Ameliorative Effects of Rhoifolin in Scopolamine-Induced Amnesic Zebrafish (Danio rerio) Model

Preparation of monoclonal antibody against rhoifolin and its application in enzyme-linked immunosorbent assay of rhoifolin and diosmin

Both rhoifolin and diosmin belong to flavonoids, which are widely present in citrus. Diosmin is not only used in the medical field in the world, but also used as a dietary supplement in the United States. Rhoifolin has a similar structure to diosmin and also exhibits antioxidant and anti-inflammatory properties. In this study, an anti-rhoifolin monoclonal antibody was prepared and an indirect competitive enzyme-linked immunosorbent assay (icELISA) method was established. The half-maximal inhibitory concentration (IC50) of icELISA was determined to be 4.83 ng/mL, and the detection range was 0.97-33.87 ng/mL. The results of UPLC-MS/MS and icELISA generally demonstrate consistency. Moreover, by exploiting the cross-reactivity of the antibody, diosmin in tablets can be detected by icELISA. The results demonstrate that the developed method has good accuracy, reproducibility, and broad application prospects.

Rhoifolin, baicalein 5,6-dimethyl ether and agathisflavone prevent amnesia induced in scopolamine zebrafish (Danio rerio) model by increasing the mRNA expression of bdnf, npy, egr-1, nfr2α, and creb1 genes

The increasing attention towards age-related diseases has generated significant interest in the concept of cognitive dysfunction associated with Alzheimer's disease (AD). Certain limitations are associated with the current therapies, and flavonoids have been reported to exhibit multiple biological activities and anti-AD effects in several AD models owing to their antioxidative, anti-inflammatory, and anti-amyloidogenic properties. In this study, we performed an initial in silico predictions of the pharmacokinetic properties of three flavonoids (rhoifolin, baicalein 5,6-dimethyl ether and agathisflavone). Subsequently, we evaluated the antiamnesic and antioxidant potential of flavonoids in concentrations of 1, 3, and 5 μg/L in scopolamine (100 μM)-induced amnesic zebrafish (Danio rerio) model. Zebrafish behavior was analyzed by novel tank diving test (NTT), Y-maze, and novel object recognition test (NOR). Acetylcholinesterase (AChE) activity, brain antioxidant status and the expression of bdnf, npy, egr1, nrf2α, creb1 genes, and CREB-1 protein level was measured to elucidate the underlying mechanism of action. Our flavonoids improved memory and decreased anxiety-like behavior of scopolamine-induced amnesia in zebrafish. Also, the studied flavonoids reduced AChE activity and brain oxidative stress and upregulated the gene expression, collectively contributing to neuroprotective properties. The results of our study add new perspectives on the properties of flavonoids to regulate the evolution of neurodegenerative diseases, especially AD, by modulating the expression of genes involved in the regulation of synaptic plasticity, axonal growth, and guidance, sympathetic and vagal transmission, the antioxidant response and cell proliferation and growth.

Rhoifolin Attenuates Concanavalin A-Induced Autoimmune Hepatitis in Mice via JAKs/STATs Mediated Immune and Apoptotic Processes

Rhoifolin (ROF) exhibits a diverse range of biological activities, encompassing anticancer, hepatoprotective, antidiabetic, antirheumatic, and antiviral properties. However, the specific protective effects and possible mechanisms of the compound against T-cell-mediated autoimmune hepatitis have not been previously elucidated. In the present study, adult male mice were administered Con A (20 mg/kg, intravenously) for 8 h. In the treated groups, mice were pretreated with ROF daily (20 mg/kg and 40 mg/kg, orally) for 7 days before Con A intoxication. The results showed that ROF significantly decreased serum biochemical indices (ALT, AST, ALP, and LDH) and regulated related oxidative stress indicators (MDA, SOD, and GSH), reduced hepatic necrosis areas and immune cells infiltration, inhibited the release of various inflammatory factors (TNF-α, IFN-γ, IL-2, and IL-17), and improved hepatic tissue apoptosis, thereby alleviating hepatic damage induced by Con A. Additionally, we have also confirmed that ROF efficiently inhibited Th1/Th17 cells polarization via modulation of the JAK2/JAK3/STAT1/STAT3 signaling pathways both in vivo and in vitro. Moreover, the molecular mechanism examination also demonstrated that ROF regulated apoptotic cascade signaling through IL-6/JAK2/STAT1/STAT3 controlling BNIP3 activity in primary hepatocytes. These effects were in good agreement with the bioinformatics analysis of ROF treatment for AIH. In conclusion, our findings provide new insights into the potential use of ROF for AIH therapy, which may result from the specific regulation of the T cell subtype polarization and the apoptosis of liver cells via modulation of the JAKs/STATs signaling pathways.

Bidirectional Effect of Triphala on Modulating Gut-Brain Axis to Improve Cognition in the Murine Model of Alzheimer's Disease

SCOPE

The emerging role of gut microbiota and their metabolites in the modulation of the gut-brain axis has received much attention as a new hope for the treatment of hard-to-treat chronic neurodegenerative diseases like Alzheimer's disease. The naturally occurring polyphenols can restore the gut-brain axis by modulating gut microbiota and brain neurotransmitters. The Indian traditional medicine Triphala, a rich source of polyphenols, has been used on humans based on Prakriti or disease conditions for many years.

METHODS AND RESULTS

In this study, the dual mode (morning and evening) action of Triphala is used to provide scientific evidence of its superior preventive and therapeutic efficacy in C57BL/6 and 5xFAD, APP/PS1 transgenic mouse model of Alzheimer's disease. The study observes that Triphala treatment has significantly improved cognitive function, by modulating the APP pathway, reducing inflammation, and restoring the gut-brain axis by increasing the gut microbiota phyla of Bacteroides, Proteobacteria, Actinobacteria, etc., involved in maintaining the gut homeostasis.

CONCLUSIONS

The study paves a new path for using dual modes of Triphala alone or in combination to treat incurable AD.

