Sleep-Promoting Effects and Possible Mechanisms of Action Associated with a Standardized Rice Bran Supplement

Optimization of Desalting Conditions for the Green Seaweed Codium fragile for Use as a Functional Food with Hypnotic Effects

Codium fragile (CF) contains various bioactive compounds, but its high salt content (39.8%) makes its use as a functional food challenging. Here, we aimed to optimize the desalination process and verify changes in functionality based on variations in salt and total phenolic contents. To optimize the CF immersion conditions for the lowest salt content and monitor the total phenolic content, a response surface methodology was used. The optimal immersion conditions were as follows: X1 (immersion temperature) = 42.8 °C; X2 (immersion time) = 1.0 h. An inverse correlation was noted between salt content and total phenolic content. Among the post-desalination processes, desalination with centrifugal dehydration (CD) significantly reduced salt content. CD ethanol extract (CD-E) induced the longest sleep duration in the pentobarbital-induced sleep test in ethanol extracts. Moreover, 1000 mg/kg CD-E had a significant effect on non-rapid eye movement sleep but did not affect delta activity. These findings highlight the potential of industrializing CF as a functional food through desalination and its promise as a natural aid for sleep promotion.

Xiaoyin-anshen formula alleviates psoriasis complicated by sleep disturbances by regulating melatonin, antioxidant enzymes, and pro-inflammatory cytokines in mice

Background

Psoriasis is a common autoimmune and chronic inflammatory dermatological disease that is mainly associated with aberrant immune response and oxidative stress (OS). OS, a crucial pathogenic factor in psoriasis, contributes to psoriasis-like inflammation mediated by the IL-23/IL-17 inflammatory axis. Sleep disturbances (SDs), highly prevalent in patients with psoriasis, exacerbate the condition by disrupting circadian rhythms and reducing melatonin levels, thus promoting OS and inflammation. Xiaoyin-Anshen formula (XYAS), a traditional Chinese medicine (TCM) formula, is composed of the Liangxue-Jiedu (LXJD) and Qingxin-Anshen (QXAS) TCM compounds and has been demonstrated to be effective in treating psoriasis complicated by SDs. However, its exact pharmacological mechanism remains uncertain. Thus, this study used animal experiments to verify whether XYAS can exert therapeutic effects on the disease by regulating melatonin (MLT) levels, protecting against OS, and inhibiting psoriasis-like skin inflammation.

Methods

A mouse model for psoriasis combined with SDs was established by smearing 62.5 mg of 5% imiquimod (IMQ) cream for seven consecutive days, along with a daily injection of p-chlorophenyl alanine (PCPA) solution at a dosage of 300 mg/kg at days 6-7. The IMQ cream was continued to be used for maintaining the model at days 8-14. Mice were randomly divided into groups: control, model, MLT, XYAS, LXJD, QXAS. Each group was treated according to its designation at days 8-14, receiving either an oral gavage of XYAS/LXJD/QXAS solution at a dosage of 2 mL/100 g per day, or a daily injection of MLT solution at a concentration of 0.25 mg/mL, with a dosage of 5 mg/kg. Immunohistological analysis, pentobarbital-induced sleep test, Western blotting, and enzyme-linked immunosorbent assay (ELISA) were performed to assess and compare pathological features, sleep conditions, localization and/or levels of manganese-dependent superoxide dismutase (mnSOD), mitochondrial cytochrome c (Cyt-C), MLT, retinoid-related orphan nuclear receptor-α (RORα), and pro-inflammatory cytokines interleukin (IL)-6, IL-17A, and tumor necrosis factor-alpha (TNF-α) among groups.

Results

MLT, XYAS, LXJD, and QXAS exhibited varying therapeutic effects on RORα regulation, OS inhibition, mitochondrial protection, and anti-inflammation. Compared to the model, the lesion severity/thickness and serum IL-6, IL-17A, and TNF-α levels were gradually reduced in the MLT, QXAS, LXJD, and XYAS. However, no statistical difference in TNF-α levels was identified between the MLT and the model groups. Additionally, skin MLT levels gradually increased in the MLT, QXAS, and XYAS groups, while RORα levels gradually increased in the MLT, QXAS, LXJD, and XYAS groups. All treatments increased mnSOD levels and reduced Cyt-C levels in skin lesions, with XYAS showing the most significant changes.

Conclusion

XYAS may treat psoriasis complicated by SDs through two main mechanisms: (1) Improving melatonin-RORα axis in the skin can lead to an increase in mnSOD and a reduction in Cyt-C levels, which provide protection against oxidative stress, mitochondrial damage, and psoriatic inflammation. (2) Reducing IL-6, IL-17A, and TNF-α production to suppress IL-23/Th17 pro-inflammatory signaling axis and epidermal hyperplasia in psoriasis.

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 K_i 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.

Effect of Black Pepper (Piper nigrum) Extract on Caffeine-Induced Sleep Disruption and Excitation in Mice

Sleep is one of the most essential factors required to maintain good health. However, the global prevalence of insomnia is increasing, and caffeine intake is a major trigger. The objective of this study was to investigate the inhibitory effect of black pepper, Piper nigrum extract (PE), on caffeine-induced sleep disruption and excitation in mice. Caffeine significantly decreased sleep duration in the pentobarbital-induced sleep test. It also resulted in a significant increase in sleep onset and a decrease in non-rapid eye movement sleep. Moreover, in an open-field test, caffeine-treated mice exhibited a significantly increased time in the center zone and total distance traveled. However, the co-administration of caffeine and PE did not result in similar arousal activities. Thus, our results suggest that PE can be used as a potential therapeutic agent to treat sleep problems and excitatory status associated with caffeine intake.

Fermented rice bran supplementation ameliorates obesity via gut microbiota and metabolism modification in female mice

We investigated the effects of fermented rice bran (FRB) administration in two groups of C57BL/6J mice. The first group was fed with a high-fat diet, and the second group was fed with a high-fat diet supplemented with the FRB for 8 weeks. FRB supplementation suppressed the high-fat-induced weight gain and considerable alterations in the intestinal microbiota profile in the second group. Among 27 bacterial genera detected in the FRB, only Enterococcus, Lactobacillus, Bacteroides, Prevotella, and the unclassified family Peptostreptococcaceae were detected in mice feces. Their abundances were not particularly increased by FRB supplementation. The abundances of Enterococcus and the unclassified family Peptostreptococcaceae were even suppressed in the second group, suggesting that FRB supplementation didn’t cause an addition of beneficial microbiome but inhibit the proliferation of specific bacteria. Fecal succinic acid concentration was significantly decreased in the second group and highly correlated with the relative abundances of Turicibacter, Enterococcus, and the unclassified family Peptostreptococcaceae. A significant increase in fumaric acid and a decrease in xylitol, sorbitol, uracil, glutamic acid, and malic acid levels were observed in the peripheral blood of the second group. FRB supplementation counteracted the high-fat-induced obesity in mice by modulating the gut microbiota and the host metabolism.

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.

Effects of GABA/β-glucan supplements on melatonin and serotonin content extracted from natural resources

OBJECTIVE

This study aimed to monitor the secretion of serotonin and melatonin in the blood serum of rats in the presence of rice bran (RB), and Sarcodon aspratus (S) extracts for sleep promotion.

BACKGROUND

Sleep is a natural physiological phenomenon, and sleep disorders may cause severe mental hazards leading to excessive daytime sleepiness (EDS). The γ-aminobutyric acid (GABA) and β-glucan are the essential active ingredients of RB and mushroom, respectively, exhibited stress-reduction and nerve stabilizing potential through regulation of melatonin and serotonin hormones.

METHODS

Cytotoxicity of the extracts (RBS) was evaluated through WST-1 assay. The melatonin and serotonin concentrations in the blood serum were measured through ELISA kits. The Ig ELISA kit measured the immunoglobulin's (IgG, IgM, and IgA) concentrations.

RESULTS

Improved cell viability was observed in RBS treated groups than control, indicating their biocompatibility. The melatonin and serotonin levels were high in RBS (5:5 and 7:3) treated groups compared to the control. Enhanced expression of immunoglobulin (Ig) A and G level was observed in RBS treated rats. The serotonergic genes (5-HTT, 5-HT 1B, and MAO-A) expression levels were upregulated in RBS treated groups vis-à-vis the control.

