Anti-anxiety effects of Apocynum venetum L. in the elevated plus maze test

Anxiolytic-like effect of Suanzaoren-Wuweizi herb-pair and evidence for the involvement of the monoaminergic system in mice based on network pharmacology

BACKGROUND

Suanzaoren-Wuweizi herb-pair (SWHP), composed of Zizyphi Spinosi Semen (Suanzaoren in Chinese) and Schisandrae Chinensis Fructus (Wuweizi in Chinese), is a traditional herbal formula that has been extensively used for the treatment of insomnia. The study aimed to explore the targets and signal pathways of Suanzaoren-Wuweizi (S-W) in the treatment of anxiety by network pharmacology, and to verify the pharmacodynamics and key targets of SWHP in mice.

METHODS

The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) as well as literature mining were used to obtain the main chemical ingredients of Suanzaoren and Wuweizi. The SwissTargetPrediction platform was used to predict drug-related targets. The GeneCards, TTD, DisGeNET and OMIM databases were used to obtain potential targets for the treatment of anxiety with the chemical components of S-W. Drug-disease intersection genes were selected, and a protein-protein interaction (PPI) network was constructed using STRING. The core targets of S-W in the treatment of anxiety were selected according to the topological parameters, and GO functional enrichment as well as KEGG pathways enrichment analyses were performed for potential targets. The relationship network of the "drug-active ingredient-disease-target-pathway" was constructed through Cytoscape 3.8.0. The pharmacodynamics of SWHP in the treatment of anxiety was evaluated by the elevated plus maze (EPM), the light/dark box test (LDB) and the open field test (OFT). The mechanisms were examined by measuring monoamine neurotransmitters in brain of mice.

RESULTS

The results showed that there were 13 active ingredients for the treatment of anxiety in the network. This includes sanjoinenine, swertisin, daucosterol, schizandrer B, wuweizisu C and gomisin-A. Additionally, there were 148 targets, such as AKT1, TNF, SLC6A4, SLC6A3, EGFR, ESR1, HSP90AA1, CCND1, and DRD2, mainly involved in neuroactive ligand-receptor interactions, the Serotonergic synapse pathway and the cAMP signaling pathway. After 1 week of treatment, SWHP (2 and 3 g/kg) induced a significant increase on the percentage of entries into and time spent on the open arms of the EPM. In the LDB test, SWHP exerted anxiolytic-like effect at 2 g/kg. In the open-field test, SWHP (2 g/kg) increased the number of central entries and time spent in central areas. The levels of brain monoamines (5-HT and DA) and their metabolites (5-HIAA, DOPAC) were decreased after SWHP treatment.

CONCLUSIONS

The anti-anxiety effect of SWHP may be mediated by regulating 5-HT, DA and other signaling pathways. These findings demonstrated that SWHP produced an anxiolytic-like effect and the mechanism of action involves the serotonergic and dopaminergic systems, although underlying mechanism remains to be further elucidated.

Neuropharmacological Study on Capsaicin in Scopolamine-injected Mice

AIM

To evaluate the potential beneficial role of Capsaicin in cognitive dysfunction, mitochondrial impairment, and oxidative damage induced by scopolamine in mice.

BACKGROUND

Capsaicin is the chief phenolic component present in red chili and is responsible for its pungent and spicy flavor. It affects TRPV1 channels in nociceptive sensory neurons and is present in the hippocampus, and hypothalamus of the brains of rodents and humans.

OBJECTIVE

The main objective is to investigate the effective role of capsaicin in attenuating cognitive dysfunction, mitochondrial impairment, and oxidative damage induced by scopolamine in mice and examine the feasible mechanisms.

METHODS

Various doses of capsaicin (5, 10, and 20 mg/kg) were given orally to mice daily for 7 consecutive days after the administration of scopolamine. Various behavioral tests (motor coordination, locomotor counts, hole board test) and biochemical assay (Pro-inflammatory cytokines, catalase, lipid peroxidation, nitrite, reduced glutathione, and superoxide dismutase), mitochondrial complex (I, II, III, and IV) enzyme activities, and mitochondrial permeability transition were evaluated in the distinct regions of the brain.

RESULTS

Scopolamine-treated mice showed a considerable reduction in the entries and duration in the light zone as well as in open arms of the elevated plus maze. Interestingly, capsaicin at different doses reversed the anxiety, depressive-like behaviors, and learning and memory impairment effects of scopolamine. Scopolamine-administered mice demonstrated substantially increased pro-inflammatory cytokines levels, impaired mitochondrial enzyme complex activities, and increased oxidative damage compared to the normal control group. Capsaicin treatment reinstated the reduced lipid peroxidation, nitric oxide, catalase, superoxide dismutase, reduced glutathione activity, decreasing pro-inflammatory cytokines and restoring mitochondrial complex enzyme activities (I, II, III, and IV) as well as mitochondrial permeability. Moreover, the IL-1β level was restored at a dose of capsaicin (10 and 20 mg/kg) only. Capsaicin reduced the scopolamine-induced acetylcholinesterase activity, thereby raising the acetylcholine concentration in the hippocampal tissues of mice. Preservation of neuronal cell morphology was also confirmed by capsaicin in histological studies. From the above experimental results, capsaicin at a dose of 10 mg/kg, p.o. for seven consecutive days was found to be the most effective dose.

CONCLUSION

The experiential neuroprotective effect of capsaicin through the restoration of mitochondrial functions, antioxidant effects, and modulation of pro-inflammatory cytokines makes it a promising candidate for further drug development through clinical setup.

Apocynum venetum, a medicinal, economical and ecological plant: a review update

Apocynum venetum L. is an important medicinal perennial rhizome plant with good ecological and economic value. Its leaves have many pharmacological effects such as anti-inflammatory, anti-depression, anti-anxiolytic, etc., while its fibers have the title of "king of wild fibers". Furthermore, it was suitable for the restoration of degraded saline soil in arid areas. An increasing studies have been published in the past years. A scientometric analysis was used to analyze the publications of Apocynum venetum L. to clearly review the pharmacology, fiber application of Apocynum venetum L. and the potential value with its similar species (Apocynum pictum Schrenk) to the environment.

