title: The cyanine Dye NK-4 improves scopolamine-induced memory impairments in mice.
abstract: The aim of this study is to evaluate the effects of NK-4, a kind of cyanine dye, on cholinergic memory deficits in mice. We examined whether NK-4 could reverse scopolamine-induced amnesia in mice since NK-4 displays a potent and selective inhibitory effect on acetylcholinesterase (AChE) in vitro. Intraperitoneal administration of NK-4 significantly reversed scopolamine-induced cognitive impairments in mice in the Y maze and the passive avoidance tests, and NK-4 also improved spatial learning ability in the Morris water maze test. Despite NK-4 displaying remarkable AChE inhibitory activity in vitro, we could not detect a significant reduction of AChE activity in brain homogenates of NK-4-treated mice. Although the mechanism through which NK-4 reverses cognitive impairments in scopolamine-treated mice remains unclear, these data suggest that NK-4 may have potential as a therapeutic agent for the treatment of dementia.
authors.affiliation: R&D Center, Hayashibara Co., Ltd., 675–1 Fujisaki, Naka-ku, Okayama 702–8006, Japan. satoko.uchida@hb.nagase.co.jp
authors.forename: Satoko
authors.initials: S
authors.lastname: Uchida
authors.forename: Shin
authors.initials: S
authors.lastname: Endo
authors.forename: Kenji
authors.initials: K
authors.lastname: Akita
authors.forename: Tsunetaka
authors.initials: T
authors.lastname: Ohta
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Fukuda
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects; D002091:Butyrylcholinesterase / Q000378:metabolism; D002232:Carbocyanines / Q000494:pharmacology / Q000627:therapeutic use*; D002540:Cerebral Cortex / Q000187:drug effects / Q000201:enzymology; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008569:Memory Disorders / Q000139:chemically induced / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D051379:Mice; D008813:Mice, Inbred ICR; D009043:Motor Activity / Q000187:drug effects; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D011916:Rats, Inbred F344; D012601:Scopolamine
chemical_list: D002232:Carbocyanines; C578584:NK-4 dye; D018696:Neuroprotective Agents; D012601:Scopolamine; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase