Design, synthesis and evaluation of activity and pharmacokinetic profile of new derivatives of xanthone and piperazine in the central nervous system.

Searching for CNS active cyclic amines derivatives containing heterocyclic xanthone core we designed and synthesized a set of fourteen novel 2- or 4-methylxanthone substituted by alkyl- or aryl-piperazine moieties. The compounds were evaluated in vivo for their potential antidepressant-like activity (in the forced swim test) and anxiolytic-like activity (four-plate test) and their inhibitory effect against rat 5-HT2 receptor was checked. The pharmacokinetic analysis of active compounds done by a non-compartmental approach have shown a rapid absorption of all studied molecules from intraperitoneal cavity and good penetration the blood-brain barrier after i.p. administration with brain to plasma ratios varied from 2.8 to 31.6. Genotoxicity and biotransformation of active compounds were studied. Compound 19 interactions with major classes of GPCRs, uptake systems and ion channels were tested and results indicated that it binds to 5-HT2A, 5-HT2B receptors and sodium channels.

The 1,3,5-Triazine Derivatives as Innovative Chemical Family of 5-HT6 Serotonin Receptor Agents with Therapeutic Perspectives for Cognitive Impairment.

Among serotonin receptors, the 5-HT6 subtype is the most controversial and the least known in the field of molecular mechanisms. The 5-HT6R ligands can be pivotal for innovative treatment of cognitive impairment, but none has reached pharmacological market, predominantly, due to insufficient "druglikeness" properties. Recently, 1,3,5-triazine-piperazine derivatives were identified as a new chemical family of potent 5-HT6R ligands. For the most active triazine 5-HT6R agents found (1-4), a wider binding profile and comprehensive in vitro evaluation of their drug-like parameters as well as behavioral studies and an influence on body mass in vivo were investigated within this work. Results indicated the most promising pharmacological/druglikeness profiles for 4-((1H-indol-3-yl)methyl)-6-(4-methylpiperazin-1-yl)-1,3,5-triazin-2-amine (3) and 4-((2-isopropyl-5-methylphenoxy)methyl)-6-(4-methylpiperazin-1-yl)-1,3,5-triazin-2-amine (4), which displayed a significant procognitive action and specific anxiolytic-like effects in the behavioral tests in vivo together with satisfied pharmaceutical and safety profiles in vitro. The thymol derivative (4) seems to be of higher importance as a new lead candidate, due to the innovative, non-indole and non-sulfone structure with the best 5-HT6R binding properties.

MF-8, a novel promising arylpiperazine-hydantoin based 5-HT7 receptor antagonist: In vitro drug-likeness studies and in vivo pharmacological evaluation.

We report the in vitro drug-likeness studies and in vivo pharmacological evaluation for a new potent 5-HT7 receptor antagonist MF-8 (5-(4-fluorophenyl)-3-(2-hydroxy-3-(4-(2-methoxyphenyl)piperazin-1-yl)propyl)-5-methylhydantoin). The in vitro tests showed good permeability, very good metabolic stability, low risk of drug-drug interactions and satisfying safety profile. Moreover, MF-8 showed excellent antidepressant-like activity in the forced swim test in rodents and promising anxiolytic-like activity in the four-plate test in mice. Regarding the potent affinity, high selectivity and antagonistic activity of MF-8 for the 5-HT7 receptor as well as excellent drug - like properties in vitro and confirmed in vivo pharmacological activity, MF-8 should be considered as a very significant molecule in the search for a new class of anti-depressant drugs.

Antibacterial activity and anxiolytic-like effect of Ziziphus joazeiro Mart. leaves in adult zebrafish (Danio rerio).

Ziziphus joazeiro Mart. is an endemic plant of the Caatinga that presents a great socioeconomic importance for the Northeast and Semiarid Region of Brazil. In view of this, this study aimed to evaluate the antibacterial activity and anxiolytic-like effects of Ziziphus joazeiro Mart leaves in adult zebrafish (Danio rerio). The characterization of the main classes of metabolites was performed through chemical reactions. The antibacterial and antibiotic potentiating activity was evaluated by broth microdilution assays. The 96 h acute toxicity, open field test and anxiety models test was evaluated in vivo on adult zebrafish. The results obtained in the phytochemical prospection evidenced the presence of flobabenic tannins, leucoanthocyanidins, flavonois, flavonones, catechins, alkaloids, steroids, and triterpenoids. EEFZJ did not show antibacterial activity for all microorganism tested (MIC ≥ 1024 µg/mL), but reduced the concentration required for bacterial growth inhibition in combination with gentamicin and norfloxacin against multidrug-resistant strains of S. aureus (SA10) and E. coli (EC06), exhibiting synergistic effect with these antibiotics (p<0.0001). In the tests in vivo, EEFZJ was found to be nontoxic, performing reduced locomotor activity and demonstrated an anxiolytic-like effect in adult zebrafish via GABAergic and Serotoninergic systems (5-HT1, 5-HT2A/2C and 5-HT3A/3B).

