| First Author | Bahia PK | Year | 2008 |
| Journal | J Neurochem | Volume | 106 |
| Issue | 5 | Pages | 2194-204 |
| PubMed ID | 18624917 | Mgi Jnum | J:138917 |
| Mgi Id | MGI:3806789 | Doi | 10.1111/j.1471-4159.2008.05542.x |
| Citation | Bahia PK, et al. (2008) Dietary flavonoid (-)epicatechin stimulates phosphatidylinositol 3-kinase-dependent anti-oxidant response element activity and up-regulates glutathione in cortical astrocytes. J Neurochem 106(5):2194-204 |
| abstractText | Flavonoids are plant-derived polyphenolic compounds with neuroprotective properties. Recent work suggests that, in addition to acting as hydrogen donors, they activate protective signalling pathways. The anti-oxidant response element (ARE) promotes the expression of protective proteins including those required for glutathione synthesis (xCT cystine antiporter, gamma-glutamylcysteine synthetase and glutathione synthase). The use of a luciferase reporter (ARE-luc) assay showed that the dietary flavan-3-ol (-)epicatechin activates this pathway in primary cortical astrocytes but not neurones. We also examined the distribution of NF-E2-related factor-2 (Nrf2), a key transcription factor in ARE-mediated gene expression. We found, using immunocytochemistry, that Nrf2 accumulated in the nuclei of astrocytes following exposure to tert-butylhydroquinone (100 muM) and (-)epicatechin (100 nM). (-)Epicatechin signalling via Nrf2 was inhibited by wortmannin implicating a phosphatidylinositol 3-kinase-dependent pathway. Finally, (-)epicatechin increased glutathione levels in astrocytes consistent with an up-regulation of ARE-mediated gene expression. Together, this suggests that flavonoids may be cytoprotective by increasing anti-oxidant gene expression. |
