Antithrombotic activity and saponin composition of the roots of Panax bipinnatifidus Seem. growing in Vietnam

Background: Panax bipinnatifidus (PB) Seem. is a highly valuable and indigenous medicinal plant wildly distributed in the northwest region of Vietnam. The PB root has been used as a tonic in Vietnamese traditional medicine, but its chemical profile and pharmacological activity have not been extensively studied. Objective: In this study, we investigated the major saponin components and antithrombosis activity of the root of PB. Materials and Methods: Individual saponins were isolated by column chromatography. The structural elucidation of the isolated saponins was based on analyses of nuclear magnetic resonance and mass spectrometry spectra. Chromatographic fingerprint analysis of the isolated compounds was run on an Agilent 1260 high-performance liquid chromatography (HPLC) system. To evaluate antithrombotic activity, in vitro anticoagulant, platelet aggregation, and clot lysis effects were successively tested by the respective protocols. Results: Two principal saponins were isolated from the butanolic fraction of the root of PB, and their structures were identified as stipuleanoside R2 (1) and araloside A methyl ester (2). The HPLC analysis suggested that the two isolated saponins are major saponins of the title plant. The biological testing showed that both the crude and butanolic extracts of PB exhibited significantly antiplatelet aggregation activity. The efficacy linearly increased according to the tested doses (0.5–5 mg/mL). On anticoagulant activity, only butanolic extract exhibited positive action via prolonged activated partial thromboplastin time and prothrombin time at the high dose. Conclusion: These results suggested that PB Seem. might bring benefits for preventing cardiovascular events through inhibition of platelet aggregation. Abbreviations Used: ADP: Adenosine diphosphate; APTT: Activated partial thromboplastin time; DMSO: Dimethyl sulfoxide; ESI-MS: Electrospray ionization-mass spectrometry; HPLC: High-performance liquid chromatography; LC-MS/MS: Liquid chromatography-tandem mass spectrometry; MAPK: Mitogen-activated protein kinase; MPA: Maximum platelet aggregation; NIMM: National Institute of Medicinal Materials; NMR: Nuclear magnetic resonance; PPP: Platelet-poor plasma;; PRP: Platelet-rich plasma; PT: Prothrombin time; TLC: Thin-layer chromatography; VNU: Vietnam National University.