WITHANICANDRIN ISOLATED FROM Datura Ferox PROMOTES ANTINOCICEPTION BY MODULATING THE ASICS AND TRPS CHANNELS AND ANTI-INFLAMMATION IN ADULT ZEBRAFISH.

This is the first study to analyze the anti-inflammatory and antinociceptive effect of withanicandrin, isolated from Datura Ferox leaves, and the possible mechanism of action involved in adult zebrafish (ZFa). To this end, the animals were treated intraperitoneally (i.p.) with withanicandrin (4; 20 and 40 mg/kg; 20 µL) and subjected to locomotor activity and acute toxicity. Nociception tests were also carried out with chemical agents, in addition to tests to evaluate inflammatory processes induced by κ-Carrageenan 1.5% and a Molecular Docking study. As a result, withanicandrin reduced nociceptive behavior by capsaicin at a dose of 40 mg/kg and by acid saline at doses of 4 and 40 mg/kg, through neuromodulation of TRPV1 channels and ASICs, identified through blocking the antinociceptive effect of withanicandrin by the antagonists capsazepine and naloxone. Furthermore, withanicandrin caused an anti-inflammatory effect through the reduction of abdominal edema, absence of leukocyte infiltrate in the liver tissue and reduction of ROS in thel liver tissue and presented better affinity energy compared to control morphine (TRPV1) and ibuprofen (COX-1 and COX-2).

Antimicrobial activity of hydralazine against methicillin-resistant and methicillin-susceptible Staphylococcus aureus.

Background: Staphylococcus aureus is a human pathogen responsible for high mortality rates. The development of new antimicrobials is urgent. Materials & methods: The authors evaluated the activity of hydralazine along with its synergism with other drugs and action on biofilms. With regard to action mechanisms, the authors evaluated cell viability, DNA damage and molecular docking. Results: MIC and minimum bactericidal concentration values ranged from 128 to 2048 µg/ml. There was synergism with oxacillin (50%) and vancomycin (25%). Hydralazine reduced the viability of biofilms by 50%. After exposure to hydralazine 2× MIC, 58.78% of the cells were unviable, 62.07% were TUNEL positive and 27.03% presented damage in the comet assay (p < 0.05). Hydralazine showed affinity for DNA gyrase and TyrRS. Conclusion: Hydralazine is a potential antibacterial.

Staphylococcus aureus is a bacterium that can cause infection. Infections of S. aureus are becoming difficult to treat, but developing new drugs is a challenge. Repurposing them may be easier. This study looks at the possibility of using hydralazine, a type of medicine used to treat high blood pressure, against S. aureus. The authors found that hydralazine can kill S. aureus and can be used with other antibiotics, including oxacillin and vancomycin. Hydralazine interferes with important processes for the multiplication and survival of this bacterium. These results are preliminary but encouraging. Further studies are needed to confirm the use of hydralazine as a new treatment for S. aureus infections.

Synthesis and anxiolytic effect of europium metallic complex containing lapachol [Eu(DBM)3. LAP] in adult zebrafish through serotonergic neurotransmission: in vivo and in silico approach.

Anxiety-related mental health problems are estimated at 3.6% globally, benzodiazepines (BZDs) are the class of drugs indicated for the treatment of anxiety, including lorazepam and diazepam. However, concerns have been raised about the short- and long-term risks associated with BZDs. Therefore, despite anxiolytic and antidepressant drugs, there is a need to develop more effective pharmacotherapies with fewer side effects than existing drugs. The present work reported the synthesis, anxiolytic activity, mechanism of action in Adult Zebrafish (Danio rerio) and in silico study of a europium metallic complex with Lapachol, [Eu(DBM)3. LAP]. Each animal (n = 6/group) was treated intraperitoneally (i.p.; 20 µL) with the synthesized complex (4, 20 and 40 mg/Kg) and with the vehicle (DMSO 3%; 20 µL), being submitted to the tests of locomotor activity and 96h acute toxicity. The light/dark test was also performed, and the serotonergic mechanism (5-HT) was evaluated through the antagonists of the 5-HTR1, 5-HTR2A/2C and 5-HTR3A/3B receptors. The complex was characterized using spectrometric techniques, and the anxiolytic effect of complex may be involved the neuromodulation of receptors 5-HT3A/3B, since the pre-treatment with pizotifen and cyproheptadine did not block the anxiolytic effect of [Eu(DBM)3. LAP], unlike fluoxetine had its anxiolytic effect reversed. In addition, molecular docking showed interaction between the [Eu(DBM)3. LAP] and 5HT3A receptor with binding energy -7.8 kcal/mol and the ADMET study showed that complex has low toxic risk. It is expected that the beginning of this study will allow the application of the new anxiolytic drugs, given the pharmacological potential of the lapachol complex.Communicated by Ramaswamy H. Sarma.

In Silico Study in MPO and Molecular Docking of the Synthetic Drynaran Analogues Against the Chronic Tinnitus: Modulation of the M1 Muscarinic Acetylcholine Receptor.

Tinnitus is a syndrome that affects the human auditory system and is characterized by a perception of sounds in the absence of acoustic stimuli, or in total silence. Research indicates that muscarinic acetylcholine receptors (mAChRs), especially the M1 type, have a fundamental role in the alterations of auditory perceptions of tinnitus. Here, a series of computer-aided tools were used, from molecular surface analysis software to services available on the web for estimating pharmacokinetics and pharmacodynamics. The results infer that the low lipophilicity ligands, that is, the 1a-d alkyl furans, present the best pharmacokinetic profile, as compounds with an optimal alignment between permeability and clearance. However, only ligands 1a and 1b have properties that are safe for the central nervous system, the site of cholinergic modulation. These ligands showed similarity with compounds deposited in the European Molecular Biology Laboratory chemical (ChEMBL) database acting on the mAChRs M1 type, the target selected for the molecular docking test. The simulations suggest that the 1 g ligand can form the ligand-receptor complex with the best affinity energy order and that, together with the 1b ligand, they are competitive agonists in relation to the antagonist Tiotropium, in addition to acting in synergism with the drug Bromazepam in the treatment of chronic tinnitus.

Potentiating-antibiotic activity and absorption, distribution, metabolism, excretion and toxicity properties (ADMET) analysis of synthetic thiadiazines against multi-drug resistant (MDR) strains.

BACKGROUND: Thiadiazines are heterocyclic compounds that contain two nitrogen atoms and one sulfur atom in their structure. These synthetic molecules have several relevant pharmacological activities, such as antifungal, antibacterial, and antiparasitic. OBJECTIVES: The present study aimed to evaluate the possible in vitro and in silico interactions of compounds derived from thiadiazines. METHODS: The compounds were initially synthesized, purified, and confirmed through HPLC methodology. Multi-drug resistant bacterial strains of Staphylococcus aureus 10 and Pseudomonas aeruginosa 24 were used to evaluate the direct and modifying antibiotic activity of thiadiazine derivatives. ADMET assays (absorption, distribution, metabolism, excretion, and toxicity) were conducted, which evaluated the influence of the compounds against thousands of macromolecules considered as bioactive targets. RESULTS: There were modifications in the chemical synthesis in carbon 4 or 3 in one of the aromatic rings of the structure where different ions were added, ensuring a variability of products. It was possible to observe results that indicate the possibility of these compounds acting through the cyclooxygenase 2 mechanism, which, in addition to being involved in inflammatory responses, also acts by helping sodium reabsorption. The amine group present in thiadiazine analogs confers hydrophilic characteristics to the substances, but this primary characteristic has been altered due to alterations and insertions of other ligands. The characteristics of the analogs generally allow easy intestinal absorption, reduce possible hepatic toxic effects, and enable possible neurological and anti-inflammatory action. The antibacterial activity tests showed a slight direct action, mainly of the IJ23 analog. Some compounds were able to modify the action of the antibiotics gentamicin and norfloxacin against multi-drug resistant strains, indicating a possible synergistic action. CONCLUSIONS: Among all the results obtained in the study, the relevance of thiadiazine analogs as possible coadjuvant drugs in the antibacterial, anti-inflammatory, and neurological action with low toxicity is clear. Need for further studies to verify these effects in living organisms is not ruled out.

Synthesis, structural, characterization, antibacterial and antibiotic modifying activity, ADMET study, molecular docking and dynamics of chalcone (E)-1-(4-aminophenyl)-3-(4-nitrophenyl)prop-2-en-1-one in strains of Staphylococcus aureus carrying NorA and MepA efflux pumps.

Chalcones have an open chain flavonoid structure that can be obtained from natural sources or by synthesis and are widely distributed in fruits, vegetables, and tea. They have a simple and easy to handle structure due to the α-ß-unsaturated bridge responsible for most biological activities. The facility to synthesize chalcones combined with its efficient in combating serious bacterial infections make these compounds important agents in the fight against microorganisms. In this work, the chalcone (E)-1-(4-aminophenyl)-3-(4-nitrophenyl)prop-2-en-1-one (HDZPNB) was characterized by spectroscopy and electronic methods. In addition, microbiological tests were performed to investigate the modulator potential and efflux pump inhibition on S. aureus multi-resistant strains. The modulating effect of HDZPNB chalcone in association with the antibiotic norfloxacin, on the resistance of the S. aureus 1199 strain, resulted in increase the MIC. In addition, when HDZPNB was associated with ethidium bromide (EB), it caused an increase in the MIC value, thus not inhibiting the efflux pump. For the strain of S. aureus 1199B, carrying the NorA pump, the HDZPNB associated with norfloxacin showed no modulatory, and when the chalcone was used in association with EB, it had no inhibitory effect on the efflux pump. For the tested strain of S. aureus K2068, which carries the MepA pump, it can be observed that the chalcone together the antibiotic resulted in an increase the MIC. On the other hand, when chalcone was used in association with EB, it caused a decrease in bromide MIC, equal to the reduction caused by standard inhibitors. Thus, these results indicate that the HDZPNB could also act as an inhibitor of the S. aureus gene overexpressing pump MepA. The molecular docking reveals that chalcone has a good binding energies -7.9 for HDZPNB/MepA complexes, molecular dynamics simulations showed that Chalcone/MetA complexes showed good stability of the structure in an aqueous solution, and ADMET study showed that the chalcone has a good oral bioavailability, high passive permeability, low risk of efflux, low clearance rate and low toxic risk by ingestion. The microbiological tests show that the chalcone can be used as a possible inhibitor of the Mep A efflux pump.Communicated by Ramaswamy H. Sarma.

Elongation on aliphatic chain improves selectivity of 2-hydroxy-3,4,6-trimethoxyphenyl chalcone on Trypanosoma cruzi.

Aim: Our objective was to investigate the trypanocidal effect of the chalcone (2E,4E)-1-(2-hydroxy-3,4,6-trimethoxyphenyl)-5-phenylpenta-2,4-dien-1-one (CPNC). Material & methods: Cytotoxicity toward LLC-MK2 host cells was assessed by MTT assay, and the effect on Trypanosoma cruzi life forms (epimastigotes, trypomastigotes and amastigotes) was evaluated by counting. Flow cytometry analysis was performed to evaluate the possible mechanisms of action. Finally, molecular docking simulations were performed to evaluate interactions between CPNC and T. cruzi enzymes. Results: CPNC showed activity against epimastigote, trypomastigote and amastigote life forms, induced membrane damage, increased cytoplasmic reactive oxygen species and mitochondrial dysfunction on T. cruzi. Regarding molecular docking, CPNC interacted with both trypanothione reductase and TcCr enzymes. Conclusion: CPNC presented a trypanocidal effect, and its effect is related to oxidative stress, mitochondrial impairment and necrosis.

Hellebrigenin triggers death of promyelocytic leukemia cells by non-genotoxic ways.

Bufadienolides are digitalis-like aglycones mainly found in skin secretions of toads. Among their biological properties, the mechanisms of antiproliferative action on tumor cells remain unclear for many compounds, including against leukemia cells. Herein, it was evaluated the mechanisms involved in the antiproliferative and genotoxic actions of hellebrigenin on tumor cell lines and in silico capacity to inhibit the human topoisomerase IIa enzyme. Firstly, its cytotoxic action was investigated by colorimetric assays in human tumor and peripheral blood mononuclear cells (PBMC). Next, biochemical and morphological studies were detailed by light microscopy (trypan blue dye exclusion), immunocytochemistry (BrdU uptake), flow cytometry and DNA/chromosomal damages (Cometa and aberrations). Finally, computational modelling was used to search for topoisomerase inhibition. Hellebrigenin reduced proliferation, BrdU incorporation, viability, and membrane integrity of HL-60 leukemia cells. Additionally, it increased G2/M arrest, internucleosomal DNA fragmentation, mitochondrial depolarization, and phosphatidylserine externalization in a concentration-dependent manner. In contrast to doxorubicin, hellebrigenin did not cause DNA strand breaks in HL-60 cell line and lymphocytes, and it interacts with ATPase domain residues of human topoisomerase IIa, generating a complex of hydrophobic and van der Waals interactions and hydrogen bonds. So, hellebrigenin presented potent anti-leukemic activity at concentrations as low as 0.06 µM, a value comparable to the clinical anticancer agent doxorubicin, and caused biochemical changes suggestive of apoptosis without genotoxic/clastogenic-related action, but it probably triggers catalytic inhibition of topoisomerase II. These findings also emphasize toad steroid toxins as promising lead antineoplasic compounds with relatively low cytotoxic action on human normal cells.

Evaluation of the antibacterial and inhibitory activity of the MepA efflux pump of Staphylococcus aureus by riparins I, II, III, and IV.

The efflux pump mechanism contributes to the antibiotic resistance of widely distributed strains of Staphylococcus aureus. Therefore, in the present work, the ability of the riparins N-(4-methoxyphenethyl)benzamide (I), 2-hydroxy-N-[2-(4-methoxyphenyl)ethyl]benzamide (II), 2, 6-dihydroxy-N-[ 2-(4-methoxyphenyl)ethyl]benzamide (III), and 3,4,5-trimethoxy-N-[2-(4-methoxyphenethyl)benzamide (IV) as potential inhibitors of the MepA efflux pump in S. aureus K2068 (fluoroquinolone-resistant). In addition, we performed checkerboard assays to obtain more information about the activity of riparins as potential inhibitors of MepA efflux and also analyzed the ability of riparins to act on the permeability of the bacterial membrane of S. aureus by the fluorescence method with SYTOX Green. A molecular coupling assay was performed to characterize the interaction between riparins and MepA, and ADMET (absorption, distribution, metabolism, and excretion) properties were analyzed. We observed that I-IV riparins did not show direct antibacterial activity against S. aureus. However, combination assays with substrates of MepA, ciprofloxacin, and ethidium bromide (EtBr) revealed a potentiation of the efficacy of these substrates by reducing the minimum inhibitory concentration (MIC). Furthermore, increased EtBr fluorescence emission was observed for all riparins. The checkerboard assay showed synergism between riparins I, II, and III, ciprofloxacin, and EtBr. Furthermore, riparins III and IV exhibited permeability in the S. aureus membrane at a concentration of 200 µg/mL. Molecular docking showed that riparins I, II, and III bound in a different region from the binding site of chlorpromazine (standard pump inhibitor), indicating a possible synergistic effect with the reference inhibitor. In contrast, riparin IV binds in the same region as the chlorpromazine binding site. From the in silico ADMET prediction based on MPO, it could be concluded that the molecules of riparin I-IV present their physicochemical properties within the ideal pharmacological spectrum allowing their preparation as an oral drug. Furthermore, the prediction of cytotoxicity in liver cell lines showed a low cytotoxic effect for riparins I-IV.

Antibacterial activity of menadione alone and in combination with oxacillin against methicillin-resistant Staphylococcus aureus and its impact on biofilms.

Introduction. Antibiotic resistance is a major threat to public health, particularly with methicillin-resistant Staphylococcus aureus (MRSA) being a leading cause of antimicrobial resistance. To combat this problem, drug repurposing offers a promising solution for the discovery of new antibacterial agents.Hypothesis. Menadione exhibits antibacterial activity against methicillin-sensitive and methicillin-resistant S. aureus strains, both alone and in combination with oxacillin. Its primary mechanism of action involves inducing oxidative stress.Methodology. Sensitivity assays were performed using broth microdilution. The interaction between menadione, oxacillin, and antioxidants was assessed using checkerboard technique. Mechanism of action was evaluated using flow cytometry, fluorescence microscopy, and in silico analysis.Aim. The aim of this study was to evaluate the in vitro antibacterial potential of menadione against planktonic and biofilm forms of methicillin-sensitive and resistant S. aureus strains. It also examined its role as a modulator of oxacillin activity and investigated the mechanism of action involved in its activity.Results. Menadione showed antibacterial activity against planktonic cells at concentrations ranging from 2 to 32 µg ml-1, with bacteriostatic action. When combined with oxacillin, it exhibited an additive and synergistic effect against the tested strains. Menadione also demonstrated antibiofilm activity at subinhibitory concentrations and effectively combated biofilms with reduced sensitivity to oxacillin alone. Its mechanism of action involves the production of reactive oxygen species (ROS) and DNA damage. It also showed interactions with important targets, such as DNA gyrase and dehydroesqualene synthase. The presence of ascorbic acid reversed its effects.Conclusion. Menadione exhibited antibacterial and antibiofilm activity against MRSA strains, suggesting its potential as an adjunct in the treatment of S. aureus infections. The main mechanism of action involves the production of ROS, which subsequently leads to DNA damage. Additionally, the activity of menadione can be complemented by its interaction with important virulence targets.

