Effect of Valerian/Hop Mixture on Sleep-Related Behaviors in Drosophila melanogaster

Combined Effects of Ziziphus jujuba, Dimocarpus longan, and Lactuca sativa on Sleep-Related Behaviors through GABAergic Signaling

We aimed to analyze the increase in the sleep-promoting effects based on the mixed ratio of botanical extracts, Ziziphus jujuba seeds, Dimocarpus longan fruits, and Lactuca sativa leaves, using animal models. Behavioral analyses, including an analysis of the total sleep time of Drosophila melanogaster, were conducted to select the optimal mixed ratio of the three botanical extracts. The effects were verified in a caffeine-induced sleepless model, specific neurotransmitter receptor antagonists, and ICR mice. In D. melanogaster exposed to 2.0% of each extract, group behavior was significantly reduced, and the mixed extracts of Z. jujuba, D. longan, and L. sativa (4:1:1 and 1:4:1) significantly increased the total sleep time with individual fruit flies. In the caffeine-induced insomnia model, mixed extracts (4:1:1 and 1:4:1) led to the highest increase in total sleep time. An analysis of locomotor ability revealed a significant reduction in the mobility percentage in the mixed extract groups (0:0:1, 1:0:1, 1:1:1, 4:1:1, and 1:4:1). The administration of Z. jujuba extract and mixed extracts (4:1:1) significantly increased the expression of GABAA-R, whereas the administration of the mixed extracts (4:1:1) and (1:4:1) significantly increased the expression of GABAB-R1 and GABAB-R2, respectively. D. longan extract and the mixed ratio (1:4:1) reduced the subjective nighttime movement and increased the total sleep time in the presence of flumazenil. An analysis of ICR mice indicated that the administration of mixed extracts (4:1:1) significantly increased sleep duration in a dose-dependent manner. These results indicated that the mixed ratio of Z. jujuba, D. longan, and L. sativa extracts, particularly the mixed ratio of 4:1:1, may have sleep-enhancing effects in fruit flies and mice. The study also identified changes in gene expression related to GABA receptors, indicating the potential mechanism for the observed sleep-promoting effects.

Herbal medicines for insomnia through regulating 5-hydroxytryptamine receptors: a systematic review

Insomnia is a common sleep disorder without effective therapy and can affect a person's life. The mechanism of the disease is not completely understood. Hence, there is a need to understand the targets related to insomnia, in order to develop innovative therapies and new compounds. Recently, increasing interest has been focused on complementary and alternative medicines for treating or preventing insomnia. Research into their molecular components has revealed that their sedative and sleep-promoting properties rely on the interactions with various neurotransmitter systems in the brain. In this review, the role of 5-hydroxytryptamine (5-HT) in insomnia development is summarized, while a systematic analysis of studies is conducted to assess the mechanisms of herbal medicines on different 5-HT receptors subtypes, in order to provide reference for subsequent research.

An Updated Review of the Genus Humulus: A Valuable Source of Bioactive Compounds for Health and Disease Prevention

The medicinal potential of hop (Humulus lupulus L.) is widely cited in ancient literature and is also allowed in several official pharmacopoeias for the treatment of a variety of ailments, mainly related to anxiety states. This is due to the plethora of phytoconstituents (e.g., bitter acids, polyphenols, prenyl flavonoids) present in the female inflorescences, commonly known as cones or strobili, endowed with anti-inflammatory, antioxidant, antimicrobial, and phytoestrogen activities. Hop has recently attracted the interest of the scientific community due to the presence of xanthohumol, whose strong anti-cancer activity against various types of cancer cells has been well documented, and for the presence of 8-prenyl naringenin, the most potent known phytoestrogen. Studies in the literature have also shown that hop compounds can hinder numerous signalling pathways, including ERK1/2 phosphorylation, regulation of AP-1 activity, PI3K-Akt, and nuclear factor NF-κB, which are the main targets of the antiproliferative action of bitter acids and prenylflavonoids. In light of these considerations, the aim of this review was to provide an up-to-date overview of the main biologically active compounds found in hops, as well as their in vitro and in vivo applications for human health and disease prevention. To this end, a quantitative literature analysis approach was used, using VOSviewer software to extract and process Scopus bibliometric data. In addition, data on the pharmacokinetics of bioactive hop compounds and clinical studies in the literature were analysed. To make the information more complete, studies on the beneficial properties of the other two species belonging to the genus Humulus, H. japonicus and H. yunnanensis, were also reviewed for the first time.