The Effect of a Tribulus-Based Formulation in Alleviating Cholinergic System Impairment and Scopolamine-Induced Memory Loss in Zebrafish (Danio rerio): Insights from Molecular Docking and In Vitro/In Vivo Approaches

Tribulus terrestris L. (Tt) has been recently gaining attention for its pharmacological value, including its neuroprotective activities. In this study, we explore the neuroprotective effects of a Tribulus terrestris extract in a zebrafish (Danio rerio) model of scopolamine (SCOP)-induced memory impairment and brain oxidative stress. SCOP, an anticholinergic drug, was employed to replicate fundamental aspects of Alzheimer's disease (AD) in animal models. The fish were treated with ethanolic leaf extract (ELE) from Tt (1, 3, and 6 mg/L) for 15 days. SCOP (100 µM) was administered 30 min before behavioral tests were conducted. Molecular interactions of the major compounds identified via UPLC-PDA/MS in Tt fractions with the active site of acetylcholinesterase (AChE) were explored via molecular docking analyses. Terrestrosin C, protodioscin, rutin, and saponin C exhibited the most stable binding. The spatial memory performance was assessed using the Y-maze test, and memory recognition was examined using a novel object recognition (NOR) test. Tt extract treatment reversed the altered locomotion patterns that were caused by SCOP administration. Biochemical analyses also verified Tt's role in inhibiting AChE, improving antioxidant enzyme activities, and reducing oxidative stress markers. The present findings pave the way for future application of Tt as a natural alternative to treat cognitive disorders.

Chemical characterization and metabolic profiling of Xiao-Er-An-Shen Decoction by UPLC-QTOF/MS

Background: Xiao-Er-An-Shen decoction (XEASD), a TCM formula composed of sixteen Chinese medicinal herbs, has been used to alleviate tic disorders (TD) in clinical practice for many years. However, the chemical basis underlying the therapeutic effects of XEASD in the treatment of TD remains unknown. Purpose: The present study aimed to determine the major chemical components of XEASD and its prototype compounds and metabolites in mice biological samples. Methods: The chemical constituents in XEASD were identified using ultra-high Performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). Following this, XEASD was orally administered to mice, and samples of plasma, urine, feces, bile, and tissue were collected in order to identify effective compounds for the prevention or treatment of TD. Result: Of the total 184 compounds identified to be discriminated in the XEASD, comprising 44 flavonoids, 26 phenylpropanoids, 16 coumarins, 16 triterpenoids, 14 amino acids, 13 organic acids, 13 alkaloids, 13 ketones, 10 cyclic enol ether terpenes, 7 citrullines, 3 steroids, and 5 anthraquinones, and others. Furthermore, we summarized 54 prototype components and 78 metabolic products of XEASD, measured with biological samples, by estimating metabolic principal components, with four prototype compounds detected in plasma, 58 prototypes discriminated in urine, and 40 prototypes identified in feces. These results indicate that the Oroxylin A glucuronide from Citri reticulatae pericarpium (CRP) is a major compound with potential therapeutic effects identified in brain, while operating positive effect in inhibiting oxidative stress in vitro. Conclusion: In summary, our work delineates the chemical basis underlying the complexity of XEASD, providing insights into the therapeutic and metabolic pathways for TD. Various types of chemicals were explored in XEASD, including flavonoids, phenylpropanoids, coumarins, organic acids, triterpenoid saponins, and so on. This study can promote the further pharmacokinetic and pharmacological evaluation of XEASD.

Antioxidant and anti-Alzheimer activities of Clivia miniata (Lindl) roots, bulbs, and aerial parts: In-vitro and in-silico studies

Clivia miniata (Lindl) is a member of the family Amaryllidaceae known for its chemically diverse alkaloids with a wide range of biological activities. Many reports revealed a direct role of oxidative stress in the early stage of Alzheimer's disease (AD). Meanwhile, β-site amyloid precursor protein cleavage enzyme 1 (BACE-1) is a molecular target for the treatment of AD. We aimed to investigate C. miniata root, bulb, and aerial part chemical profiling, antioxidant, BACE-1, and AChE enzyme inhibitory activities. Results showed that the total root had the most potent radical scavenging activity as compared to the total bulb and aerial part, respectively. Ethanol root extract had the most potent BACE-1 inhibitory activity (IC50 = 0.02 ± 0.001 µg/mL) as compared to the bulb and aerial part (IC50 = 0.93 ± 0.13, 1.80 ± 0.24 µg/mL), respectively. Moreover, the total root extract mitigated AChE enzyme activity more than total bulb and aerial fractions with IC50 values of (0.06 ± 0.02, 0.58 ± 0.3, and 1.89 ± 0.42 µg/mL, respectively. Bioassay-guided acid-base fractionation confirmed superior BACE-1 inhibitory activity of the root fractions particularly, methylene chloride and ethyl acetate fractions with (IC50 values of 0.21 ± 0.60 and 0.01 ± 0.001 µg/mL), respectively. UPLC-MS analysis of ethyl acetate and methylene chloride fractions of C. miniata root led to the identification of eight phenolics and thirteen alkaloids, respectively. Molecular docking studies against BACE-1 protein revealed that lycorine di-hexoside, miniatine, and cliviaaline were the most promising hits. Further investigation of anti-AD potential of the aforementioned small molecules is required.

