Isoliquiritigenin, a Chalcone Compound, Enhances Spontaneous Inhibitory Postsynaptic Response

Abstract

Isoliquiritigenin (ILTG) is a chalcone compound and shows various pharmacological properties, including antioxidant and anti-inflammatory activities. In recent study, we have reported a novel role of ILTG in sleep through a positive allosteric modulation ofgamma-aminobutyric acid type A (GABAA)-benzodiazepine (BZD) receptors. However, the effect of ILTG in GABAAR-mediatedsynaptic response in brain has not been tested yet. Here we report that ILTG significantly prolonged the decay of spontaneousinhibitory postsynaptic currents (sIPSCs) mediated by GABAAR in mouse hippocampal CA1 pyramidal neurons without affectingamplitude and frequency of sIPSCs. This enhancement was fully inhibited by flumazenil (FLU), a specific GABAA-BZD receptorantagonist. These results suggest a potential role of ILTG as a modulator of GABAergic synaptic transmission.