Involvement of GABAergic non-benzodiazepine sites in the anxiolytic-like and sedative effects of the flavonoid baicalein in mice

Combination of UPLC-Q-TOF/MS and network pharmacology to reveal the mechanism of Chaihu-jia-Longgu-Muli decoction for treating vertigo with anxiety disorder

Chaihu-jia-Longgu-Muli decoction (CLMD) has been proven clinically effective in treating vertigo with anxiety disorder. However, the mechanism is not clear. This study aimed to explore the mechanism of CLMD in treating vertigo with anxiety disorder based on ultra-performance liquid chromatography-quadrupole time-of-flight/mass spectrometry (UPLC-Q-TOF/MS) and network pharmacology. UPLC-Q-TOF/MS was performed to identify the compounds in blood and the targets of compounds of CLMD in vertigo and anxiety were searched using databases. A protein-protein interaction network was built to screen the core targets. The core targets were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. In addition, the vertigo with anxiety rat model was used to verify the results. A total of 22 compounds were absorbed into the blood. Eighty-one potential targets associated with CLMD for vertigo with anxiety disorder were identified through network pharmacological analysis. Subsequently, GO and KEGG analysis showed that CLMD treatment for vertigo with anxiety disorder is associated with neurotransmitter levels and other pertinent physiological processes. The results of the animal experiments showed that CLMD decreased the levels of serotonin, norepinephrine and dopamine, alleviating the symptoms of vertigo and anxiety disorder in model rats. The study revealed CLMD could alleviate vertigo and anxiety symptoms through reducing the levels of neurotransmitters.

The Neuroprotective Effects of Oroxylum indicum Extract in SHSY-5Y Neuronal Cells by Upregulating BDNF Gene Expression under LPS Induced Inflammation

The brain-derived neurotrophic factor (BDNF) plays a crucial role during neuronal development as well as during differentiation and synaptogenesis. They are important proteins present in the brain that support neuronal health and protect the neurons from detrimental signals. The results from the present study suggest BDNF expression can be increase up to ~8-fold by treating the neuroblastoma cells SHSY-5Y with an herbal extract of Oroxylum indicum (50 μg/mL) and ~5.5-fold under lipopolysaccharides (LPS)-induced inflammation conditions. The Oroxylum indicum extract (Sabroxy) was standardized to 10% oroxylin A, 6% chrysin, and 15% baicalein. In addition, Sabroxy has shown to possess antioxidant activity that could decrease the damage caused by the exacerbation of radicals during neurodegeneration. A mode of action of over expression of BDNF with and without inflammation is proposed for the Oroxylum indicum extract, where the three major hydroxyflavones exert their effects through additive or synergistic effects via five possible targets including GABA, Adenoside A2A and estrogen receptor bindings, anti-inflammatory effects, and reduced mitochondrial ROS production.

Potential mechanisms of traditional Chinese medicine in treating insomnia: A network pharmacology, GEO validation, and molecular-docking study

The purpose of this study is to investigate the potential mechanisms of Chinese herbs for the treatment of insomnia using a combination of data mining, network pharmacology, and molecular-docking validation. All the prescriptions for insomnia treated by the academician Qi Wang from 2020 to 2022 were collected. The Ancient and Modern Medical Case Cloud Platform v2.3 was used to identify high-frequency Chinese medicinal herbs and the core prescription. The Traditional Chinese Medicine Systems Pharmacology and UniProt databases were utilized to predict the effective active components and targets of the core herbs. Insomnia-related targets were collected from 4 databases. The intersecting targets were utilized to build a protein-protein interaction network and conduct gene ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis using the STRING database, Cytoscape software, and clusterProfiler package. Gene chip data (GSE208668) were obtained from the Gene Expression Omnibus database. The limma package was applied to identify differentially expressed genes (DEGs) between insomnia patients and healthy controls. To create a "transcription factor (TF)-miRNA-mRNA" network, the differentially expressed miRNAs were entered into the TransmiR, FunRich, Targetscan, and miRDB databases. Subsequently, the overlapping targets were validated using the DEGs, and further validations were conducted through molecular docking and molecular dynamics simulations. Among the 117 prescriptions, 65 herbs and a core prescription were identified. Network pharmacology and bioinformatics analysis revealed that active components such as β-sitosterol, stigmasterol, and canadine acted on hub targets, including interleukin-6, caspase-3, and hypoxia-inducible factor-1α. In GSE208668, 6417 DEGs and 7 differentially expressed miRNAs were identified. A "TF-miRNA-mRNA" network was constructed by 4 "TF-miRNA" interaction pairs and 66 "miRNA-mRNA" interaction pairs. Downstream mRNAs exert therapeutic effects on insomnia by regulating circadian rhythm. Molecular-docking analyses demonstrated good docking between core components and hub targets. Molecular dynamics simulation displayed the strong stability of the complex formed by small molecule and target. The core prescription by the academician Qi Wang for treating insomnia, which involves multiple components, targets, and pathways, showed the potential to improve sleep, providing a basis for clinical treatment of insomnia.

Advances in Flavonoid Research: Sources, Biological Activities, and Developmental Prospectives

At present, the occurrence of a large number of infectious and non-communicable diseases poses a serious threat to human health as well as to drug development for the treatment of these diseases. One of the most significant challenges is finding new drug candidates that are therapeutically effective and have few or no side effects. In this respect, the active compounds in medicinal plants, especially flavonoids, are potentially useful compounds with a wide range of pharmacological activities. They are naturally present in nature and valuable in the treatment of many infectious and non-communicable diseases. Flavonoids are divided into fourteen categories and are mainly derived from plant extraction, chemical synthesis and structural modification, and biosynthesis. The structural modification of flavonoids is an important way to discover new drugs, but biosynthesis is currently considered the most promising research direction with the potential to revolutionize the new production pipeline in the synthesis of flavonoids. However, relevant problems such as metabolic pathway analyses and cell synthesis protocols for flavonoids need to be addressed on an urgent basis. In the present review, new research techniques for assessing the biological activities of flavonoids and the mechanisms of their biological activities are elucidated and their modes of interaction with other drugs are described. Moreover, novel drug delivery systems, such as nanoparticles, bioparticles, colloidals, etc., are gradually becoming new means of addressing the issues of poor hydrophilicity, lipophilicity, poor chemical stability, and low bioavailability of flavonoids. The present review summarizes the latest research progress on flavonoids, existing problems with their therapeutic efficacy, and how these issues can be solved with the research on flavonoids.

Inhibitory effect of γ-ray-modified hydroxymethylated baicalins on NO production

Baicalin, a glucuronic flavone, is the major active component in the medicinal plant Scutellaria baicalensis. Herein, baicalin was irradiated by γ-rays to afford four unusual flavanones, baicalinols A (2), B (3), and C (4) and peroxybaicaleinol (5), and two known flavones, oroxylin A (6) and baicalein (7). The structures of the hydroxymethylated products were elucidated using nuclear magnetic resonance spectroscopy and mass spectrometry, and their absolute configuration was established using electronic circular dichroism spectroscopy. Novel hydroxymethylated flavanones 2 and 3 suppressed both nitric oxide (NO) production and the expression of inducible NO synthase and showed significantly higher anti-inflammatory activities in lipopolysaccharide-stimulated macrophages than the parent compound. These newly generated hydroxymethylated flavanones can be potentially used for treating inflammatory diseases.