Antioxidant and Enzyme Inhibitory Activities of Rhoifolin Flavonoid: In Vitro and in Silico Studies

Rhoifolin (apigenin-7-O-β-neohesperidoside) belongs to the class of flavonoids and was reported to exhibit anti-inflammatory, cytotoxic, antidiabetic, hepatoprotective, and cardioprotective activities. The current study presents the in-vitro evaluation of the antioxidative effects of rhoifolin by many assays, namely DPPH, CUPRAC, ABTS, phosphomolybdenum, and FRAP. Enzyme inhibitory potential was also evaluated for acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, amylase, and glucosidase enzymes. While results revealed weak antioxidant activities for rhoifolin, the compound demonstrated some promising enzyme inhibitory effects against BChE (4.03 mg GALAE/g) and tyrosinase (7.44 mg KAE/g) but was not active on AChE. Regarding anti-diabetic enzymes, the compound was active on amylase but did not show any inhibition effect on glucosidase. In-silico molecular docking study was performed for rhoifolin on the active site of NADPH oxidase, BChE, and amylase enzymes to verify the observed enzyme inhibitory effect. Good binding affinities were observed for rhoifolin on all the docked enzymes, revealing numerous hydrogen bonds, carbon-hydrogen, van der Waals interactions. This is the first study to evaluate the enzyme inhibition potential of rhoifolin. We concluded that the increase in the degree of glycosylation might decrease the antioxidant abilities of flavonoids and that rhoifolin had moderate enzyme inhibition abilities to be investigated in future studies.

Direct Evidence for Using Coriandrum sativum var. microcarpum Essential Oil to Ameliorate Scopolamine-Induced Memory Impairment and Brain Oxidative Stress in the Zebrafish Model

Essential oil from Coriandrum sativum has been demonstrated to provide various pharmacological properties, such as antioxidant, antimicrobial, antibacterial, antifungal, antidiabetic, anticonvulsive, anxiolytic-antidepressant, and anti-aging properties. This study investigated the mechanism of Coriandrum sativum var. microcarpum essential oil (CSEO, 25, 150, and 300 μL/L) and cognitive impairment and brain oxidative stress in a scopolamine (SCOP, 100 μM) zebrafish model (Danio rerio) of cognitive impairment. Spatial memory, response to novelty, and recognition memory were assessed using the Y-maze test and the novel object recognition test (NOR), while anxiety-like behavior was investigated using the novel tank diving test (NTT). The cholinergic system activity and brain oxidative stress were also evaluated. CSEO was administered to zebrafish once a day for 21 days, while SCOP and galantamine (GAL, 1 mg/L) were delivered 30 min before behavioral testing and euthanasia. Our data revealed that SCOP induced memory dysfunction and anxiety-like behavior, while CSEO improved memory performance, as evidenced by behavioral tasks. Moreover, CSEO attenuated SCOP-induced brain oxidative stress and decreased acetylcholinesterase (AChE) activity. The results demonstrated the potential use of the CSEO in providing beneficial effects by reducing memory deficits and brain oxidative stress involved in the genesis of a dementia state.

Rhoifolin protects cecal ligation and puncture induced sepsis mice model by regulating inflammatory pathway

Sepsis is a systemic infection affects several organs, which needs novel therapy for the management of it, thus protective effect of Rhoifolin was estimated against sepsis. Cecal ligation and puncture (CLP) method was used to induce sepsis and thereafter mice were treated with rhoifolin (10 and 20 mg/kg, p.o.) for one week. Food intake and survival rate was determined sepsis mice, moreover liver function test and cytokines was estimated in the serum of sepsis mice. In the lung tissue homogenate, oxidative stress parameters were determined, histopathological analysis was performed in liver and lung tissue of sepsis mice. Food intake and percentage of survival was improved in rhoifolin treated group than sham group. Level of liver function enzyme and cytokine was reduced significantly in the serum of rhoifolin treated sepsis mice. Treatment with rhoifolin ameliorates the altered oxidative stress parameters, and mRNA expression of Toll-like receptor 4 (TLR-4) in lung tissue of sepsis mice. Histopathological changes were also reverse in rhoifolin treated group than sham group of mice. In conclusion, result of report indicates Rhoifolin treatment reduces oxidative stress and inflammation in CLP induced sepsis mice, as it regulates TLR4/MyD88/NF-κB pathway.

In Vitro Antiviral Effect and Potential Neuroprotection of Salvadora persica L. Stem Bark Extract against Lipopolysaccharides-Induced Neuroinflammation in Mice: LC-ESI-MS/MS Analysis of the Methanol Extract

Neuroinflammation is a serious immunomodulatory complex disorder that causes neurological and somatic ailments. The treatment of brain inflammation with new drugs derived from natural sources is a significant therapeutic goal. Utilizing LC-ESI-MS/MS analysis, the active constituents of Salvadora persica extract (SPE) were identified tentatively as exerting antioxidant and anti-inflammatory effects in natural medicine. Herein, we determined the antiviral potential of SPE against herpes simplex virus type 2 (HSV-2) using the plaque assay. HSV-2 is a neurotropic virus that can cause neurological diseases. SPE exhibited promising antiviral potential with a half-maximal cytotoxic concentration (CC50) of 185.960 ± 0.1 µg/mL and a half-maximal inhibitory concentration (IC50) of 8.946 ± 0.02 µg/mL. The in vivo study of the SPE impact against lipopolysaccharide (LPS)-induced neuroinflammation was performed using 42 mice divided into seven groups. All groups were administered LPS (0.25 mg/kg) intraperitoneally, except for the normal and SPE groups 1 and 2. Groups 5, 6, and 7 received 100, 200, and 300 mg/kg SPE. It was revealed that SPE inhibited acetylcholinesterase in the brain. It increased superoxide dismutase and catalase while decreasing malondialdehyde, which explains its antioxidative stress activity. SPE downregulated the gene expression of the inducible nitric oxide synthase, as well as the apoptotic markers (caspase-3 and c-Jun). In addition, it decreased the expression of the proinflammatory cytokines (interleukin-6 and tumor necrosis factor-alpha). Mice administered SPE (300 mg/kg) with LPS exhibited normal neurons in the cerebral cortices, hippocampus pyramidal layer, and cerebellum, as determined by the histopathological analysis. Therefore, using S. persica to prevent and treat neurodegeneration could be a promising new therapeutic strategy to be explored.

