Lactobacillus brevis M2-Fermented Whey Protein Hydrolysate Increases Slow-Wave Sleep via GABAA Receptors in Rodent Models.

In this study, we investigated the effects of whey protein hydrolysate (WPH) fermented with Lactobacillus brevis on sleep behavior and GABAergic mechanisms in rodent models. Fermentation converted the glutamate in WPH to high (3.15 ± 0.21 mg/mL) levels of γ-aminobutyric acid (GABA). Fermented WPH (WP-SF) enhanced sleep duration in mice by increasing GABA content in the brain. The increase in sleep duration induced by WP-SF resulted from an increase in delta wave activity during non-rapid eye movement sleep, and its sleep-promoting effect in a caffeine-induced insomnia model was characterized by an increase in delta waves. WP-SF increased GABAergic receptors at both mRNA and protein levels. Cotreatment with GABAA receptor antagonists abolished the sleep-promoting effects of WP-SF, indicating that WP-SF shares binding sites with antagonists on GABAA receptors. Collectively, WP-SF effectively increased sleep duration by enhancing delta wave activity through GABAergic activation; thus, it is suggested as a functional food-grade ingredient for promoting sleep.

Lactitol Alleviates Loperamide-Induced Constipation in Sprague Dawley Rats by Regulating Serotonin, Short-Chain Fatty Acids, and Gut Microbiota.

The objective of this study was to examine the impact of lactitol on constipation caused by loperamide in Sprague Dawley rats, with a particular emphasis on its underlying mechanisms and potential health advantages. The lactitol effectively improved fecal parameters, intestinal tissue structure, and the expression of constipation-related gene expression and proteins. Lactitol alleviated fecal weight and water content altered by loperamide and enhanced gastrointestinal transit. The administration also restored mucosal and muscular layer thickness. Mechanistically, lactitol upregulated the mRNA expression and/or protein levels of mucins (MUC2 and MUC4), occludin, claudin-1, and zonula occludens, indicating improved intestinal barrier function. Lactitol positively regulated the composition of cecal microbiota, leading to an increased relative abundance of Bifidobacterium, Lactobacillus, and Romboutsia. Conversely, lactitol decreased the relative abundance of Prevotella, Aerococcus, Muribaculum, Blautia, and Ruminococcus. This study demonstrated the potential of lactitol to relieve constipation by modulating the gut microbiota. These findings suggest that lactitol is an alternative to traditional laxatives and has potential as a health-promoting food sweetener.

Characterization of a novel sulfated-rhamnoglucuronan isolated from Korean seaweed Ulva pertusa and its efficacy for treatment of inflammatory bowel disease in mice.

This study aimed to isolate Ulva pertusa polysaccharide (UPP), which elicits anti-inflammatory bowel disease (IBD) effects, from the Korea seaweed U. pertusa and identify its structure. Firstly, UPP was isolated from U. pertusa using hydrothermal extraction and ethanol precipitation. UPP is a novel polysaccharide that exhibits unique structural features such as 3-sulfated rhamnose, glucuronic acid, iduronic acid, and 3-sulfated xylose, which are repeated in 1,4-glycosidic bonds. Prophylactic oral administration of UPP in mice with dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) suppressed the levels of inflammatory cytokines and MAPK- and NF-κB-related factors in the serum and colon tissue. Tight junction (TJ)-related factors such as occludin, claudin-1, and mucin were effectively augmented by UPP in the colon tissue. In addition, UPP administration prevented the DSS treatment-led cecal short chain fatty acid imbalance, and this effect was most evident for propionic acid. In conclusion, UPP isolated from the Korean U. pertusa demonstrates potent anti-IBD activity. Characterization of this ulvan revealed its unique structure. Moreover, its efficacy may be associated with its anti-inflammatory effects and regulation of gut microbiota and TJ proteins. Thus, this study provides new insights into the biological effects of UPP in IBD.

Immunostimulating effects of ulvan type polysaccharide isolated from Korean Ulva pertusa in cyclophosphamide-induced immunosuppressed BALB/c mice.

