Differential effects of new breviscapine on arachidonic acid metabolisms in blood cells and endothelial cells.

New breviscapine (NB) is the soluble sodium and calcium salts of 4'-scutellarin-7-glucuronide extracted from the Chinese herb Erigeron breviscapus (Vant) Hand-Mazz. It inhibited platelet thromboxane B2 production without alteration of HETE. It also inhibited 6-ketoprostaglandin F1 alpha production by endothelial cells. For leukocytes, NB did not affect thromboxane B2 production. However, it potentiated the effect of calcimycin in stimulating LTB4 formation. These results indicate that NB exerts differential effects on the arachidonic acid metabolism in different blood cells and endothelial cells.