Promnesic, Anxiolytic and Antioxidant Effects of Glaucosciadium cordifolium (Boiss.) Burtt & Davis Essential Oil in a Zebrafish Model of Cognitive Impairment

The purpose of this study was to investigate the effect of Glaucosciadium cordifolium essential oil (GCEO, 25 and 150 µL/L) on anxiety and learning and memory impairment induced by scopolamine (SCOP) in zebrafish. The chemical composition was analyzed by GC-MS, and the results showed that the highest content was limonene followed by α- and β-pinene, p-cymene and α-phellandrene. The dementia model was induced by SCOP (100 µM), whereas GCEO and galantamine (GAL, 1 mg/L) were delivered to the SCOP-induced model. It was found that GCEO significantly improved memory impairment and anxiety-like response induced by SCOP through the Y-maze, novel object recognition (NOR) test, and novel tank diving tests (NTT). Biochemical analyses showed that GCEO reduced SCOP-induced oxidative damage. Additionally, the cholinergic system activity was improved in the SCOP-induced model by decreasing the acetylcholinesterase (AChE) activity following the exposure to GCEO. It was clear that as a mixture, GCEO displays positive action in improving memory impairment through restoring cholinergic dysfunction and brain antioxidant status.

An Insight into Diverse Activities and Targets of Flavonoids

BACKGROUND

Flavonoids belong to the chemical class of polyphenols and are in the category of secondary metabolites imparting a wide protective effect against acute and chronic diseases.

OBJECTIVE

The study aims to investigate and summarize the information of various flavonoids extracted, isolated from various sources, and possess different pharmacological properties by acting on multiple targets.

METHODS

This comprehensive review summarizes the research information related to flavonoids and their pharmacological action targets from various sources like PubMed, Google Scholar and Google websites.

RESULTS

Extracted information in the paper discusses various therapeutic effects of flavonoids isolated from medicinal plant sources, which have the property to inhibit several enzymes, which finally results in health benefits like anti-cancer, anti-bacterial, antioxidant, anti-allergic, and anti-viral effects. This study also showed the different solvents and methods involved in the extraction and characterization of the isolated phytochemical constituents.

CONCLUSION

The findings showed the contribution of several flavonoids in the management and inhibition of various acute and chronic sicknesses by acting on different sites in the body. This study may lead to gaining interest for more research on the bioactives of different medicinal plants for the discovery of new lead compounds or further improvement of the efficacy of the existing compound.

Zebrafish: A Pharmacological Model for Learning and Memory Research

Learning and memory are essential to organism survival and are conserved across various species, especially vertebrates. Cognitive studies involving learning and memory require using appropriate model organisms to translate relevant findings to humans. Zebrafish are becoming increasingly popular as one of the animal models for neurodegenerative diseases due to their low maintenance cost, prolific nature and amenability to genetic manipulation. More importantly, zebrafish exhibit a repertoire of neurobehaviors comparable to humans. In this review, we discuss the forms of learning and memory abilities in zebrafish and the tests used to evaluate the neurobehaviors in this species. In addition, the pharmacological studies that used zebrafish as models to screen for the effects of neuroprotective and neurotoxic compounds on cognitive performance will be summarized here. Lastly, we discuss the challenges and perspectives in establishing zebrafish as a robust model for cognitive research involving learning and memory. Zebrafish are becoming an indispensable model in learning and memory research for screening neuroprotective agents against cognitive impairment.

Differential Metabolomic Fingerprinting of the Crude Extracts of Three Asteraceae Species with Assessment of Their In Vitro Antioxidant and Enzyme-Inhibitory Activities Supported by In Silico Investigations

The Asteraceae is a large family, rich in ornamental, economical, and medicinally valuable plants. The current study involves the analytical and pharmacological assessment of the methanolic extracts of three less investigated Asteraceae plants, namely Echinops ritro, Centaurea deflexa, and Tripleurospermum decipiens, obtained by three different extraction methodologies viz. maceration (MAC), ultrasound-assisted extraction (UAE), and homogenizer-assisted extraction (HAE). LC-MS-MS analysis of E. ritro, C. deflexa, and T. decipiens extracts led to the identification of ca. 29, 20, and 33 metabolites, respectively, belonging to flavonoids, phenolic acids, and fatty acids/amides. Although there were significant differences in the quantitative metabolite profiles in the extracts of E. ritro and T. decipiens based on the used extraction method, no significant variation was observed in the extracts of C. deflexa in the three implemented extraction techniques. The antioxidant activities of the nine extracts were assessed in vitro using six different assays viz. DPPH, ABTS, CUPRAC, FRAP, PDA, and metal chelation assay (MCA). The HAE/UAE extracts of E. ritro and the UAE/ MAC extracts of C. deflexa displayed the highest antioxidant activity in the DPPH assay, while the UAE extract of T. decipiens showed the strongest antioxidant activity in both the CUPRAC and MCA assays. The enzyme inhibitory activities of the nine extracts were studied in vitro on five different enzymes viz. tyrosinase, α-amylase, α-glucosidase, acetylcholinesterase (AChE), and butyrylcholinestrase (BChE), affecting various pathological diseases. Concerning C. deflexa, its MAC /UAE extracts showed the strongest inhibition on α-amylase, while its UAE/HAE extracts displayed strong inhibitory power on AChE. However, no significant difference was observed on their effects on tyrosinase or BChE. For T. decipiens, its UAE/HAE showed potent inhibition to α-glucosidase, MAC/ HAE significantly inhibited AChE and BChE, while UAE could strongly inhibit tyrosinase enzyme. For E. ritro, all extracts equally inhibited α-amylase and α-glucosidase, MAC/HAE strongly affected tyrosinase, HAE/MAC best inhibited BChE, while HAE inhibited AChE to a greater extent. Chemometric analysis using PCA plot was able to discriminate between the plant samples and between the implemented extraction modes. The in vitro enzyme inhibitory activities of the extracts were supported by in silico data, where metabolites, such as the lignan arctiin and the flavonoid vicenin-2, dominating the extract of C. deflexa, displayed strong binding to AChE. Similarly, chlorogenic and dicaffeoyl quinic acids, which are some of the major metabolites in the extracts of E. ritro and T. decipiens, bound with high affinity to α-glucosidase.

