Discovery of 7, 4'-dimethoxy-3-hydroxyflavone as a protease-activated receptor 4 antagonist with antithrombotic activity and less bleeding tendency in mice.

Abstract

There is growing evidence of the importance of protease-activated receptor 4 (PAR4), one of thrombin receptors, as a therapeutic target in thrombotic cardiovascular diseases. In the present study, we utilized ligand-based virtual screening, bioassay, and structure-activity relationship study to discover PAR4 antagonists with new chemical scaffolds from natural origin, and examined their application as antiplatelet agents. By using these approaches, we have identified a flavonoid, 7, 4'-dimethoxy-3-hydroxyflavone, that exhibits anti-PAR4 activity. 7, 4'-Dimethoxy-3-hydroxyflavone inhibited PAR4-mediated human platelet aggregation, GPIIb/IIIa activation, and P-selectin secretion. Also, it inhibited PAR4 downstream signaling pathways, including Ca2+/protein kinase C, Akt, and MAP kinases ERK and p38, in human platelets, and suppressed PAR4-mediated β-arrestin recruitment in CHO-K1 cells exogenously expressed human PAR4. In a microfluidic system, 7, 4'-dimethoxy-3-hydroxyflavone reduced thrombus formation on collagen-coated chambers at an arterial shear rate in recalcified whole blood. Furthermore, mice treated with 7, 4'-dimethoxy-3-hydroxyflavone were significantly protected from FeCl3-induced carotid arterial occlusions, without significantly affecting tail bleeding time. In conclusion, 7, 4'-dimethoxy-3-hydroxyflavone represents a new class of nature-based PAR4 antagonist, it shows effective in vivo antithrombotic properties with less bleeding tendency, and could be a potential candidate for developing new antiplatelet agents.

• Authors: Ying-Ting Lin, Yu Li, Hui-Ching Hsu, Ju-Ying Tsai, Jia-Hau Lee, Chi-Jung Tai, Ming-Jung Wu, Chin-Chung Wu
• Journal: Biochemical pharmacology (Biochem Pharmacol) Vol. 202 Pg. 115152 (08 2022) ISSN: 1873-2968 [Electronic] England
• PMID: 35752281 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2022 Elsevier Inc. All rights reserved.

Chemical References

• 3-hydroxyflavone
• Fibrinolytic Agents
• Flavonoids
• Platelet Aggregation Inhibitors
• protease-activated receptor 4
• Receptors, Thrombin
• Thrombin
• 7,4'-dimethoxy-3-hydroxyflavone

Topics

• Animals
• Humans
• Mice
• Blood Platelets
• Fibrinolytic Agents (metabolism)
• Flavonoids (metabolism, pharmacology, therapeutic use)
• Platelet Aggregation
• Platelet Aggregation Inhibitors (metabolism)
• Receptors, Thrombin (metabolism)
• Thrombin (metabolism)
• Thrombosis (drug therapy, metabolism)