Crocin, a carotenoid pigment, promotes non-rapid eye movement sleep

2014 Fiscal Year Final Research Report

• Project/Area Number: 25670047
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Natural medicines
• Research Institution: University of Tsukuba
• Principal Investigator: ARITAKE Kosuke 筑波大学, 国際統合睡眠医科学研究機構, 准教授 (70390804)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: ノンレム睡眠 / カロテノイド色素 / ヒスタミンH1受容体 / サイクロデキストリングルカノトランスフェラーゼ

Outline of Final Research Achievements

We compared the effects of crocin in wild-type mice, mice lacking of histamine H1 receptor (H1R) gene, dopamine D2 receptor (D2R) gene or adenosine A1 receptor (A1R) gene by monitoring the locomotor activities and electro encephalogram. In wild-type mice, D2R KO and A1R KO, crocin significantly decreased the locomotor activities and increased the time spent in non-REM sleep. In H1R KO mice, effects of crocin on locomotor activities and non-REM sleep were suppressed. Crocin did not show any specific binding affinities against H1R nor inhibited the histamine release. These results strongly suggested that crocin indirectly suppressed histamine arousal system to induce sleep.
We found enzymatically synthesized crocin-glycoside shows better property in chemical stabilities and photo stabilities than crocin.

Free Research Field

薬理学