Screening of active fractions with antithrombotic effect from Caragana jubata

The antithrombotic effect of Caragana jubata (Pall.)Poir.ethanolic extract (TE)was evaluated by inferior vena cava thrombosis in rats and acute pulmonary thrombosis in mice. To search for the bioactive fractions of TE, comparison on acute pulmonary thrombosis was made between the two main fractions of TE (TE-1 and TE-2). Besides, pharmacological effects of TE, TE-1 and TE-2 on bleeding time and clotting time were also studied. Reference substances combined with UPLC/DAD-q-TOF-MS were applied to identify the main six compounds and other chemical constituents of the TE. The results showed that TE could significantly reduce the rat thrombosis weight in all doses (P<0.01) and improve the protective rate to mice in medium and high doses (P<0.05). TE-2 showed a stronger effect on protecting the mice from paralysis or death and prolonging the bleeding time and clotting time than TE-1. Chemical constituents in TE mainly include isoflavones, pterocarpans and stilbenoids. Constituents in TE-2 were mainly isoflavones and pterocarpans, while those in TE-1 were mainly stilbenoids, which could be inferred that all of these three kinds of constituents may be responsible for the antithrombotic effects of Caragana jubata.