De novo design of bioactive phenol and chromone derivatives for inhibitors of Spike glycoprotein of SARS-CoV-2 in silico.

This work presents the synthesis of 12 phenol and chromone derivatives, prepared by the analogs, and the possibility of conducting an in silico study of its derivatives as a therapeutic alternative to combat the SARS-CoV-2, pathogen responsible for COVID-19 pandemic, using its S-glycoprotein as a macromolecular target. After the initial screening for the ranking of the products, it was chosen which structure presented the best energy bond with the target. As a result, derivative 4 was submitted to a molecular growth study using artificial intelligence, where 8436 initial structures were obtained that passed through the interaction filters and similarity to the active glycoprotein pocket through the MolAICal computational package. Thus, 557 Hits with active configuration were generated, which is very promising compared to the BLA reference link for inhibiting the biological target. Molecular dynamics also simulated these compounds to verify their stability within the active protein site to seek new therapeutic propositions to fight against the pandemic. The Hit 48 and 250 are the most active compounds against SARS-CoV-2. In summary, the results show that the Hit 250 would be more active than the natural compound, which could be further developed for further testing against SARS-CoV-2. The study employs the de novo approach to design new drugs, combining artificial intelligence and molecular dynamics simulations to create efficient molecular structures. This research aims to contribute to the development of effective therapeutic strategies against the pandemic.

Heterocyclic chalcone (E)-1-(2-hydroxy-3,4,6-trimethoxyphenyl)-3-(thiophen-2-yl) prop-2-en-1-one derived from a natural product with antinociceptive, anti-inflammatory, and hypoglycemic effect in adult zebrafish.

Diabetes is a disease linked to pathologies, such as chronic inflammation, neuropathy, and pain. The synthesis by the Claisen-Schmidt condensation reaction aims to obtain medium to high yield chalconic derivatives. Studies for the synthesis of new chalcone molecules aim at the structural manipulation of aromatic rings, as well as the replacement of rings by heterocycles, and combination through chemical reactions of synthesized structures with other molecules, in order to enhance biological activity. A chalcone was synthesized and evaluated for its antinociceptive, anti-inflammatory and hypoglycemic effect in adult zebrafish. In addition to reducing nociceptive behavior, chalcone (40 mg/kg) reversed post-treatment-induced acute and chronic hyperglycemia and reduced carrageenan-induced abdominal edema in zebrafish. It also showed an inhibitory effect on NO production in J774A.1 cells. When compared with the control groups, the oxidative stress generated after chronic hyperglycemia and after induction of abdominal edema was significantly reduced by chalcone. Molecular docking simulations of chalcone with Cox -1, Cox-2, and TRPA1 channel enzymes were performed and indicated that chalcone has a higher affinity for the COX-1 enzyme and 4 interactions with the TRPA1 channel. Chalcone also showed good pharmacokinetic properties as assessed by ADMET. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03696-8.

Screening of Potential Inhibitors Targeting the Main Protease Structure of SARS-CoV-2 via Molecular Docking, and Approach with Molecular Dynamics, RMSD, RMSF, H-Bond, SASA and MMGBSA.

Severe Acute Respiratory Syndrome caused by a coronavirus is a recent viral infection. There is no scientific evidence or clinical trials to indicate that possible therapies have demonstrated results in suspected or confirmed patients. This work aims to perform a virtual screening of 1430 ligands through molecular docking and to evaluate the possible inhibitory capacity of these drugs about the Mpro protease of Covid-19. The selected drugs were registered with the FDA and available in the virtual drug library, widely used by the population. The simulation was performed using the MolAiCalD algorithm, with a Lamarckian genetic model (GA) combined with energy estimation based on rigid and flexible conformation grids. In addition, molecular dynamics studies were also performed to verify the stability of the receptor-ligand complexes formed through analyses of RMSD, RMSF, H-Bond, SASA, and MMGBSA. Compared to the binding energy of the synthetic redocking coupling (-6.8 kcal/mol/RMSD of 1.34 Å), which was considerably higher, it was then decided to analyze the parameters of only three ligands: ergotamine (-9.9 kcal/mol/RMSD of 2.0 Å), dihydroergotamine (-9.8 kcal/mol/RMSD of 1.46 Å) and olysio (-9.5 kcal/mol/RMSD of 1.5 Å). It can be stated that ergotamine showed the best interactions with the Mpro protease of Covid-19 in the in silico study, showing itself as a promising candidate for treating Covid-19.

Antimicrobial, Antibiofilm Activities and Synergic Effect of Triterpene 3ß,6ß,16ß-trihydroxyilup-20(29)-ene Isolated from Combretum leprosum Leaves Against Staphylococcus Strains.

Antimicrobial resistance is a natural phenomenon and is becoming a huge global public health problem, since some microorganisms not respond to the treatment of several classes of antibiotics. The objective of the present study was to evaluate the antibacterial, antibiofilm, and synergistic effect of triterpene 3ß,6ß,16ß-trihydroxyilup-20(29)-ene (CLF1) against Staphylococcus aureus and Staphylococcus epidermidis strains. Bacterial susceptibility to CLF1 was evaluated by minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assay. In addition, the effect combined with antibiotics (ampicillin and tetracycline) was verified by the checkerboard method. The biofilms susceptibility was assessed by enumeration of colony-forming units (CFUs) and quantification of total biomass by crystal violet staining. The compound showed bacteriostatic and bactericidal activity against all Staphylococcal strains tested. The synergistic effect with ampicillin was observed only for S. epidermidis strains. Moreover, CLF1 significantly inhibited the biofilm formation and disrupted preformed biofilm of the all strains. Scanning electron microscopy (SEM) images showed changes in the cell morphology and structure of S. aureus ATCC 700698 biofilms (a methicillin-resistant S. aureus strain). Molecular docking simulations showed that CLF1 has a more favorable interaction energy than the antibiotic ampicillin on penicillin-binding protein (PBP) 2a of MRSA, coupled in different regions of the protein. Based on the results obtained, CLF1 proved to be a promising antimicrobial compound against Staphylococcus biofilms.

Indole Alkaloids of Rauvolfia ligustrina and Their Anxiolytic Effects in Adult Zebrafish.

Rauvolfia species are well known as producers of bioactive monoterpene indole alkaloids, which exhibit a broad spectrum of biological activities. A new vobasine-sarpagan-type bisindole alkaloid (1: ) along with six known monomeric indoles (2, 3/4, 5: , and 6/7: ) were isolated from the ethanol extract of the roots of Rauvolfia ligustrina. The structure of the new compound was elucidated by interpretation of their spectroscopic data (1D and 2D NMR and HRESIMS) and comparison with published data for analog compounds. The cytotoxicity of the isolated compounds was screened in a zebrafish (Danio rerio) model. The possible GABAergic (diazepam as the positive control) and serotoninergic (fluoxetine as the positive control) mechanisms of action in adult zebrafish were also evaluated. No compounds were cytotoxic. Compound 2: and the epimers 3: /4: and 6: /7: showed a mechanism action by GABAA, while compound 1: showed a mechanism action by a serotonin receptor (anxiolytic activity). Molecular docking studies showed that compounds 2: and 5: have a greater affinity by the GABAA receptor when compared with diazepam, whereas 1: showed the best affinity for the 5HT2AR channel when compared to risperidone.

Isolation, characterization and in silico study of propenamide alkaloids from Hymenoepmecis bicolor poison against active µ-opioid receptor.

Some insects produce venoms to defend against predators and directly interact with opioid receptors. In the present study, it was identified two alkaloids in the wasp venom species Hymenoepimecis bicolor. It was demonstrated that these could act as potential inhibitors of opioid receptors through their robust affinity to the receptors. The interaction profile was given to opioid receptors (µOR), with 60% of targets similar to alkaloid 1, with 0.25 probability, and 46.7% of targets similar to alkaloid 2, with a probability 0.17 of affinity as a target, which is considered signaling macromolecules and can mediate the most potent analgesic and addictive properties of opiate alkaloids. Notably, both alkaloids showed -7.6 kcal/mol affinity to the morphine agonies through six residues, Gly124, Asp147, Trp293, Ile296, Ile322, and Tyr326. These observations suggest further research on opioid receptors using in vitro studies of possible therapeutic applications.Communicated by Ramaswamy H. Sarma.