Natural product-based pharmacological studies for neurological disorders

Central nervous system (CNS) disorders and diseases are expected to rise sharply in the coming years, partly because of the world's aging population. Medicines for the treatment of the CNS have not been successfully made. Inadequate knowledge about the brain, pharmacokinetic and dynamic errors in preclinical studies, challenges with clinical trial design, complexity and variety of human brain illnesses, and variations in species are some potential scenarios. Neurodegenerative diseases (NDDs) are multifaceted and lack identifiable etiological components, and the drugs developed to treat them did not meet the requirements of those who anticipated treatments. Therefore, there is a great demand for safe and effective natural therapeutic adjuvants. For the treatment of NDDs and other memory-related problems, many herbal and natural items have been used in the Ayurvedic medical system. Anxiety, depression, Parkinson's, and Alzheimer's diseases (AD), as well as a plethora of other neuropsychiatric disorders, may benefit from the use of plant and food-derived chemicals that have antidepressant or antiepileptic properties. We have summarized the present level of knowledge about natural products based on topological evidence, bioinformatics analysis, and translational research in this review. We have also highlighted some clinical research or investigation that will help us select natural products for the treatment of neurological conditions. In the present review, we have explored the potential efficacy of phytoconstituents against neurological diseases. Various evidence-based studies and extensive recent investigations have been included, which will help pharmacologists reduce the progression of neuronal disease.

Structural characterization and immunoregulatory activity of a neutral polysaccharide from the roots of Apocynum venetum L

The structural characteristics and immunoregulatory activities of neutral heteropolysaccharide (AVRP-N) separated from the roots of Apocynum venetum L. were extensively investigated. The results showed that the weight average molecular mass (Mw) of AVRP-N was 6.430 × 10³ Da. Moreover, the backbone is composed of natural acetylated (1 → 4)-β-D-Man and (1 → 5)-α-L-Ara domains. The mannan is composed of →4)-β-D-Manp-(1→, →4)-β-D-Glcp-(1→, and the terminal group α-D-Galp-(1→ attached to →4,6)-β-D-Manp-(1→ at O-6. Araban is composed of →5)-α-L-Araf-(1→; the terminal group α-L-Araf-(1→attached to→2,3,5)-α-L-Araf-(1→ at O-2, O-3 and →3,5)-α-L-Araf-(1→ at O-3. In addition, the senior structure shows that AVRP-N has a triple-helix conformation. Furthermore, AVRP-N exhibited immunomodulatory effects, which could significantly regulate the proliferation of mouse splenic lymphocytes by enhancing the secretion of the cytokines (IFN-γ, IL-2, IL-4, and IL-10). Our results provide new structural and immunoregulatory information for natural polysaccharides derived from Apocynum venetum L.

Ethnopharmacology, Biological Evaluation, and Chemical Composition of Ziziphus spina-christi (L.) Desf.: A Review

Medicinal plants are the primary raw materials used in the production of medicinal products all over the world. As a result, more study on plants with therapeutic potential is required. The tropical tree Ziziphus spina belongs to the Rhamnaceae family. Biological reports and traditional applications including management of diabetes and treatment of malaria, digestive issues, typhoid, liver complaints, weakness, skin infections, urinary disorders, obesity, diarrhoea, and sleeplessness have all been treated with different parts of Z. spina all over the globe. The plant is identified as a rich source of diverse chemical compounds. This study is a comprehensive yet detailed review of Z. spina based on major findings from around the world regarding ethnopharmacology, biological evaluation, and chemical composition. Scopus, Web of Science, BioMed Central, ScienceDirect, PubMed, Springer Link, and Google Scholar were searched to find published articles. From the 186 research articles reviewed, we revealed the leaf extract to be significant against free radicals, microbes, parasites, inflammation-related cases, obesity, and cancer. Chemically, polyphenols/flavonoids were the most reported compounds with a composition of 66 compounds out of the total 193 compounds reported from different parts of the plant. However, the safety and efficacy of Z. spina have not been wholly assessed in humans, and further well-designed clinical trials are needed to corroborate preclinical findings. The mechanism of action of the leaf extract should be examined. The standard dose and safety of the leaf should be established.

The chloroplast genome sequence and phylogenetic analysis of Apocynum venetum L

Apocynum venetum L. (Apocynaceae) is valuable for its medicinal compounds and fiber content. Native A. venetum populations are threatened and require protection. Wild A. venetum resources are limited relative to market demand and a poor understanding of the composition of A. venetum at the molecular level. The chloroplast genome contains genetic markers for phylogenetic analysis, genetic diversity evaluation, and molecular identification. In this study, the entire genome of the A. venetum chloroplast was sequenced and analyzed. The A. venetum cp genome is 150,878 bp, with a pair of inverted repeat regions (IRA and IRB). Each inverted repeat region is 25,810 bp, which consist of large (LSC, 81,951 bp) and small (SSC, 17,307 bp) single copy areas. The genome-wide GC content was 38.35%, LSC made up 36.49%, SSC made up 32.41%, and IR made up 43.3%. The A. venetum chloroplast genome encodes 131 genes, including 86 protein-coding genes, eight ribosomal RNA genes, and 37 transfer RNA genes. This study identified the unique characteristics of the A. venetum chloroplast genome, which will help formulate effective conservation and management strategies as well as molecular identification approaches for this important medicinal plant.

Isoquercitrin from Apocynum venetum L. produces an anti-obesity effect on obese mice by targeting C-1-tetrahydrofolate synthase, carbonyl reductase, and glutathione S-transferase P and modification of the AMPK/SREBP-1c/FAS/CD36 signaling pathway in mice in vivo

In the present study, mice with high-fat-diet-induced obesity were used in investigating the anti-obesity effects of an aqueous extract and isoquercitrin from Apocynum venetum L.

Natural Products: Ray of Hope for Anxiety Disorders

Background:

Anxiety, a familiar form of psychiatric disorder, influences numerous persons throughout the world. These psychological disorders frequently need an enduring regime of recommended medicines and impose huge costs on human societies. For the last few decenniums, discovery in the field of natural neurophysiology garnered a lot of recognition because of its least side effects.

Objective:

Many people find it helpful to discover an effective herbal remedy for anxiety with fewer detrimental repercussions. The purpose of the present article is to report medicinal plant species used as anti-anxiety agents, which in turn, are helpful to develop new anti-anxiety herbal formulations.

Method:

An unlimited, semantic electronic and manual exploration of PubMed, Cumulative Index of Nursing and Allied Health Literature, ISI, Google Scholar, Elsevier's abstract and citation database, and the database libraries was carried using keywords such as medicinal plants, herbal drugs, traditional medicine, and anxiety for recognizing natural medications in the management of anxiety disorders.

