Ten Representative Saponins on Tissue Factor Expression in Human Monocytes: Structure–Activity Relationships and Molecular Docking

Abstract

Saponins have significant bioactivities in treating cardiovascular disease. Whereas there is a lack of in-depth knowledge about how saponins prevent cardiovascular disease. Tissue factor (TF) is the major initiator of the coagulation cascade and plays an important role in hemostasis and thrombosis. However structure–activity relationships (SARs) of saponins inhibiting TF activity have not been discussed in detail at present. To further clarify the relationships between saponins and TF, in this study, 10 representative saponins were selected to study the inhibitory effect on TF procoagulant activity of monocytes by an improved chromogenic substrate method, and the possible SARs were preliminarily analyzed. Furthermore, molecular docking analysis suggested that 4 representative saponins had a good affinity with TF/FVIIa. In addition, a representative saponin, ruscogenin, decreased both messenger ribonucleic acid and protein levels of TF in human monocytes partly due to its downregulation of nuclear factor kappa-light-chain-enhancer of activated B cells and c-Jun N-terminal kinase pathways. In conclusion, this study provides further explanation for the cardiovascular protection of saponins, and the analysis of SARs between inhibiting TF activity and saponins will be helpful to explore the therapeutic TF inhibitors.