The Potential of Flavonoids and Flavonoid Metabolites in the Treatment of Neurodegenerative Pathology in Disorders of Cognitive Decline

Flavonoids are a biodiverse family of dietary compounds that have antioxidant, anti-inflammatory, antiviral, and antibacterial cell protective profiles. They have received considerable attention as potential therapeutic agents in biomedicine and have been widely used in traditional complimentary medicine for generations. Such complimentary medical herbal formulations are extremely complex mixtures of many pharmacologically active compounds that provide a therapeutic outcome through a network pharmacological effects of considerable complexity. Methods are emerging to determine the active components used in complimentary medicine and their therapeutic targets and to decipher the complexities of how network pharmacology provides such therapeutic effects. The gut microbiome has important roles to play in the generation of bioactive flavonoid metabolites retaining or exceeding the antioxidative and anti-inflammatory properties of the intact flavonoid and, in some cases, new antitumor and antineurodegenerative bioactivities. Certain food items have been identified with high prebiotic profiles suggesting that neutraceutical supplementation may be beneficially employed to preserve a healthy population of bacterial symbiont species and minimize the establishment of harmful pathogenic organisms. Gut health is an important consideration effecting the overall health and wellbeing of linked organ systems. Bioconversion of dietary flavonoid components in the gut generates therapeutic metabolites that can also be transported by the vagus nerve and systemic circulation to brain cell populations to exert a beneficial effect. This is particularly important in a number of neurological disorders (autism, bipolar disorder, AD, PD) characterized by effects on moods, resulting in depression and anxiety, impaired motor function, and long-term cognitive decline. Native flavonoids have many beneficial properties in the alleviation of inflammation in tissues, however, concerns have been raised that therapeutic levels of flavonoids may not be achieved, thus allowing them to display optimal therapeutic effects. Dietary manipulation and vagal stimulation have both yielded beneficial responses in the treatment of autism spectrum disorders, depression, and anxiety, establishing the vagal nerve as a route of communication in the gut-brain axis with established roles in disease intervention. While a number of native flavonoids are beneficial in the treatment of neurological disorders and are known to penetrate the blood–brain barrier, microbiome-generated flavonoid metabolites (e.g., protocatechuic acid, urolithins, γ-valerolactones), which retain the antioxidant and anti-inflammatory potency of the native flavonoid in addition to bioactive properties that promote mitochondrial health and cerebrovascular microcapillary function, should also be considered as potential biotherapeutic agents. Studies are warranted to experimentally examine the efficacy of flavonoid metabolites directly, as they emerge as novel therapeutic options.

Baicalein exerts anxiolytic and antinociceptive effects in a mouse model of posttraumatic stress disorder: Involvement of the serotonergic system and spinal delta-opioid receptors

Post-traumatic stress disorder (PTSD) is a serious mental disease featured by a stress dysfunction that occurs after an individual has faced intense mental stress, often accompanied by anxiety and chronic pain. Currently, the mainstream drug for PTSD is serotonin reuptake inhibitors (SSRIs), however, their pain management for patients is limited. Baicalein, a Chinese traditional herbal medicine, has shown promising results in treating anxiety, depression, and pain. In this study, we found that baicalein may alleviate single prolonged stress (SPS)-induced PTSD-like behaviors in mice without altering baseline nociceptive sensitivity or activity. Meanwhile, baicalein increased the noradrenaline (NE) and serotonin (5-HT) content and decreased the ratio of 5-hydroxyindoleacetic acid (5-HIAA)/5-HT by inhibiting the activity of monoamine oxidase A (MAO-A) in SPS-induce mice. The anxiolytic and antinociceptive effects induced by baicalein were totally abolished by 5-HT depleting agents. Moreover, the anxiolytic effects of baicalein could be abolished by the 5-HT_1A receptor antagonist WAY-100635, and the analgesic effects could be abolished by delta-opioid receptor antagonists in the spinal. Taken together, our study provides compelling evidence that baicalein reversed anxiety-like behaviors and neuropathic pain in PTSD through serotonergic system and spinal delta-opioid receptors.

Combining genetic engineering and bioprocess concepts for improved phenylpropanoid production

The group of natural aromatic compounds known as phenylpropanoids has diverse applications, but current methods of production which are largely based on synthesis from petrochemicals or extraction from agricultural biomass are unsustainable. Bioprocessing is a promising alternative, but improvements in production titers and rates are required to make this method profitable. Here the recent advances in genetic engineering and bioprocess concepts for the production of phenylpropanoids are presented for the purpose of identifying successful strategies, including adaptive laboratory evolution, enzyme engineering, in-situ product removal, and biocatalysis. The pros and cons of bacterial and yeast hosts for phenylpropanoid production are discussed, also in the context of different phenylpropanoid targets and bioprocess concepts. Finally, some broad recommendations are made regarding targets for continued improvement and areas requiring specific attention from researchers to further improve production titers and rates.

Exploration of potential inhibitors for SARS-CoV-2 Mpro considering its mutants via structure-based drug design, molecular docking, MD simulations, MM/PBSA, and DFT calculations

The main protease (Mpro) of SARS-COV-2 plays a vital role in the viral life cycle and pathogenicity. Due to its specific attributes, this 3-chymotrypsin like protease can be a reliable target for the drug design to combat COVID-19. Since the advent of COVID-19, Mpro has undergone many mutations. Here, the impact of 10 mutations based on their frequency and five more based on their proximity to the active site was investigated. For comparison purposes, the docking process was also performed against the Mpros of SARS-COV and MERS-COV. Four inhibitors with the highest docking score (11b, α-ketoamide 13b, Nelfinavir, and PF-07321332) were selected for the structure-based ligand design via fragment replacement, and around 2000 new compounds were thus obtained. After the screening of these new compounds, the pharmacokinetic properties of the best ones were predicted. In the last step, comparative molecular dynamics (MD) simulations, molecular mechanics Poisson-Boltzmann surface area calculations (MM/PBSA), and density functional theory calculations were performed. Among the 2000 newly designed compounds, three of them (NE1, NE2, and NE3), which were obtained by modifications of Nelfinavir, showed the highest affinity against all the Mpro targets. Together, NE1 compound is the best candidate for follow-up Mpro inhibition and drug development studies.

Baicalin Ameliorates Corticosterone-Induced Depression by Promoting Neurodevelopment of Hippocampal via mTOR/GSK3 β Pathway

OBJECTIVE

To investigate the role of hippocampal neurodevelopment in the antidepressant effect of baicalin.

METHODS

Forty male Institute of Cancer Research mice were divided into control, corticosterone (CORT, 40 mg/kg), CORT+baicalin-L (25 mg/kg), CORT+baicalin-H (50 mg/kg), and CORT+fluoxetine (10 mg/kg) groups according to a random number table. An animal model of depression was established by chronic CORT exposure. Behavioral tests were used to assess the reliability of depression model and the antidepressant effect of baicalin. In addition, Nissl staining and immunofluorescence were used to evaluate the effect of baicalin on hippocampal neurodevelopment in mice. The protein and mRNA expression levels of neurodevelopment-related factors were detected by Western blot analysis and real-time polymerase chain reaction, respectively.

RESULTS

Baicalin significantly ameliorated the depressive-like behavior of mice resulting from CORT exposure and promoted the development of dentate gyrus in hippocampus, thereby reversing the depressive-like pathological changes in hippocampal neurons caused by CORT neurotoxicity. Moreover, baicalin significantly decreased the protein and mRNA expression levels of glycogen synthase kinase 3 β (GSK3 β), and upregulated the expression levels of cell cycle protein D1, p-mammalian target of rapamycin (mTOR), doublecortin, and brain-derived neurotrophic factor (all P<0.01). There were no significant differences between baicalin and fluoxetine groups (P>0.05).

CONCLUSION

Baicalin can promote the development of hippocampal neurons via mTOR/GSK3 β signaling pathway, thus protect mice against CORT-induced neurotoxicity and play an antidepressant role.

Effect of the Citrus Flavone Nobiletin on Circadian Rhythms and Metabolic Syndrome

The importance of the circadian clock in maintaining human health is now widely acknowledged. Dysregulated and dampened clocks may be a common cause of age-related diseases and metabolic syndrome Thus, circadian clocks should be considered as therapeutic targets to mitigate disease symptoms. This review highlights a number of dietary compounds that positively affect the maintenance of the circadian clock. Notably the polymethoxyflavone nobiletin has shown some encouraging results in pre-clinical experiments. Although many more experiments are needed to fully elucidate its exact mechanism of action, it is a promising candidate with potential as a chronotherapeutic agent.