GC-MS profiling of Vitex pinnata bark lipophilic extract and screening of its anti-TB and cytotoxic activities

Tuberculosis is a highly infectious ailment worldwide. The emergence of multi-drug resistance and serious adverse effects of anti-TB drugs have led to the continuous search of natural candidates. This study aimed to analyse the chemical profile of Vitex pinnata (VP) bark lipophilic extract using GC-MS also evaluating its anti-TB and cytotoxic activities. GC-MS revealed a total of 81 compounds which representing 86% identified compounds. In vitro anti-TB of VP lipophilic extract was evaluated using the Microplate Alamar Blue Assay which exhibited MIC value of 62.5 µg/mL. In vitro cytotoxicity was evaluated using Water Soluble formazan assay recording IC₅₀ > 100 and 200 µg/mL using Vero and A-549 cell lines, respectively. In silico docking study was performed on the major identified compounds, n-nonane showed the most favourable binding affinity (ΔG) equals to -33.34 Kcal/mol. The results obtained herein unravelled the potential use of VP n-hexane extract as a natural anti-TB.

Neuroprotective Effect of Yucca schidigera Roezl ex Ortgies Bark Phenolic Fractions, Yuccaol B and Gloriosaol A on Scopolamine-Induced Memory Deficits in Zebrafish

Y. schidigera contains a number of unusual polyphenols, derivatives of resveratrol and naringenin, called spiro-flavostilbenoids, which have potent in vitro anti-inflammatory, antioxidant, and moderate cholinesterase inhibitory activities. To date, these compounds have not been tested in vivo for the treatment of neurodegenerative diseases. The aim of the present study was to evaluate the effects of both single spiro-flavostilbenoids (yuccaol B and gloriosaol A) and phenolic fractions derived from Y. schidigera bark on scopolamine-induced anxiety and memory process deterioration using a Danio rerio model. Detailed phytochemical analysis of the studied fractions was carried out using different chromatographic techniques and Nuclear Magnetic Resonance (NMR). The novel tank diving test was used as a method to measure zebrafish anxiety, whereas spatial working memory function was assessed in Y-maze. In addition, acetylcholinesterase/butyrylcholinesterase (AChE/BChE) and 15-lipooxygenase (15-LOX) inhibition tests were performed in vitro. All pure compounds and fractions under study exerted anxiolytic and procognitive action. Moreover, strong anti-oxidant capacity was observed, whereas weak inhibition towards cholinesterases was found. Thus, we may conclude that the observed behavioral effects are complex and result rather from inhibition of oxidative stress processes and influence on cholinergic muscarinic receptors (both 15-LOX and scopolamine assays) than effects on cholinesterases. Y. schidigera is a source of substances with desirable properties in the prevention and treatment of neurodegenerative diseases.

The potential mechanism of Bupleurum against anxiety was predicted by network pharmacology study and molecular docking

Bupleurum chinense DC. (Chaihu) is a traditional Chinese medicine (TCM) used in the treatment of anxiety. But the anxiolytic mechanisms of bupleurum are still unclear. Therefore, this unknown is predicted by network pharmacology study with molecular docking in the present study. The components of bupleurum were obtained from the databases. Genes associated with components and disease were also provided by databases. Overlapping genes between components and disease were analyzed. The network of medicine-components-targets-disease was constructed, visualized, and analyzed. Protein-protein interaction (PPI), gene ontology (GO), pathway enrichment (KEGG) and molecular docking were conducted to predict the potential mechanisms of bupleurum on anxiety. A total of 9 bioactive components derived from bupleurum with 80 target genes were involved in anxiety. Neurotransmitter receptor activity, G protein-coupled amine receptor activity, regulation of blood circulation, neuroactive ligand-receptor interaction, calcium signaling pathway and salivary secretion may play significant roles in the anxiolytic of bupleurum. Molecular docking implicated that ACHE and MAOA showed high affinity for stigmasterol. Based on network pharmacology study with molecular docking, multi-component-multi-target-multi-pathway action mode of bupleurum on anxiety was elaborated. Stigmasterol might be the core bioactive component, while ACHE and MAOA might be the core target genes in the pharmacological profile of bupleurum on anxiety.

Rhoifolin ameliorates osteoarthritis via the Nrf2/NF-κB axis: in vitro and in vivo experiments

OBJECTIVE

Osteoarthritis (OA) is an age-related degenerative disease accompanied by an increasing number of senescent cells and chronic low-grade inflammation. Rhoifolin (ROF) showed considerable inhibition to inflammation, but its role in chondrocyte senescence and OA progress has not been fully characterized. We aimed to evaluate the protective effects of ROF on OA through a series of in vitro and in vivo experiments.

METHODS

The role of ROF in the expression of senescence-associated secretory phenotype (SASP) factors was investigated using RT-qPCR, western blotting, and ELISA. Chondrocyte senescence was assessed by SA-β-gal staining. We applied molecular docking to screen candidate proteins regulated by ROF. Meanwhile, SASP factors and cellular senescence were further assessed after the transfection of Nrf2 siRNA. In the anterior cruciate ligament transection (ACLT) rat model, X-ray, hematoxylin-eosin (HE), and Masson's staining were performed to evaluate the therapeutic effects of ROF on OA.

RESULTS

We found that ROF inhibited SASP factors expression and senescence phenotype in IL-1β-treated chondrocytes. Furthermore, ROF suppressed IL-1β-induced activation of the NF-κB pathway cascades. Also, molecular docking and knock-down studies demonstrated that ROF might bind to Nrf2 to suppress the NF-κB pathway. In vivo, ROF ameliorated the OA process in the ACLT rat model.

