Effects of Chronic Administration of Green Tea Ethanol Extract on Sleep Architecture in Mice: A Comparative Study with a Representative Stimulant Caffeine.

Wakefulness is defined as a state in which individuals can react to a change in situations. The number of people staying awake and compensating for lack of sleep has increased in recent years. Caffeine, a representative stimulant, is the most extensively consumed compound globally and is mainly consumed through coffee. Although green tea (Camellia sinensis L.) contains high caffeine content like coffee, its arousal-inducing effects have not yet been studied. In the present study, we aimed to identify the arousal-inducing effect of GT during a chronic administration period (three weeks) using analysis of sleep architecture. Treatment with GT (1500 mg/kg) significantly elevated the sleep latency and wakefulness throughout the treatment period, and chronic administration of GT consistently maintained an increase in wakefulness for up to 3 h. During the treatment period, the arousal-inducing effect of GT (1500 mg/kg) occurred without any change in the tolerance phenomenon or withdrawal symptoms, similar to that observed with caffeine (25 mg/kg). GT (1500 mg/kg) containing 95.6 mg/kg of caffeine did not produce a better arousal-inducing effect than caffeine at 25 mg/kg. These results indicate that the arousal-inducing effect of GT persisted for three weeks without adverse effects and that GT can control the arousal-inducing effects of caffeine due to the hypnotic effects of its other constituents.

Correction: Curcuminoids, a major turmeric component, have a sleep-enhancing effect by targeting the histamine H1 receptor.

Correction for 'Curcuminoids, a major turmeric component, have a sleep-enhancing effect by targeting the histamine H1 receptor' by Min Young Um et al., Food Funct., 2022, 13, 12697-12706, https://doi.org/10.1039/D2FO02087D.

Marine Polyphenol Phlorotannins as a Natural Sleep Aid for Treatment of Insomnia: A Review of Sedative-Hypnotic Effects and Mechanism of Action.

Insomnia is a common sleep disorder. Natural sleep aids are gaining worldwide popularity as alternatives to prescription drugs for improving sleep. Recently, numerous studies have investigated the sedative-hypnotic effects of the polyphenols of terrestrial plants. The hypnotic effects of marine polyphenols have also been studied in recent years. Phlorotannins are marine polyphenols that are found only in brown algae. Phlorotannins exert sedative-hypnotic effects via the gamma-aminobutyric acid type A-benzodiazepine receptor. In addition, the brown seaweed Ecklonia cava supplement containing phlorotannins has been approved by the Ministry of Food and Drug Safety as a health-functional ingredient that helps improve sleep quality. Currently, it is meaningful to deal with the sedative-hypnotic effects of phlorotannins as natural sleep aids. The current review comprehensively presents the sedative-hypnotic effects in animal models and human clinical trials as well as their mechanism of action, extraction, purification, and safety.

Effects of Green Kiwifruit Peel Extract on Sleep-Wake Profiles in Mice: A Polysomnographic Study Based on Electroencephalogram and Electromyogram Recordings.

In the previous study, it was reported that green kiwifruit peel ethanol extract (GKPEE) increases sleep duration and decreases sleep latency in pentobarbital-treated mice. The pentobarbital-induced sleep test can be used to verify sleep quantity, which includes factors such as sleep duration and latency, but not sleep quality. In the present study, the sleep-promoting effects of GKPEE were investigated by the analysis of electroencephalogram (EEG) and electromyogram in mice and were compared with the results of diazepam (DZP), a representative sedative-hypnotic agent. The acute administration of GKPEE (250, 500 and 1000 mg/kg) increased the amount of non-rapid eye movement sleep (NREMS) and decreased sleep latency in a dose-dependent manner. The effect of GKPEE at 1000 mg/kg produced persistently significantly different results until the second hour of time-course changes. In particular, GKPEE did not produce any change in delta activity compared to DZP. Furthermore, sub-chronic administration (15 days) of GKPEE (500 mg/kg) continued sleep-promoting effects, whilst the EEG power density of NREMS did not show significant differences, indicating that there were no tolerance phenomena. Our findings suggest that GKPEE may be a promising natural sleep aid for treating sleep disorders. In addition, considering the number of by-products discarded each year by the food industry, the application of GKPEE here contributes to the utilization of processed kiwifruit by-products and can help to solve environmental problems.

Curcuminoids, a major turmeric component, have a sleep-enhancing effect by targeting the histamine H1 receptor.

