Proteins derived from latex of C. procera maintain coagulation homeostasis in septic mice and exhibit thrombin- and plasmin-like activities.

The proteins derived from the latex (LP) of Calotropis procera are well known for their anti-inflammatory property. In view of their protective effect reported in the sepsis model, they were evaluated for their efficacy in maintaining coagulation homeostasis in sepsis. Intraperitoneal injection of LP markedly reduced the procoagulation and thrombocytopenia observed in mice infected with Salmonella; while in normal mice, LP produced a procoagulant effect. In order to understand its mechanism of action, the LP was subjected to ion-exchange chromatography, and the three subfractions (LPPI, LPPII, and LPPIII) thus obtained were tested for their proteolytic effect and thrombin- and plasmin-like activities in vitro. Of the three subfractions tested, LPPII and LPPIII exhibited proteolytic effect on azocasein and exhibited procoagulant effect on human plasma in a concentration-dependent manner. Like trypsin and plasmin, these subfractions produced both fibrinogenolytic and fibrinolytic effects that were mediated through the hydrolysis of the Aα, Bβ, and γ chains of fibrinogen and α-polymer and γ-dimer of fibrin clot, respectively. This study shows that the cysteine proteases present in the latex of C. procera exhibit thrombin- and plasmin-like activities and suggests that these proteins have therapeutic potential in various conditions associated with coagulation abnormalities.