Baicalein Alleviates Testicular Ischemia-Reperfusion Injury in a Rat Model of Testicular Torsion-Detorsion

Testicular torsion/detorsion-induced ischemia/reperfusion injury is partly due to the overgeneration of reactive oxygen species. Baicalein, a main bioactive constituent derived from the dried root of Scutellaria baicalensis Georgi, possesses powerful antioxidative and anti-inflammatory properties. Therefore, we designed the research to explore the possible protective effect of baicalein against testicular ischemia-reperfusion injury. Sprague-Dawley rats were randomized into 4 groups, including control, testicular ischemia-reperfusion, testicular ischemia-reperfusion+vehicle injection, and testicular ischemia-reperfusion+baicalein therapy groups. The control group received surgical exposure of the left testis without torsion-detorsion. In the testicular ischemia-reperfusion group, the left testis underwent 720° counterclockwise torsion for two hours and then was allowed detorsion. Rats in the testicular ischemia-reperfusion+vehicle injection group received intraperitoneal injection of the vehicle at detorsion. In the baicalein-treated group, the intraperitoneal administration of baicalein dissolved in the vehicle was performed at detorsion. At four hours or three months following testicular detorsion, testicular tissues were removed to detect the levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) which can recruit neutrophils into the testis, myeloperoxidase activity (an index of neutrophil infiltration in the testis), protein expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in neutrophils which can catalyze reactive oxygen species production, malondialdehyde concentration (a common marker of reactive oxygen species), and spermatogenesis. Both testicular ischemia-reperfusion and testicular ischemia-reperfusion+vehicle injection significantly increased the TNF-α and IL-1β levels, myeloperoxidase activity, NADPH oxidase protein expression, and malondialdehyde concentration, while decreased spermatogenesis in ipsilateral testes. In contrast, baicalein administration remarkably reduced TNF-α and IL-1β levels, myeloperoxidase activity, NADPH oxidase protein expression, and malondialdehyde concentration and also elevated spermatogenesis in ipsilateral testes. The results of our experiment demonstrate that baicalein alleviates testicular ischemia-reperfusion injury by inhibiting TNF-α and IL-1β secretion, neutrophil infiltration in the testis, and NADPH oxidase protein expression in neutrophils to reduce reactive oxygen species production.

Baicalein prevents stress-induced anxiety behaviors in zebrafish model

Baicalein is a flavonoid mainly obtained from plants with wide range of biological activities, including neuroprotection. An acute and unexpected chronic stress (UCS) protocol has recently been adapted to zebrafish, a popular vertebrate model in brain research. The present study was aimed to evaluate baicalein's anti-anxiety potential in a zebrafish model by induction, which included neuropharmacological evaluation to determine behavioural parameters in the novel tank diving test (NTDT) and light-dark preference test (LDPT). The toxicity was also assessed using the brine shrimp lethality assay, and the 50% lethal concentration (LC50) was determined. The animals were then stressed for 7 days before being treated with different doses of baicalein (1 and 2 mg/L) for another 7 days in UCS condition. Due to acute stress and UCS, the frequency of entries and time spent in the 1) top region and 2) light area of the novel tank reduced significantly, indicating the existence of elevated anxiety levels. The biological activity of baicalein was demonstrated by its high LC50 values (1,000 μg/ml). Additionally, baicalein administration increased the frequency of entries and duration spent in the light region, indicating a significant decrease in anxiety levels. Overall, the present results showed that baicalein has a therapeutic advantage in reversing the detrimental consequences of UCS and acute stress, making it is a promising lead molecule for new drug design, development, and therapy for stress.

Anti-neuropathic effect of 7,3'-dihydroxyflavone in paclitaxel induced peripheral neuropathy in mice involving GABAA, KATP channel and adenosine receptors

Peripheral neuropathy induced by chemotherapeutic agents is the most common dose-limiting adverse effect observed in patients during and after treatment of malignancies. Many flavones have been reported to ameliorate neuropathy of different origin in experimental animals and their possible mode of action explored. The present study aims to investigate 7,3'-dihydroxyflavone for its anti-neuropathic effect against paclitaxel induced peripheral neuropathy in mice by employing behavioural tests such as mechanical allodynia, cold allodynia and thermal hyperalgesia. The possible involvement of GABA_A, K_ATP channels and adenosine receptors in the anti-neuropathic effect of 7,3'-dihydroxyflavone was also studied by employing suitable interacting drugs. Treatment with 7,3'-dihydroxyflavone (50, 100 or 200 mg/kg, s.c) significantly and dose-dependently reduced the paw withdrawal response score in both mechanical and cold allodynia and also increased the tail flick response time in thermal hyperalgesia due to paclitaxel-induced neuropathy. Pre-treatment with glibenclamide (10 mg/kg, i.p), caffeine (50 mg/kg, i.p) or bicuculline (2 mg/kg, i.p) significantly reversed the anti-neuropathic effect of 7,3'-dihydroxyflavone in behavioral tests. In conclusion, the present investigation identified 7,3'-dihydroxyflavone as a potential candidate with anti-neuropathic effect against paclitaxel induced peripheral neuropathy involving K_ATP channels, adenosine and GABA_A receptors.

Evidence and Characteristics of Traditional Chinese Medicine for Coronary Heart Disease Patients With Anxiety or Depression: A Meta-Analysis and Systematic Review

Aims: The objective of this study was to assess the efficacy and potential mechanisms of Chinese herbal medicine (CHM) for treating coronary heart disease (CHD) patients with anxiety or depression.

Methods: A systematic literature search was performed. Screening studies, extracting data, and assessing article quality were carried out independently by two researchers. The active ingredients of CHM for the treatment of CHD with anxiety or depression were analyzed by the network pharmacology, and the main potential mechanisms were summarized by the database of Web of Science.

Results: A total of 32 studies were included. The results showed that compared with the blank control groups, CHM was more beneficial in treating anxiety or depression in patients with CHD [anxiety: OR = 3.22, 95% CI (1.94, 5.35), p &lt; 0.00001, I2 = 0%; depression: OR = 3.27, 95% CI (1.67, 6.40), p = 0.0005, I2 = 0%], and the efficacy of CHM was not inferior to that of Western medicine (WM) [anxiety: OR = 1.58, 95%CI (0.39, 6.35), p = 0.52, I2 = 67%; depression: OR = 1.97, 95%CI (0.73, 5.28), p = 0.18, I2 = 33%,]. Additionally, CHM also showed a significant advantage in improving angina stability (AS) in CHD patients with anxiety or depression compared with blank groups [anxiety: SMD = 0.55, 95%CI (0.32, 0.79), p &lt; 0.00001, I2 = 0%; depression: p = 0.004] and WM groups [anxiety: SMD = 1.14, 95%CI (0.80, 1.47), p &lt; 0.00001, I2 = 0%; depression: SMD = 12.15, 95%CI (6.07, 18.23), p &lt; 0.0001, I2 = 0%]. Angina frequency (AF) and electrocardiogram (ECG) analysis after using CHM demonstrated similar trends. Based on the network pharmacology, quercetin, kaempferol, luteolin, beta-sitosterol, puerarin, stigmasterol, isorhamnetin, baicalein, tanshinone IIa, and nobiletin were most closely and simultaneously related to the pathological targets of CHD, anxiety, and depression. The main underlying mechanisms might involve anti-damage/apoptosis, anti-inflammation, antioxidative stress, and maintaining neurotransmitter homeostasis.

Conclusion: CHM exhibited an obvious efficacy in treating CHD patients with anxiety or depression, especially for improving the symptom of angina pectoris. The most active compounds of CHM could simultaneously act on the pathological targets of CHD, anxiety, and depression. Multiple effective components and multiple targets were the advantages of CHM compared with WM.

Therapeutic and prophylactic effect of flavonoids in post-COVID-19 therapy

The high incidence of post-covid symptoms in humans confirms the need for effective treatment. Due to long-term complications across several disciplines, special treatment programs emerge for affected patients, emphasizing multidisciplinary care. For these reasons, we decided to look at current knowledge about possible long-term complications of COVID-19 disease and then present the effect of flavonoids, which could help alleviate or eliminate complications in humans after overcoming the COVID-19 infection. Based on articles published from 2003 to 2021, we summarize the flavonoids-based molecular mechanisms associated with the post-COVID-19 syndrome and simultaneously provide a complex view regarding their prophylactic and therapeutic potential. Review clearly sorts out the outcome of post-COVID-19 syndrome according particular body systems. The conclusion is that flavonoids play an important role in prevention of many diseases. We suggest that flavonoids as critical nutritional supplements, are suitable for the alleviation and shortening of the period associated with the post-COVID-19 syndrome. The most promising flavonoid with noteworthy therapeutic and prophylactic effect appears to be quercetin.