Neuropharmacological Activities of Ceiba aesculifolia (Kunth) Britten & Baker f (Malvaceae).

Ceiba aesculifolia (Kunth) Britten & Baker f (Malvaceae) is used for the folk treatment of mood disorders. C. aesculifolia bark was extracted in ethanol, and the extract (CAE) was chemically standardized using gas chromatography-mass spectrometry (GC-MS). This study evaluated the effects of CAE (10-100 mg/kg p.o.) on anxiolytic-like activity, sedation, locomotor activity, depression-like activity, and spatial working memory using in vivo rodent models. A possible mechanism for the anxiolytic-like and antidepressant-like actions induced by CAE was assessed using neurotransmission pathway inhibitors. Myristic acid was one of the compounds found in CAE using GC-MS. This study also evaluated the anxiolytic-like activity and the sedative actions of myristic acid and assessed a possible mechanism of action using neurotransmission pathway inhibitors and an in silico analysis. CAE elicited anxiolytic-like activity and antidepressant-like effects (ED50 = 57 mg/kg). CAE (10-100 mg/kg) did not affect locomotor coordination or induce sedation. The anxiolytic-like and antidepressant-like actions of CAE were reverted by prazosin, suggesting a possible participation of the noradrenergic system. The anxiolytic-like activity of myristic acid was reverted by the co-administration of prazosin and partially reverted by ketanserin. The docking study revealed that myristic acid can form favorable interactions within 5-HT2A and α1A-adrenoreceptor binding pockets.

Neuropharmacological assessment in mice and molecular docking of piperazine derivative LQFM212.

Piperazine derivatives are an attractive class of chemical compounds for the treatment of various mental illness. Herein, we demonstrated the synthesis of LQFM212, a piperazine derivative, behavioral evaluation in mice and computational studies. In neuropharmacological assessment, LQFM212 treatment at doses of 18, 54 or 162 µmol/kg increased the sleep duration in sodium pentobarbital-induced sleep test. LQFM212 at dose of 162 µmol/kg increased climbing time in the chimney test and decreased the number of squares crossed in the open field test, suggesting that LQFM212 in high doses reduces spontaneous movement. However, LQFM212 treatment at the doses of 18 or 54 µmol/kg increased the preference for the center of field which could be indicative of anxiolytic-like effects. In elevated plus maze and light-dark box tests, LQFM212 treatment altered all parameters observed that demonstrate anxiolytic-like activity. These effects were reversed by flumazenil, mecamylamine, WAY-100635 and PCPA, but not with ketanserin, showing that anxiolytic-like activity involve benzodiazepine site of GABAA receptor, nicotinic and serotonergic pathways. Molecular docking of LQFM212 showed that the ligand has more interactions with GABAA receptor than with 5-HT1A receptor. Despite the involvement of benzodiazepine site on anxiolytic-like effect of LQFM212, treatment with this compound did not alter cognitive function in the step-down avoidance test. In this sense, this piperazine derivative is a good prototype for treating anxiety disorders with putative mechanism of action.

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

Anxiety disorders are common worldwide and novel compounds are investigated for anxiolytic effect. A few studies have demonstrated the anxiolytic-like activity of natural and synthetic flavonoids. 5-methoxyflavone, a synthetic flavone derivative, has been reported to exhibit central nervous system depressant (sedative-hypnotic) effect in an earlier study. The present study was designed to investigate whether 5-methoxyflavone possesses anxiolytic-like activity in mice by employing two unconditioned models of anxiety such as elevated plus maze and light-dark box test. The possible role played by GABAergic (GABAA) and serotonergic (5HT1A) systems in the anxiolytic-like effect of 5-methoxyflavone was also investigated in the elevated plus maze test. Molecular docking studies were performed to ascertain the interaction of 5-methoxyflavone with GABAA (α2 subunit-containing) and 5HT1A receptors. 5-methoxyflavone treatment in mice (10, 20 or 40 mg/kg, i.p) increased the number of entries and time spent in the open arms in an elevated plus maze (p < 0.001). In the light-dark box test a significant increase in the time spent in light compartment (p < 0.001) and prolonged latency to enter the dark compartment (p < 0.01) were also observed. Pretreatment of mice with 5HT1A antagonist pindolol (10 mg/kg, i.p) or GABAA antagonist bicuculline (2 mg/kg, i.p) significantly attenuated the effect of 5-methoxyflavone in the elevated plus maze test. In silico studies provided evidences for good binding affinity of 5-methoxyflavone towards GABAA (α2 subunit-containing) and serotonergic (5HT1A) receptors by H-bond interactions. In conclusion, the present study identified a novel anxiolytic-like effect of 5-methoxyflavone involving GABAergic and serotonergic mechanisms.