Results:

Literary review collected the information of potential anti-anxiety plants. Data support the effectiveness of some popular herbal remedies by indicating high-quality scientific studies and support several clinically efficacious natural plants as anxiolytics.

Conclusion:

Evidence-based studies indicate that natural plant treatment is an efficient way to manage anxiety disorders; the benefits outweigh the risks.

Does intermittent fasting associated with aerobic training influence parameters related to the gut-brain axis of Wistar rats?

BACKGROUND

Intermittent fasting (IF) and aerobic training have demonstrated beneficial effects on intestinal microbiota composition, but little is known about benefits to the brain through the gut-brain axis. The present study aimed to evaluate gut-brain axis parameters in Wistar rats submitted to IF associated or not with aerobic training.

METHODS

Male rats were evaluated for training performance and then randomized into 4 groups of ten: sedentary control (SC), trained control (TC), sedentary intermittent fasting (SIF), and trained intermittent fasting (TIF), and evaluated during four weeks.

RESULTS

The adiposity index was similar among the TC (2.15±0.43%), SIF (1.98±0.69%) and TIF (1.86±0.51%) groups, and differed from SC (2.98±0.80%). TIF had lower counts of lactic acid bacteria, while SIF had higher counts of Bifidobacterium and Enterococcus. TIF had the highest amount of formic acid in faeces (44.44±2.40 μmol/g) and lowest amount of succinic acid in the gut (0.38±0.00 μmol/g), while SIF had the highest propionic acid amount in the faeces (802.80±00.33 μmol/g) and the lowest amount of lactic acid in the gut (0.85±0.00 μmol/g). TIF demonstrated a tendency towards an anxiolytic effect and SIF showed potential antidepressant effect. IF caused different brain and intestinal injuries. TIF rats presented a diffuse and intense marking of IL-1β in the hippocampus.

CONCLUSION

IF and aerobic exercise, associated or not, can modulate parameters related to the gut-brain axis of Wistar rats, and some benefits may be related to the amounts of organic acids.

Mucuna pruriens Administration Minimizes Neuroinflammation and Shows Anxiolytic, Antidepressant and Slimming Effects in Obese Rats

This study evaluated the effect of Mucuna pruriens (MP) administration on neuroinflammation and behavioral and murinometric parameters in obese rats. Proximate composition, oligosaccharide and phenolic compound profile of MP were determined. Wistar adult male rats were randomized into healthy (HG) and obese group (OG). The HG consumed a control chow diet while OG consumed a cafeteria diet for eight weeks. Then, they were subdivided into: Healthy (HG); Healthy with MP administration (HGMP); Obese (OG); Obese with MP administration (OGMP), with the consumption of the respective diets remaining for another eight weeks, in addition to gavage with MP extract to supplemented groups (750 mg/kg weight). MP presented a composition rich in proteins and phenolic compounds, especially catechin, in addition to 1-kestose and levodopa. Supplementation reduced food intake, body weight, and thoracic and abdominal circumferences in obese rats. MP showed anxiolytic and antidepressant effects and reduced morphological damage and expression of interleukin 6 in the hippocampus of obese rats. MP treatment showed satietogenic, slimming, anxiolytic and antidepressant effects, besides to minimizing hippocampal neuroinflammation in obese rats. Our results demonstrated the potential anti-obesity of MP which are probably related to the high content of bioactive compounds present in this plant extract.

Salt stress decreases seedling growth and development but increases quercetin and kaempferol content in Apocynum venetum

Apocynum venetum L. is a traditional Chinese medicinal herb with great potential to treat angiocardiopathy. Its major medicinal constituents are flavonoids. However, the natural habitats of A. venetum are typically affected by salt stress, which can modify both biomass and accumulation of medicinal compounds. In this study, the effects of salt stress on growth and development of A. venetum, accumulation of flavonoids and expression patterns of genes involved in flavonoid biosynthesis were evaluated. In general, the growth and development of seedlings (seedling height, root length, leaf length, leaf width and seed germination) were inhibited by salt stress. Unlike typical halophytes, there was no optimal NaCl concentration range that promoted growth and development, but seedlings had an elevated DW/FW ratio under salt stress (induced by irrigation with 50, 100, 200 or 400 mm NaCl). Furthermore, quercetin and kaempferol were significantly accumulated in A. venetum seedlings under salt stress, resulting in a balanced content and reduced FW. Moreover, the expression of AvCHS, AvCHI and AvF3GT was inhibited by salt stress; however, AvF3'H, AvF3H and AvFLS, which are involved in the flavonol synthesis pathway, were up-regulated under salt stress, consistent with a decrease in total flavonoids and an increase of flavonols (quercetin and kaempferol). In summary, cultivation of A. venetum in saline soils appeared to be feasible and improved the medicinal quality of A. venetum (quercetin and kaempferol accumulation under salt stress), thus this species can effectively utilize saline soil resources.

The complete chloroplast genome of Apocynum venetum (Apocynaceae)

Apocynum venetum (A. venetum) has high medicinal value that belongs to the family Apocynaceae. Here, we reported the complete chloroplast (cp) genome of A. venetum, which was 150,858 bp in length. The cp genome was characterized by a typical quadripartite structure composed of a large single-copy region (LSC 81,919 bp) and a small single-copy region (SSC 17,257 bp) interspersed by a pair of 25,841 bp inverted repeat regions (IRs), and it contained 86 protein-coding genes, eight rRNAs, and 37 tRNAs. A maximum-likelihood (ML) phylogenetic tree indicated that A. venetum was closely related to Trachelospermum jasminoides.

The preventive effect of Apocynum venetum polyphenols on D-galactose-induced oxidative stress in mice

Apocynum venetum is a traditional medicine that is rich in polyphenols. Apocynum venetum polyphenol extract (AVP) contains the active substances neochlorogenic acid, chlorogenic acid, rutin, isoquercitrin, astragaloside and rosmarinic acid. In the present study, the preventive effect of AVP against D-galactose-induced oxidative stress was studied in a mouse model. The sera, skin, livers and spleens of mice were examined using hematoxylin and eosin staining, reverse transcription-quantitative PCR and western blot analysis. The biochemical results showed that AVP improved the thymus, brain, heart, liver, spleen and kidney indices in a mouse model of oxidative stress. AVP was also able to reverse the reduction in levels of superoxide dismutase (SOD), glutathione peroxidase and glutathione, and increased the levels of nitric oxide and malondialdehyde identified in the serum, liver, spleen and brain of mice exposed to oxidative stress. Pathological observations confirmed that AVP could inhibit oxidative damage to the skin, liver and spleen of mice caused by D-galactose. Further molecular biological experiments also demonstrated that AVP increased the expression of neuronal nitric oxide synthase, endothelial nitric oxide synthase, Cu/Zn-SOD, Mn-SOD, catalase, heme oxygenase-1, nuclear factor-erythroid 2-related factor 2, γ-glutamylcysteine synthetase and NAD(P)H quinone dehydrogenase 1 and reduced the expression of inducible nitric oxide synthase in the liver and spleen of treated mice compared to controls. Notably, the preventive effect of AVP against D-galactose-induced oxidative damage in mice was better than that of the confirmed antioxidant vitamin C. In conclusion, AVP exhibited an antioxidant effect and the AVP-rich Apocynum venetum may be considered a plant resource with potential antioxidative benefits.