Baicalin coadministration with lithium chloride enhanced neurogenesis via GSK3β pathway in corticosterone induced PC-12 cells

Accumulating studies suggest that hippocampal neurogenesis plays a crucial role in the pathological mechanism of depression. As a classic antidepressant, lithium chloride can play an antidepressant role by inhibiting GSK3β and promoting neurogenesis. Correspondingly, baicalin is a compound extracted from natural plants, which shows potential antidepressant effect, however, whether baicalin exerts antidepressant effects by promoting neurogenesis still needs further investigation. In the current study, we established an in vitro depression model through corticosterone induced PC-12 cells, and explored the potential mechanism of baicalin's antidepressant effect by comparing it with lithium chloride alone and the coadministration with lithium chloride. We used CCK-8 assay, EdU staining and cell cycle analysis to evaluate the state of cell survival and cell proliferation. The protein expression levels of neurodevelopmental related factors DCX, BDNF, and the GSK3β pathway-related proteins and mRNA were detected by Western blot and Real-time PCR. The results showed that baicalin could decrease the expression level of GSK3β, while upregulate the expression level of DCX, BDNF, Cyclin D1-CDK4/6, thus promoted cell proliferation and survival in CORT induced PC-12 cells. Moreover, this effect was enhanced when baicalin and lithium chloride were coadministration. Taking the above results together, we conclude that baicalin can promote the proliferation and development of PC-12 cells by regulating GSK3β pathway, so as to reverse the depressive-like pathological changes induced by corticosterone.

Identification of Potential Human Ryanodine Receptor 1 Agonists and Molecular Mechanisms of Natural Small-Molecule Phenols as Anxiolytics

Natural small-molecule phenols (NSMPs) possess certain ubiquitous bioactivities including the anxiolytic effect. Ryanodine receptor 1 (RyR1) may be one of the potentially critical pharmacological targets for studying the anxiolytic activity of NSMPs. However, detailed molecular mechanisms of NSMPs have not been fully clarified. This research was intended to identify potent hRyR1 agonists from NSMPs and investigate whether RyR1 plays a role in their anxiolytic effect. Homology modeling and molecular docking analysis were performed using Accelrys Discovery Studio 2.5. The most appropriate concentrations of NSMPs to activate RyR1 were measured using the MTT assay. Fluorescence analyses of the intracellular calcium levels and western blotting analysis were carried out to validate whether NSMPs could regulate the calcium flux to some extent by activating RyR1. The results demonstrated that xanthotoxol and 5-hydroxy-1,4-naphthalenedione can be screened as hit compounds for potential agonists of hRyR1 to exert the anxiolytic effect. In conclusion, NSMPs might be a kind of pharmacological signal carrier, acting on RyR1 as an agonist and resulting in calcium ion mobilization from intracellular calcium ion store.

Pharmacological significance of extra-oral taste receptors

It has recently been shown that taste receptors, in addition to being present in the oral cavity, exist in various extra-oral organs and tissues such as the thyroid, lungs, skin, stomach, intestines, and pancreas. Although their physiological function is not yet fully understood, it appears that they can help regulate the body's homeostasis and provide an additional defense function against pathogens. Since the vast majority of drugs are bitter, the greatest pharmacological interest is in the bitter taste receptors. In this review, we describe how bitter taste 2 receptors (TAS2Rs) induce bronchodilation and mucociliary clearance in the airways, muscle relaxation in various tissues, inhibition of thyroid stimulating hormone (TSH) in thyrocytes, and release of glucagon-like peptide-1 (GLP-1) and ghrelin in the digestive system. In fact, substances such as dextromethorphan, chloroquine, methimazole and probably glimepiride, being agonists of TAS2Rs, lead to these effects. TAS2Rs and taste 1 receptors (TAS1R2/3) are G protein-coupled receptors (GPCR). TAS1R2/3 are responsible for sweet taste perception and may induce GLP-1 release and insulin secretion. Umami taste receptors, belonging to the same superfamily of receptors, perform a similar function with regard to insulin. The sour and salty taste receptors work in a similar way, both being channel receptors sensitive to amiloride. Finally, gene-protein coupled receptor 40 (GPR40) and GPR120 for fatty taste perception are also protein-coupled receptors and may induce GLP-1 secretion and insulin release, similar to those of other receptors belonging to the same superfamily.

Medicinal Plants for Insomnia Related to Anxiety: An Updated Review

Sleep disorders are common among the general population and can generate health problems such as insomnia and anxiety. In addition to standard drugs and psychological interventions, there are different complementary plant-based therapies used to treat insomnia and anxiety. This review aimed to find and examine the most recent research on the use of herbal medicines for treating anxiety and insomnia as compiled from clinical trials, as well as to assess the safety and efficacy of these medicines and to elucidate their possible mechanisms of action. The process entailed a search of PubMed, Scopus, and the Cochrane Library databases from 2010 to 2020. The search terms included "sleep disorder", "insomnia", "sedative", "hypnotic", "anxiety", "anxiolytic", and "clinical trial", combined with the search terms "herbs" and "medicinal plants", in addition to individual herbal medicines by both their common and scientific names. This updated review, which focuses mainly on clinical trials, includes research on 23 medicinal plants and their combinations. Essential oils and their associations have also been reviewed. The efficacy of medicinal plants depends on treatment duration, types of study subjects, administration route, and treatment method. More clinical trials with an adequate, standardized design are necessary, as are more preclinical studies to continue studying the mechanisms of action. As a result of our work, we can conclude that the 3 plants with the most potential are valerian, passionflower, and ashwagandha, with the combination of valerian with hops and passionflower giving the best results in the clinical tests.

Baicalein 5,6-Dimethyl Ether Prevents Memory Deficits in the Scopolamine Zebrafish Model by Regulating Cholinergic and Antioxidant Systems

Baicalein 5,6-dimethyl ether, a bioactive flavonoid isolated for the first time from Alnus rugosa, was explored for its capability to relieve memory deficits and decrease oxidative stress. We examined the neuropharmacological effects of baicalein 5,6-dimethyl ether on scopolamine (Sco)-induced zebrafish (Danio rerio) anxiety, amnesia, and brain oxidative stress and attempted to elucidate the underlying mechanisms. Anxiety-like behavior, exploratory behavior, and memory performance were measured using novel tank-diving test (NTT), Y-maze, and novel object recognition (NOR) tests. For 10 days, baicalein 5,6-dimethyl ether (1, 3, and 5 µg/L) was administered through immersion, whereas Sco (100 μM) was delivered 30 min before behavioral tests. Treatment with baicalein 5,6-dimethyl ether reduced anxiety and memory impairment, and increased exploratory behavior in specific tests, along with significant protection from neuronal oxidative stress in the brain tissue of Sco-treated zebrafish. Antioxidant and anti-acetylcholinesterase (AChE) activities of baicalein 5,6-dimethyl ether in the Sco-induced zebrafish were further confirmed using in vivo assays. In Sco-treated zebrafish, baicalein 5,6-dimethyl ether regulated cholinergic function by inhibiting AChE activity. Baicalein 5,6-dimethyl ether may be a promising candidate compound for treating anxiety and amnesia by restoring cholinergic activity and reducing brain oxidative stress, according to our findings.

Natural Compounds as Medical Strategies in the Prevention and Treatment of Psychiatric Disorders Seen in Neurological Diseases

Psychiatric disorders are frequently encountered in many neurological disorders, such as Alzheimer’s and Parkinson diseases along with epilepsy, migraine, essential tremors, and stroke. The most common comorbid diagnoses in neurological diseases are depression and anxiety disorders along with cognitive impairment. Whether the underlying reason is due to common neurochemical mechanisms or loss of previous functioning level, comorbidities are often overlooked. Various treatment options are available, such as pharmacological treatments, cognitive-behavioral therapy, somatic interventions, or electroconvulsive therapy. However oral antidepressant therapy may have some disadvantages, such as interaction with other medications, low tolerability due to side effects, and low efficiency. Natural compounds of plant origin are extensively researched to find a better and safer alternative treatment. Experimental studies have shown that phytochemicals such as alkaloids, terpenes, flavonoids, phenolic acids as well as lipids have significant potential in in vitro and in vivo models of psychiatric disorders. In this review, various efficacy of natural products in in vitro and in vivo studies on neuroprotective and their roles in psychiatric disorders are examined and their neuro-therapeutic potentials are shed light.

