Bioactivity-Guided Fractionation of Dragon's Blood Phenolic Extracts Reveals Loureirin D as a P2Y12 Inhibitor Mediating Antiplatelet Effects.

Dragon's Blood, from the Dracaena cochinchinensis plant, is known for enhancing blood circulation. Its main components are Dragon's Blood phenolic extracts (DBE). To pinpoint the active DBE constituents that are effective against thrombosis and understand their mechanism of action, the PT-stroke model was employed to assess DBE's antithrombotic effects on cerebral blood flow and platelet aggregation. This investigation demonstrates that DBE enhances cerebral blood flow and inhibits ADP-induced platelet aggregation in photothrombotic (PT) stroke models. An FeCl3-induced carotid artery thrombosis model was developed to test the antithrombotic activity of four DBE fractions. Through screening with this model, the ethyl acetate (EA) and methanol fractions were identified as the principal active components that effectively reduced thrombus weight and improved hemodynamics. Furthermore, the EA fraction was found to preserve the integrity of the blood-brain barrier. Phytochemical isolation allowed for the identification of compounds in the EA fractions, and UHPLC-MS was performed to characterize DBE and its active components in the bloodstream. In vitro ADP-induced platelet aggregation assays highlighted the active compounds. Through phytochemical analysis, Loureirin D (compound 17) was identified as a predominant constituent present in plasma. In vitro assays revealed that compounds 1 and 17 possess strong antiplatelet activity, with Loureirin D being confirmed as a selective P2Y12 receptor antagonist via molecular docking and cellular thermal shift assays. These findings substantiate Loureirin D as a pivotal antithrombotic component in DBE and its potential as a P2Y12-targeting therapeutic agent for thrombosis treatment.