Thrombin inhibitory activity of some polyphenolic compounds

Area of Science:

• Biochemistry
• Pharmacology
• Natural Product Chemistry

Background:

• Thrombin (active plasma coagulation factor II) is a serine protease vital for blood coagulation.
• Inhibiting thrombin is a key strategy for developing novel antithrombotic pharmacotherapies.
• Polyphenolic compounds are widely studied for their diverse biological activities.

Purpose of the Study:

• To investigate the effects of various polyphenolic compounds on thrombin activity.
• To characterize the interaction between selected polyphenols and thrombin.
• To explore the potential of polyphenols as a source for nature-based direct thrombin inhibitors.

Main Methods:

• Biochemical assays to measure thrombin amidolytic and proteolytic activity.
• Biosensor analysis using BIAcore to study polyphenol-thrombin interactions.
• Lineweaver-Burk kinetic analysis to determine inhibition mechanisms.

Main Results:

• Six polyphenols (cyanidin, quercetin, silybin, cyanin, (+)-catechin, (-)-epicatechin) inhibited thrombin amidolytic activity.
• Cyanidin, quercetin, and silybin affected thrombin's proteolytic activity.
• Cyanidin and quercetin showed strong binding to thrombin, while cyanin and (-)-epicatechin exhibited weaker binding.
• Polyphenol aglycones acted as competitive thrombin inhibitors.

Conclusions:

• Certain polyphenolic compounds, particularly cyanidin and quercetin, demonstrate significant inhibitory effects on thrombin.
• These findings suggest that polyphenols can serve as a basis for developing safe, orally bioavailable direct thrombin inhibitors.
• Nature-derived compounds offer a promising avenue for novel anticoagulant drug discovery.