Relieving psychological stress and improving sleep quality by bergamot essential oil use before bedtime and upon awakening: A randomized crossover trial.

OBJECTIVES: The COVID-19 pandemic increased psychological stress and decreased sleep quality, especially among young people. Aromatherapy alleviates psychological stress, and bergamot essential oil helps improve depression. This study aimed to verify whether bergamot essential oil use alleviates psychological stress due to the COVID-19 pandemic and improves sleep quality and morning wakefulness. DESIGN: A placebo-controlled, randomized, open-label, two-arm, two-period crossover trial. INTERVENTIONS: Each intervention period was 1 week, with a 1-week washout period between the two periods. Participants used a bergamot or placebo spray before bedtime and upon awakening in each period. MAIN OUTCOME MEASURES: The primary outcome measures were sleep quality and morning wakefulness, assessed using the Ogri-Shirakawa-Azumi sleep inventory MA version (OSA-MA). The secondary outcome measures were depression, anxiety, and stress, assessed using the Depression Anxiety Stress Scales-21 (DASS-21). RESULTS: A total of 48 university students participated in the study. A significant improvement was observed in "sleepiness on rising," "refreshing on rising," and "sleep length" in the bergamot group. Additionally, a significant improvement was observed in depression, anxiety, and stress. CONCLUSION: Using bergamot essential oil before bedtime helps relax the mind and body and provides sound sleep. It also improves mood and wakefulness when used upon awakening. Using aromatic essential oils is expected to relieve psychological stress and improve sleep quality and morning wakefulness.

Correction to: Laxative effect of repeated Daiokanzoto is attributable to decrease in aquaporin-3 expression in the colon.

The article Laxative effect of repeated Daiokanzoto is attributable to decrease in aquaporin-3 expression in the colon, written by Risako Kon, Miho Yamamura, Yukari Matsunaga, Hiroshi Kimura, Moe Minami, Saki Kato, Nobutomo Ikarashi, Kiyoshi Sugiyama, was originally published electronically on the publisher's internet portal (currently SpringerLink) on 27 January 2018 without open access.

Laxative effect of repeated Daiokanzoto is attributable to decrease in aquaporin-3 expression in the colon.

Daiokanzoto (DKT) exerts its laxative effect via colonic inflammation caused by sennoside A in Daio (rhubarb). Previously, we showed that the laxative effect of sennoside A is related to decreased aquaporin-3 (AQP3) expression in mucosal epithelial cells due to colonic inflammation. We also found that a combination of glycyrrhizin, an ingredient in Kanzo (glycyrrhiza), and sennoside A attenuates the inflammatory response induced by sennoside A and reduces its laxative effect. These findings indicate that DKT may be a long-term treatment for chronic constipation, but there is no evidence supporting this hypothesis. In this study, we analyzed the laxative effect of repeated DKT administration, focusing on AQP3 expression in the colon. After rats were treated for 7 days, decreased AQP3 expression and the onset of diarrhea were observed in the DKT group, but were not seen in the Daio group either. Although the relative abundance of gut microbiota after repeated DKT administration was similar to that after control treatment, Daio reduced Lactobacillaceae, Bifidobacteriaceae, and Bacteroidaceae levels and markedly increased Lachnospiraceae levels. In this study, we show that DKT has a sustained laxative effect, even upon repeated use, probably because it maintains decreased AQP3 expression and gut microbiota homeostasis. This outcome therefore indicates that DKT can be used as a long-term treatment for chronic constipation.