Vasodilator ginkgo

Penile erection occurs by relaxation of the smooth muscle of the corpus cavernosum, increasing blood flow into the penis and producing erection and rigidity. In a parallel fashion, vaginal pressure stimulation increases blood velocity and flow into clitoral arteries (Lavoisier et al. 1995). Cavernosal vasodilation is accomplished by neurotransmitters released from the cavernosal nerve and endothelial cells. One of the most important transmitters in this cascade is nitric oxide (NO), which induces synthesis of cyclic GMP from guanylate cyclase (Rajfer et al. 1992). Thus, ginkgo s vascular mechanisms could be responsible for some of the putative sexual effects. 

Ginkgo leaf extract appears to act primarily as a mild cerebral vasodilator that increases cerebral blood flow and reduces blood viscosity. Ginkgolides inhibit platelet activating factor, and this may improve microcircula-tory blood flow in atherosclerotic disease with slightly increased risk of bleeding. There appears to be an antioxidant effect that may be neuroprotective. Although some studies suggested a monoamine oxidase inhibitor (MAOI) effect, this is considered to have questionable clinical relevance. 

D. Kava is often recommended for anxiety, and it appears significantly more effective than placebo for this condition. Garlic is used for cardiovascular benefits, saw palmetto for prostatic hypertrophy, and ginkgo as a cerebral vasodilator. Echinacea is considered an immunomodulating herb with potential benefit in viral illnesses. 

In animal models and some human studies, ginkgo has been shown to increase blood flow, reduce blood viscosity, and promote vasodilation, thus enhancing tissue perfusion. Enhancement of endogenous nitric oxide (see Chapter 19) and antagonism of platelet-activating factor may be involved. 

Wu Y, Li S, Cui W, Zu X, Du J, Wang F (2008) Ginkgo biloba extract improves coronary blood flow in healthy elderly adults role of endotheliimi-dependent vasodilation. Phytomedicine 15(3) 164—169. doi 10.1016/j.phymed.2007.12.002... 

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