This study aimed to determine the immunostimulatory activities of ulvan type polysaccharides isolated from Ulva pertusa. First, U. pertusa polysaccharide (UPP) mainly consists of rhamnose, glucuronic acid, iduronic acid, and xylose, which are typical ulvan type monosaccharides. UPP induced phosphorylation of the mitogen-activated protein kinase and nuclear factor-kappa B pathways in macrophages, subsequently triggering cytokine release and phagocytosis. The effects were closely associated with pattern recognition receptors such as dectin-1, mannose receptor, CD11b, CD14, and Toll-like receptors 2 and 4. Moreover, prophylactic administration of UPP was found to protect against body weight loss and lymphatic organ damage in cyclophosphamide-induced immunosuppressed mice. In addition, UPP demonstrated significant stimulatory effects on various immunocytes, such as T cells, B cells, macrophages, and natural killer cells derived from the spleen. These effects were closely related to the mitogen-activated protein kinase and nuclear factor-kappa B pathways, and significant secretion of immunostimulatory cytokines such as IL-6, -12, and TNF-α was noted in both blood and spleen samples. Impairment of the short-chain fatty acid balance in the cecum was prevented by UPP administration in a dose-dependent manner. Consequently, these results suggest that the UPP isolated from U. pertusa contributes to immune system activation.

Improvement of sleep duration and quality through GABAA receptor by whey protein hydrolysate containing DIQK as the active main compound.

This study characterized the sleep activity, sleep mechanism, and active peptides of whey protein hydrolysates selected through behavioral analysis of fruit-flies (Drosophila melanogaster). Sleep-inducing whey protein (WP) hydrolysate was selected through fruit fly behavior analysis, and sleep activity was measured using a pentobarbital model and electroencephalographic analysis. The mechanism of action was confirmed using a γ-aminobutyric acid (GABA) receptor antagonist, and the active peptide was identified using liquid chromatography-mass spectroscopy. Whey protein hydrolysate, prepared using Alcalase and Prozyme (WP-AP), increased sleep time in a dose-dependent manner. WP-AP significantly increased not only sleep time but also slow-wave sleep and showed an insomnia-alleviating effect in a caffeine-induced insomnia mouse model. In addition, the gene and protein expression levels of GABA sub-type A (GABAA) receptors increased in the brains of mice orally administered with WP-AP. Through peptide analysis, the mixture of DIQK, VPPF peptide, and GABA contained in WP-AP was estimated to exhibit sleep activity, and due to its high content, DIQK was speculated to be the main sleep -inducing ingredient. These results indicate that WP-AP has the potential to be used as a new ingredient to improve sleep quality.

Efficacy and safety of galacto-oligosaccharide in the treatment of functional constipation: randomized clinical trial.

The efficacy and safety of galacto-oligosaccharides (GOS) in treating functional constipation were evaluated in a four-week randomized, double-blind clinical trial on 63 patients who met Rome IV criteria (34 GOS, 29 placebo group). The number of bowel movements per day and changes in the shape of bowel movements in the treatment group significantly improved compared to those in the control group after four weeks. The Patient Assessment Constipation Quality of Life questionnaire showed that satisfaction with constipation significantly increased in the treatment group. The levels of Bifidobacterium sp. and Lactobacillus sp. significantly increased after four weeks of GOS treatment compared to those measured at baseline. No significant adverse drug reactions were identified in any indicator except for pulse rate. Thus, the prebiotic GOS can be safely used in foods and pharmaceuticals to alleviate symptoms of functional constipation by improving the intestinal flora.

Lactobacillus brevis-Fermented Gamma-Aminobutyric Acid Ameliorates Depression- and Anxiety-Like Behaviors by Activating the Brain-Derived Neurotrophic Factor-Tropomyosin Receptor Kinase B Signaling Pathway in BALB/C Mice.

This study investigated the effects of Lactobacillus brevis-fermented gamma-aminobutyric acid (LB-GABA) on depressive and anxiety-like behaviors with the underlying molecular mechanism in a chronic stress model of BALB/c mice. LB-GABA attenuates both neuronal cell death and the increase of monoamine oxidase activity induced by hydrogen peroxide. Behavioral tests revealed that GABA significantly increased sucrose preference and reduced immobility time in both tail suspension and forced swimming tests. LB-GABA increased exploration of the open arms in the elevated plus maze and restored activity in the open field. Moreover, LB-GABA lowered stress hormone and inflammatory mediator levels. Mechanistically, LB-GABA increased protein levels of BDNF and TrkB, activating downstream targets (AKT, ERK, and CREB), crucial for neuronal survival and plasticity. Furthermore, LB-GABA protected hippocampal neurons from stress-induced cell death and increased serotonin and dopamine levels. Overall, LB-GABA has the potential to alleviate stress-induced depression and anxiety-like symptoms and neuroinflammation by activating the BDNF-TrkB signaling pathway.

