Objective: In vitro evaluate the antiaggregation and anticoagulation properties of aqueous plant extracts, including Viburnum opulus flowers and fruits, Urtica dioica leaves, Coffea arabica leaves, and shepherd's purse (Capsella bursa-pastoris) herb. Methods: In vitro assessment of anticoagulation activity was conducted by examining the impact on activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen levels. Anti-aggregation activity was evaluated using the Born turbidimetric method. Results: The research found that the phytoextracts examined did not impact the concentration of fibrinogen and PT. However, they did slightly prolong the APTT, and this effect was statistically significant compared to the control. Coffea arabica leaves, and Viburnum opulus fruit extracts showed substantial anticoagulant activity (30% and 29% sodium heparin, respectively; p-value <0.05 for both). Extracts of Viburnum opulus fruits and Coffea arabica leaves significantly prolong the latent period before collagen-induced platelet aggregation by up to 116.7% and 118.8% of the intact platelet index, respectively. Every sample analyzed showed a significant decrease in the maximum platelet aggregation amplitude compared to the control. The most notable impact was with Urtica dioica and Coffea arabica leaf extracts, which reduced the percentage to 85.9% and 89.2% of the control, respectively. These extracts exhibited 77.6% and 59.7% of the effectiveness of acetylsalicylic acid, with Coffea arabica extract showing a significant difference (p<0.05) compared to the reference drug. All plant extracts, except Capsella bursa-pastoris extract, which reduced this indicator, significantly prolonged the time needed to reach maximum aggregation. Coffea arabica extract had the most significant impact, showing 223.8% of the efficacy of acetylsalicylic acid (p<0.05). The extracts (excluding Capsella bursa-pastoris) significantly decreased the platelet aggregation rate. The most notable impact was observed with extracts of Viburnum opulus flowers and Coffea arabica leaves, which yielded an inhibitory effect on the rate of aggregation of acetylsalicylic acid (-10%/min relative to intact platelets, p<0.05), reducing aggregation rate by -5.2% and -6%/min compared to control, respectively. Conclusion: The samples analyzed in our study show weak anticoagulation activity, with the most noticeable effects in extracts of coffee leaves and viburnum fruits. Additionally, we found that the antiaggregation activity of the extracts of coffee leaves, nettles, and viburnum fruits was much more substantial, comparable to or even surpassing the effect of acetylsalicylic acid in some cases. Keywords: Anticoagulation properties, antiaggregation activity, Viburnum opulus, Urtica dioica, Coffea arabica, Capsella bursa-pastoris.