In Vitro Analysis of Antioxidant, Anticancer, and Bioactive Components of Apocynum venetum Tea Extracts

The dry leaf of Apocynum venetum tea extracts (AVTEs) belonging to the Apocynaceae family is a traditional Chinese medicine. The aim of this study is to identify the bioactive components of AVTE and analyse its antioxidant and anticancer activity in vitro. Method. Flavones and polyphenols in AVTE were determined by high-performance liquid chromatography (HPLC) assay. The scavenging capacity of tea extracts to 1,1-diphenyl-2-picrylhydrazyl (DPPH); 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS); hydroxyl (OH); and superoxide anion-free radicals were investigated by spectrophotometry. We also detailed the cytotoxicity assay of AVTE (50, 100, and 200 μg/mL) to human embryonic kidney 293T cells, the protective effect of AVTE on 293T cells induced by hydrogen peroxide (0.3 mmol/L), and the anticancer effect against the human hepatoma HepG2 cells via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. We investigated the antioxidative effects of AVTE in human embryonic kidney 293T cells and the anticancer mechanism in HepG2 human hepatoma cells via quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR) assay. Results. HPLC analysis showed that AVTEs contain neochlorogenic acid, chlorogenic acid, rutin, isoquercetin, isochlorogenic acid B, astragalin, isochlorogenic acid C, rosmarinic acid, quercetin, and trans-cinnamic acid. These extracts have high antioxidant activity and dose-dependent relation through free radical scavenging experiments. The cell viability of 293T cells treated with hydrogen peroxide (0.3 mmol/L) was significantly lower than that of normal cells, and the cell viability of oxidatively stressed 293T cells after AVTE (50, 100, and 200 μg/mL) treatment was significantly improved (P<0.05). Moreover, cytotoxicity experiments showed that the survival rate of 293T cells was over 90%, but the proliferation of HepG2 cells was significantly inhibited in a dose-dependent manner by AVTE. Furthermore, cytoprotective effects in 293T cells were induced via upregulation of glutathione peroxidase (GSH-Px), GSH, superoxide dismutase (SOD), and catalase (CAT) antioxidant-related factors, as well as apoptosis in HepG2 cells was induced via upregulation of caspase-3, caspase-9, p21, and p53 apoptosis-associated factors, as assessed via mRNA expression levels after treatment with AVTE, which were consistent with the results of antioxidant gene detections. As a conclusion, AVTE appears to be an effectively functional drink, due to its rich functional components and antioxidant and anticancer activities.

Apoptosis induction effect of Apocynum venetum polyphenol on human U87 glioma cells via NF-κB pathway

Aim: Apocynum venetum polyphenol (AVP) was used in in vitro glioma cells culture to prove the growth inhibitory effect of AVP on human U87 glioma cells via NF-κB pathway. Materials & methods: The MTT assay, DAPI morphology, quantitative PCR and western blot experiments were used for determination in vitro. Results & conclusion: AVP can also induce U87 cancer cells apoptosis illustrated by DAPI morphology. AVP could enhance the mRNA and protein expression of IκB-α, TNF-α, TRAIL, caspase-3 and caspase-9 in U87 cancer cells and reduce those of NF-κBp65, cIAP-1, cIAP-2, TGF-β2, CyclinD1, VEGF and IL-8. After ammonium pyrrolidine dithiocarbamate (PDTC) treatment, the NF-κBp65 expression was reduced in U87 cells, and AVP could raise these effects. The results of HPLC indicate that AVP mainly contains six constituents. The growth inhibitory effects of AVP on U87 glioma cells are predominantly from these natural active constituents.

Nectandra grandiflora essential oil and its isolated sesquiterpenoids minimize anxiety-related behaviors in mice through GABAergic mechanisms

Nectandra grandiflora Ness (Lauraceae) essential oil (EO) main constituent, the sesquiterpenoid (+)-dehydrofukinone (DHF), has sedative and anticonvulsant effects through GABAergic mechanisms. Other DHF-related sesquiterpenoids have been identified in the EO, such as, dehydrofukinone epoxide (DFX), eremophil-11-en-10-ol (ERM) and selin-11-en-4-α-ol (SEL). However, the neuronal effects of these compounds in mammals remain unknown. Therefore, the aim of this study was to evaluate the anxiolytic potential of the N. grandiflora EO and the isolated compounds in in mice. For this purpose, mice were administered orally with vehicle, 10, 30 or 100 mg/kg EO, DHF, DFX, ERM or SEL or 1 mg/kg diazepam. Locomotion and ethological parameters in the open field (OF) and elevated plus maze (EPM) were recorded. We also examined the effect of DFX, ERM and SEL on the membrane potential and calcium influx in synaptosomes, and the presence of the compounds in the cortical tissue using gas chromatography. EOs and isolated compounds reduced anxiety-related parameters in the EPM (open arms time and entries, end activity, head dipping) and OF (center time and entries, total rearing, unprotected rearing, sniffing, grooming) without alter ambulation or induce sedation. Flumazenil (2 mg/kg, i.p.) altered the anxiolytic-like effect of all treatments and vanished the DFX, ERM and SEL-induced changes in membrane potential. However, FMZ did not blocked the DFX-, ERM- and SEL-induced inhibition of calcium influx. Therefore, our results suggest that N. grandiflora EO and isolated compounds induced anxiolytic-like effect in mice due to positive modulation of GABAa receptors and/or inhibition of neuronal calcium influx.