Improved digestibility and bioavailability of pea protein following enzymatic treatment and fermentation by lactic acid bacteria.

Peas (Pisum sativum L.) have a potential commercial value because of their high protein content, non-GMO status, low allergenicity. This study examined changes in the digestion and absorption properties of enzyme-modified and fermented pea protein (EFPP) produced through enzymatic treatment of pea protein and fermentation with lactic acid bacteria. EFPP was digested 22.50% more than isolated pea protein (IPP) during the first 15 min in vitro digestion model. Based on the Caco-2 cell monolayer model, EFPP showed 38.40% higher bioavailability than IPP. Gel Permeation Chromatography showed that the average molecular weight of EFPP was 98.79% lower than that of IPP. The secondary structure of protein was analyzed by Fourier transform infrared spectrometry and it showed a 53.92% reduction in ß-sheet of EFPP than IPP. These results indicate that enzyme treatment and fermentation of pea protein reduced the molecular weight, modified the secondary structure, and improved digestibility and bioavailability.

Protective Effects of Whey Protein Hydrolysate, Treadmill Exercise, and Their Combination against Scopolamine-Induced Cognitive Deficit in Mice.

In this study, the potential of whey protein hydrolysate (WPH) and treadmill exercise to prevent cognitive decline was investigated, along with their neuroprotective mechanisms. Cognitive dysfunction was induced in mice with 1 mg/kg of scopolamine, followed by the administration of WPH at 100 and 200 mg/kg and/or treadmill exercise at 15 m/min for 30 min five days per week. Both WPH administration and treadmill exercise significantly improved the memory of mice with scopolamine-induced cognitive impairment, which was attributed to several key mechanisms, including a reduction in oxidative stress based on decreased levels of reactive oxygen species and malondialdehyde in the brain tissue and an increase in acetylcholine by increasing choline acyltransferase and decreasing acetylcholine esterase levels. Exercise and WPH also exerted neuroprotective effects by inhibiting the hyperphosphorylation of tau proteins, enhancing the expression of the brain-derived neurotrophic factor, and inhibiting apoptosis by reducing the Bax/Bcl2 ratio in conjunction with the downregulation of the mitogen-activated protein kinase pathway. Moreover, the impact of WPH and treadmill exercise extended to the gut microbiome, suggesting a potential link with cognitive improvement. These findings suggest that both WPH intake and treadmill exercise are effective strategies for mitigating cognitive impairment, providing promising avenues for treating neurodegenerative diseases.

Characteristics and Absorption Rate of Whey Protein Hydrolysates Prepared Using Flavourzyme after Treatment with Alcalase and Protamex.

The purpose of this study was to evaluate the physicochemical properties of whey protein hydrolysate and determine changes in absorption rate due to enzymatic hydrolysis. The molecular weight distribution analysis of whey protein concentrate (WPC) and low-molecule whey protein hydrolysate (LMWPH) using the Superdex G-75 column revealed that LMWPH is composed of peptides smaller than those in WPC. Fourier-transform infrared spectroscopy indicated differences in peak positions between WPC and LMWPH, suggesting hydrolysis-mediated changes in secondary structures. Moreover, LMWPH exhibited higher thermal stability and faster intestinal permeation than WPC. Additionally, oral LMWPH administration increased serum protein content at 20 min, whereas WPC gradually increased serum protein content after 40 min. Although the total amount of WPC and LMWPH absorption was similar, LMWPH absorption rate was higher. Collectively, LMWPH, a hydrolysate of WPC, has distinct physicochemical properties and enhanced absorptive characteristics. Taken together, LMWPH is composed of low-molecular-weight peptides with low antigenicity and has improved absorption compared to WPC. Therefore, LMWPH can be used as a protein source with high bioavailability in the development of functional materials.

Yeast Hydrolysate Inhibits Lipid Accumulation via Regulation of Lipid Accumulation-Related Genes in a Drosophila Model of High-Sugar Diet-Induced Obesity.

