Anti-Platelet Fraction from Galega officinalis L. Inhibits Platelet Aggregation

A fraction from crude extract of Galega officinalis L. was purified by gel filtration on Sephadex G-25, Sepharose 4B, and ion-exchange chromatography on diethylaminoethyl (DEAE)-cellulose. The fraction with molecular weight 100-140 kDa appears to have a polysaccharide nature, including protein. The fraction inhibits platelet aggregation initiated by 25 μM adenosine 5′-diphosphate (ADP), 100 μg/ml collagen, and 0.8 U/ml thrombin with the 50% inhibiting concentration (IC₅₀) being 11.2 μg/ml for ADP, and the IC₁₀₀ being 15.1 μg/ml for collagen and IC₁₀₀ 19.6 μg/ml for thrombin.