Ginkgo biloba neuroprotective effects

Flavonoids in the diet have been widely promoted as important antioxidant contributors. Their neuroprotective properties, because of this effect, have been demonstrated by several workers. However, they have also been demonstrated to have MAOI activity and this has been proposed as part of the explanation of the use of the common herb, St Johns Wort, Hypericum perforatum L., as an antidepressant. This dual role has now been proposed for a variety of flavonoids, such as kaempferol (22) from the leaves of Ginkgo biloba L., a widely used herbal product which has been suggested as a preventative agent against neurodegeneration. Quercetin (23), similarly, has also shown to inhibit MAO-B " and reverse the effects of induced catalepsy, which mimics the bradykinesia associated with PD. Tangeretin (24) also inhibits MAO-B and crosses the blood brain barrier in a rat model. 

Ahlemeyer B, Krieglstein J. Neuroprotective effects of Ginkgo biloba extract. Cell Mol Life Sci 2003 60 1779-1792. 

Ahlemeyer, B. and J. Krieglstein. 1998. Neuroprotective effects of Ginkgo biloba extract. In Lawsib, L. D. and R. Bauer (eds.). Phytomedicines of Europe, Chemistry and Biological Activity. American Chemical Society. Washington, D.C. p. 210-220. 

Wu, W.R., and X.Z. Zhu. 1999. Involvement of monoamine oxidase inhibition in neuroprotective and neurorestorative effects of Ginkgo biloba extract against MPTP-induced nigrostriatal dopamineigic toxicity in C57 mice. Life Sci. 65 (2) 157-164. 

Calapai G, Crupi A, Fiienzuoli F, Marciano MC, Squadrito F, Inferrera G, Parisi A, Rizzo A, Crisafulli C, Fiore A, Caputi AP (2000) Neuroprotective effects of Ginkgo biloba extract in brain ischemia are mediated by inhibition of nitric oxide synthesis. Life Sci... 

Chandrasekaran K, Mehrabian Z, Spiimewyn B, Drieu K, Fiskum G (2001) Neuroprotective effects of bilobalide, a component of the Ginkgo biloba extract (EGb 761), in gtabil global brain ischemia. Brain Res 922(2) 282-292... 

Hirooka K, Tokuda M, Miyamoto O, Itano T, Baba T, Shiraga F (2004) The Ginkgo biloba extract (EGb 761) provides a neuroprotective effect on retinal ganglion cells in a rat model of chronic glaucoma. Curr Eye Res 28(3) 153-157. doi 10.1076/ ceyr.28.3.153.26246... 

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