Research Progress on Natural Product Ingredients' Therapeutic Effects on Parkinson's Disease by Regulating Autophagy

Parkinson's disease (PD) is a common neurodegenerative disease in middle-aged and older adults. Abnormal proteins such as α-synuclein are essential factors in PD's pathogenesis. Autophagy is the main participant in the clearance of abnormal proteins. The overactive or low function of autophagy leads to autophagy stress. Not only is it difficult to clear abnormal proteins but also it can cause damage to neurons. In this article, the effects of natural products ingredients, such as salidroside, paeoniflorin, curcumin, resveratrol, corynoxine, and baicalein, on regulating autophagy and protecting neurons were discussed in detail to provide a reference for the research and development of drugs for the treatment of PD.

Flavonoids as an Intervention for Alzheimer's Disease: Progress and Hurdles Towards Defining a Mechanism of Action

Attempts to develop a disease modifying intervention for Alzheimer's disease (AD) through targeting amyloid β (Aβ) have so far been unsuccessful. There is, therefore, a need for novel therapeutics against alternative targets coupled with approaches which may be suitable for early and sustained use likely required for AD prevention. Numerous in vitro and in vivo studies have shown that flavonoids can act within processes and pathways relevant to AD, such as Aβ and tau pathology, increases in BDNF, inflammation, oxidative stress and neurogenesis. However, the therapeutic development of flavonoids has been hindered by an ongoing lack of clear mechanistic data that fully takes into consideration metabolism and bioavailability of flavonoids in vivo. With a focus on studies that incorporate these considerations into their experimental design, this review will evaluate the evidence for developing specific flavonoids as therapeutics for AD. Given the current lack of success of anti-Aβ targeting therapeutics, particular attention will be given to flavonoid-mediated regulation of tau phosphorylation and aggregation, where there is a comparable lack of study. Reflecting on this evidence, the obstacles that prevent therapeutic development of flavonoids will be examined. Finally, the significance of recent advances in flavonoid metabolomics, modifications and influence of the microbiome on the therapeutic capacity of flavonoids in AD are explored. By highlighting the potential of flavonoids to target multiple aspects of AD pathology, as well as considering the hurdles, this review aims to promote the efficient and effective identification of flavonoid-based approaches that have potential as therapeutic interventions for AD.

The Role of Traditional Chinese Herbal Medicines and Bioactive Ingredients on Ion Channels: A Brief Review and Prospect

Traditional Chinese Medicines (TCMs), particularly the Chinese herbal medicines, are valuable sources of medicines and have been used for centuries. The term "TCMs" both represents to the single drug agent like Salvia miltiorrhiza, Ligusticum chuanxiong and Angelica sinensis, and those herbal formulas like Jingshu Keli, Wenxin Keli and Danzhen powder. In recent years, the researches of TCMs developed rapidly to understand the scientific basis of these herbs. In this review, we collect the studies of TCM and their containing bioactive compounds, and attempt to provide an overview for their regulatory effects on different ion channels including Ca2+, K+, Na+, Cl- channels and TRP, P2X receptors. The following conditions are used to limit the range of our review. (i) Only the herbal materials are included in this review and the animal- and mineral-original TCMs are excluded. (ii) The major discussions in this review focus on single TCM agent and the herbal formulas are only discussed for a little. (iii) Those most famous herbal medicines like Capsicum annuum (pepper), Curcuma longa (ginger) and Cannabis sativa (marijuana) are excluded. (iv) Only those TCM herbs with more than 5 research papers confirming their effects on ion channels are discussed in this review. Our review discusses recently available scientific evidences for TCMs and related bioactive compounds that have been reported with the modulatory effects on different ion channels, and thus provides a new ethnopharmacological approach to understand the usage of TCMs.

Anxiolytic-like activity of 5-methoxyflavone in mice with involvement of GABAergic and serotonergic systems - in vivo and in silico evidences

Anxiety disorders are common worldwide and novel compounds are investigated for anxiolytic effect. A few studies have demonstrated the anxiolytic-like activity of natural and synthetic flavonoids. 5-methoxyflavone, a synthetic flavone derivative, has been reported to exhibit central nervous system depressant (sedative-hypnotic) effect in an earlier study. The present study was designed to investigate whether 5-methoxyflavone possesses anxiolytic-like activity in mice by employing two unconditioned models of anxiety such as elevated plus maze and light-dark box test. The possible role played by GABAergic (GABA_A) and serotonergic (5HT_1A) systems in the anxiolytic-like effect of 5-methoxyflavone was also investigated in the elevated plus maze test. Molecular docking studies were performed to ascertain the interaction of 5-methoxyflavone with GABA_A (α₂ subunit-containing) and 5HT_1A receptors. 5-methoxyflavone treatment in mice (10, 20 or 40 mg/kg, i.p) increased the number of entries and time spent in the open arms in an elevated plus maze (p < 0.001). In the light-dark box test a significant increase in the time spent in light compartment (p < 0.001) and prolonged latency to enter the dark compartment (p < 0.01) were also observed. Pretreatment of mice with 5HT_1A antagonist pindolol (10 mg/kg, i.p) or GABA_A antagonist bicuculline (2 mg/kg, i.p) significantly attenuated the effect of 5-methoxyflavone in the elevated plus maze test. In silico studies provided evidences for good binding affinity of 5-methoxyflavone towards GABA_A (α₂ subunit-containing) and serotonergic (5HT_1A) receptors by H-bond interactions. In conclusion, the present study identified a novel anxiolytic-like effect of 5-methoxyflavone involving GABAergic and serotonergic mechanisms.

Members of the family <i>Lamiaceae</i> Lindl. as sources of medicinal plant raw materials to obtain neurotropic drugs

The aim of this work is to review and analyze the data published in the modern scientific literature obtained in pharmacological, pharmacognostic and pharmacotechnological studies of various types of raw materials obtained from members of the family Lamiaceae L., which were sources of biologically active substances, pharmaceutical substances, total extracts and the drugs – with a neurotropic activity.

Materials and methods. For the review, we used the information of scientific literature from open and accessible sources of the last twenty years, located in the scientific and technical libraries of institutions, as well as in electronic databases: Elibrary, PubMed, Scopus, Cyberleninka, GoogleAcademy, J-Stage. The search inquiries were: the species of the family Lamiaceae (Russian and Latin), the samples of medicinal plant materials based on them as well as the names of the drugs and biologically active substances obtained from these raw materials.

Results. When working with the sources of scientific information, the main attention was paid to pharmacologic tests performed during the studies on laboratory animals and proving the presence of neurotropic activity in the studied objects – essential oils and extracts from plant raw materials: aqueous, aqueous alcoholic, and methanol ones. It has been established that the potential of the therapeutic and preventive application of pharmaceutical substances and drugs based on the medicinal plant materials obtained from 30 genera members of the Lamiaceae family, remains unrealized despite the close attention of various researchers.

Conclusion. This review comprised 71 species from 30 genera. Despite the significant level of the previous study presented in the analysis of this publication, an enormous potential of this family’s species remains unexplored. In the future, they can be of both – pharmacognostic and practical interest, in particular, in creation of new medicinal preparations of the neurotropic action based on them.

Potential Antidepressant Effects of Scutellaria baicalensis, Hericium erinaceus and Rhodiola rosea

Recent studies focused on the pharmacology and feasibility of herbal compounds as a potential strategy to target a variety of human diseases ranging from metabolic to brain disorders. Accordingly, bioactive ingredients which are found within a variety of herbal compounds are reported to produce both neuroprotective and psychotropic activities which may help to combat mental disorders such as depression, anxiety, sleep disturbances and cognitive alterations. In the present manuscript, we focus on three herbs which appear effective in mitigating anxiety or depression with favourable risk-benefit profiles, namely Scutellaria baicalensis (S. baicalensis), Hericium erinaceus (H. erinaceus) and Rhodiola rosea (R. rosea). These three traditional folk medicinal herbs target the main biochemical events that are implicated in mental disorders, mimicking, to some extent, the mechanisms of action of conventional antidepressants and mood stabilizers with a wide margin of tolerability. In detail, they rescue alterations in neurotransmitter and neuro-endocrine systems, stimulate neurogenesis and the synthesis of neurotrophic factors, and they counteract oxidative stress, mitochondrial dysfunction and inflammation. Albeit the encouraging results that emerge from both experimental and clinical evidence, further studies are needed to confirm and better understand the mental-health promoting, and specifically, the antidepressant effects of these herbs.

