ABSTRACT
The Ginkgo bi1oba extract (GBE) is a complex enriched with many active ingredients prepared from the leaves of Ginkgo biloba, several components of which are known to have vasoregulatory activity of arteries, capillaries and veins resulting in increased blood flow. Among the fractions of GBE, nonginkgolide nonflavonoid fraction (NGF) has the most potent relaxing effect on vascular smooth muscle. We subfractionated NGF and speculated that some of subfractions might have very potent relaxing effect on corpus cavernosal smooth muscle in both human and animals. To investigate the effect of subfractions of NGF on the corpus cavernosal smooth muscle and the possibility whether they could be used for the treatment of impotence, we have studied on the human and rabbit corpus cavernosum using organ bath and electrical field stimulation experiments. The results suggested that subfractions of NGF, especially 304U-1, have relaxing effect on corpus cavernosum tissue. 304U-1 which showed the most potent relaxing effect can be possibly used as a drug for intracavernosal injection therapy. Considering the fact that the value of ED50 is too high, further fractionation and in vivo study are needed before clinical usage in an oral form.