A new piperazine derivative: 1-(4-(3,5-di-tert-butyl-4-hydroxybenzyl) piperazin-1-yl)-2-methoxyethan-1-one with antioxidant and central activity.

In the scope of a research program aimed at developing new drugs for the treatment of central nervous system diseases, we describe herein the synthesis and pharmacological evaluation of 1-(4-(3,5-di-tert-butyl-4-hydroxybenzyl) piperazin-1-yl)-2-methoxyethan-1-one (LQFM180). This compound showed antioxidant activity in two models, electroanalytical assays, and DPPH activity. Moreover, in behavioral tests as the open field test LQFM180 (9.4, 18.8, and 37.6 mg/kg, per oral (p.o.)), we detected anxiolytic-like activity. In the sodium pentobarbital-induced sleep test, LQFM180, in all doses, decreased the latency to sleep and increased sleep duration, indicating central depressant activity; moreover, in the chimney test, LQFM180 did not alter motor activity. LQFM180 (18.8 mg/kg, p.o.) increased the time and number of entries on open arms in the elevated plus maze test, suggesting anxiolytic-like activity, which was reversed by NAN-190 and p-chlorophenylalanine, indicating a role of the serotonergic pathway on this effect. In the forced swimming test, LFQM180 (18.8 mg/kg, p.o.) decreased immobility time, suggesting antidepressant-like activity, which was reversed by monoaminergic antagonists, indicating a role for the serotonergic, noradrenergic, and dopaminergic pathways. Competition binding assays showed that LQFM180 was able to bind to the α1B, 5-HT1A, and D2 receptors, however, within the low micromolar range. We conclude that LQFM180 should be considered as a scaffold for drug candidate development.

Tert-butyl 4-((1-phenyl-1H-pyrazol-4-yl) methyl) piperazine-1-carboxylate (LQFM104)- New piperazine derivative with antianxiety and antidepressant-like effects: Putative role of serotonergic system.

The piperazine derivatives correspond to an extensive chemical class of compounds with numerous neuropharmacological activities, including antidepressant (e.g., nefazodone, trazodone) and anxiolytic (e.g., buspirone) properties. Therefore, aiming to identify a new antidepressant and antianxiety lead-compound, our group designed, synthesized, and investigated the effects of a new piperazine compound, namely, LQFM104, on the behavior of mice. Male albino Swiss mice were treated with LQFM104 prior to predictive behavioral tests as open field (OFT), elevated plus maze (EPM), forced swimming (FST), and tail suspension tests (TST). The participation of the serotonergic system was evaluated by pretreatment with a 5-HT1A antagonist receptor (WAY100635) and serotonin (5-HT) synthesis inhibitor (p-chlorphenylalanine, pCPA) before oral administration of LQFM104 and behavioral tests. The treatment with LQFM104 did not interfere with locomotor activity but revealed suggestive data of anxiolytic-like effects by the increase in the time spent in the center of the OFT. This activity was confirmed by the results obtained in the EPM, and it was abolished after pretreatment with WAY100635 and pCPA. The immobility time decreased in both the FST and TST. The antidepressant-like activity was completely abolished after WAY100635 pretreatment. Altogether, these data revealed that LQFM104 possesses anxiolytic and antidepressant-like properties in behavioral tests on mice, and these activities are possibly mediated, directly and/or indirectly, by serotonergic pathways.

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 (5HT1a) 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.

Search for new potential anticonvulsants with anxiolytic and antidepressant properties among derivatives of 4,4-diphenylpyrrolidin-2-one.

