Joseph A Lutz1, Megan Carter2, Logan Fields2, Susan Barron2, John M Littleton2. 1. Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky. 2. Department of Psychology, College of Arts and Sciences, University of Kentucky, Lexington, Kentucky.
Abstract
BACKGROUND: Ethanol (EtOH) causes neurotoxicity via several mechanisms including neuroinflammation (during EtOH exposure), and excitotoxicity (during EtOH withdrawal [EWD]). Alpha7 nicotinic acetylcholine receptor (nAChR) selective agonists have the potential to reduce both. The aim of this study was to evaluate the anti-inflammatory and neuroprotective potential of rhamnetin, a dietary flavonoid with alpha7 nAChR selective activity, in an in vitro model of EtOH-induced neurotoxicity. METHODS: The anti-inflammatory and neuroprotective properties of rhamnetin were assessed in neonatal organotypic hippocampal slice cultures undergoing EWD (or not) and challenged with N-methyl-D-aspartate (NMDA) and/or lipopolysaccharide (LPS). Neurotoxicity was determined using propidium iodide uptake, and the inflammatory response was evaluated by measuring the release of tumor necrosis factor (TNF)-alpha (NO; quantified by ELISA) and nitric oxide (quantified by the Griess reaction) into culture media. RESULTS: As predicted, rhamnetin reduced LPS-induced release of TNF-alpha and NO both under control conditions and during EWD. Additionally, rhamnetin had no effect on NMDA-induced neurotoxicity under control conditions, but significantly reduced NMDA toxicity during EWD. In contrast, rhamnetin had no effect on neurotoxicity induced by NMDA and LPS combined despite reducing TNF-alpha and NO levels under these conditions. CONCLUSIONS: Rhamnetin is anti-inflammatory and neuroprotective during EWD and therefore has potential value in treating neurotoxicity caused by EtOH.
BACKGROUND:Ethanol (EtOH) causes neurotoxicity via several mechanisms including neuroinflammation (during EtOH exposure), and excitotoxicity (during EtOH withdrawal [EWD]). Alpha7 nicotinic acetylcholine receptor (nAChR) selective agonists have the potential to reduce both. The aim of this study was to evaluate the anti-inflammatory and neuroprotective potential of rhamnetin, a dietary flavonoid with alpha7 nAChR selective activity, in an in vitro model of EtOH-induced neurotoxicity. METHODS: The anti-inflammatory and neuroprotective properties of rhamnetin were assessed in neonatal organotypic hippocampal slice cultures undergoing EWD (or not) and challenged with N-methyl-D-aspartate (NMDA) and/or lipopolysaccharide (LPS). Neurotoxicity was determined using propidium iodide uptake, and the inflammatory response was evaluated by measuring the release of tumor necrosis factor (TNF)-alpha (NO; quantified by ELISA) and nitric oxide (quantified by the Griess reaction) into culture media. RESULTS: As predicted, rhamnetin reduced LPS-induced release of TNF-alpha and NO both under control conditions and during EWD. Additionally, rhamnetin had no effect on NMDA-induced neurotoxicity under control conditions, but significantly reduced NMDAtoxicity during EWD. In contrast, rhamnetin had no effect on neurotoxicity induced by NMDA and LPS combined despite reducing TNF-alpha and NO levels under these conditions. CONCLUSIONS:Rhamnetin is anti-inflammatory and neuroprotective during EWD and therefore has potential value in treating neurotoxicity caused by EtOH.
Authors: R Douglas Shytle; Takashi Mori; Kirk Townsend; Martina Vendrame; Nan Sun; Jin Zeng; Jared Ehrhart; Archie A Silver; Paul R Sanberg; Jun Tan Journal: J Neurochem Date: 2004-04 Impact factor: 5.372
Authors: M A Prendergast; B R Harris; P J Mullholland; J A Blanchard; D A Gibson; R C Holley; J M Littleton Journal: Neuroscience Date: 2004 Impact factor: 3.590