CONCLUSION

Based on these results, we anticipated that RBS supplements could promote the sleep phenomenon by elevating the serotonin/melatonin level in the blood through the serotonergic system. Therefore, RBS supplements can be utilized as functional food material for sleep promotion.

Standardized rice bran extract improves hepatic steatosis in HepG2 cells and ovariectomized rats

BACKGROUD/OBJECTIVES

Hepatic steatosis is the most common liver disorder, particularly in postmenopausal women. This study investigated the protective effects of standardized rice bran extract (RBS) on ovariectomized (OVX)-induced hepatic steatosis in rats.

MATERIALS/METHODS

HepG2 cells were incubated with 200 µM oleic acid to induce lipid accumulation with or without RBS and γ-oryzanol. OVX rats were separated into three groups and fed a normal diet (ND) or the ND containing 17β-estradiol (E2; 10 µg/kg) and RBS (500 mg/kg) for 16 weeks.

RESULTS

RBS supplementation improved serum triglyceride and free fatty acid levels in OVX rats. Histological analysis showed that RBS significantly attenuated hepatic fat accumulation and decreased hepatic lipid, total cholesterol, and triglyceride levels. Additionally, RBS suppressed the estrogen deficiency-induced upregulation of lipogenic genes, such as sterol regulatory element-binding protein 1 (SREBP1), acetyl-CoA carboxylase 1, fatty acid synthase, glycerol-3-phosphate acyltransferase, and stearoyl-CoA desaturase 1.

CONCLUSIONS

RBS and γ-oryzanol effectively reduced lipid accumulation in a HepG2 cell hepatic steatosis model. RBS improves OVX-induced hepatic steatosis by regulating the SREBP1-mediated activation of lipogenic genes, suggesting the benefits of RBS in preventing fatty liver in postmenopausal women.

PCC0208009, an indirect IDO1 inhibitor, alleviates neuropathic pain and co-morbidities by regulating synaptic plasticity of ACC and amygdala

BACKGROUND AND PURPOSE

Indoleamine 2, 3-dioxygenase 1 (IDO1) has been linked to neuropathic pain and IDO1 inhibitors have been shown to reduce pain in animals. Some studies have indicated that IDO1 expression increased after neuropathic pain in hippocampus and spinal cord, whether these changes existing in anterior cingulate cortex (ACC) and amygdala remains obscure and how IDO1 inhibition leads to analgesia is largely unknown. Here, we evaluated the antinociceptive effect of PCC0208009, an indirect IDO1 inhibitor, on neuropathic pain and examined the related neurobiological mechanisms.

EXPERIMENTAL APPROACH

The effects of PCC0208009 on pain, cognition and anxiogenic behaviors were evaluated in a rat model of neuropathic pain. Motor disorder, sedation and somnolence were also assessed. Biochemical techniques were used to measure IDO1-mediated signaling changes in ACC and amygdala.

KEY RESULTS

In rats receiving spinal nerve ligation (SNL), IDO1 expression level was increased in ACC and amygdala. PCC0208009 attenuated pain-related behaviors in the formalin test and SNL model and increased cognition and anxiogenic behaviors in SNL rats at doses that did not affect locomotor activity and sleeping. PCC0208009 inhibited IDO1 expression in ACC and amygdala by inhibiting the IL-6-JAK2/STAT3-IDO1-GCN2-IL-6 pathway. In addition, PCC0208009 reversed synaptic plasticity at the functional and structural levels by suppressing NMDA2B receptor and CDK5/MAP2 or CDK5/Tau pathway in ACC and amygdala.

CONCLUSION AND IMPLICATIONS

These results support the role of IDO1-mediated molecular mechanisms in neuropathic pain and suggest that the IDO1 inhibitor PCC0208009 demonstrates selective pain suppression and could be a useful pharmacological therapy for neuropathic pain.

