Effects of Mucuna pruriens protease inhibitors on Echis carinatus venom.

The medicinal plant Mucuna pruriens, with reputed anti-snake venom properties has been reported to contain a kunitz-type trypsin inhibitor. This study was undertaken to further evaluate the protease inhibitory potential of gpMuc, a multiform glycoprotein, and other protein fractions from M. pruriens seeds against trypsin, chymotrypsin, Echis carinatus snake venom, ecarin and thrombin. The results showed that gpMuc inhibited both trypsin and chymotrypsin activities and was thermally stable, maintaining its trypsin inhibitory activity at temperatures of up to 50°C. Its structural conformation was also maintained at pH ranges of 4-7. Immunoreactivity study confirms that it contains protease-recognizing epitope on one of its isoforms. The whole protein extract of M. pruriens seeds inhibited prothrombin activation by ecarin and whole E. carinatus venom, and also thrombin-like activity using chromogenic assay.