The increasing frequency of processed food consumption has led to the higher ingestion of sugar, increasing the risk of chronic diseases, such as obesity. Yeast hydrolysates (YHs) inhibit body fat accumulation. However, the action mechanism of YH in relation to high-sugar diet-induced obesity is still unclear. Therefore, this study aimed to evaluate the biological effects of YH on lipid accumulation and verify behavioral changes and carbohydrate metabolic gene regulation in high-sugar diet-fed fruit flies. Adult male flies (Drosophila melanogaster; 2-5 days old) were exposed to 20% sucrose for obesity induction. In high-sugar-fed Drosophila, the effect of YH was compared with that of yeast extract. The effects of YH on body conditions and lipid droplet size were quantified and analyzed. Behavioral factors were evaluated by analyzing circadian rhythm patterns and neurotransmitter content, and a molecular approach was used to analyze the expression of metabolism-related genes. Dietary supplementation with YH did not reduce total sugar content, but significantly decreased the triglyceride (TG) levels in Drosophila. A behavioral analysis showed that the total number of night-time activities increased significantly with YH treatment in a dose-dependent manner. In addition, YH effectively regulated the gene expression of insulin-like peptides related to carbohydrate metabolism as well as genes related to lipogenesis. The TG content was significantly reduced at a YH concentration of 0.5%, confirming that the active compound in YH effectively suppresses fat accumulation. These findings support that YH is a potential anti-obesity food material via regulating carbohydrate metabolism in Drosophila.

Combination of Cysteine and Glutathione Prevents Ethanol-Induced Hangover and Liver Damage by Modulation of Nrf2 Signaling in HepG2 Cells and Mice.

Excessive alcohol consumption increases oxidative stress, leading to alcoholic liver disease. In this study, the protective effects of a mixture of cysteine and glutathione against ethanol-induced hangover and liver damage were evaluated in mice and HepG2 cells. Ethanol (2 mL/kg) was orally administered to the mice 30 min before receiving the test compounds (200 mg/kg), and the behavioral and oxidative stress-related biochemical parameters altered by ethanol were analyzed. Acute ethanol administration increased anxiety behavior and decreased balance coordination in mice (p < 0.001); however, a mixture of cysteine and glutathione (MIX) in a 3:1 ratio improved alcohol-induced behavior more effectively than the individual compounds (p < 0.001). The MIX group showed higher ethanol-metabolizing enzyme activity than the control group (p < 0.001) and significantly suppressed the elevation of serum alcohol (p < 0.01) and acetaldehyde (p < 0.001) levels after 1 h of ethanol administration. In HepG2 cells, 2.5 mM MIX accelerated ethanol metabolism and reduced cytochrome P450 2E1 mRNA expression (p < 0.001). MIX also increased the expression of antioxidant enzymes through the upregulation of nuclear erythroid 2-related factor 2 (Nrf2) signaling and consequently suppressed the overproduction of reactive oxygen species and malondialdehyde (p < 0.001). Collectively, MIX alleviates the hangover symptoms and attenuates the alcohol-induced oxidative stress by regulating the Nrf2 pathway.

Effects of Dendropanax morbiferus Leaf Extract on Sleep Parameters in Invertebrate and Vertebrate Models.

Dendropanax morbiferus is highly valued in traditional medicine and has been used to alleviate the symptoms of numerous diseases owing to its excellent antioxidant activity. This study aimed to evaluate the sleep promotion and related signaling pathways of D. morbiferus extract (DE) via behavioral analysis, molecular biological techniques, and electrophysiological measurements in invertebrate and vertebrate models. In Drosophila, the group treated with 4% DE experienced decreased subjective nighttime movement and sleep bout and increased total sleeping time. Moreover, substantial changes in locomotor activity, including distance moved, velocity, and movement, were confirmed in the 4% DE-treated group. Compared to Drosophila in which insomnia and oxidative stress were induced by exposure to 0.1% caffeine, the DE-treated group improved sleep-related parameters to the level of the normal group. In the Drosophila model, exposure to 4% DE upregulated the expression of gamma-aminobutyric acid (GABA)-related receptors and serotonin receptor (5-HT1A), along with the expression of antioxidant-related factors, glutathione, and catalase. In the pentobarbital-induced sleep test using ICR mice, the duration of sleep was markedly increased by high concentration of DE. In addition, through the electroencephalography analysis of SD-rats, a significant increase in non-rapid-eye-movement sleep and delta waves was confirmed with high concentrations of DE administration. The increase in sleep time and improvement in sleep quality were confirmed to be related to the expression of altered GABA receptors and the enhancement of the contents of the neurotransmitters GABA and serotonin (5-HT) because of high DE administration. High-dose administration of DE also increased the expression of antioxidant-related factors in the brain and significantly decreased malondialdehyde content. Taken together, DE induced improvements in sleep quantity and quality by regulating neurotransmitter content and related receptor expression, along with high antioxidant activity, and may have a therapeutic effect on sleep disorders.

