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- 2019
The flavonoid, 2′Keywords: Photothrombotic stroke,inflammation,tonic inhibition,motor behaviour,γ-aminobutyric acid Abstract: Tonic inhibitory currents, mediated by extrasynaptic GABAA receptors, are elevated at a delay following stroke. Flavonoids minimise the extent of cellular damage following stroke, but little is known about their mode of action. We demonstrate that the flavonoid, 2′-methoxy-6-methylflavone (0.1–10?μM; 2′MeO6MF), increases GABAA receptor tonic currents presumably via δ-containing GABAA receptors. Treatment with 2′MeO6MF 1–6?h post focal ischaemia dose dependently decreases infarct volume and improves functional recovery. The effect of 2′MeO6MF was attenuated in δ?/? mice, indicating that the effects of the flavonoid were mediated via δ-containing GABAA receptors. Further, as flavonoids have been shown to have multiple modes of action, we investigated the anti-inflammatory effects of 2′MeO6MF. Using a macrophage cell line, we show that 2′MeO6MF can dampen an LPS-induced elevation in NFkB activity. Assessment of vehicle-treated stroke animals revealed a significant increase in circulating IL1β, TNFα and IFγ levels. Treatment with 2′MeO6MF dampened the stroke-induced increase in circulating cytokines, which was blocked in the presence of the pan-AKT inhibitor, GSK690693. These studies support the hypothesis that compounds that potentiate tonic inhibition via δ-containing GABAA receptors soon after stroke can afford neuroprotection
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