The effects of cinnamaldehyde on acute or chronic stress-induced anxiety-related behavior and locomotion in male mice

Anxiety and stress are considered as universal psychiatric exhibitions of the present societies and lifestyles. Several experiments have been conducted to examine natural anxiolytic agents to find out an alternative to synthetic anxiolytic drugs. The present study investigated the anxiolytic effects of cinnamaldehyde (Cin) on mice behavior in the elevated plus maze (EPM) and open field (OF) tests. Sixty male Swiss mice, weighing 20-30 g, were divided into six groups including: acute stress + mazola oil; chronic stress + oil; acute stress + Cin (20 mg/kg); chronic stress + Cin; non-stress + oil; and non-stress + Cin groups. The groups were administered for seven days (once a day). The acute stress + Cin group showed a meaningful rise in the percentage of entries into the open arms compared to the acute stress + oil group (p <.05). The percentage of time spent in the open arms in the chronic stress + Cin group was significantly higher compared to the chronic stress + oil group (p < .01). The percentage of entries into the open arms increased significantly (p < .01) in the chronic stress + Cin group in comparison with the chronic stress + oil group. The Cin treated groups showed significant increases in the time spent in the center area and in the number of entries into the center area compared with the oil treated groups in OF test. The number of entries into the arms (total activity), as well as locomotor activity was not significant among groups. The results of the present study indicated that Cin, as a natural product, might have anxiolytic effects in mice behavior in the EPM and OF tests. Lay summary  The results demonstrated that the administration of cinnamaldehyde (Cin) produced anxiolytic effects in mice. Natural antioxidant products have been reported effective for anxiety. Synthetic medications have notable adverse effects. Therefore, these natural substances with broad therapeutic applicability are able to reduce anxiety-related behavior with rare side effects. According to the results, Cin could decrease anxiety-related behavior in mice.

Effects of a hydroethanolic extract of Boophone disticha bulb on anxiety-related behaviour in naive BALB/c mice

ETHNOPHARMACOLOGICAL RELEVANCE

Boophone disticha is one of the most important medicinal bulbs of Southern Africa. Previous in vitro studies have shown that it's crude ethanolic extracts and some alkaloidal phytoconstituents possesses high affinity for the serotonin transporter protein (SERT) and serotonin receptor 1a (5HT_1a) which are both implicated in the pathogenesis and treatment of anxiety disorders. However, there are no in vivo studies that validates the anxiolytic actions of the plant.

AIM OF THE STUDY

This study was therefore set to determine the anxiolytic-like activity of an orally administered hydroethanolic extract of B. disticha bulbs in naive mice using the behavioural tests of anxiety.

MATERIALS AND METHODS

Naïve adult male BALB/c mice were randomly placed into five treatment groups (n=6-10): vehicle control (10ml/kg 0.9% NaCl), positive control (1mg/kg diazepam) and the hydroethanolic extract of B. disticha (10, 25 and 40mg/kg p.o.). Souk test, elevared plus maze and open field tests were used to evaluate the anxiolytic-like activity of the B. disticha extract.

RESULTS

Diazepam-treated mice exhibited higher number of sector visits and line crossings in the ST, rearings in the OF and head dips in the EPM than the control (p<0.05). B. disticha extract treated groups expressed higher sector visits at 10mg/kg, and, unprotected head dips at 25mg/kg in the ST, as well as, open arm time entries at 10mg/kg dose, and unprotected head dips at all doses in the EPM than the control group (p<0.05). The 25mg/kg B. disticha dose group exhibited highest anxiolytic-like activity in both the ST and OF, while the 10mg/kg was most active in the EPM.

CONCLUSION

The extract of B. disticha exerted good anxiolytic-like activity in both the ST and OF at medium dose (25mg/kg), while the low dose (10mg/kg) showed prominent anxiolytic-like activity in the EPM.

Quality Evaluation of Apocyni Veneti Folium from Different Habitats and Commercial Herbs Based on Simultaneous Determination of Multiple Bioactive Constituents Combined with Multivariate Statistical Analysis

Apocyni Veneti Folium (AVF) is a kind of staple traditional Chinese medicine with vast clinical consumption because of its positive effects. However, due to the habitats and adulterants, its quality is uneven. To control the quality of this medicinal herb, in this study, the quality of AVF was evaluated based on simultaneous determination of multiple bioactive constituents combined with multivariate statistical analysis. A reliable method based on ultra-fast liquid chromatography tandem triple quadrupole mass spectrometry (UFLC-QTRAP-MS/MS) was developed for the simultaneous determination of a total of 43 constituents, including 15 flavonoids, 6 organic acids, 13 amino acids, and 9 nucleosides in 41 Luobumaye samples from different habitats and commercial herbs. Furthermore, according to the contents of these 43 constituents, principal component analysis (PCA) was employed to classify and distinguish between AVF and its adulterants, leaves of Poacynum hendersonii (PHF), and gray relational analysis (GRA) was performed to evaluate the quality of the samples. The proposed method was successfully applied to the comprehensive quality evaluation of AVF, and all results demonstrated that the quality of AVF was higher than the PHF. This study will provide comprehensive information necessary for the quality control of AVF.

Apocynum venetum Leaf Extract Exerts Antidepressant-Like Effects and Inhibits Hippocampal and Cortical Apoptosis of Rats Exposed to Chronic Unpredictable Mild Stress

We investigated the effects of Apocynum venetum leaf extract (AVLE) on depressive behaviors and neuronal apoptosis in a chronic unpredictable mild stress (CUMS) rat model of depression. Rats were randomly divided into six groups: control, chronic unpredictable mild stress, fluoxetine, AVLE30, AVLE60, and AVLE120. Except for the control group, all rats were submitted to chronic unpredictable mild stress paradigms for four weeks to induce depressive behavior. Neuronal apoptosis was assessed by the terminal deoxynucleotidyl transferase- (TDT-) mediated dUTP-biotin nick end-labeling (TUNEL) method. The expression levels of apoptosis-related proteins, such as B-cell lymphoma 2 (Bcl-2), Bcl-2 Associated X Protein (Bax), cysteine-aspartic acid protease-3 and protease-9 (caspase-3 and caspase-9), cytochrome c (cyt-C), brain-derived neurotrophic factor (BDNF), and cAMP-response element binding (CREB) protein, were evaluated by western blot. Treatment with AVLE (60 or 120 mg/kg/day) significantly improved depressive behavior. Increased apoptosis of hippocampus and cortical neurons were observed in CUMS rats, while 120 mg/kg/day of AVLE significantly reversed these changes and achieved the best antidepressant-like effects among the doses tested. Moreover, AVLE (120 mg/kg) significantly increased Bcl-2, BDNF, and CREB protein expression and decreased Bax, cyt-C, and caspase family protein expression. Our results indicate that AVLE has potent antidepressant activity, likely due to its ability to suppress neuronal apoptosis.