Novel hypnotics of Japanese traditional herbal medicines to caffeine-induced insomnia in Drosophila by using Newly-developed automated sleep and rhythm analysis system (AutoCircaS)

Sleep in Drosophila was defined in the year 2000 by using Drosophila Activity Monitor (DAM) system. But DAM is very small tube space and one fly per tube is very limited to analyze for fly social behavior. To overcome such demerits of DAM system, we developed a novel automated sleep and rhythm analysis system (AutoCircaS) which monitors and records any behaviors like social mating, sleep, and circadian rhythm in flies (Drosophila) and small fishes medaka (Oryzias latipes) in free space using the time-lapse (one frame per 10 sec) imaging. AutoCircaS can detect the caffeine-induced insomnia in flies in light-dark (LD) and constant dark (DD) conditions. Thus, using the AutoCircaS, we discovered that Japanese traditional herbal medicines, KyushinKannouGan-ki (KKG), NouKassei (NK) as well as, and Sansoninto, significantly improved caffeine-induced insomnia in flies. The data suggest that AutoCircaS is useful for sleep analysis of small animals and screening of new sedative-hypnotics from many origins.

Neuromodulatory and Protective Effects Induced by the Association of Herbal Extracts from Valeriana officinalis, Ziziphus jujuba, and Humulus lupulus with Melatonin: An Innovative Formulation for Counteracting Sleep Disorders

Background: The use of herbal extracts could represent an advantageous approach for treating sleeping disorders, especially in mild-to-moderate conditions, before the onset of a specific therapy with first-line drugs. Specifically, the focus was posed about the use of extracts from Valeriana officinalis, Ziziphus jujuba, and Humulus lupulus. Multiple studies demonstrated the efficacy of these medicinal plants to positively manage insomnia symptoms. Additionally, their efficacy in the treatment of sleeping disorders could also be improved by their pharmacological association. In the present study, extracts from Valeriana officinalis, Ziziphus jujuba, Humulus lupulus, melatonin, and their pharmacological association, Vagonotte® MEL, were studied for potential application in the treatment of insomnia. Methods: The extracts and melatonin were tested on hypothalamic neurons and tissue for evaluating biocompatibility and protective and neuromodulatory effects. The neuromodulatory effects were evaluated as orexin A gene expression and serotonin steady state level, in the hypothalamus. Results: The extracts and melatonin, although with evident differences, were effective as antioxidant and anti-inflammatory agents; additionally, they were also able to reduce the hypothalamic gene expression of orexin A and the steady state level of serotonin, playing master roles in wakefulness. It is noteworthy that the formulation displayed all the effects of the single ingredients, without any sign of toxicity and pharmacological interference in the hypothalamus. Conclusions: Concluding, the present study explored the biological effects of melatonin and herbal extracts with phytotherapy interest in V. officinalis, Z. jujuba, and H. lupulus. The study demonstrated their intrinsic scavenging/reducing activity, together with protective and neuromodulatory effects in the hypothalamus, with a significant reduction of both orexin A gene expression and serotonin steady state level. Additionally, the study also considered their pharmacological association, which displayed an overall pharmacological spectrum mirroring, including all the effects of the single ingredients, without showing any sign of toxicity in the brain and interference between the extracts and melatonin.

Binding activity of Valeriana fauriei root extract on GABAA receptor flunitrazepam sites and distribution of its active ingredients in the brain of mice - A comparison with that of V. officinalis root

ETHNOPHARMACOLOGICAL RELEVANCE

Valeriana fauriei root (VF) is a crude drug registered in the Japanese Pharmacopeia 17th Edition and a known substitute for V. officinalis (VO). Although VO has been pharmacologically evaluated for its sedative effects and mechanism of action, data regarding VF remain scarce.

AIM OF THE STUDY

We compared the binding affinity of VF and VO extracts, as well as examined the active ingredients in the VF extract, on flunitrazepam sites of γ-aminobutyric acid receptor type A (GABA_A receptor). Furthermore, we confirmed whether these active ingredients were distributed in the brain of mice orally administered the VF extract.

MATERIALS AND METHODS

We prepared the assay system to evaluate the binding activity of flunitrazepam sites of GABA_A receptor using a 96-well plate and assessed the activities of VF and VO extracts. We then analyzed their constituents using HPLC with principal component analysis (PCA) and evaluated active ingredients correlated with their activities. The distribution of active ingredients in the plasma and brain of mice orally administered the VF extract prepared with different emulsifiers were analyzed by LC-MS/MS.

