Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan; Department of Applied Biological Science, Graduate School of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan; School of Integrative and Global Majors (SIGMA), University of Tsukuba, Tsukuba, Ibaraki, Japan.
Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan; Department of Applied Biological Science, Graduate School of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan.
Nutrition. 2020 Jul-Aug;75-76:110751. doi: 10.1016/j.nut.2020.110751. Epub 2020 Feb 4.
Cocoa contains many chemical compounds that affect the physiological functions of experimental animals and humans. The present study used a mouse model characterized by disrupted circadian rhythms of locomotor activity and sleep-wake cycles to determine whether natural cocoa improves chronic sleep disorders (CSDs) induced by psychophysiological stress.
Mice were fed a high-fat, high-sucrose diet supplemented with 2.0% natural cocoa and stressed for 30 d to induce CSDs.
Dietary cocoa restored the amplitude reduction of day-night activity rhythms by improving reduced nocturnal wheel-running activities during CSDs. Electroencephalography revealed that dietary cocoa significantly ameliorated CSD-induced increases in wakefulness during the first half of the inactive phase and in nonrapid eye movement sleep during the first half of the active phase. The attenuation of circadian rapid eye movement sleep rhythms and increased electroencephalography slow-wave activity (a marker of nonrapid eye movement sleep intensity) induced by CSDs improved in mice supplemented with cocoa. Dietary cocoa notably did not affect wheel-running activity rhythms or sleep-wake cycles under normal conditions. Dietary cocoa significantly increased the hypothalamic mRNA expression of Hspa1 a that encodes HSP70 and is associated with sleep regulation. Furthermore, Hspa1 a expression was not induced by CSDs in mice supplemented with cocoa.
These findings suggest that dietary cocoa exerts beneficial effects on insomnia and circadian sleep disorders induced by psychophysiological stress.
可可含有许多影响实验动物和人类生理功能的化学物质。本研究使用一种以运动活动和睡眠-觉醒周期的昼夜节律紊乱为特征的小鼠模型，确定天然可可是否能改善心理生理性应激引起的慢性睡眠障碍（CSD）。
给小鼠喂食高脂肪、高蔗糖饮食，并补充 2.0%的天然可可，使其应激 30 天以诱导 CSD。
饮食可可通过改善 CSD 期间夜间车轮活动减少，恢复了昼夜活动节律幅度的降低。脑电图显示，饮食可可显著改善了 CSD 诱导的不活动期前半段觉醒和活动期前半段非快速眼动睡眠的增加。可可补充剂可改善 CSD 诱导的快速眼动睡眠节律衰减和脑电图慢波活动增加（非快速眼动睡眠强度的标志物）。可可补充剂还显著改善了 CSD 诱导的下丘脑 Hspa1a（编码 HSP70 的基因）的 mRNA 表达，而 Hspa1a 与睡眠调节有关。此外，在可可补充的小鼠中，CSD 并未诱导 Hspa1a 的表达。
这些发现表明，饮食可可对心理生理性应激引起的失眠和昼夜睡眠障碍有有益的作用。