Antidepressant and anxiolytic activity of Lavandula officinalis aerial parts hydroalcoholic extract in scopolamine-treated rats

CONTEXT

Anxiety and depression are common in Alzheimer's disease (AD). Despite some evidence, it is difficult to confirm Lavandula officinalis Chaix ex Vill (Lamiaceae) as an anxiolytic and antidepressant drug.

OBJECTIVE

The effects of L. officinalis extract were studied in scopolamine-induced memory impairment, anxiety and depression-like behaviour.

MATERIALS AND METHODS

Male NMRI rats were divided into control, scopolamine alone-treated group received scopolamine (0.1 mg/kg) intraperitoneally (i.p.), daily and 30 min prior to performing behavioural testing on test day, for 12 continuous days and extract pretreated groups received aerial parts hydro alcoholic extract (i.p.) (100, 200 and 400 mg/kg), 30 min before each scopolamine injection. Memory impairment was assessed by Y-maze task, while, elevated plus maze and forced swimming test were used to measure anxiolytic and antidepressive-like activity.

RESULTS

Spontaneous alternation percentage in Y maze is reduced by scopolamine (36.42 ± 2.60) (p ≤ 0.001), whereas lavender (200 and 400 mg/kg) enhanced it (83.12 ± 5.20 and 95 ± 11.08, respectively) (p ≤ 0.05). Also, lavender pretreatment in 200 and 400 mg/kg enhanced time spent on the open arms (15.4 ± 3.37 and 32.1 ± 3.46, respectively) (p ≤ 0.001). On the contrary, while immobility time was enhanced by scopolamine (296 ± 4.70), 100, 200 and 400 mg/kg lavender reduced it (193.88 ± 22.42, 73.3 ± 8.25 and 35.2 ± 4.22, respectively) in a dose-dependent manner (p ≤ 0.001).

DISCUSSION AND CONCLUSION

Lavender extracts improved scopolamine-induced memory impairment and also reduced anxiety and depression-like behaviour in a dose-dependent manner.

Site-specific accumulation and dynamic change of flavonoids in Apocyni Veneti Folium

Site-specific accumulation of flavonoids in Apocyni Veneti Folium was determined by laser scanning confocal microscope (LSCM) and the localization of catechins also was observed via vanillin-HCl staining under the conventional optical microscope. The contents of five flavonoids in Apocyni Veneti Folium from different harvest times and growth parts were measured using HPLC method. LSCM observation showed that flavonoids are accumulated in cuticle of epidermal cells and vessel walls, especially in protoplasts and nucleolus of the collenchyma cells and the epidermal cells. Catechins are localized in the palisade parenchyma cells and vessel walls, particularly in the laticifers found in the phloem. On the basis of the difference of the maximal emission wavelength between quercetin and kaempferol derivatives which have fluorescence behavior by appropriate treatment, kaempferol and its derivatives are localized exclusively in the cuticle. Results showed that the content of astragalin in Apocyni Veneti Folium from different parts revealed the decreasing trend, while hyperin and isoquercitrin were higher in June and July analyzed by HPLC. In summary, the site-specific accumulation of flavonoids in Apocyni Veneti Folium can be determined by LSCM and vanillin-HCl staining. The contents of flavonoids in Apocyni Veneti Folium are correlated with harvest times and growth parts.

The ethnobotany of psychoactive plant use: a phylogenetic perspective

Psychoactive plants contain chemicals that presumably evolved as allelochemicals but target certain neuronal receptors when consumed by humans, altering perception, emotion and cognition. These plants have been used since ancient times as medicines and in the context of religious rituals for their various psychoactive effects (e.g., as hallucinogens, stimulants, sedatives). The ubiquity of psychoactive plants in various cultures motivates investigation of the commonalities among these plants, in which a phylogenetic framework may be insightful. A phylogeny of culturally diverse psychoactive plant taxa was constructed with their psychotropic effects and affected neurotransmitter systems mapped on the phylogeny. The phylogenetic distribution shows multiple evolutionary origins of psychoactive families. The plant families Myristicaceae (e.g., nutmeg), Papaveraceae (opium poppy), Cactaceae (peyote), Convolvulaceae (morning glory), Solanaceae (tobacco), Lamiaceae (mints), Apocynaceae (dogbane) have a disproportionate number of psychoactive genera with various indigenous groups using geographically disparate members of these plant families for the same psychoactive effect, an example of cultural convergence. Pharmacological traits related to hallucinogenic and sedative potential are phylogenetically conserved within families. Unrelated families that exert similar psychoactive effects also modulate similar neurotransmitter systems (i.e., mechanistic convergence). However, pharmacological mechanisms for stimulant effects were varied even within families suggesting that stimulant chemicals may be more evolutionarily labile than those associated with hallucinogenic and sedative effects. Chemically similar psychoactive chemicals may also exist in phylogenetically unrelated lineages, suggesting convergent evolution or differential gene regulation of a common metabolic pathway. Our study has shown that phylogenetic analysis of traditionally used psychoactive plants suggests multiple ethnobotanical origins and widespread human dependence on these plants, motivating pharmacological investigation into their potential as modern therapeutics for various neurological disorders.

Newtonoate as an active principle of Newtonia griffoniana for anxiolytic activity in Swiss mice

BACKGROUND

Newtonia griffoniana (Mimosaceae) is a Central African rain forest tree, whose bark extracts are used in Cameroonian folk medicine for the treatment of anxiety and sleep disorders.

METHODS

We evaluated the anxiolytic effects of N. griffoniana stem bark methanol extract and its major isolated constituent 2,3,4-trihydroxybutylpentatriacontanoate (newtonoate) on the elevated plus maze.

RESULTS

Significant increases in the percentage of entries into open arms were induced by both N. griffoniana extract (100 and 150 mg/kg BW; p<0.01) and newtonoate (doses of 3 and 15 mg/kg BW; p<0.05). Conversely, decreases in the percentage of entries into closed arms were observed at the same doses. In addition, N. griffoniana methanol extract (100 mg/kg) and the isolated newtonoate (30 mg/kg) induced significant (p<0.01 and p<0.05, respectively) increases in the time spent in the open arms, while inducing a decrease in the time spent in the closed arms. Newtonoate treatment also decreased head dipping number at doses of 3 and 15 mg/kg, while N. griffoniana methanol extract induced the same effect at 200 mg/kg.

