Exploring a New Serine Protease from Cucumis sativus L

Procoagulant serine glycoprotease from Cucumis sativus L.: action on human fibrinogen and fibrin clot

Upon examination of the fruit extract of Cucumis sativus L. for its pharmacological benefits, it was previously observed that it has potential proteolytic, fibrinogenolytic and procoagulant activities. These properties can be attributed to the presence of the protease. In this regard, the present study comprised of purification and characterization of protease. Purification of the enzyme involved ammonium sulfate precipitation followed by gel filtration and ion exchange chromatography. The purified cucumis protease (CPro) exhibits homogeneity as attested by SDS-PAGE and RP-HPLC with a retention time of 14.246 min with molecular mass ~75.3 kDa. CPro was identified as a glycoprotein and serine protease. Azocasein is the preferred substrate for CPro as it showed low K_m value of 0.3809 mg/ml. Purified CPro exhibits optimum activity at 37 °C and pH 8. CPro shows its involvement in hemostasis-the very first step in wound healing. CPro degrades the subunits of human fibrinogen in the order Aα > Bβ > γ. It also hydrolyzes the subunits of the partially cross-linked fibrin clot in the order α-polymer > γ-γ dimer > β-chain. CPro reduced the clotting time of citrated plasma, prothrombin time and activated partial thromboplastin time of plasma. CPro is neither hemorrhagic nor edema-inducing, thus considered to be a non-toxic protease. This work provides evidence for the use of cucumber extract in wound healing and authenticates its use in cosmetics.

Exploring hemostatic and thrombolytic potential of heynein - A cysteine protease from Ervatamia heyneana latex

ETHNOPHARMACOLOGICAL RELEVANCE

The latex of Ervatamia heyneana (Wall.) T. Cooke plant has been used for wound healing and various skin diseases by Indian tribes and folklore.

AIM OF THE STUDY

To validate the scientific basis of heynein - a key protease of Ervatamia heyneana, in hemostasis and wound healing process.

MATERIALS AND METHODS

The latex from E. heyneana was processed and subjected to two step purification. The purified heynein was assayed for proteolytic activity using casein as substrate and also attested by zymography. The inhibition studies confirmed the nature of heynein. Pure fibrinogen was used for fibrinogenolytic activity and citrated plasma was used for coagulant and fibrinolytic activities. The edema inducing action and hemorrhagic activity of heynein were assessed on mice model.

RESULTS

The purified heynein exhibited proteolytic activity, which was confirmed by caseinolytic assay and zymography. The inhibition studies confirmed heynein to be a cysteine protease. Heynein showed complete hydrolysis of all the three subunits of human fibrinogen (Aα, Bβ, γ). It exhibited strong pro-coagulant activity by reducing plasma clotting time from 248 to 39s at 40µg concentration. Heynein cleaved α polymer subunit in fibrin clot and did not induce edema and hemorrhage in mice models. The non-hemorrhagic nature was supported with histopathological studies of skin samples.

CONCLUSION

Heynein displays strong pro-coagulant action associated with fibrin(ogen)olytic activity. This provides basis for the observed pharmacological action of Ervatamia heyneana and thereby justifies its use in folk medicine.