Nanoparticle-Mediated Dual Targeting: An Approach for Enhanced Baicalin Delivery to the Liver

In this study, water-soluble chitosan lactate (CL) was reacted with lactobionic acid (LA), a disaccharide with remarkable affinity to hepatic asialoglycoprotein (ASGP) receptors, to form dual liver-targeting LA-modified-CL polymer for site-specific drug delivery to the liver. The synthesized polymer was used to encapsulate baicalin (BA), a promising bioactive flavonoid with pH-dependent solubility, into ultrahigh drug-loaded nanoparticles (NPs) via the ionic gelation method. The successful chemical conjugation of LA with CL was tested and the formulated drug-loaded LA-modified-CL-NPs were assessed in terms of particle size (PS), encapsulation efficiency (EE) and zeta potential (ZP) using full factorial design. The in vivo biodistribution and pharmacokinetics of the designed NPs were assessed using ^99mTc-radiolabeled BA following oral administration to mice and results were compared to ^99mTc-BA-loaded-LA-free-NPs and ^99mTc-BA solution as controls. Results showed that the chemical modification of CL with LA was successfully achieved and the method of preparation of the optimized NPs was very efficient in encapsulating BA into nearly spherical particles with an extremely high EE exceeding 90%. The optimized BA-loaded-LA-modified-CL-NPs showed an average PS of 490 nm, EE of 93.7% and ZP of 48.1 mV. Oral administration of ^99mTc-BA-loaded-LA-modified-CL-NPs showed a remarkable increase in BA delivery to the liver over ^99mTc-BA-loaded-LA-free-CL-NPs and ^99mTc-BA oral solution. The mean area under the curve (AUC_0-24) estimates from liver data were determined to be 11-fold and 26-fold higher from ^99mTc-BA-loaded-LA-modified-CL-NPs relative to ^99mTc-BA-loaded-LA-free-CL-NPs and ^99mTc-BA solution respectively. In conclusion, the outcome of this study highlights the great potential of using LA-modified-CL-NPs for the ultrahigh encapsulation of therapeutic molecules with pH-dependent/poor water-solubility and for targeting the liver.

Neuroprotective Polyphenols: A Modulatory Action on Neurotransmitter Pathways

BACKGROUND

Balance in neurotransmission is essential for the proper functioning of the nervous system and even a small, but prolonged disturbance, can induce the negative feedback mechanisms leading to various neuropathologies. Neurodegenerative and mood disorders such as Alzheimer's, Parkinson's or affective disorders are increasing medical and social problems. Among the wide spectrum of potentially destructive events, oxidative stress and disrupted metabolism of some neurotransmitters such as acetylcholine, GABA, glutamate, serotonin or dopamine appear to play a decisive role. Biologically active plant polyphenols have been shown to exert a positive impact on the function of the central nervous system by modulation of metabolism and the action of some neurotransmitters.

METHODS

Based on published research, the pharmacological activities of some naturally occurring polyphenols have been reviewed, with a focus on their potential therapeutic importance in the regulation of neurotransmitter systems.

RESULTS

Phytochemicals can be classified into several groups and most of them possess anticancer, antioxidative, anti-inflammatory and neuroprotective properties. They can also modulate the metabolism or action of some neurotransmitters and/or their receptors. Based on these properties, phytochemicals have been used in traditional medicine for ages, although it was focused mainly on treating symptoms. However, growing evidence indicates that polyphenols may also prevent or slow neurological diseases.

CONCLUSION

Phytochemicals seem to be less toxic than synthetic drugs and they can be a safer alternative for currently used preparations, which exert adverse side effects. The neuroprotective actions of some plant polyphenols in the regulation of neurotransmitters metabolism, functioning of neurotransmitters receptors and antioxidative defense have potential therapeutic applications in various neurodegenerative disorders.

An electrochemical sensing platform amplified with a Au@Ag nanoparticle-decorated three-dimensional N-doped graphene aerogel for ultrasensitive determination of baicalein

A novel electrochemical method for highly sensitive determination of baicalein was developed with Au@Ag/3DNGA as signal amplifier.

Awareness and current knowledge of epilepsy

Epilepsy is a severe neural disorder that affects approximately fifty million individuals globally. Despite the fact that for most of the people with epilepsy, convulsions are better controlled by current accessible antiepileptic medicines, yet there are more than 30% of individuals affected with medically intractable epilepsy and around 30-40% of all patients with epilepsy affected by many adverse reactions and convulsion resistance to the present antiepileptic drugs. Consequently, various scientists attempt to develop new strategies to treat epilepsy, for instance, to find out novel antiepileptic ingredients from traditional medicines. This work aims to present a complete summary of natural medicines prescribed as antiepileptic agents all over the world by ethnic groups and different tribes. We undertook an extensive bibliographic analysis by searching peer reviewed papers and classical textbooks and further consulting well accepted worldwide scientific databases. We carried out PubMed, EMbase and CENTRAL searches by means of terms such as "antiepileptic" and "anti-convulsant" activity of plants. Medicinal plants have been prescribed to treat epilepsy and have been recognized as antiepileptic medicines. In this review, a variety of herbs have been reviewed for thorough studies such as Cuminum cyminum, Butea monosperma, Solanum americanum, Anacyclus pyrethrum, Leonotis leonurus, Elaeocarpus ganitrus and Angelica archangelica. This paper shows that it was high time experimental studies are increased to obtain novel potential active principles from medicinal plants. Plant extracts and their chemical constituents should be further evaluated to clarify their mechanisms of action. This paper provides a solid base upon which to further investigate the clinical efficacy of medicinal plants that are both currently prescribed by physicians as traditional antiepileptic agents, but also could be effective as an antiepileptic drug with further research and study.

Central nervous system evaluation of an ethanol extract of Bidens odorata Cav (Asteraceae) leaves, and its antinociceptive interaction with paracetamol and naproxen

INTRODUCTION

Bidens odorata Cav (Asteraceae) is a medicinal plant employed for the treatment of pain, anxiety, and depression. This study aimed to evaluate some neuropharmacological effects of an ethanol extract of B. odorata (BOE) and assess its antinociceptive interaction with naproxen and paracetamol.

MATERIALS AND METHODS

The following neuropharmacological effects were evaluated with the ethanolic extract of B. odorata leaves (BOE) (10-200 mg/kg p.o.): the strychnine-induced-convulsion assay (anticonvulsant effect), rotarod test (locomotor activity), tail suspension test (anti-depressant-like activity), cylinder exploratory test (anxiolytic-like actions), and pentobarbital-induced sleep test (sedative effect). The interaction of the BOE-paracetamol and BOE-naproxen combinations were evaluated with the acetic acid-induced writhing test. The ED₅₀ value of each drug was estimated and the combinations of paracetamol and naproxen with BOE were calculated.

RESULTS

BOE (100-200 mg/kg) showed anti-convulsant activity by increasing the latency to occurrence of strychnine-induced convulsions, antidepressant-like effects by 28% and 33%, respectively, exerted anxiolytic actions (ED₅₀ = 125 mg/kg), but did not affect motor locomotion. The pre-treatment with 2 mg/kg flumazenil or 20 mg/kg pentylenetetrazol partially reverted the anxiolytic activity shown by BOE alone. BOE (200 mg/kg) prolonged the duration of sleep with similar effect in comparison to clonazepam (1.5 mg/kg). The combinations of BOE-paracetamol (1:1) and BOE-naproxen (1:1) showed antinociceptive synergism.

CONCLUSION

BOE induces sedative and anticonvulsant effects. The anxiolytic actions shown by BOE are probably induced by the participation of the GABAergic system. BOE exerts antinociceptive synergistic interaction with paracetamol and naproxen probably by the participation of nitric oxide and ATP-sensitive K⁺ channels, respectively.

