Inhibition of amyloid-β aggregation and caspase-3 activation by the Ginkgo biloba extract EGb761

Yuan Luo1, Julie V Smith1, Vijaykumar Paramasivam1, Adam J Burdick1, Kenneth J. Curry1, Justin P. Buford1, Ikhlas A. Khan1, William J. Netzer1, Huaxi Xu1, Peter Butko1
1Departments of Biological Sciences and Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS 39406; National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677; Laboratory of Cellular and Molecular Neuroscience, The Rockefeller University, New York, NY 10021; and School of Life Sciences, Xiaman University, Fujian, China

Tóm tắt

Standardized extract from the leaves of the Ginkgo biloba tree, labeled EGb761, has been used in clinical trials for its beneficial effects on brain functions, particularly in connection with age-related dementias and Alzheimer's disease (AD). Substantial experimental evidence indicates that EGb761 protects against neuronal damage from a variety of insults, but its cellular and molecular mechanisms remain unknown. Using a neuroblastoma cell line stably expressing an AD-associated double mutation, we report that EGb761 inhibits formation of amyloid-β (Aβ) fibrils, which are the diagnostic, and possibly causative, feature of AD. The decreased Aβ fibrillogenesis in the presence of EGb761 was observed both in the conditioned medium of this Aβ-secreting cell line and in solution in vitro . In the cells, EGb761 significantly attenuated mitochondrion-initiated apoptosis and decreased the activity of caspase 3, a key enzyme in the apoptosis cell-signaling cascade. These results suggest that ( i ) neuronal damage in AD might be due to two factors: a direct Aβ toxicity and the apoptosis initiated by the mitochondria; and ( ii ) multiple cellular and molecular neuroprotective mechanisms, including attenuation of apoptosis and direct inhibition of Aβ aggregation, underlie the neuroprotective effects of EGb761.

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Tài liệu tham khảo

10.2174/1389450003349380

Christen Y. (2001) Adv. Ginkgo biloba Extr. Res.8,1-12.

Luo Y. (2001) J. Alz. Dis.3,401-407.

10.1016/0197-4580(94)90125-2

10.1172/JCI8508

10.1146/annurev.neuro.21.1.479

10.1126/science.293.5538.2192

10.1073/pnas.051627098

10.1016/S0896-6273(00)80115-4

10.1006/nbdi.2001.0431

10.1016/S0002-9440(10)65460-0

10.1038/47513

10.1248/cpb.49.1170

10.1016/S0896-6273(00)80291-3

10.1073/pnas.94.8.3748

10.1016/S0006-3495(94)80591-0

10.1016/S0076-6879(99)09031-X

10.1016/S0092-8674(00)80085-9

10.1126/science.281.5381.1309

10.1126/science.281.5381.1312

10.1073/pnas.90.22.10573

10.1016/S0006-8993(96)01060-8

10.1523/JNEUROSCI.19-20-08876.1999

10.1074/jbc.273.13.7185

10.1038/35102591

10.1074/jbc.M008128200

10.1016/S0006-8993(97)01003-2

10.1038/nm0798-822

10.1016/S0304-3940(00)00834-X

Ramassamy C., Christen, Y. & Poirier, J. (2001) Adv. Ginkgo biloba Extr. Res.8,71-89.

10.1016/S0006-8993(00)03131-0

Smith J. V. Burdick A. J. Golik P. Khan I. Wallace D. & Luo Y. (2002) Cell. Mol. Biol. in press.

10.1016/S0006-8993(98)00763-X

10.1126/science.2218531

10.1128/CDLI.8.2.325-332.2001

10.1146/annurev.cellbio.15.1.269

10.1523/JNEUROSCI.20-04-01386.2000

10.1073/pnas.111126298