RESULTS

The ethanol extract of VF exhibited significantly higher activity on flunitrazepam sites of GABA_A receptor than VO. For the VF extract, kessyl glycol diacetate (KGD) was markedly associated with the binding activities; however, active ingredients included KGD, kessyl glycol 8-acetate (KG8), α-kessyl acetate (α-KA), and coniferyl isovalerate (CI). For VO, valerenic acid and five other compounds were associated with the binding affinity on flunitrazepam sites of GABA_A receptor. On emulsifying the VF extract with a fat-soluble glycerin fatty acid ester, the plasma and brain distributions of KGD tended to be higher, those of KG8 were significantly more than 10-times higher, and those of α-KA was lower than those of the VF extract emulsified with water-soluble gum arabic, after oral administration in mice.

CONCLUSIONS

Based on the binding activity on flunitrazepam sites of GABA_A receptor and brain distribution, KGD, KG8, and α-KA can be considered active ingredients of VF. The addition of a fat-soluble emulsifier promoted the absorption of KGD, the main active ingredient, and KGD was metabolized to KG8 in the body. The present results suggest a possible mechanism underlying the sedative effect for VF, and these three compounds can be used as marker compounds to evaluate the quality of VF products.

Fermented Gamma Aminobutyric Acid Improves Sleep Behaviors in Fruit Flies and Rodent Models

The aim of this study was to investigate the effect of Lactobacillus brevis-fermented γ-aminobutyric acid (LB-GABA) on sleep behaviors in invertebrate and vertebrate models. In Drosophila melanogaster, LB-GABA-treated group showed an 8-9%-longer sleep duration than normal group did. LB-GABA-treated group also showed a 46.7% lower level of nighttime activity with a longer (11%) sleep duration under caffeine-induced arousal conditions. The LB-GABA-mediated inhibition of activity was confirmed as a reduction of total movement of flies using a video tracking system. In the pentobarbital-induced sleep test in mice, LB-GABA (100 mg/kg) shortened the time of onset of sleep by 32.2% and extended sleeping time by 59%. In addition, mRNA and protein level of GABAergic/Serotonergic neurotransmitters were upregulated following treatment with LB-GABA (2.0%). In particular, intestine- and brain-derived GABAA protein levels were increased by sevenfold and fivefold, respectively. The electroencephalography (EEG) analysis in rats showed that LB-GABA significantly increased non-rapid eye movement (NREM) (53%) with the increase in theta (θ, 59%) and delta (δ, 63%) waves, leading to longer sleep time (35%), under caffeine-induced insomnia conditions. LB-GABA showed a dose-dependent agonist activity on human GABAA receptor with a half-maximal effective concentration (EC50) of 3.44 µg/mL in human embryonic kidney 293 (HEK293) cells.

Use of Plant-Derived Natural Products in Sleep Disturbances

Sleep disorders have a high prevalence both in the general population and especially in specific populations such older adults and oncologic patients. Impacting on quality of life, they often translate in drug prescription, with consequent increased risk of drug-drug interactions and adverse drug reactions. In the last years several products derived from plants have been developed with the aim of treating insomnia with lower risk of side effects. Despite several studies have been performed with this aim, the available evidence is inconclusive, and reviews summarizing the most recent evidences on the effectiveness of plant-derived products in treating insomnia are lacking.This narrative review aims at summarizing the evidences of the mechanism of action, effectiveness and safety of the most commonly used plant-derived products for the treatment of sleep disorders (Valerian, Lemon balm, Passionflower, Chamomile, Hops, and Jujube).

Isolation of a sleep-promoting compound from Polygonatum sibiricum rhizome

The aim of this study was to identify sleep-promoting substance from Polygonatum sibiricum rhizome extract (PSE) with the regulation of sleep architecture. PSE showed a decrease in sleep latency time and an increase in the sleeping time. In the electroencephalography analysis of rats, PSE (150 mg/kg) showed an increase of non-rapid eye movement by 38% and a decrease of rapid eye movement by 31% compared to the control. This sleep-promoting activity was found to be involved in the GABAA-BDZ receptor. The chemical structure of the pure compound was determined by the 1H and 13C nuclear magnetic resonance spectroscopy and gas chromatography mass spectrometry analysis; active compound was glyceryl-1-monolinoleate. The commercial standard glyceryl-1-monolinoleate showed a similar inhibitory concentration on [3H]-flumazenil binding to GABAA-BDZ receptors with final active fraction of PSE. The results indicate that glyceryl-1-monolinoleate is a major active compound responsible for the PSE-derived sleep promotion.