Yeast-Hydrolysate-Derived 1-Methyl-1,2,3,4-tetrahydro-ß-carboline-3-carboxylic Acid Inhibits Fat Accumulation during Adipocyte Differentiation.

This study aimed to investigate the impact of yeast hydrolysate (YH) on lipogenesis, elucidate its mechanistic action, and identify the active compounds responsible for its anti-adipogenic effects. YH (2 mg/mL) significantly reduced Oil Red O-stained lipids. YH (2 mg/mL) also downregulated C/EBPß and upregulated KLF2, both of which are early adipogenic factors. Moreover, YH (2 mg/mL) decreased C/EBPα, PPARγ, FABP4, FAS, ACC, and HMGCR mRNA expression. Additionally, YH significantly downregulated SEBP1c and SREBP2 and their target genes, which govern fatty acid and cholesterol metabolism; however, 2 mg/mL YH had a greater suppressive effect on SREBP1c than on SREBP2. YH (2 mg/mL) also significantly reduced the mRNA level of G6PD and malic enzyme, which are enzymes that synthesize NADPH for lipid synthesis, compared with the control. Furthermore, 1-methyl-1,2,3,4-tetrahydro-ß-carboline-3-carboxylic acid (MTCA) was identified as the active compound with anti-adipogenic effects using solvent fractionation and chromatographic analysis of YH, and 1.1 µg/mL MTCA significantly downregulated SREBP1c/SREBP2 mRNAs by 47.8% and 69.2%, respectively, along with the target genes FAS, ACC, and HMGCR by 79.0%, 77.0%, and 40.9%, respectively. Collectively, YH effectively suppressed adipogenic lipid storage by downregulating SREBP- and NADPH-synthesizing genes. These findings suggest that YH containing MTCA has the potential to act as an anti-obesity agent.

Modulation of gut microbiota ecosystem by a glucan-rich snail mucin heteropolysaccharide attenuates loperamide-induced constipation.

The present study aimed to investigate the effect of oral administration of snail-derived mucin extract (SM) on ameliorating constipation symptoms of loperamide-induced constipated rats (n = 6). The analytical results indicated that SM mainly contains a glucan-rich snail mucin heteropolysaccharide with high molecular weights (108.5-267.9 kDa), comprising primarily of glucose (64.9 %) and galactose (22.4 %) with some deoxyhexoses (5.0 %) and hexosamines (4.9 %). Daily SM administration at doses of 10-40 mg/kg/day to the loperamide-induced constipated rats significantly (p < 0.05) ameliorated the deterioration in fecal parameters, such as numbers and weight of feces, fecal water contents, and gastrointestinal transit ratio. The histomorphometric results showed that the loperamide-induced decreases in the thickness of mucosal and muscularis mucosae layers as well as the distribution of mucin and c-KIT-positive areas were significantly (p < 0.05) improved via SM consumption at all doses tested. SM administration at all doses significantly increased the expression of genes encoding tryptophan hydroxylases (TPH1 and TPH2; p < 0.05), tight junction molecules (OCLN, CLDN1, and TJP1; p < 0.05), and mucin (MUC2 and MUC4; p < 0.05), but significantly decreased the aquaporin-encoding genes (AQP3 and AQP8; p < 0.05). Gut microbial community analysis indicated that SM administration could modulate loperamide-induced dysbiosis by increasing the phyla Actinobacteria (11.72-12.64 % at 10-40 mg/kg doses; p < 0.05) and Firmicutes (79.33 % and 74.24 % at 20 and 40 mg/kg doses; p < 0.05) and decreasing the phyla Bacteroidetes (5.98-12.47 % at 10-40 mg/kg doses; p < 0.05) and Verrucomicrobia (2.21 % and 2.78 % at 20 and 40 mg/kg doses; p < 0.05), suggesting that SM administration is effective in ameliorating constipation by controlling gut microbial communities. These findings can be utilized as fundamental data for developing novel functional materials using SM to prevent or treat constipation.