Turmeric (Curcuma longa) had been considered as a universal panacea in functional foods and traditional medicines. In recent, the sedative-hypnotic effect of turmeric extract (TE) was reported. However, sleep-promoting compounds in TE have been not yet demonstrated. Curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) are the major constituents of turmeric being responsible for its various biological activities. Therefore, they can be first assumed to be sedative-hypnotic compounds of TE. In the present study, we aimed to investigate the effects and underlying mechanisms of curcuminoids and each constituent on the sleep-wake cycle of mice. Molecular docking studies, histamine H1 receptor (H1R) binding assays, and H1R knockout animal studies were used to investigate the molecular mechanisms underlying the sleep-promoting effects. Curcuminoids and their constituents reduced sleep latency and increased sleep duration in the pentobarbital-induced sleep test in mice. In addition, curcuminoids significantly increased the duration of NREMS and reduced sleep latency without altering the REMS and delta activity. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin were predicted to interact with H1R in the molecular model. In the binding affinity assay, we found that curcuminoids, as well as their constituents, significantly bind to H1R with the Ki value of 1.49 µg mL-1. Furthermore, sleep latency was reduced and NREMS frequency was increased following curcuminoid administration in wild-type mice but not in H1R knockout mice. Therefore, we conclude that curcuminoids reduce sleep latency and enhance the quantity of NREMS by acting as modulators of H1R, indicating their usefulness in treating insomnia.

Preventive Measures Against COVID-19 in Small- and Mid-sized Enterprises from an Early Stage of the Epidemic in Daegu and Gyeongsangbuk-do.

Background: In the early stage of the coronavirus disease 2019 (COVID-19) epidemic, small- and mid-sized enterprises (SMEs) may be an important transmission consideration. The study aimed to identify the pattern of COVID-19 prevention measures during the outbreaks in Daegu and Gyeongsangbuk-do at the early stage of COVID-19. Moreover, we investigated whether SME size and past experiences affected the preventive measures implemented in the region. Methods: A survey detailing the general characteristics and implementation of 12 preventive activities was conducted in 122 SMEs in Daegu and Gyeongsangbuk-do. The survey was analyzed by size and operation period. Results: The study subjects consisted of 53 (43.4%) workplaces with 1-5 employees, 50 (40.9%) workplaces with 6-30 employees, and 19 (15.6%) workplaces with 31-49 employees. The lowest three items among those surveyed were 'symptomatic workers to stay home for 3-4 days' (17.2%), 'work remotely' (18.9%), and 'video meetings' (20.5%). There were significant differences in the rate of several preventive measures implemented. The larger sized SMEs, the higher the number of implementations (p < 0.01). The operation period had no significant relationship with the implementation of preventive measures. The same pattern was observed in multiple generalized linear regression with covariate adjustment. Conclusion: Preventive measures among SMEs with fewer than 50 employees were identified. Even within SMEs, a gap in preventive measures according to size was confirmed. To prevent the spread of infection and protect workers' right to health, different support for different sized SMEs is necessary.

Comparison of Imitation Crab Sticks with Real Snow Crab (Chionoecetes opilio) Leg Meat Based on Physicochemical and Sensory Characteristics.

Recently, many manufacturers have been developing or producing imitation crab sticks (ICSs) that are highly similar to real snow crab leg meat (RC). This study evaluated the similarities between commercial ICSs and RC based on the analysis of physicochemical and sensory properties. Normal ICS (NS) and premium ICSs either with real crab leg meat (PS-RC) or without it (PS) were compared with RC. The sensory evaluation results showed that PS and NS had the highest and lowest levels of similarity to RC, respectively. The carbohydrate contents of ICSs (10-23%) were higher than that of RC (0.5%). Among ICSs, PS showed more similarity with RC than NS and PS-RC in terms of gel strength and texture profiles. PS-RC and PS showed a microstructural pattern that slightly imitated the muscle fiber arrangement of RC. The electric tongue analysis of taste compounds, such as sugars, free amino acids, and nucleotides, showed that the taste profile of ICSs is distinctly different from that of RC. The electronic nose analysis identified 32 volatile compounds, while the principal component analysis using electronic nose data successfully distinguished three clusters: PS-RC and PS, RC, and NS. Our results could provide useful information for the development of ICSs with higher similarity to RC.

Arousal-Inducing Effect of Garcinia cambogia Peel Extract in Pentobarbital-Induced Sleep Test and Electroencephalographic Analysis.

