Milk Thistle’s Secret Weapon: Thromboelastometry Reveals How Silybin Modulates Coagulation in Human Plasma In Vitro

Background: Silybin, the primary active constituent of the milk thistle extract silymarin, has been historically recognized for its hepatoprotective properties. More recently, its potential effects on blood coagulation have garnered attention, suggesting a broader pharmacological profile. Methods: This study aimed to investigate silybin’s impact on hemostasis using rotational thromboelastometry (ROTEM) in normal human plasma. ROTEM enables the dynamic assessment of clot formation, providing a detailed analysis of coagulation processes in real-time. We specifically focused on the effects of silybin concentrations of 10 µM, 50 µM, and 100 µM on the ROTEM parameters compared to controls using normal human plasma with 0.1% dimethyl sulfoxide (DMSO). The parameters derived from the tests included clotting time (CT), α-angle (α), and amplitude at 10 and 20 min (A10 and A20) for each of the three channels: intrinsic pathway thromboelastometry (INTEM), extrinsic pathway thromboelastometry (EXTEM), and fibrinogen thromboelastometry (FIBTEM). Each measurement was performed four times. Results: Analysis of the INTEM assay results demonstrated that silybin at concentrations of 10 µM and 50 µM significantly reduced clotting time (CT) compared to the control. Additionally, all tested silybin concentrations significantly decreased the α-angle in the INTEM test. In the EXTEM assay, no significant effect on CT was observed at any silybin concentration. However, consistent with the INTEM findings, all silybin concentrations resulted in a significant reduction in the α-angle. In the FIBTEM assay, silybin at 10 µM and 50 µM significantly shortened CT. Furthermore, all tested concentrations led to a significant decrease in the α-angle and A20, while a reduction in A10 was observed only at the 50 µM concentration compared to the control. Conclusions: This study demonstrates that silybin modulates ROTEM parameters in a manner that tends to vary with concentration, with the strongest effects observed at lower concentrations (10–50 µM), notably reducing CT, α-angle, and clot firmness (A10, A20). These findings suggest a potential role of silybin in influencing coagulation dynamics.