EXTRACTS OF GINKGO-BILOBA AND GINSENOSIDES EXERT CEREBRAL VASORELAXATION VIA A NITRIC-OXIDE PATHWAY

1. Extracts from the leaves of Ginkgo biloba (EGb) and ginsenosides (G S) have been reported to be effective at increasing vascular relaxatio n. In the present study, the actions of EGb and GS on the vascular fun ctions of procine basilar arteries were investigated in vitro using ti ssue bath techniques. 2. Both EGb and GS relaxed the basilar artery in a concentration-dependent and partly endothelium-dependent manner. Ho wever, EGb appeared to be more potent than GS. Relaxation induced by t ransmural nerve stimulation (TNS) was significantly enhanced by EGb (7 .5, 15 and 30 mu g/mL) and GS (20, 40 and 80 mu g/mL) in both endothel ium-intact and -denuded basilar arteries. Enhanced TNS-induced relaxat ions were abolished by 0.3 mmol/L N-L-arginine. 3. The present study d emonstrates that nitric oxide plays a primary role in TNS-induced rela xation as well as in EGb- and GS-enhanced relaxation within the cerebr al vasculature. In addition, our data support the potential of these c ompounds as therapeutic strategies in cerebral ischaemia and other rel ated vascular dysfunctions.