Caffeine, a natural stimulant, is known to be effective for weight loss. On this basis, we screened the arousal-inducing effect of five dietary supplements with a weight loss effect (Garcinia cambogia, Coleus forskohlii, Camellia sinensis L., Irvingia gabonensis, and Malus pumila M.), of which the G. cambogia peel extract (GC) showed a significant arousal-inducing effect in the pentobarbital-induced sleep test in mice. This characteristic of GC was further evaluated by analysis of electroencephalogram and electromyogram in C57L/6N mice, and it was compared to that of the positive control, caffeine. Administration of GC (1500 mg/kg) significantly increased wakefulness and decreased non-rapid eye movement sleep, similar to that of caffeine (25 mg/kg), with GC and caffeine showing a significant increase in wakefulness at 2 and 6 h, respectively. Compared to that of caffeine, the shorter duration of efficacy of GC could be advantageous because of the lower possibility of sleep disturbance. Furthermore, the arousal-inducing effects of GC (1500 mg/kg) and caffeine (25 mg/kg) persisted throughout the chronic (3 weeks) administration study. This study, for the first time, revealed the arousal-inducing effect of GC. Our findings suggest that GC might be a promising natural stimulant with no side effects. In addition, it is preferential to take GC as a dietary supplement for weight loss during the daytime to avoid sleep disturbances owing to its arousal-inducing effect.

Changes in the Physical Properties of Calcium Alginate Gel Beads Under a Wide Range of Gelation Temperature Conditions.

Until now, most studies using calcium alginate gel (CAG) have been conducted primarily at room temperature (20 °C) without considering gelation temperature. Moreover, the effects of gelation temperature on the physical properties of CAG beads have not been studied in detail. We aimed to study the effect of gelation temperature on the physical properties (diameter, sphericity, and rupture strength) of CAG beads. Response surface methodology was used in this study. The independent variables were sodium alginate concentration (X1, 1.2%-3.6%, w/v), calcium lactate concentration (X2, 0.5%-4.5%, w/v), gelation temperature (X3, 5-85 °C), and gelation time (X4, 6-30 min). Diameter (Y1, mm), sphericity (Y2, %), and rupture strength (Y3, kPa) were selected as the dependent variables. A decrease in gelation temperature increased the diameter, sphericity and rupture strength of the CAG beads. Additionally, the CAG beads prepared at 5 °C exhibited the highest rupture strength (3976 kPa), lowest calcium content (1.670 mg/g wet), and a regular internal structure. These results indicate that decreasing the gelation temperature slows the calcium diffusion rate in CAG beads, yielding a more regular internal structure and increasing the rupture strength of the beads.

Effects of Thermal Treatment on the Physical Properties of Edible Calcium Alginate Gel Beads: Response Surface Methodological Approach.

Calcium alginate gel (CAG) has been widely investigated for the development of artificial foods; however, there are few studies on its thermal stability. This study aimed to monitor changes in the physical properties of CAG beads during heat treatment using response surface methodology. Heating temperature (X1, 40-100 °C) and heating time (X2, 5-60 min) were chosen as independent variables. The dependent variables were rupture strength (Y1, kPa), size (Y2, µm), and sphericity (Y3, %). The heating temperature (X1) was the independent variable that had a significant effect on the rupture strength (Y1) and size (Y2). Rupture strength (Y1) increased as the heating temperature (X1) increased; at the same time, the CAG beads size (Y2) decreased. With all conditions, the values of sphericity (Y3) were over 94%. SEM images revealed that increase in the rupture strength of the CAG beads by heat treatment resulted from their porous structures. Loss of moisture by syneresis, occurring with heat treatment, was judged to create a dense porous structure of CAG beads. Our findings offer useful information for cooking or sterilizing food products utilizing CAG beads. In addition, thermal treatment could be applied to produce hard CAG beads with a high rupture strength.

Multi-field merit-function-based regression method for Wide Field Infrared Survey Telescope grism system alignment.

The grating prism (grism), slitless spectrometer aboard the Wide Field Infrared Survey Telescope enables a survey of emission-line galaxies. To facilitate its opto-mechanical alignment, a six-degree-of-freedom element was fabricated using alignment fiducials and integral flats and used to measure a wavefront by using an infrared interferometer placed at various field points over a 20×14 deg field of view in the grism coordinate frame. Modeling identified E2 to be the most sensitive element to the grism wavefront error and was used to efficiently align the system. The merit function regression method for a wide field of view was further used to verify the higher efficiency and accuracy of the proposed alignment technique compared with the conventional sensitivity table method.

Merit function regression method for efficient alignment control of two-mirror optical systems.

The precision alignment of high-performance, wide-field optical systems is generally a difficult and often laborious process. We report a new merit function regression method that has the potential to bring to such an optical alignment process higher efficiency and accuracy than the conventional sensitivity table method. The technique uses actively damped least square algorithm to minimize the Zernike coefficient-based merit function representing the difference between the designed and misaligned optical wave fronts. The application of this method for the alignment experiment of a Cassegrain type collimator of 900mm in diameter resulted in a reduction of the mean system rms wave-front error from 0.283 lambda to 0.194 lambda;, and in the field dependent wave-front error difference from +/-0.2 lambda to +/-0.014 lambda in just two alignment actions. These results demonstrate a much better performance than that of the conventional sensitivity table method simulated for the same steps of experimental alignment.