CONCLUSIONS

ROF inhibits SASP factors expression and senescence phenotype in chondrocytes and ameliorates the progression of OA via the Nrf2/NF-κB axis, which supports ROF as a potential therapeutic agent for the treatment of OA.

Neuroprotective Potential of Guiera senegalensis (Combretaceae) Leaf Hydroethanolic Extract against Cholinergic System Dysfunctions and Oxidative Stress in Scopolamine-Induced Cognitive Impairment in Zebrafish (Danio rerio)

Guiera senegalensis JF Gmel. (Combretaceae) (GS) is a plant used in traditional medicine in West Africa for the treatment of several diseases, such as epilepsy and depression. However, its potential benefits in improving scopolamine (Sco)-induced memory impairment and brain oxidative stress in zebrafish have been investigated. In the present study, zebrafish (Danio rerio) were treated with GS (1, 4, and 8 μg/L) for 19 days as well as Sco (100 µM) 30 min before behavioral tests. Behavioral performance was assessed by the Y-maze test and novel object recognition test (NOR), whereas anxiety response was evaluated in the novel tank diving test (NTT). Subsequently, high-performance liquid chromatography (HPLC) was used to evaluate the GS chemical composition. Sco promoted oxidative stress and acetylcholinesterase (AChE) activity. Moreover, both oxidative stress parameters and AChE activity were ameliorated by GS treatment. Accordingly, the present findings further provided the potential use of GS as a natural, alternative treatment against cognitive disorders associated to Alzheimer's disease (AD).

GC/MS Profiling, Anti-Collagenase, Anti-Elastase, Anti-Tyrosinase and Anti-Hyaluronidase Activities of a Stenocarpus sinuatus Leaves Extract

Today, skin care products and cosmetic preparations containing natural ingredients are widely preferred by consumers. Therefore, many cosmetic brands are encouraged to offer more natural products to the market, such as plant extracts that can be used for their antiaging, antiwrinkle, and depigmentation properties and other cosmetic purposes. In the current study, the volatile constituents of the hexane-soluble fraction of a Stenocarpus sinuatus (family Proteaceae) leaf methanol extract (SSHF) were analyzed using GC/MS analysis. Moreover, the antiaging activity of SSHF was evaluated through in vitro studies of anti-collagenase, anti-elastase, anti-tyrosinase, and anti-hyaluronidase activities. In addition, an in silico docking study was carried out to identify the interaction mechanisms of the major compounds in SSHF with the active sites of the target enzymes. Furthermore, an in silico toxicity study of the identified compounds in SSHF was performed. It was revealed that vitamin E (α-tocopherol) was the major constituent of SSHF, representing 52.59% of the extract, followed by γ-sitosterol (8.65%), neophytadiene (8.19%), β-tocopherol (6.07%), and others. The in vitro studies showed a significant inhibition by SSHF of collagenase, elastase, tyrosinase, and hyaluronidase, with IC₅₀ values of 60.03, 177.5, 67.5, and 38.8 µg/mL, respectively, comparable to those of the positive controls epigallocatechin gallate (ECGC, for collagenase, elastase, hyaluronidase) and kojic acid (for tyrosinase). Additionally, the molecular docking study revealed good acceptable binding scores of the four major compounds, comparable to those of ECGC and kojic acid. Besides, the SSHF identified phytoconstituents showed no predicted potential toxicity nor skin toxicity, as determined in silico. In conclusion, the antiaging potential of SSHF may be attributed to its high content of vitamin E in addition to the synergetic effect of other volatile constituents. Thus, SSHF could be incorporated in pharmaceutical skin care products and cosmetics after further studies.

Wound-Healing Potential of Rhoifolin-Rich Fraction Isolated from Sanguisorba officinalis Roots Supported by Enhancing Re-Epithelization, Angiogenesis, Anti-Inflammatory, and Antimicrobial Effects

A wound is a complicated bioprocess resulting in significant tissue damage, which is worsened by a secondary bacterial infection, commonly Pseudomonas aeruginosa and Staphylococcus aureus. The goal of our study was to investigate the metabolic profile and possible wound-healing effect of Sanguisorba officinalis roots rhoifolin rich fraction (RRF). The LC-ESI-MS/MS analysis of S. officinalis roots crude ethanol extract resulted in a tentative identification of 56 bioactive metabolites, while a major flavonoid fraction was isolated by column chromatography and identified by thin-layer chromatography coupled with electrospray ionization/mass spectrometry (TLC-ESI/MS), where rhoifolin was the major component representing 94.5% of its content. The antibiofilm activity of RRF on the mono-species and dual-species biofilm of P. aeruginosa and S. aureus was investigated. RRF exhibited inhibitory activity on P. aeruginosa and S. aureus mono-species biofilm at 2× minimum inhibitory concentration (MIC) and 4× MIC values. It also significantly inhibited the dual-species biofilm at 4× MIC values. Moreover, the wound-healing characteristics of RRF gel formulation were investigated. Rats were randomly allocated into four groups (eight rats in each): Untreated control; Blank gel; Betadine cream, and RRF gel groups. Animals were anesthetized, and full-thickness excisional skin wounds were created on the shaved area in the dorsal skin. The gels were topically applied to the wound's surface daily for 10 days. The results demonstrated that RRF had a promising wound-healing effect by up-regulating the platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), and fibronectin, while metalloproteinase-1 (MMP-1), interleukin-6 (IL-6), IL-1β, and nitric oxide (NO) levels were suppressed. It also enhanced the immune staining of transforming growth factor (TGF-β) and improved histopathological findings. Furthermore, it displayed an immunomodulatory action on lipopolysaccharide-induced peripheral blood mononuclear cells. Hence, the wound-healing effect of rhoifolin was confirmed by supporting re-epithelization, angiogenesis, antibacterial, immunomodulatory, and anti-inflammatory activities.

