Rice Research Institute, Kameda Seika Co., Ltd., Niigata 950-0198, Niigata, Japan.
Department of Mental Health, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan.
Nutrients. 2023 Aug 7;15(15):3491. doi: 10.3390/nu15153491.
The rice endosperm protein (REP) hydrolysate containing the following rice endosperm protein derived oligopeptides QQFLPEGQSQSQK, LPEGQSQSQK, and pEQFLPEGQSQSQK (a -terminal pyroglutamate residue-modified peptide) reportedly showed an antidepressant-like effect in an animal model. We investigated the effect of the REP hydrolysate on healthy humans who self-reported mental fatigue with subjectively low vigor. Seventy-six participants (age: 20-64 years) were randomly allocated to two groups. The influence of the REP hydrolysate on the mood state was evaluated in two studies: single intake (Study 1) and repeated intake over 4 weeks (Study 2). A salivary stress marker, Chromogranin A (CgA), was measured in Study 1. The single intake of the REP hydrolysate significantly improved the Profile of Mood Status 2nd edition for adults (POMS 2) subscale of Tension-Anxiety. Additionally, the salivary CgA concentrations were remarkably reduced after the single intake of the REP hydrolysate. Though a single intake of the REP hydrolysate did not significantly influence the other subscales and the TMD of the POMS 2 and the Euthymia Scale, both the subjective and objective results supported the possible effect of the REP hydrolysate on reducing anxiety and nervousness. No significant positive effects on the subjective mood state (Euthymia Scale and POMS 2) and sleep quality (Insomnia Severity Index) were observed in the trial setting employed for Study 2. In conclusion, a single intake of REP hydrolysate might help relax the subjective feelings of tension and anxiety. The effectiveness of repeated REP hydrolysate intake needs to be tested in a different clinical setting.
含水稻胚乳蛋白衍生寡肽 QQFLPEGQSQSQK、LPEGQSQSQK 和 pEQFLPEGQSQSQK（末端吡咯烷酮羧酸修饰肽）的水稻胚乳蛋白水解物据称在动物模型中具有抗抑郁作用。我们调查了 REP 水解物对自我报告精神疲劳、主观活力低的健康人群的影响。76 名参与者（年龄：20-64 岁）被随机分为两组。在两项研究中评估了 REP 水解物对情绪状态的影响：单次摄入（研究 1）和重复摄入 4 周（研究 2）。研究 1 中测量了唾液应激标志物嗜铬粒蛋白 A（CgA）。单次摄入 REP 水解物可显著改善成人心境状态问卷 2 版（POMS 2）的紧张-焦虑分量表。此外，REP 水解物单次摄入后，唾液 CgA 浓度显著降低。虽然 REP 水解物单次摄入对 POMS 2 的其他分量表和 TMD 以及欣快量表没有显著影响，但主观和客观结果均支持 REP 水解物对减轻焦虑和紧张感的可能作用。在研究 2 中使用的试验设置中，REP 水解物单次摄入对主观情绪状态（欣快量表和 POMS 2）和睡眠质量（失眠严重程度指数）没有显著的积极影响。总之，单次摄入 REP 水解物可能有助于放松紧张和焦虑的主观感受。需要在不同的临床环境中测试重复摄入 REP 水解物的效果。