BACKGROUND: The aim of this study was to synthesize a series of new N-Mannich bases derived from 4,4-diphenylpyrrolidin-2-one having differently substituted 4-phenylpiperazines as potential anticonvulsant agents with additional (beneficial) pharmacological properties. METHODS: The target compounds 8-12 were prepared in one step from the 4-substituted phenylpiperazines, paraformaldehyde, and synthesized 4,4-diphenylpyrrolodin-2-one (7) by a Mannich-type reaction. The obtained compounds were assessed and tested for their anticonvulsant activity in two screening mouse models of seizures, i.e., the maximal electroshock (MES) test and in the subcutaneous pentylenetetrazole (scPTZ) test. The effect of these compounds on animals' motor coordination was measured in the rotarod test. A selected 4,4-diphenyl-1-((4-phenylpiperazin-1-yl)methyl)pyrrolidin-2-one (8) was evaluated in vivo for its anxiolytic- and antidepressant-like properties. Its impact on animals' locomotor activity was also evaluated. RESULTS: Compound 8 showed protection (25%) in the MES and in the scPTZ tests at the dose of 100mg/kg and was not neurotoxic. In the four-plate test, compound 8 at the dose of 30mg/kg showed a statistically significant (p<0.05) anxiolytic-like activity. In the forced swim test, it reduced the immobility time by 24.3% (significant at p<0.05), which indicates its potential antidepressant-like properties. In the locomotor activity test, compound 8 significantly reduced animals' locomotor activity by 79.9%. CONCLUSION: The results obtained make a new derivative of 4,4-diphenyl-1-((4-phenylpiperazin-1-yl)methyl)pyrrolidin-2-one (8) a promising lead structure for further development.

The anxiolytic-like activity of a novel N-cycloalkyl-N-benzoylpiperazine derivative.

BACKGROUND: Anxiety-related disorders are among the most common mental illnesses in the world for which benzodiazepines, buspirone and antidepressant drugs remain the first-line treatment. These drugs have good efficacy but they have numerous disadvantages, such as drug abuse potential, delayed onset of action or tolerance. A literature review reveals that a variety of piperazine derivatives may exhibit interesting pharmacological properties, including anxiolytic-like, antidepressant, nootropic and antinociceptive activities demonstrated in animal models, as well as an antioxidant capacity shown in some in vitro tests. Hence, the aim of this study was the synthesis and preliminary pharmacological in vivo evaluation of a novel N-cycloalkyl-N-benzoylpiperazine derivative, compound 9. METHODS: The test compound 9 was synthesized from a cyclic ketone 6,6-dimethylbicyclo[3.1.0]hexan-3-one (compound 7) and N-benzoylpiperazine. The final product was evaluated in vivo for its anxiolytic-like and antinociceptive activity after intraperitoneal (ip) administration. Its impact on animals' locomotor activity and motor performance was also evaluated. RESULTS: At the dose of 50mg/kg the test compound 9 showed statistically significant (p<0.01) anxiolytic-like activity in the four plate test. This effect was completely abolished by pretreatment with naloxone hydrochloride (1mg/kg; ip). Compound 9 did not influence animals' locomotor activity or motor coordination. No antinociceptive effect was demonstrated in the hot plate test. CONCLUSIONS: The anxiolytic-like properties of N-bicyclo-[3.1.0]hexyl derivative (9) in the four plate test are mediated by the opioid system. The results obtained make this compound a promising lead structure for further development of anxiolytic drugs.

Rubimetide, humanin, and MMK1 exert anxiolytic-like activities via the formyl peptide receptor 2 in mice followed by the successive activation of DP1, A2A, and GABAA receptors.

Rubimetide (Met-Arg-Trp), which had been isolated as an antihypertensive peptide from an enzymatic digest of spinach ribulose-bisphosphate carboxylase/oxygenase (Rubisco), showed anxiolytic-like activity prostaglandin (PG) D2-dependent manner in the elevated plus-maze test after administration at a dose of 0.1mg/kg (ip.) or 1mg/kg (p.o.) in male mice of ddY strain. In this study, we found that rubimetide has weak affinities for the FPR1 and FPR2, subtypes of formyl peptide receptor (FPR). The anxiolytic-like activity of rubimetide (0.1mg/kg, ip.) was blocked by WRW4, an antagonist of FPR2, but not by Boc-FLFLF, an antagonist of FPR1, suggesting that the anxiolytic-like activity was mediated by the FPR2. Humanin, an endogenous agonist peptide of the FPR2, exerted an anxiolytic-like activity after intracerebroventricular (icv) administration, which was also blocked by WRW4. MMK1, a synthetic agonist peptide of the FPR2, also exerted anxiolytic-like activity. Thus, FPR2 proved to mediate anxiolytic-like effect as the first example of central effect exerted by FPR agonists. As well as the anxiolytic-like activity of rubimetide, that of MMK1 was blocked by BW A868C, an antagonist of the DP1-receptor. Furthermore, anxiolytic-like activity of rubimetide was blocked by SCH58251 and bicuculline, antagonists for adenosine A2A and GABAA receptors, respectively. From these results, it is concluded that the anxiolytic-like activities of rubimetide and typical agonist peptides of the FPR2 were mediated successively by the PGD2-DP1 receptor, adenosine-A2A receptor, and GABA-GABAA receptor systems downstream of the FPR2.