Polygonatum sibiricum rhizome promotes sleep by regulating non-rapid eye movement and GABAergic/serotonergic receptors in rodent models

The aim of this study is to investigate the sleep-promoting effect of a water extract of the Polygonatum sibiricum rhizome (PSE) in rodent models. PSE contained oleamide (0.10 mg/g extract) and glyceryl monolinoleate (0.17 mg/g extract), which are recognized as sleep-promoting substances. In pentobarbital-induced sleep model at hypnotic level, PSE (160 mg/kg) administration significantly decreased sleep latency time by 29% (2.7 min) and increased sleep duration time by 70% (68.4 min) compared with the normal control (3.8 min and 40.7 min, respectively). In the electroencephalography (EEG) analysis of rats, PSE-mediated sleep promotion accompanied the change of sleep architecture including increase of non-rapid eye movement (NREM) and decrease of REM. This sleep promoting effect was more obvious in caffeine-induced awakening model; total sleep time was increased by 40% along with increased NREM by PSE treatment at 160 mg/kg. In addition, PSE significantly increased the protein and mRNA levels of GABA_A-R2 and 5-HT1A receptor, the major sleep-related neurotransmitter receptors. Furthermore, glyceryl monolinoleate and oleamide effectively bound to GABA_A receptor in a competitive binding assay. These results indicate that PSE-mediated sleep-promoting effect is associated with the extension of NREM and upregulation of GABA_A-R2 and 5-HT1A, and is mediated by binding to the GABA_A receptor in vertebrate models.

Valerian/Cascade mixture promotes sleep by increasing non-rapid eye movement (NREM) in rodent model

The aim of this study was to investigate the beneficial effect of Valerian/Cascade mixture on sleeping in mammal models. In pentobarbital-induced sleep model, Valerian, Cascade, and Valerian/Cascade mixture significantly reduced the latency time for sleeping, and total sleeping time effectively increased in these sample groups compared with the control. Valerian/Cascade mixture increased sleep duration by 37%. The mixture significantly increased the non-rapid eye movement (NREM) sleep time by 53% compared with the control, while REM sleeping time was decreased by 33% with Valerian/Cascade mixture, in Electroencephalography (EEG) analysis, resulting in the increase of total sleep time and the decrease of awakening. This sleep-promoting effect was obvious in caffeine-induced awakening model; Valerian, Cascade, and the mixture significantly enhanced NREM and total sleep time, which were reduced by caffeine. Caffeine-induced increase of awakening was effectively deceased to the normal level by these three samples. In particular, delta wave responsible for deep sleep in NREM was greatly increased by the mixture in both normal and caffeine-induced awake models. This sleep-promoting effect of Valerian/Cascade mixture was shown to be due to the upregulation of gamma-aminobutyric acid A receptor (GABA_AR). Valerian/Cascade mixture showed 91% binding capacity to GABA_A-BZD receptor. Two compounds, Valerenic acid and Xanthohumol, were shown to significantly contribute to the binding activity of Valerian/Cascade mixture on the GABA receptor.

Changes in Drosophila melanogaster Sleep-Wake Behavior Due to Lotus (Nelumbo nucifera) Seed and Hwang Jeong (Polygonatum sibiricum) Extracts

We evaluated the sleep enhancement activity of the medicinal herbs valerian (Valeriana officinalis), jujube (Ziziphus jujube), lotus seed (Nelumbo nucifera), Gastrodia elata, Polygonatum sibiricum, and baekbokryung (Poria cocos), which can relieve insomnia in a Drosophila model. Locomotor activity was measured in the Drosophila model to evaluate the sleep activity of Korean medicinal herbs traditionally used as sleep aids. The group treated with lotus seed extract showed less nocturnal activity. Treatment with 10 or 20 mg/mL of P. sibiricum significantly reduced nocturnal activity compared to the control group (P<0.05). The activity and sleep bouts of fruit flies were significantly decreased by a high-dose treatment (10 mg/mL) of lotus or P. sibiricum extracts at night. Caffeine-treated Drosophila showed increased nocturnal activity and decreased total sleep time (P<0.05). Flies receiving the 10 mg-doses of lotus seed or P. sibiricum extract showed significantly different nocturnal locomotor activity and total sleep time compared to caffeine-treated Drosophila. Lotus seed and P. sibiricum extracts are attractive and valuable sleep-potentiating nutraceuticals.

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.