Sleep-Enhancing Effect of Water Extract from Jujube (Zizyphus jujuba Mill.) Seeds Fermented by Lactobacillus brevis L32.

Although Ziziphus jujuba Mill (jujube) is used in folk medicine for hypnotic sedative, anxiolytic, and many other purposes, to date, only a few studies have revealed its sleep-promoting effects and related mechanisms. Currently, drugs used for the treatment of sleep disorders have various side effects, so it is essential to develop safe natural materials. Therefore, we evaluated the sleep-enhancing activity and mechanism of action of an aqueous extract of jujube seeds (ZW) fermented with Lactobacillus brevis L-32 in rodent models. The starch contained in ZW was removed by enzymatic degradation and fermented with L. brevis to obtain a fermented product (ZW-FM) with a high γ-aminobutyric acid (GABA) content. To evaluate the sleep-promoting effect of ZW-FM, pentobarbital-induced sleep tests were performed on ICR mice, and electroencephalography analysis was undertaken in Sprague Dawley rats. Additionally, the awakening relief effects of ZW-FM were confirmed in a caffeine-induced insomnia model. Finally, the mechanism of sleep enhancement by ZW-FM was analyzed using GABA receptor type A (GABAA) antagonists. The ZW-FM-treated groups (100 and 150 mg/kg) showed increased sleep time, especially the δ-wave time during non-rapid eye movement (NREM) sleep. In addition, the 150 mg/kg ZW-FM treatment group showed decreased sleep latency and increased sleep time in the insomnia model. In particular, NREM sleep time was increased and REM sleep time, which was increased by caffeine treatment, was decreased by ZW-FM treatment. ZW-FM-induced sleep increase was inhibited by the GABAA receptor antagonists picrotoxin, bicuculline, and flumazenil, confirming that the increase was the result of a GABAergic mechanism. These results strongly suggest that the increased GABA in water extract from jujube seeds fermented by L. brevis acts as a sleep-promoting compound and that the sleep-promoting activity is related to GABAA receptor binding.

Preparation of Hypoallergenic Whey Protein Hydrolysate by a Mixture of Alcalase and Prozyme and Evaluation of Its Digestibility and Immunoregulatory Properties.

Whey protein (WP) has nutritional value, but the presence of ß-lactoglobulin (ß-LG) and α-lactalbumin (α-LA) cause allergic reactions. In this study, hypoallergenic whey protein hydrolyate (HWPH) was prepared by decomposing ß-LG and α-LA of WP using exo- and endo-type proteases. The enzyme mixing ratio and reaction conditions were optimized using response surface methodology (RSM). Degradation of α-LA and ß-LG was confirmed through gel electrophoresis, and digestion, and absorption rate, and immunostimulatory response were measured using in vitro and in vivo systems. Through RSM analysis, the optimal hydrolysis conditions for degradation of α-LA and ß-LG included a 1:1 mixture of Alcalase and Prozyme reacted for 10 h at a 1.0% enzyme concentration relative to substrate. The molecular weight of HWPH was <5 kDa, and leucine was the prominent free amino acid. Both in vitro and in vivo tests showed that digestibility and intestinal permeability were higher in HWPH than in WP. In BALB/c mice, as compared to WP, HWPH reduced allergic reactions by inducing elevated Type 1/Type 2 helper T cell ratio in the blood, splenocytes, and small intestine. Thus, HWPH may be utilized in a variety of low allergenicity products intended for infants, adults, and the elderly.

Sleep-promoting activity of amylase-treated Ashwagandha (Withania somnifera L. Dunal) root extract via GABA receptors.

