Jatrophone Inhibits Platelet Rich Plasma Aggregation from Man,Rat and Guinea-pig Induced by Different Agents

The effect of jatrophone (2.5–100 μM ), a diterpene isolated from Jatropha elliptica , upon the aggregation (platelet rich plasma) induced by several agents in different animal species was examined. At the same range of inhibitory concentrations (24.0–43.0 μM ) previously shown to inhibit contractions triggered by different agents in isolated muscle preparations, jatrophone markedly inhibited platelet aggregation. This effect was dose-dependent and it was reversible for up to 30 min. It is concluded that this nonspecific effect could reflect an action of jatrophone either at an intracellular step in the signal transduction process, which is common to different agonists, or at the level of extracellular and/or intracellular Ca²⁺ mobilization.