Antagonistic effects of extract from leaves of ginkgo biloba on glutamate neurotoxicity.

AIM

To determine whether the extract of leaves of Ginkgo biloba L (EGb) and several active constituents of EGb have protective effects against glutamate (Glu)-induced neuronal damage.

METHODS

Microscopy and image analysis of nucleus areas in the arcuate nuclei (AN) of mice were made. The neuronal viability in primary cultures from mouse cerebral cortex was assessed using MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] staining and the intracellular free calcium concentration ([Ca2+]i) of single neuron was measured using Fura-2.

RESULTS

EGb (2.5 mg.L-1) and its constituent ginkgolide B (Gin B, 2 mg.L-1) protected the neuronal viability against Glu-induced injury, and prevented the Glu-induced elevation in [Ca2+]i. EGb (3-10 mg.kg-1) attenuated the decrease of nucleus areas in arcuate nuclei induced by Glu (1 g.kg-1, s.c.).

CONCLUSION

EGb and Gin B prevent neurons from Glu neurotoxicity through reduction of the rise in [Ca2+]i.