CONCLUSIONS

These results suggest that N. griffoniana bark extract has anxiolytic properties, which justify its use in folk medicine. Such effects are at least partly mediated by newtonoate.

Effect of Hydroalcoholic Extract of Rosmarinus officinalis L. Leaf on Anxiety in Mice

In today’s stressful world, psychopathy (especially anxiety) is receiving increased importance. Most of the drugs used to treat this disease have several side effects. Medicinal plants derived from natural products have fewer side effects and can be used in the treatment of this disease. The aim of this study was to evaluate the effect of the hydroalcoholic extract of Rosmarinus officinalis L. on anxiety in mice. In this experimental study, 50 male mice were randomly divided into 5 groups. To evaluate anxiety, the Elevated Plus Maze test was performed. The control group received normal saline, the positive control group received diazepam (1 mg/kg) as intraperitoneal injection, and the experimental groups received doses of 100, 200, and 400 mg/kg body weight of rosemary extract. The data were analyzed using SPSS 15 and ANOVA statistical tests. The results show that rosemary extract dose-dependently increases the mice spending time and the entries number of mice in plus maze open arms (indicating less stress). This effect at a dose of 400 mg/kg was similar to diazepam, which, in comparison to the control group, was statistically significant ( P < .01), while the evaluation of locomotor activity in treated groups, compared with the control groups, showed no significant difference ( P > .05). On the other hand, the rosemary extract, similar to the standard drug diazepam, showed an anti-anxiety effect. This effect is probably due to the presence of flavonoids in this plant and their antioxidant property.

Extraction, Preconcentration and Isolation of Flavonoids from Apocynum venetum L. Leaves Using Ionic Liquid-Based Ultrasonic-Assisted Extraction Coupled with an Aqueous Biphasic System

BACKGROUND

Ionic liquids (ILs) are considered as green solvents, and widely applied for the extraction of various compounds.

METHODS

The present research focuses on the extraction of flavonoids from Apocynum venetum L. leaves by ultrasound-assisted extraction (UAE). Several major influencing factors were optimized. Then, an aqueous biphasic system (ABS) was applied for further isolation of flavonoids.

RESULTS

The flavonoids were mainly distributed in the top phase, while impurities were extracted to the bottom phase. The parameters influencing the extraction, namely type and concentration of salt, temperature, and pH, were studied in detail. Under optimized conditions (72.43% IL extract, 28.57% (NH4)2SO4, 25 °C temperature, pH 4.5), the preconcentration factor and extraction efficiency were found to be 3.78% and 93.35%, respectively.

CONCLUSIONS

This simple and efficient methodology is expected to see great use in the extraction and isolation of pharmaceutically active components from medicinal plant resources.

Anxiolytic and sedative activities of aqueous leaf extract of Dichrocephala integrifolia (Asteraceae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Dichrocephala integrifolia (Asteraceae) is commonly used in the folk medicine in Cameroon to treat various ailments including headaches, jaundice, filariasis, neuritis and children's night agitation. It is also known to have anxiolytic properties. Since there were no scientific data supporting the above claims, we therefore aimed to evaluate the anxiolytic and sedative effects of the aqueous leaf extract of D. integrifolia.

MATERIALS AND METHODS

The extract used was obtained after maceration of leaves of D. integrifolia in water at room temperature. The anxiolytic effect was tested by the elevated plus-maze (EPM) and Open Field tests while the sedative effect was evaluated by the diazepam-induced sleep test.

RESULTS

D. integrifolia significantly induced an increase in the percentage of entries into open arms and a decrease in percentage of entries into closed arms at the dose of 22 mg/kg BW. The extract also induced a decrease of rearing and head dipping at the doses of 22 and 40 mg/kg BW during the EPM test. In addition, D. integrifolia extract induced a significant increase of crossing and time spent at the center of the experimental set at the dose of 40 mg/kg BW during the open field test. Lastly, D. integrifolia caused a significant reduction of the latency to sleep and an increase of total sleep time at the doses of 22 and 40 mg/kg BW in the diazepam-induced sleep test.

CONCLUSION

The results obtained in this study suggest that the aqueous leaf extract of D. integrifolia is endowed with anxiolytic and sedative properties, which justify its traditional use.

Anti-stress effects of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol in immobilized mice

Panax ginseng C.A. MEYER (Araliaceae), which contains ginsenosides as its main components, has been shown to have various biological effects, including anti-inflammatory, anxiolytic, anti-stress, and anti-tumor effects. Orally administered ginsenoside Rb1 and Re are metabolized to 20(S)-protopanaxadiol (PPD) and compound K via ginsenoside Rd and 20(S)-protopanaxatriol (PPT) and ginsenoside Rh1 via ginsenoside Rg1 by gut microbiota, respectively. Therefore, we investigated the anti-stress effects of these metabolites, PPD and PPT, by measuring their anxiolytic and anti-inflammatory effects in immobilized mice. Treatment with PPD and PPT prior to immobilization stress increased the time spent in open arms and open arm entries in the elevated plus-maze (EPM) test. The anxiolytic effects of PPD (10 mg/kg) and PPT (10 mg/kg) were comparable to that of buspirone (1 mg/kg). This observed anxiolytic effect of PPD was significantly blocked by flumazenil or bicuculline, and the effect of PPT was blocked by WAY-100635. Treatment with PPD also potently suppressed immobilization stress-induced serum levels of corticosterone and interleukin (IL)-6 by the enzyme-linked immunosorbent assay. However, PPT treatment did not suppress them. Based on these findings, PPD and PPT may exhibit the anxiolytic effect via γ-aminobutyrateA (GABAA) receptor(s) and serotonergic receptor(s), respectively, and PPD may have an anti-inflammatory effect that is more potent than that of PPT.

Study of the effect of extract of Thymus vulgaris on anxiety in male rats

There is some evidence in traditional medicine for the effectiveness of Thymus vulgaris (百里香 bǎi lǐ xiāng) in the treatment of anxiety in humans. The elevated plus-maze (EPM) has broadly been used to investigate anxiolytic and anxiogenic compounds. The present study investigated the effects of extract of T. vulgaris on rat behavior in the EPM. In the present study, the data were obtained from male Wistar rats. Animals were divided into four groups: saline group and T. vulgaris groups (50 mg/kg, 100 mg/kg, and 200 mg/kg infusion for 7 days by feeding). During the test period, the total distance covered by animals, the number of open- and closed-arm entries, and the time spent in open and closed arms of the EPM were recorded. T. vulgaris increased open-arm exploration and open-arm entry in the EPM, whereas extract of this plant has no effects on the total distance covered by animals and the number of closed-arm entries. The results of the present experiment indicate that T. vulgaris may have an anxiolytic profile in rat behavior in the EPM test, which is not influenced by the locomotor activity. Further research is required to determine the mechanisms by which T. vulgaris extract exerts an anxiolytic effect in rats.