Neuroprotective Effects of Baicalein on Acrolein-induced Neurotoxicity in the Nigrostriatal Dopaminergic System of Rat Brain

Elevated levels of acrolein, an α,β-unsaturated aldehyde are detected in the brain of patients with Parkinson's disease (PD). In the present study, the neuroprotective effect of baicalein (a phenolic flavonoid in the dried root of Scutellaria baicalensis Georgi) on acrolein-induced neurodegeneration of nigrostriatal dopaminergic system was investigated using local infusion of acrolein in the substantia nigra (SN) of rat brain. Systemic administration of baicalein (30 mg/kg, i.p.) significantly attenuated acrolein-induced elevations in 4-hydroxy-2-noneal (a product of lipid peroxidation), N-(3-formyl-3,4-dehydropiperidino)lysine (a biomarker of acrolein-conjugated proteins), and heme-oxygenase-1 levels (a redox-regulated protein) in the infused SN, indicating that baicalein inhibited acrolein-induced oxidative stress and protein conjugation. Furthermore, baicalein reduced acrolein-induced elevations in glial fibrillary acidic protein (a biomarker of activated astrocytes), ED-1 (a biomarker of activated microglia), and mature cathepsin B levels (a cysteine lysosomal protease), suggesting that baicalein attenuated acrolein-induced neuroinflammation. Moreover, baicalein attenuated acrolein-induced caspase 1 activation (a pro-inflammatory caspase) and interleukin-1β levels, indicating that baicalein prevented acrolein-induced inflammasome activation. In addition, baicalein significantly attenuated acrolein-induced caspase 3 activation (a biomarker of apoptosis) as well as acrolein-induced elevation in receptor interacting protein kinase (RIPK) 3 levels (an initiator of necroptosis), indicating that baicalein attenuated apoptosis and necroptosis. At the same time, baicalein mitigated acrolein-induced reduction in dopamine levels in the striatum ipsilateral to acrolein-infused SN. In conclusion, our data suggest that baicalein is neuroprotective via inhibiting oxidative stress, protein conjugation, and inflammation. Furthermore, baicalein prevents acrolein-induced program cell deaths, suggesting that baicalein is therapeutically useful for slowing PD progression.

Phytochemicals and cognitive health: Are flavonoids doing the trick?

Flavonoids constitute a large group of polyphenolic compounds with numerous effects on behaviour and cognition. These effects vary from learning and memory enhancement to an improvement of general cognition. Furthermore, flavonoids have been implicated in a) neuronal proliferation and survival, by acting on a variety of cellular signalling cascades, including the ERK/CREB/BDNF and PI3K/Akt pathway, b) oxidative stress reduction and c) relief from Alzheimer's disease-type symptoms. From an electrophysiological aspect, they promote long term potentiation in the hippocampus, supporting the hypothesis of synaptic plasticity mediation. Together, these actions reveal a neuroprotective effect of flavonoid compounds in the brain. Therefore, flavonoid intake could be a potential clinical direction for prevention and/or attenuation of cognitive decline deterioration which accompanies various brain disorders. The purpose of the current review paper was to summarise all these effects on cognition, describe the possible pathways via which they may act on a cellular level and provide a better picture for future research towards this direction.

The Phytochemistry of Cherokee Aromatic Medicinal Plants

Background: Native Americans have had a rich ethnobotanical heritage for treating diseases, ailments, and injuries. Cherokee traditional medicine has provided numerous aromatic and medicinal plants that not only were used by the Cherokee people, but were also adopted for use by European settlers in North America. Methods: The aim of this review was to examine the Cherokee ethnobotanical literature and the published phytochemical investigations on Cherokee medicinal plants and to correlate phytochemical constituents with traditional uses and biological activities. Results: Several Cherokee medicinal plants are still in use today as herbal medicines, including, for example, yarrow (Achillea millefolium), black cohosh (Cimicifuga racemosa), American ginseng (Panax quinquefolius), and blue skullcap (Scutellaria lateriflora). This review presents a summary of the traditional uses, phytochemical constituents, and biological activities of Cherokee aromatic and medicinal plants. Conclusions: The list is not complete, however, as there is still much work needed in phytochemical investigation and pharmacological evaluation of many traditional herbal medicines.

Structure-Dependent Activity of Natural GABA(A) Receptor Modulators

GABA(A) receptors are ligand-gated ion channels consisting of five subunits from eight subfamilies, each assembled in four hydrophobic transmembrane domains. This pentameric structure not only allows different receptor binding sites, but also various types of ligands, such as orthosteric agonists and antagonists, positive and negative allosteric modulators, as well as second-order modulators and non-competitive channel blockers. A fact, that is also displayed by the variety of chemical structures found for both, synthetic as well as nature-derived GABA(A)-receptor modulators. This review covers the literature for natural GABA(A)-receptor modulators until the end of 2017 and discusses their structure-activity relationship.

Medicinal Plants of the Family Lamiaceae in Pain Therapy: A Review

Recently, numerous side effects of synthetic drugs have lead to using medicinal plants as a reliable source of new therapy. Pain is a global public health problem with a high impact on life quality and a huge economic implication, becoming one of the most important enemies in modern medicine. The medicinal use of plants as analgesic or antinociceptive drugs in traditional therapy is estimated to be about 80% of the world population. The Lamiaceae family, one of the most important herbal families, incorporates a wide variety of plants with biological and medical applications. In this study, the analgesic activity, possible active compounds of Lamiaceae genus, and also the possible mechanism of actions of these plants are presented. The data highlighted in this review paper provide valuable scientific information for the specific implications of Lamiaceae plants in pain modulation that might be used for isolation of potentially active compounds from some of these medicinal plants in future and formulation of commercial therapeutic agents.

Multidimensional chemobehavior analysis of flavonoids and neuroactive compounds in zebrafish

The comparative analysis of complex behavioral phenotypes is valuable as a reductionist tool for both drug discovery and defining chemical bioactivity. Flavonoids are a diverse class of chemicals that elicit robust neuroactive and hormonal actions, though bioactivity information is limited for many, particularly for neurobehavioral endpoints. Here, we used a zebrafish larval chemomotor response (LCR) bioassay to comparatively evaluate a suite of 24 flavonoids, and in addition a panel of 30 model neuroactive compounds representing diverse modes of action (e.g. caffeine, chlorpyrifos, methamphetamine, nicotine, picrotoxin). Naïve larval zebrafish were exposed to concentration ranges of each compound at 120 hour post-fertilization (hpf) and locomotor activity measured for 5 h. The model neuroactive compounds were largely behaviorally bioactive (20 of 30) with most effects phenotypic of their known modes of action. Flavonoids rapidly and broadly elicited hyperactive locomotor effects (22 of 24). Multidimensional analyses compared responses over time and identified three distinct bioactive groups of flavonoids based on efficacy and potency. Using GABAergics to modulate hyperactive responses, two flavonoids, (S)-equol and kaempferol were tested for GABA_A receptor antagonism, as well as a known GABA_A receptor antagonist, picrotoxin. Pharmacological intervention with positive allosteric modulators of the GABA_A receptor, alfaxalone and chlormethiazole, ameliorated the hyperactive response to picrotoxin, but not for (S)-equol or kaempferol. Taken together, these studies demonstrate that flavonoids are differentially bioactive and that the chemobehavioral effects likely do not involve a GABA_A receptor mediated mode of action. Overall, the integrative zebrafish platform provides a useful framework for comparatively evaluating high-content chemobehavioral data for sets of structurally- and mechanistically-related flavonoids and neuroactive compounds.

The sedative activity of flavonoids from Passiflora quadrangularis is mediated through the GABAergic pathway

The aim of this study was to investigate the sedative activity of the aqueous leaf extract of Passiflora quadrangularis, a species that is widely cultivated and consumed in South America, and to identify its main constituents and elucidate the involvement of the GABAergic pathway in its mechanism of action. The bioguided fractionation of the crude extract showed a positive relationship between the sedative activity of the extract and its flavonoids. The methods employed to identify and isolate its main flavonoids resulted in the identification of vitexin-2''-O-xyloside, vitexin-2''-O-glucoside, orientin-2''-O-xyloside and orientin-2''-O-glucoside. Vitexin-2"-O-xyloside, the major flavonoid of the extract, showed sedative activity after oral administration in mice.