Detection of Histamine Based on Gold Nanoparticles with Dual Sensor System of Colorimetric and Fluorescence

Gold nanoparticles (Au-NPs), with the dual sensor system of colorimetric and fluorescence responses, were developed for the determination of histamine as a spoilage monitor for distinguishing lifetime and freshness of aquatic products. Upon addition of histamine, the absorption coefficient orders of magnitude via the interaction of free electrons and photons were affected, and the characteristic absorption peak of Au-NPs was red-shifted from 520 nm to 664 nm. Meanwhile, the large amino groups in the networks of histamine-Au-NPs with high molecular orbital exhibited excellent fluorescence behavior at 415 nm. Au-NPs offered a range of 0.001-10.0 μM and 0.01-1.0 μM with a limit of detection of 0.87 nM and 2.04 nM by UV-vis and fluorescence spectrum assay, respectively. Moreover, Au-NPs could be used to semiquantitatively analyze histamine with the naked eye, since the significant colorimetric and fluorescence reaction of Au-NPs solution that coincided with different concentrations of histamine can be observed as the histamine concentration was 0.1-1.0 μM. Both of the dual-sensor systems of Au-NPs were successfully applied to the quantitative analysis of histamine in fresh salmon muscle, suggesting the simplicity and rapidity in the dual detection approaches of Au-NPs might be suitable for spoilage assay of aquatic food to ensure food safety.

Hypnotic Effects of Lactobacillus fermentum PS150TM on Pentobarbital-Induced Sleep in Mice

The bidirectional communication between the gastrointestinal tract and the central nervous system appears to be functionally linked to the intestinal microbiome, namely the microbiome-gut-brain axis (MGBA). Probiotics with health benefits on psychiatric or neurological illnesses are generally called psychobiotics, and some of them may also be able to improve sleep by targeting the MGBA. This study aimed to investigate the effects of a psychobiotic strain, Lactobacillus fermentum PS150TM (PS150TM), on sleep improvement by using a pentobarbital-induced sleep mouse model. Compared with the vehicle control group, the oral administration of PS150TM, but not the other L. fermentum strains, significantly decreased the sleep latency and increased the sleep duration of mice, suggesting strain-specific sleep-improving effects of PS150TM. Moreover, the ingestion of diphenhydramine, an antihistamine used to treat insomnia, as a drug control group, only increased the sleep duration of mice. We also found that the sleep-improving effects of PS150TM are time- and dose-dependent. Furthermore, the oral administration of PS150TM could attenuate a caffeine-induced sleep disturbance in mice, and PS150TM appeared to increase the expression of the gene encoding the adenosine 1 receptor in the hypothalamus of mice, as assessed by quantitative real-time polymerase chain reaction. Taken together, our results present a potential application of PS150TM as a dietary supplement for sleep improvement.

Rice bran extract supplement improves sleep efficiency and sleep onset in adults with sleep disturbance: A randomized, double-blind, placebo-controlled, polysomnographic study

We previously reported that rice bran extract supplement (RBS) administration to mice decreased sleep latency and induced non-rapid eye movement (NREM) sleep via inhibition of the histamine H₁ receptor. Based on this, we performed the first clinical trial to investigate whether RBS would be beneficial to subjects with disturbed sleep. We performed a randomized, double‐blinded, placebo‐controlled, 2-week study. Fifty subjects with sleep disturbance were enrolled and received either RBS (1,000 mg/day) or placebo. Polysomnography was performed, and Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale (ESS), and Fatigue Severity Scale were administered at the initiation and termination of the study. Compared with the placebo, RBS led to significant polysomnographic changes, including decreased sleep latency (adjusted, P = 0.047), increased total sleep time (P = 0.019), and improved sleep efficiency (P = 0.010). Additionally, the amount of stage 2 sleep significantly increased in the RBS group. When adjusted for caffeine intake, wakefulness after sleep onset, total wake time, and delta activity tended to decrease in the RBS group. RBS administration decreased ESS scores. There were no reported serious adverse events in both groups. RBS improved sleep in adults with sleep disturbance. Trial registration: WHO ICTRP, KCT0001893.

