title: The flavonoid apigenin delays forgetting of passive avoidance conditioning in rats.
abstract: The present experiments were performed to study the effect of the flavonoid apigenin (20 mg/kg intraperitoneally (i.p.), 1 h before acquisition), on 24 h retention performance and forgetting of a step-through passive avoidance task, in young male Wistar rats. There were no differences between saline- and apigenin-treated groups in the 24 h retention trial. Furthermore, apigenin did not prevent the amnesia induced by scopolamine (1mg/kg, i.p., 30 min before the acquisition). The saline- and apigenin-treated rats that did not step through into the dark compartment during the cut-off time (540 s) were retested weekly for up to eight weeks. In the saline treated group, the first significant decline in passive avoidance response was observed at four weeks, and complete memory loss was found five weeks after the acquisition of the passive avoidance task. At the end of the experimental period, 60% of the animals treated with apigenin still did not step through. These data suggest that 1) apigenin delays the long-term forgetting but did not modulate the 24 h retention of fear memory and 2) the obtained beneficial effect of apigenin on the passive avoidance conditioning is mediated by mechanisms that do not implicate its action on the muscarinic cholinergic system.
authors.affiliation: 1Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain.
authors.forename: Miroljub
authors.initials: M
authors.lastname: Popović
authors.forename: María
authors.initials: M
authors.lastname: Caballero-Bleda
authors.forename: Obdulio
authors.initials: O
authors.lastname: Benavente-García
authors.forename: Julián
authors.initials: J
authors.lastname: Castillo
mesh_terms: D000647:Amnesia / Q000139:chemically induced / Q000188:drug therapy; D000818:Animals; D047310:Apigenin / Q000494:pharmacology*; D001362:Avoidance Learning / Q000187:drug effects*; D003213:Conditioning, Psychological / Q000187:drug effects*; D005239:Fear / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects*; D008569:Memory Disorders / Q000139:chemically induced / Q000188:drug therapy*; D051381:Rats; D017208:Rats, Wistar; D012601:Scopolamine / Q000494:pharmacology
chemical_list: D005419:Flavonoids; D047310:Apigenin; D012601:Scopolamine
keywords: Apigenin; flavonoids; forgetting; memory retention; passive avoidance; scopolamine