Anti-platelet action of GU-7, a 3-arylcoumarin derivative, purified from glycyrrhizae radix.

We have purified GU-7, a 3-arylcoumarin derivative, from glycyrrhizae radix, which is a crude drug of kampo herbal medicines. This was identified to be a new chemical compound and was found to have an anti-platelet action. GU-7 inhibited platelet aggregation, phosphorylation of 40K and 20K dalton proteins, inositol 1,4,5-trisphosphate production, intraplatelet calcium increase and phosphodiesterase activity in vitro. The data indicate that GU-7 inhibits platelet aggregation by increasing intraplatelet cAMP concentration. We have already reported the existence of aldose reductase inhibitors in some kampo medicines. In addition to the aldose reductase inhibiting action, anti-platelet action may also explain the mechanism by which kampo medicines are effective to diabetic neuropathy.