Effects of Chronic Administration of a Standardized Rice Bran Supplement on Sleep Architecture and Profiles in Mice: A Comparative Study with a Hypnotic Drug Zolpidem.

This study aimed to investigate the effects of chronic administration of rice bran supplement (RBS) on sleep and to compare these effects with those of the hypnotic drug zolpidem (ZPD). During the three-week treatment period, ZPD initially reduced sleep latency, but that reduction effect of sleep latency gradually diminished over time and significantly decreased non-rapid eye movement sleep (NREMS). In contrast, RBS reduced sleep latency and increased NREMS on the first day, and these effects persisted throughout the treatment period. Additionally, RBS altered the time course of NREMS, which persisted until day 21. Importantly, while RBS did not affect delta activity during the treatment period, the ZPD group experienced a decrease in delta activity on the first day, which recovered by day 21. Our findings suggest that RBS does not induce tolerance during chronic administration and does not alter sleep architecture upon discontinuation, indicating that it could be utilized as a natural sleep aid suitable for long-term consumption.