Zebrafish as a Useful Tool in the Research of Natural Products With Potential Anxiolytic Effects

Zebrafish (Danio rerio) is a popular and valuable species used in many different biomedical research areas. The complex behavior that fish exhibit in response to different stimuli allows researchers to explore the biological and pharmacological basis of affective and mood disorders. In this sense, anxiety is commonly studied in preclinical research with animal models in rodents. During the last decade, those models have been successfully adapted to zebrafish. Stressful stimuli, such as novel environments, chemical substances, light conditions, and predator images, can trigger defensive behaviors considered indicators of an anxiety-like state. In the first stage, models were adapted and validated with different stressors and anxiolytic drugs with promising results and are now successfully used to generate scientific knowledge. In that sense, zebrafish allows several routes of administration and other methodological advantages to explore the anxiolytic effects of natural products in behavioral tests as novel tank, light-dark chamber, and black/white maze, among others. The present work will review the main findings on preclinical research using adult zebrafish to explore anxiolytics effects of natural products as plant secondary metabolites such as flavonoids, alkaloids and terpenes or standardized extracts of plants, among others. Scientific literature confirms the utility of zebrafish tests to explore anxiety-like states and anxiolytic-like effects of plant secondary metabolites, which represent a useful and ethical tool in the first stages of behavioral.

In Vitro and In Vivo Studies of Anti-Lung Cancer Activity of Artemesia judaica L. Crude Extract Combined with LC-MS/MS Metabolic Profiling, Docking Simulation and HPLC-DAD Quantification

Artemisia judaica L. (Family: Asteraceae) exhibited antioxidant, anti-inflammatory, and antiapoptotic effects. The in vitro cytotoxic activity of A. judaica ethanolic extract was screened against a panel of cancer cell lines. The results revealed its cytotoxic activity against a lung cancer (A549) cell line with a promising IC50 of 14.2 μg/mL compared to doxorubicin as a standard. This was confirmed through the downregulation of antiapoptotic genes, the upregulation of proapoptotic genes, and the cell cycle arrest at the G2/M phase. Further in vivo study showed that a solid tumor mass was significantly reduced, with a tumor inhibition ratio of 54% relative to doxorubicin therapy in a Xenograft model. From a chemical point of view, various classes of natural products have been identified by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). The docking study of the detected metabolites approved their cytotoxic activity through their virtual binding affinity towards the cyclin-dependent kinase 2 (CDK-2) and epidermal growth factor receptor (EGFR) active sites. Finally, A. judaica is a fruitful source of polyphenols that are well-known for their antioxidant and cytotoxic activities. As such, the previously reported polyphenols with anti-lung cancer activity were quantified by high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Rutin, quercetin, kaempferol, and apigenin were detected at concentrations of 6 mg/gm, 0.4 mg/gm, 0.36 mg/gm, and 3.9 mg/gm of plant dry extract, respectively. It is worth noting that kaempferol and rutin are reported for the first time. Herein, A. judaica L. may serve as an adjuvant therapy or a promising source of leading structures in drug discovery for lung cancer treatment.

Origanum vulgare ssp. hirtum (Lamiaceae) Essential Oil Prevents Behavioral and Oxidative Stress Changes in the Scopolamine Zebrafish Model

Origanum vulgare ssp. hirtum has been used as medicinal herbs promoting antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities. We investigated the protective effects and the mechanism of O. vulgare ssp. hirtum essential oil (OEO) on cognitive impairment and brain oxidative stress in a scopolamine (Sco)-induced zebrafish (Danio rerio) model of cognitive impairment. Our results show that exposure to Sco (100 µM) leads to anxiety, spatial memory, and response to novelty dysfunctions, whereas the administration of OEO (25, 150, and 300 µL/L, once daily for 13 days) reduced anxiety-like behavior and improved cognitive ability, which was confirmed by behavioral tests, such as the novel tank-diving test (NTT), Y-maze test, and novel object recognition test (NOR) in zebrafish. Additionally, Sco-induced brain oxidative stress and increasing of acetylcholinesterase (AChE) activity were attenuated by the administration of OEO. The gas chromatography-mass spectrometry (GC-MS) analyses were used to elucidate the OEO composition, comprising thymol (38.82%), p-cymene (20.28%), and γ-terpinene (19.58%) as the main identified components. These findings suggest the ability of OEO to revert the Sco-induced cognitive deficits by restoring the cholinergic system activity and brain antioxidant status. Thus, OEO could be used as perspective sources of bioactive compounds, displaying valuable biological activities, with potential pharmaceutical applications.

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.

Effects of the Hydroethanolic Extract of Lycopodium selago L. on Scopolamine-Induced Memory Deficits in Zebrafish

This scientific research focused on the production of hydroethanolic extract of the plant species Lycopodium selago L. (L. selago) by the ultrasound-assisted extraction (USAE) and the identification of biocompounds with high antioxidant activity is of interest for possible phytotherapeutic treatment against Alzheimer's disease (AD). The extract was phytochemically analyzed to investigate polyphenols, flavonoids, and identify the sesquiterpenoid alkaloid huperzine A (HupA), which is known in the literature for its great relevance in AD. Evaluation and comparison of the antioxidant activity of the extract were performed by four complementary spectrophotometric methods (DPPH, FRAP, ABTS, ORAC). In vitro tests of the extract showed an excellent reciprocal link between the concentration of polyphenols and the measurement of the antioxidant activity of the extract with the sesquiterpenoid HupA. To confirm the antioxidant activity, L. selago hydroethanolic extract was administered in vivo to zebrafish (Danio rerio) with a pattern of scopolamine-induced cognitive impairment. Moreover, this study explored a possible correlation between the expression of oxidative stress markers in the brain tissue with the behavior of the scopolamine zebrafish model. In vivo tests showed that this fern could be used as a nutritional supply and as a phytotherapeutic method to prevent or treat various neurodegenerative diseases that call for high-nutritive-value medications.

