A novel selective inhibitor to thrombin-induced platelet aggregation purified from the leech Whitmania pigra.

BACKGROUND/AIM: The dried whole body of the leech Whitmania pigra, a well-known traditional Chinese medicine, has been widely used to treat thrombus diseases for thousands of years. However, its bioactive constituents were reported rarely. The aim of our study was to investigate antithrombotic components of it. METHODS: The antithrombotic peptide was purified using a combination of anion-exchange chromatography, ultrafiltration and reverse-phase HPLC. the sequence of the peptide was determined using MALDI-TOF-MS-MS. Anti-platelet aggregation activity in vitro was evaluated using a turbidimetric method, and antithrombotic effect in vivo was assessed in an arterio-venous shunt thrombosis model in rats. RESULTS: A novel antithrombotic peptide named WP-30, with the sequence VISRTQSNVQAAWGQVGGHAADYSAVAIER, was isolated from the dried whole body of the leech W. pigra. WP-30 selectively inhibited thrombin-induced anti-platelet aggregation in vitro, and potently attenuated thrombus formation in rats in vivo. CONCLUSIONS: Taken together, we found a novel peptide from leech bodies, and this peptide showed antiplatelet aggregation and antithrombotic effects.

Synergy Effects of Three Plant Extracts on Protection of Gastric Mucosa.

The gastric mucosa protection effect of three natural plant extracts, Hericium erinaceus (HE), Centella asiatica (CA) and Amomum villosum (AV), were evaluated using the indomethacin damage model. Compared with a single extract, a combination of HE/CA/AV, especially with the ratios of 80:10:10, 45:45:10 and 45:10:45, showed significant synergistic effects for protection of the gastric mucosa with gastric ulcer inhibition rates of 97.8 ± 0.7%, 86.5 ± 2.8% and 86.1 ± 3.6%, respectively. Microscopic appearances of the gastric mucosa were carried out to help confirm the results.