Ashwagandha (Withania somnifera L. Dunal), an Indian medicinal plant that has been used for centuries to treat insomnia, exhibits a variety of biological activities, such as improving cognitive function, immunity and anxiety. In this study, the effect of enzyme-treated Ashwagandha root extract (EA) and on sleep was evaluated using rodent models. Starch contained in the Ashwagandha root extract was removed by amylase treatment to prepare EA. To evaluate the sleep-promoting activity of EA, a pentobarbital-induced sleep test and electroencephalogram analysis were performed. In addition, the sleep-promoting mechanism of EA was elucidated by analyzing the expression of sleep-related receptors. In the pentobarbital-induced sleep test, EA dose-dependently increased sleep duration. Additionally, electroencephalogram analysis revealed that EA significantly increased δ-wave and non-rapid eye movement sleep times, which are involved in deep sleep, thereby improving sleep quality and quantity. EA also effectively relieved caffeine-induced insomnia symptoms. Furthermore, the γ-aminobutyric acid (GABA) content in the brain and mRNA and protein expression of GABAA, GABAB1, and serotonin receptors were significantly increased by EA compared to the normal group. In particular, EA showed sleep-promoting activity by binding to various GABAA receptor sites. Collectively, EA exhibited sleep-promoting activity through the GABAergic system and may be used as a functional material to improve sleep deprivation.

Heukharang lettuce (Lactuca sativa L.) leaf extract displays sleep-promoting effects through GABAA receptor.

ETHNOPHARMACOLOGICAL RELEVANCE: Although lettuce is traditionally known to have hypnotic and sedative effects, to date, only a few studies have documented its sleep-promoting effects and elucidated the related mechanisms. AIM OF THE STUDY: We aimed to investigate the sleep-promoting activity of Heukharang lettuce leaf extract (HLE) with increased lactucin content, known as a sleep-promoting substance in lettuce, in animal models. MATERIALS AND METHODS: To evaluate the effect of HLE on sleep behavior, analysis of electroencephalogram (EEG), gene expression of brain receptors, and activation mechanisms using antagonists were investigated in rodent models. RESULTS: High-performance liquid chromatography analysis showed that HLE contained lactucin (0.78 mg/g of extract) and quercetin-3-glucuronide (1.3 mg/g of extract). In the pentobarbital-induced sleep model, the group administered 150 mg/kg of HLE showed a 47.3% increase in sleep duration time as compared to the normal group (NOR). The EEG analysis showed that the HLE significantly increased non-rapid eye movement (NREM), where delta waves were improved by 59.5% when compared to the NOR, resulting in increased sleep time. In the caffeine-induced arousal model, HLE significantly decreased the awake time increased by caffeine administration (35.5%) and showed a similar level to NOR. In addition, HLE increased the gene and protein expression of gamma-aminobutyric acid receptor type A (GABAA), GABA type B, and 5-hydroxytryptamine (serotonin) receptor 1A. In particular, in comparison to the NOR, the group administered 150 mg/kg HLE showed an increase in expression levels of GABAA and protein by 2.3 and 2.5 times, respectively. When the expression levels were checked using GABAA receptor antagonists, HLE showed similar levels to NOR, as the sleep duration was reduced by flumazenil (45.1%), a benzodiazepine antagonist. CONCLUSIONS: HLE increased NREM sleep and significantly improved sleep behavior due to its action on the GABAA receptors. The collective findings suggest that HLE can be used as a novel sleep-enhancing agent in the pharmaceutical and food industries.

The Preparation and Physiochemical Characterization of Tenebrio molitor Chitin Using Alcalase.

Chitin is mostly produced from crustaceans, but it is difficult to supply raw materials due to marine pollution, and the commonly used chemical chitin extraction method is not environmentally friendly. Therefore, this study aims to establish a chitin extraction process using enzymes and to develop edible insect-derived chitin as an eco-friendly new material. The response surface methodology (RSM) was used to determine the optimal conditions for enzymatic hydrolysis. The optimal conditions for enzymatic hydrolysis by RSM were determined to be the substrate concentration (7.5%), enzyme concentration (80 µL/g), and reaction time (24 h). The solubility and DDA of the mealworm chitosan were 45% and 37%, respectively, and those of the commercial chitosan were 61% and 57%, respectively. In regard to the thermodynamic properties, the exothermic peak of mealworm chitin was similar to that of commercial chitin. In the FT-IR spectrum, a band was observed in mealworm chitin corresponding to the C=O of the NHCOCH3 group at 1645 cm-1, but this band showed low-intensity C=O in the mealworm chitosan due to deacetylation. Collectively, mealworm chitosan shows almost similar physical and chemical properties to commercial chitosan. Therefore, it is shown that an eco-friendly process can be introduced into chitosan production by using enzyme-extracted mealworms for chitin/chitosan production.