Hericium erinaceus (Bull.) Pers. Ethanolic Extract with Antioxidant Properties on Scopolamine-Induced Memory Deficits in a Zebrafish Model of Cognitive Impairment

Hericium erinaceus (H. erinaceus) is a rare and appreciated fungal species belonging to the division Basidiomycota used for centuries in traditional Chinese medicine for its medicinal value. This species of mushrooms brings the most diverse benefits for the human body, and can have beneficial effects for treating Alzheimer’s disease (AD). This study investigated whether ethanolic extract from the fungal biomass of H. erinaceus enhances cognitive function via the action on cholinergic neurons using the scopolamine (SCOP)-induced zebrafish (Danio rerio) model of memory impairment. The ethanolic extract from the fungal biomass of H. erinaceus was previously obtained using an ultrasonic extraction method (UE). The administration of H. erinaceus extract to zebrafish, with a pattern of AD induced by scopolamine, showed an improvement in memory evaluated by behavioral and biochemical tests on brain tissue. These results suggest that H. erinaceus has preventive and therapeutic potentials in managing memory deficits and brain oxidative stress in zebrafish with AD.

Tris (1-chloro-2-propyl) phosphate exposure to zebrafish causes neurodevelopmental toxicity and abnormal locomotor behavior

The organophosphate flame retardant, tris (1-chloro-2-propyl) phosphate (TCPP), is ubiquitous in environmental matrices; however, there is a paucity of information concerning its systemic toxicity. Herein, we investigated the effects of TCPP exposure on zebrafish neurodevelopment and swimming behavior to elucidate the underlying molecular mechanisms of neurotoxicity. Under TCPP gradient concentration exposure, the hatching rates were declined by up to 33.3% in 72 hpf, and the malformation rates increased from 15% to 50%. Meanwhile, TCPP led to abnormal behaviors including decreased locomotive activity in the dark and slow/insensitive responses to sound and light stimulation of larvae. TCPP caused excessive apoptosis and ROS accumulation in early embryonic development, with hair cell defects and structural deformity of neuromast. Abnormal expression of neurodevelopment (pax6a, nova1, sox11b, syn2a, foxo3a and robo2) and apoptosis-related genes (baxa, bcl2a and casp8) revealed molecular mechanisms regarding abnormal behavioral and phenotypic symptoms. Chronic TCPP exposure led to anxiety-like behavior and excessive panic, lower capacity for discrimination and risk avoidance, and conditioned place preference in adults. Social interaction tests demonstrated that long-term TCPP stress resulted in unsociable, eccentric, lonely and silent behaviors in adults. Zebrafish memory and cognitive function were severely reduced as concluded from T-maze tests. Potential mechanisms triggering behavioral abnormality were attributed to histopathological injury of diencephalon, abnormal changes in nerve-related genes at transcription and expression levels, and inhibited activity of AChE by TCPP stress. These findings provide an important reference for risk assessment and early warning to TCPP exposure, and offer insights for prevention/mitigation of pollutant-induced nervous system diseases.

Anxiolytic, Promnesic, Anti-Acetylcholinesterase and Antioxidant Effects of Cotinine and 6-Hydroxy-L-Nicotine in Scopolamine-Induced Zebrafish (Danio rerio) Model of Alzheimer's Disease

Cotinine (COT) and 6-hydroxy-L-nicotine (6HLN) are two nicotinic derivatives that possess cognitive-improving abilities and antioxidant properties in different rodent models of Alzheimer's disease (AD), eluding the side-effects of nicotine (NIC), the parent molecule. In the current study, we evaluated the impact of COT and 6HLN on memory deterioration, anxiety, and oxidative stress in the scopolamine (SCOP)-induced zebrafish model of AD. For this, COT and 6HLN were acutely administered by immersion to zebrafish that were treated with SCOP before testing. The memory performances were assessed in Y-maze and object discrimination (NOR) tasks, while the anxiety-like behavior was evaluated in the novel tank diving test (NTT). The acetylcholinesterase (AChE) activity and oxidative stress were measured from brain samples. The RT-qPCR analysis was used to evaluate the npy, egr1, bdnf, and nrf2a gene expression. Our data indicated that both COT and 6HLN attenuated the SCOP-induced anxiety-like behavior and memory impairment and reduced the oxidative stress and AChE activity in the brain of zebrafish. Finally, RT-qPCR analysis indicated that COT and 6HLN increased the npy, egr1, bdnf, and nrf2a gene expression. Therefore, COT and 6HLN could be used as tools for improving AD conditions.

Thymus vulgaris Essential Oil Protects Zebrafish against Cognitive Dysfunction by Regulating Cholinergic and Antioxidants Systems

Thymus vulgaris L. is an aromatic herb used for medicinal purposes such as antimicrobial, spasmolytic, antioxidant, anti-inflammatory, antinociceptive, antitumor, and may have beneficial effects in the treatment of Alzheimer’s disease. The present study aimed to investigate whether Thymus vulgaris L. essential oil enhances cognitive function via the action on cholinergic neurons using scopolamine (Sco)-induced zebrafish (Danio rerio) model of memory impairments. Thymus vulgaris L. essential oil (TEO, 25, 150, and 300 µL/L) was administered by immersion to zebrafish once daily for 13 days, whereas memory impairment was induced by Sco (100 μM), a muscarinic receptor antagonist, delivered 30 min before behavioral tests. Spatial memory was assessed using the Y-maze test and novel object recognition test (NOR). Anxiety and depression were measured in the novel tank diving test (NTT). Gas Chromatograph-Mass Spectrometry (GC-MS) analysis was used to study the phytochemical composition of TEO. Acetylcholinesterase (AChE) activity and oxidative stress response in the brain of zebrafish were determined. TEO ameliorated Sco-induced increasing of AChE activity, amnesia, anxiety, and reduced the brain antioxidant capacity. These results suggest that TEO may have preventive and/or therapeutic potentials in the management of memory deficits and brain oxidative stress in zebrafish with amnesia.