Continuous intake of quercetin-rich onion powder may improve emotion but not regional cerebral blood flow in subjects with cognitive impairment

• Published in: Heliyon 2023-08, Vol.9 (8), p.e18401, Article e18401
• Main Authors: Hayashi, Yuichi, Hyodo, Fuminori, Tana, Nakagawa, Kiyomi, Ishihara, Takuma, Matsuo, Masayuki, Shimohata, Takayoshi, Nishihira, Jun, Kobori, Masuko, Nakagawa, Toshiyuki
• Format: Article
• Language: English
• Subjects: Alzheimer's disease; Behavioral and psychological symptoms of dementia; blood flow; brain; cognition; cognitive disorders; dementia; Depression; diet; head; homeostasis; Mild cognitive impairment; onions; people; quercetin; Redox; tomography
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2023.e18401

Depression in later life is associated with dementia. Changes in motivated behavior are an important mechanism contributing to dysfunctional cognitive control in depression. Although continuous intake of quercetin-rich onion suppresses cognitive decline in aged people by improving their emotional condition, the effect of quercetin-rich onion on emotional condition in people living with cognitive impairment remains unclear. In this randomized, double-blind, placebo-controlled study of subjects with cognitive impairment, we found that subjects wrote more adjectives and adverbs per sentence on the Mini-Mental State Examination after intake of quercetin-rich onion powder than before intake, although regional cerebral blood flow on n-isopropyl-4-[123]iodoamphetamine hydrochloride single-photon emission computed tomography was not changed. In the EPM, mice that had received a quercetin-supplemented chow diet made a significantly increased number of exploratory head dips from the open arms of the maze. Moreover, the 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl decay rate, reflecting redox activity, was increased in mice fed a quercetin-added diet. These results indicate that quercetin-rich onion may affect motivated behavior in subjects with cognitive impairment, for whom quercetin intake may preserve redox homeostasis in the brain.