet aggregation. the tetrameric stilbenes 1 was the only compound that exhibited inhibitory effects on thrombin-induced platelet aggregation without trap-6 mediated platelet aggregation. conclusion: the findings revealed the inhibitory effects of oligostilbenes on human platelet aggregation through a target-specific experimental design. it suggests that oligostilbenes from this plant might be applied as antiplatelet aggregation agents in platelet hyperreactivity- related diseases.