Genistein inhibits glutamate-induced apoptotic processes in primary neuronal cell cultures: an involvement of aryl hydrocarbon receptor and estrogen receptor/glycogen synthase kinase-3beta intracellular signaling pathway.
Neuroscience 2007;
145:592-604. [PMID:
17261353 DOI:
10.1016/j.neuroscience.2006.11.059]
[Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2006] [Revised: 11/22/2006] [Accepted: 11/30/2006] [Indexed: 01/26/2023]
Abstract
Phytoestrogens prevent neuronal damage, however, mechanism of their neuroprotective action has not been fully elucidated. This study aimed to evaluate the effects of genistein on glutamate-induced apoptosis in mouse primary neuronal cell cultures. Glutamate (1 mM) enhanced caspase-3 activity and lactate dehydrogenase (LDH) release in the hippocampal, neocortical and cerebellar neurons in time-dependent manner, and these data were confirmed at the cellular level with Hoechst 33342 and calcein AM staining. Genistein (10-10,000 nM) significantly inhibited glutamate-induced apoptosis, and the effect of this isoflavone was most prominent in the hippocampal cells. Next, we studied an involvement of estrogen and aryl hydrocarbon receptors in anti-apoptotic effects of genistein. A high-affinity estrogen receptor antagonist, ICI 182, 780 (1 microM), reversed, whereas less specific antagonist/partial agonist, tamoxifen (1 microM), either intensified or partially inhibited genistein effects. Aryl hydrocarbon receptor antagonist, alpha-naphthoflavone (1 microM), exhibited a biphasic action: it enhanced genistein action toward a short-term exposure (3 h) to glutamate, but antagonized genistein action toward prolonged exposure (24 h) to that insult. SB 216763 (1 microM), which preferentially inhibits glycogen synthase kinase-3beta (GSK-3beta), potentiated genistein effects. These data point to strong effects of genistein at low micromolar concentrations in various brain tissues against glutamate-evoked apoptosis. Moreover, this study provided evidence for involvement of aryl hydrocarbon receptor and estrogen receptor/GSK-3beta intracellular signaling pathway in anti-apoptotic action of genistein.
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