A Standardized Phlorotannin Supplement Attenuates Caffeine-Induced Sleep Disruption in Mice

In our previous studies, a standardized phlorotannin (brown seaweed polyphenol) supplement (PS) exhibited sleep-promoting effects via type A γ-aminobutyric acid-benzodiazepine receptors in mice. In addition, in human clinical trials, it decreased wake after sleep onset in adults with sleep disturbance. In this follow-up study, we investigated whether PS attenuates caffeine-induced sleep disruption in mice. The effects of PS were evaluated in a caffeine model by analyzing sleep architecture based on electroencephalogram and electromyogram findings, and were compared with the effects of a well-known sedative-hypnotic drug zolpidem (ZPD). As expected, oral administration of caffeine (25 mg/kg) significantly increased sleep latency and decreased the amount of non-rapid eye movement sleep (NREMS). In the caffeine + PS and caffeine + ZPD groups, PS (500 mg/kg) attenuated caffeine-induced sleep disruption, and its effects were comparable with those of ZPD (10 mg/kg). In particular, PS inhibited the arousal effects of caffeine without change in delta activity during NREMS, whereas ZPD produced a decrease in the delta activity. Considering global trends in coffee and energy drink consumption, our finding suggest that PS may be useful to relieve transitory insomnia symptoms caused by caffeine consumption, unlike the prescription drug ZPD.

Romaine Lettuce/Skullcap Mixture Improves Sleep Behavior in Vertebrate Models

The aim of this study is to investigate the effects of romaine lettuce leaves extract (RE), skullcap root extract (SE) and their mixture on sleep behaviors in vertebrate models. HPLC analysis showed that RE contains lactucopicrin (0.02±0.01 mg/g extract), chlorogenic acid (4.05±0.03 mg/g extract), caffeic acid (2.38±0.03 mg/g extract), and chicoric acid (7.02±0.32 mg/g extract) as main phenolic compounds, while SE includes baicalin (99.4±0.5 mg/g extract), baicalein (8.28±0.21 mg/g extract), and wogonin (3.09±0.32 mg/g extract). The mixture of RE (100 mg/g extract) and SE (40 mg/g extract) increased total sleep time by 50.9% compared with the control in pentobarbital-induced sleep model. In electroencephalography (EEG) analysis, RE/SE mixture significantly increased Non-Rapid Eye Movement (NREM), in which delta wave was enhanced by around 40% compared with normal control, leading to the increase of sleep time. In caffeine-induced wake model, RE/SE mixture greatly decreased (53%) caffeine-induced wake time, showing a similar level to normal control. In addition, caffeine-induced decreased of NREM and delta wave effectively increased with RE/SE mixture; NREM and delta wave increased by 85% and 108%, respectively. Furthermore, RE/SE mixture was shown to bind to a gamma-aminobutyric acid type A (GABAA)-benzodiazepine (BZD) receptor stronger than RE or SE single extract. Taken together, RE/SE mixture effectively improved sleep behavior with the increase of NREM via GABAA-BZD receptor binding. RE/SE mixture can be used as an herbal agent for sleep disorders.

Hydrolysate Preparation with High Content of 5-Hydroxytryptophan from Liquid Egg Protein and Its Sleep-Potentiating Activity

Alcalase hydrolysis of liquid egg white was used to produce 5-hydroxytryptophan (HTP) under various conditions and investigate the sleep-potentiating activity of liquid egg white hydrolysate (LEH) on pentobarbital-induced sleep. Alcalase hydrolysis yielded the highest content of 5-HTP (13.50 μg/mL), while neutrase hydrolysis showed the lowest 5-HTP content (5.23 μg/mL). The liquid egg white to water ratio (1:1) was optimal for the production of 5-HTP with high amino-nitrogen (A-N) content and degree of hydrolysis. The 5-HTP, amino-nitrogen, and degree of hydrolysis increased until 24 h of hydrolysis and slightly increased thereafter during hydrolysis with 2% and 5% enzyme addition. 5-HTP administration at doses of 6 and 9 mg/kg significantly increased sleep duration and decreased sleep latency time compared to that in the control (p<0.05). LEH (150 mg/mouse), which was equivalent to 5-HTP at 6 mg/kg, significantly decreased sleep latency time and increased sleep duration time compared to that in the control (p<0.05). Oral administration of LEH showed sleep-potentiating effects because of 5-HTP. The sleep-potentiating activity of LEH may have occurred through 5-HTP in our pentobarbital-induced sleep model. LEH may be a valuable alternative to sleep enhancement and may be used as a sleep-potentiating agent.