Support for Natural Small-Molecule Phenols as Anxiolytics

Natural small-molecule phenols (NSMPs) share some bioactivities. The anxiolytic activity of NSMPs is attracting attention in the scientific community. This paper provides data supporting the hypothesis that NSMPs are generally anxiolytic. The anxiolytic activities of seven simple phenols, including phloroglucinol, eugenol, protocatechuic aldehyde, vanillin, thymol, ferulic acid, and caffeic acid, were assayed with the elevated plus maze (EPM) test in mice. The oral doses were 5, 10 and 20 mg/kg, except for phloroglucinol for which the doses were 2.5, 5 and 10 mg/kg. All tested phenols had anxiolytic activity in mice. The phenolic hydroxyl group in 4-hydroxycinnamic acid (4-OH CA) was essential for the anxiolytic activity in the EPM test in mice and rats compared to 4-chlorocinnamic acid (4-Cl CA). The in vivo spike recording of rats’ hippocampal neurons also showed significant differences between 4-OH CA and 4-Cl CA. Behavioral and neuronal spike recording results converged to indicate the hippocampal CA1 region might be a part of the anxiolytic pathways of 4-OH CA. Therefore, our study provides further experimental data supporting NSMPs sharing anxiolytic activity, which may have general implications for phytotherapy because small phenols occur extensively in herbal medicines.

Bitter substances from plants used in traditional Chinese medicine exert biased activation of human bitter taste receptors

The number and variety of bitter compounds originating from plants are vast. Whereas some bitter chemicals are toxic and should not be ingested, other compounds exhibit health beneficial effects, which is manifest in the cross-cultural believe that the bitterness of medicine is correlated with the desired medicinal activity. The bitter taste receptors in the oral cavity serve as sensors for bitter compounds and, as they are expressed in numerous extraoral tissues throughout the body, may also be responsible for some physiological effects exerted by bitter compounds. Chinese herbal medicine uses bitter herbs since ancient times for the treatment of various diseases; however, the routes by which these herbs modify physiology are frequently not well understood. We therefore screened 26 bitter substances extracted from medical herbs for the activation of the 25 human bitter taste receptors. We identified six receptors activated by in total 17 different bitter compounds. Interestingly, we observed a bias in bitter taste receptor activation with 10 newly identified agonists for the broadly tuned receptor TAS2R46, seven agonists activating the TAS2R14 and two compounds activating narrowly tuned receptors, suggesting that these receptors play dominant roles in the evaluation and perhaps physiological activities of Chinese herbal medicines.

Neuropharmacological profile and chemical analysis of fresh rhizome essential oil of Curcuma longa (turmeric) cultivated in Southwest Nigeria

BACKGROUND

Curcuma longa (turmeric) is commonly used as spice and also used to treat fever, cough and febrile convulsions in Nigeria. This study determined the chemical composition of the essential oil of C. longa and evaluated its neuropharmacological activity in mice.

METHODS

Essential oil of C. longa (EOCL) fresh rhizome was obtained by hydrodistillation and its chemical composition determined by GC-MS. Acute toxicity (LD50) profile of the essential oil was determined orally (p.o.) and intraperitoneally (i.p.); and the EOCL (50-200 mg/kg, i.p.) was evaluated for its behavioural, anxiolytic, sedative and anticonvulsant activities using appropriate models in Albino mice (Vom Strain, Jos, Nigeria).

RESULTS

Analysis of the oil showed the presence of 23 compounds with turmerone (35.9%) being the major component. The LD50 values obtained for the mice were 2154 mg/kg, p.o., and 693 mg/kg, i.p. The EOCL (50-200 mg/kg, i.p.) caused significant (p < 0.01) inhibition of rearing {F(4,20) = 9} and locomotor {F(3,16) = 42} activity; decreased head dips in hole board {F (4,20) = 4}; increased the time spent in the open arms of the elevated pus maze {F (4,20) = 9}; prolonged total sleeping time {F (4,20) = 21} induced by ketamine injection, and protected mice against pentylenetetrazol-induced convulsions.

CONCLUSION

The major component of the essential oil of this C. longa species was turmerone; the oil was slightly toxic orally but moderately toxic intraperitoneally in mice; exhibited significant anxiolytic, sedative and anticonvulsant activities in mice.

Pikuni-Blackfeet traditional medicine: Neuroprotective activities of medicinal plants used to treat Parkinson's disease-related symptoms

ETHNOPHARMACOLOGICAL RELEVANCE

Parkinson's disease (PD) is a multifactorial neurodegenerative disorder affecting 5% of the population over the age of 85 years. Current treatments primarily involve dopamine replacement therapy, which leads to temporary relief of motor symptoms but fails to slow the underlying neurodegeneration. Thus, there is a need for safe PD therapies with neuroprotective activity. In this study, we analyzed contemporary herbal medicinal practices used by members of the Pikuni-Blackfeet tribe from Western Montana to treat PD-related symptoms, in an effort to identify medicinal plants that are affordable to traditional communities and accessible to larger populations.

AIM OF THE STUDY

The aims of this study were to (i) identify medicinal plants used by the Pikuni-Blackfeet tribe to treat individuals with symptoms related to PD or other CNS disorders, and (ii) characterize a subset of the identified plants in terms of antioxidant and neuroprotective activities in cellular models of PD.

MATERIALS AND METHODS

Interviews of healers and local people were carried out on the Blackfeet Indian reservation. Plant samples were collected, and water extracts were produced for subsequent analysis. A subset of botanical extracts was tested for the ability to induce activation of the Nrf2-mediated transcriptional response and to protect against neurotoxicity elicited by the PD-related toxins rotenone and paraquat.

RESULTS

The ethnopharmacological interviews resulted in the documentation of 26 medicinal plants used to treat various ailments and diseases, including symptoms related to PD. Seven botanical extracts (out of a total of 10 extracts tested) showed activation of Nrf2-mediated transcriptional activity in primary cortical astrocytes. Extracts prepared from Allium sativum cloves, Trifolium pratense flowers, and Amelanchier arborea berries exhibited neuroprotective activity against toxicity elicited by rotenone, whereas only the extracts prepared from Allium sativum and Amelanchier arborea alleviated PQ-induced dopaminergic cell death.

CONCLUSIONS

Our findings highlight the potential clinical utility of plants used for medicinal purposes over generations by the Pikuni-Blackfeet people, and they shed light on mechanisms by which the plant extracts could slow neurodegeneration in PD.

Treatment of Insomnia With Traditional Chinese Herbal Medicine

Insomnia is a condition with sleep problems and many people suffered from it. Chronic insomnia can last for long time and it will severely affect people's health and the quality of life. In conventional medicine, the most commonly used the medicine is benzodiazepine. It is effective but also has significant side effects. Patients try to use some kinds of alternative medicines. Chinese medicinal herbs and formulas have been used in the treatment of insomnia for more than 2000 years in China. In recent decades, Chinese herbal medicine has been widely used in the Western countries. Many clinical studies including randomized controlled clinical trials and research on pharmacological action mechanisms of the herbs for treatment of insomnia have been conducted. It is very important and very helpful to review the published research papers to gather the available information for a critical analysis. This chapter evaluated the data from both of clinical studies and pharmacological researches on the therapeutic formulas and on some key herbs used in the treatment of insomnia. Clinical studies showed a very wide spectrum of herbs that were used in clinical treatment of insomnia. This was due to different syndrome patterns happened with insomnia. This brought complexity and difficulties to identify which are the essential key herbs or formulas. It was found Suanzaoren decoction (Ziziphus spinose decoction ) is the most frequently used formula for the treatment of insomnia. Based on the clinical data, several herbs were identified as most frequently used sedative and hypnotic herbs in Chinese herbal medicine including Suanzaoren (Ziziphus spinose ), Fuling (Poria cocos ), and Gancao (Glycyrrhiza uralensis ). The underlying pharmacological action mechanisms discovered in the studies on some key herbs used in the treatment of insomnia were evaluated. The major pharmacological action mechanisms shared by most of the sedative herbs are to act through the neurotransmitter gamma-aminobutyric acid (GABA) or via stimulation of GABAA_A receptor. Some herbs exert sedative activities via inhibition of 5-hydroxytryptamine 1A receptor. Another mechanism shown by some herbs is to upregulate the expression of orexin-A, leptin, orexin receptor-1, and leptin receptor in the brain, reducing insomnia-induced negative consequences, and thus indirectly help improvement of insomnia.