The neuroprotective effects of an extract of Gastrodia elata

Ethnopharmacological relevance: Gastrodia elata (GE) Blume (family Orchidaceae) is a traditional Chinese herbal medicine for treating headaches, dizziness, tetanus, and epilepsy, indicating neuronal protective functions. Aim of the study: To evaluate the neuroprotection of GE and its molecular mechanism in preventing serum deprivation-induced PC12 cell apoptosis. Materials and methods: An MIT assay and Hoechst staining were used to respectively validate serum deprivation-induced cell death and apoptosis. Cyclic (c)AMP formation and protein kinase (PK)A activity were also measured after GE treatment. Western blotting was used to detect the phosphorylation of the cAMP response element-binding (CREB) protein. Transient transfection of a dominant negative CREB was used to validate the importance of CREB. Results: GE targeted the adenosine A(2A) receptor (A(2A)-R). GE increased cAMP formation, PKA activity, and phosphorylation of the CREB protein. GE-induced CREB protein phosphorylation and protection was blocked by a PKA inhibitor and overexpression of the dominant negative CREB, respectively. Conclusions: These results support the neuroprotective effects of GE. The protective mechanism might be mediated through an A(2A)-R/cAMP/PKA/CREB-dependent pathway. (C) 2011 Elsevier Ireland Ltd. All rights reserved.