Apocynum venetum Attenuates Acetaminophen-Induced Liver Injury in Mice

Apocynum venetum L. (A. venetum) has long been used in oriental folk medicine for the treatment of some liver diseases; however, the underlying mechanisms remain to be fully elucidated. Acetaminphen (APAP) is a widely used analgesic drug that can cause acute liver injury in overdose situations. In this study, we investigated the potential protective effect of A. venetum leaf extract (ALE) against APAP-induced hepatotoxicity. Mice were intragastrically administered with ALE once daily for 3 consecutive days prior to receiving a single intraperitoneal injection of APAP. The APAP group showed severe liver injury characterized by the noticeable fluctuations in the following parameters: serum aminotransferases; hepatic malondialdehyde (MDA), 3-nitrotyrosine (3-NT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione (GSH). These liver damages induced by APAP were significantly attenuated by ALE pretreatments. A collective analysis of histopathological examination, DNA laddering and western blot for caspase-3 and cytochrome c indicated that the ALE is also capable of preventing APAP-induced hepatocyte death. Hyperoside, isoquercitrin and their derivatives have been identified as the major components of ALE using HPLC-MS/MS. Taken together, the A. venetum possesses hepatoprotective effects partially due to its anti-oxidant action.

Discrimination between Leave of Apocynum venetum and Its Adulterant, A. pictum Based on Antioxidant Assay and Chemical Profiles Combined with Multivariate Statistical Analysis

An integrated approach including chemical and biological assessments was developed to investigate the differences between Apocynum venetum L. (AV) and its adulterant, Apocynum pictum Schrenk (AP). Ten flavonoids were tentatively identified by ultra-visible and mass spectra data. The chemical component, hyperoside, was identified as a critical parameter for discrimination of two species from the results of principal component analysis (PCA) and quantitative analysis. The anti-oxidative power of the herbal extracts were determined using 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) assay and H₂O₂-induced cell damage on LO2 cells. The results of the biological assays suggested that the chemical differences between AV and AP do lead to difference in activity and AV is demonstrated to have higher anti-oxidant activity.

Apocynum venetum Leaf Attenuates Myocardial Ischemia/Reperfusion Injury by Inhibiting Oxidative Stress

Apocynum venetum, a Chinese medicinal herb, is reported to be neuroprotective. However, whether Apocynum venetum leaf extract (AVLE) protects against ischemic myocardium remains elusive. Our present study was aimed to observe the effects of AVLE preconditioning on myocardial ischemia/reperfusion (MI/R) injury and to investigate the possible mechanisms. Rats were treated with AVLE (500 mg/kg/d, o.g.) or distilled water once daily for one week. Afterward, all the animals were subjected to 30 min of myocardial ischemia followed by 4 h of reperfusion. AVLE preconditioning for one week significantly improved cardiac function following MI/R. Meanwhile, AVLE reduced infarct size, plasma creatine kinase (CK)/lactate dehydrogenase (LDH) activities and myocardial apoptosis at the end of reperfusion in rat hearts. Moreover, AVLE preconditioning significantly inhibited superoxide generation, gp91phox expression, malonaldialdehyde formation and enhanced superoxide dismutase (SOD) activity in I/R hearts. Furthermore, AVLE treatment increased Akt and extracellular regulated protein kinases 1/2 (ERK1/2) phosphorylations in I/R rat heart. Either the Phosphatidylinositide 3-kinase (PI3K) inhibitor wortmannin or the ERK1/2 inhibitor PD98059 blocked AVLE-stimulated anti-oxidative effects and cardioprotection. Our study demonstrated for the first time that AVLE reduces oxidative stress and exerts cardioprotection against MI/R injury in rats.

Porous membrane ultrafiltration-A novel method for enrichment of the active compounds from micro-plasma samples

To enrich the active compounds from plasma samples, a novel and simple method has been developed using a porous membrane envelope based on the ultrafiltration technique combining with high-performance liquid chromatography. The ultrafiltration device is a sealed porous membrane envelope prepared with a polypropylene sheet to effectively separate the active small molecules and large biomolecules, and a sample carrier is held inside the envelope to load plasma samples. The enrichment of hyperoside and isoquercitrin from rat plasma was used as an example. Significant factors of this method, such as membrane types, the desorption solvent, and the desorption time were optimized for the ultrafiltration method. Under the optimal conditions, correlation coefficients of 0.999 and 0.998 were obtained for hyperoside and isoquercitrin, respectively, with a linear range between 0.5 and 100μg/mL. The absolute extraction recoveries from 83.2% to 86.8% were achieved. The detection limits of the method for hyperoside and isoquercitrin were 0.22 and 0.20μg/mL, respectively. Compared with protein precipitation, solid-phase extraction and commercial ultrafiltration membrane methods, our proposed method demonstrates lower detection limits and lower cost for extraction. Also, it consumes less plasma samples and is found to be applicable to biological samples.

Discovery of anxiolytic 2-ferrocenyl-1,3-thiazolidin-4-ones exerting GABAA receptor interaction via the benzodiazepine-binding site

Herein, we report on the synthesis, spectral, crystallographic and electrochemical properties of a small library of N-substituted 2-ferrocenyl-1,3-thiazolidin-4-ones, designed as novel GABAA benzodiazepine-binding site ligands. The anxiolytic properties of the title compounds were evaluated in several different in vivo models, whereas the involvement of the GABAA receptor complex in the activity of the most potent compound, 2-ferrocenyl-3-(4-methoxyphenylethyl)-1,3-thiazolidin-4-one, was inferred from experiments with known GABAA-targeting agents. Ligand docking experiments revealed that the high, dose-dependent, anxiolytic activity of the new compounds might be due to their favorable interactions with the benzodiazepine-binding site of the GABAA receptor complex. The incorporation of the ferrocene core and fine tuning of the distance between the thiazolidinone core and an additional aromatic ring were judged to be crucial structural requirements for the observed anxiolytic effect.