Background. The Melilotus plants are highly valued in herbal medicine, recommended for the prevention and treatment of thrombotic vein inflammation and varicose veins. Their health-promoting properties primarily result from the presence of coumarin and its derivatives. The aim of the study was to determine whether honey enriched with dried Melilotus albus flowers has  the ability to inhibit platelet aggregation. The inhibitory activity of rapeseed honey (control sample), rapeseed honey enriched with 1 % w/w of M. albus dried flowers and pure coumarin were evaluated against ADP (5 µМ) and collagen (2 µg/ml) induced aggregation of rat platelets. Platelet aggregation was measured by the turbidimetric method. Moreover, the quantitative  polyphenolic profile determined using HPLC-PDA and volatile compounds profiles obtained by GC-MS methods for rapeseed and M. albus enriched honey were compared to identify the
chemical factors that limit platelet aggregation.
Results and conclusions. A beneficial, dose-dependent effect of enriched honey on the inhibition of the aggregation process was demonstrated, and for the highest concentration used (20 %), the inhibition of aggregation induced by ADP and collagen amounted to 75 % and 90%, respectively. A weaker inhibitory effect was found for pure rapeseed honey at 20 % concentration – 40 % and 55 % of inhibition, respectively and pure coumarin (0.5 mg/ml) – 44 % and 20 %, respectively. The results obtained demonstrated that rapeseed honey enriched with M. albus flowers possesses  antiplatelet activity resulting from the synergistic effect of coumarin and other bioactive compounds occurred in dried M. albus flowers, including phenolic and volatile components.. However,  the mechanism of this action needs further study.