Anxiolytic-like effect of danshensu [(3-(3,4-dihydroxyphenyl)-lactic acid)] in mice.

AIMS: Danshensu [3-(3,4-dihydroxyphenyl)-lactic acid], a phenylpropanoid compound isolated from Prunella vulgaris var. lilacina, is a well-known antioxidant. Although its antioxidant activity and cardioprotective effect have been reported, the pharmacological properties of danshensu in the central nervous system remain unclear. We investigated whether danshensu exerts anxiolytic-like activity in mice. MAIN METHODS: We conducted monoamine oxidase A (MAO-A) inhibition assay on danshensu in vitro, and behavioral tests including the elevated plus-maze test (EPM), the hole-board test, the rotarod test and the open field test were employed. KEY FINDINGS: We found that danshensu significantly inhibited the activity of MAO-A in vitro. The administration of danshensu (3 or 10mg/kg) produced a significant anxiolytic-like effect in the EPM and hole-board test. In addition, no changes in the spontaneous locomotor activity and no myorelaxant effects were observed compared to the control group; these effects were confirmed with the open field test and the rotarod test. Moreover, the anxiolytic-like properties of danshensu were antagonized by a dopamine D1 receptor antagonist (SCH 23390) but not by a 5-HT1A receptor antagonist (WAY 100635) or an α1-adrenergic receptor antagonist (prazosin). SIGNIFICANCE: These results indicate that danshensu exerts its anxiolytic-like properties, in part, through dopaminergic neurotransmitter signaling.

Identification of novel ß-lactoglobulin-derived peptides, wheylin-1 and -2, having anxiolytic-like activity in mice.

SCOPE: We found that thermolysin digest of ß-lactoglobulin, a major protein of bovine milk whey, exhibited anxiolytic-like activity in a behavioral experiment in mice, and then identified active components from the digest. METHODS AND RESULTS: In the elevated plus-maze test, thermolysin digest of ß-lactoglobulin had anxiolytic-like activity after intraperitoneal administration in mice. We identified several low-molecular-weight peptides in a fraction separated by reverse-phase HPLC having the most potent anxiolytic-like activities. Among them, Met-His and Met-Lys-Gly, corresponding to ß-lactoglobulin (145-146) and (7-9), had anxiolytic-like activity at a dose of 0.3-1 and 3 mg/kg, respectively, after intraperitoneal administration. We named Met-His and Met-Lys-Gly wheylin-1 and -2, respectively. Next, we focused on wheylin-1, a more potent peptide with anxiolytic-like activity than wheylin-2. Wheylin-1 (1 mg/kg) had anxiolytic-like activity after oral administration. In the open-field test, wheylin-1 was also active. The anxiolytic-like activity of wheylin-1 was blocked by bicuculline, an antagonist of γ-amino butyric acid type A (GABA(A)) receptor, suggesting that wheylin-1 exhibited anxiolytic-like activity via the GABA(A) system. CONCLUSION: Novel ß-lactoglobulin-derived peptides, wheylin-1 and -2, may exhibit anxiolytic-like activities.

The influence of ionotropic and metabotropic glutamate receptor ligands on anxiety-like effect of amphetamine withdrawal in rats.

Chronic amphetamine use results in anxiety-like states after drug cessation. The aim of the study was to determine a role of ionotropic and metabotropic glutamate receptor ligands in amphetamine-evoked withdrawal anxiety in the elevated plus-maze test in rats. In our study memantine (8 and 12 mg/kg), a noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist did not reduce amphetamine withdrawal anxiety. Acamprosate (NMDA and metabotropic glutamate 5 receptor (mGluR5) antagonist) at the dose 200 and 400mg/kg showed anxiolytic-like effect, thus increasing the percent of time spent in open arms and a number of open arm entries. mGluR5 selective antagonist, MTEP (3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine hydrochloride) and mGluR2/3 agonist, LY354740 (1S,2S,5R,6S)-2-aminobicyclo[3.1.0]hexane-2,6-dicarboxylic acid), caused effects similar to acamprosate at doses 1.25-5mg/kg and 2.5-5mg/kg, respectively. None of the glutamate ligands influenced locomotor activity of rats when given to the saline-treated group. Taking into account the positive correlation between amphetamine withdrawal-induced anxiety and relapse to amphetamine taking, our results suggest that modulation of mGluRs may prevent relapse to amphetamine and might pose a new direction in amphetamine abuse therapy.