Sertraline has in vitro activity against both mature and forming biofilms of different Candida species.

Candida spp. infections are a serious health problem, especially in patients with risk factors. The acquisition of resistance, often associated with biofilm production, makes treatment more difficult due to the reduced effectiveness of available antifungals. Drug repurposing is a good alternative for the treatment of infections by Candida spp. biofilms. The present study evaluated the in vitro antibiofilm activity of sertraline in reducing the cell viability of forming and matured biofilms, in addition to elucidating whether effective concentrations are safe. Sertraline reduced biofilm cell viability by more than 80 % for all Candida species tested, acting at low and safe concentrations, both on mature biofilm and in preventing its formation, even the one with highest virulence. Its preventive mechanism seemed to be related to binding with ALS3. These data indicate that sertraline is a promising drug with anticandidal biofilm potential in safe doses. However, further studies are needed to elucidate the antibiofilm mechanism and possible application of pharmaceutical forms.

Anxiolytic and anticonvulsant effect of Ibuprofen derivative through GABAergic neuromodulation in adult Zebrafish.

Anxiety and epilepsy affect millions of people worldwide, and the treatment of these pathologies involves the use of Benzodiazepines, drugs that have serious adverse effects such as dependence and sedation, so the discovery of new anxiolytic and antiepileptic drugs are necessary. Many routes for synthesizing ibuprofen derivatives have been developed, and these derivatives have shown promising pharmacological effects. Therefore, this study aims to evaluate its anxiolytic and anticonvulsant effect against the adult Zebrafish animal model of Ibuprofen (IBUACT) and its interaction with the GABAergic receptor through in silico studies. The light/dark preference test (Scototaxis test) was used to evaluate the anxiolytic behavior of adult Zebrafish acutely treated with IBUACT and Diazepam, and their anticonvulsant effects were investigated through the pentylenetetrazol (PTZ)-induced seizure model. Animals treated with IBUACT showed anxiolytic behavior similar to Diazepam, and pretreatment with flumazenil reversed this behavior. PTZ-induced seizures were delayed by IBUACT in all three stages and were shown to bind strongly in the Diazepam region of GABAA. In addition, this work presents evidence of new pharmacological applications of ibuprofen derivative in pathologies of the central nervous system (CNS), opening the horizon for new studies.Communicated by Ramaswamy H. Sarma.

Naphthoquinones biflorin and bis-biflorin (Capraria biflora) as possible inhibitors of the fungus Candida auris polymerase: molecular docking, molecular dynamics, MM/GBSA calculations and in silico drug-likeness study.

A new worldwide concern has emerged with the recent emergence of infections caused by Candida auris. This reflects its comparative ease of transmission, substantial mortality, and the increasing level of resistance seen in the three major classes of antifungal drugs. Efforts to create a better design for structure-based drugs that described numerous modifications and the search for secondary metabolic structures derived from plant species are likely to reduce the virulence of several fungal pathogens. In this context, the present work aimed to evaluate in silico two naphthoquinones isolated from the roots of Capraria biflora, biflorin, and its dimmer, bis-biflorin, as potential inhibitors of Candida auris polymerase. Based on the simulation performed with the two naphthoquinones, biflorin and bis-biflorin, it can be stated that bis-biflorin showed the best interactions with Candida auris polymerase. Still, biflorin also demonstrated favorable coupling energy. Predictive pharmacokinetic assays suggest that biflorin has high oral bioavailability and more excellent metabolic stability compared to the bis-biflorin analogue. constituting a promising pharmacological tool.Communicated by Ramaswamy H. Sarma.

GABAA and serotonergic receptors participation in anxiolytic effect of chalcones in adult zebrafish.

The prevalence of anxiety is a significant public health problem, being the 24th leading cause of disability in individuals affected by this disorder. In this context, chalcones, a flavonoid subclass obtained from natural or synthetic sources, interact with central nervous system (CNS) receptors at the same binding site as benzodiazepines, the primary drugs used in the treatment of anxiety. Thus, our study investigates the anxiolytic effect of synthetic chalcones derived from the natural product 2-hydroxy-3,4,6-trimethoxyacetophenone isolated from Croton anisodontus Müll.Arg. in modulating anxiolytic activity via GABAergic and serotoninergic neurotransmission in an adult zebrafish model. Chalcones 1 and 2 were non-toxic to adult zebrafish and showed anxiolytic activity via GABAA receptors. Chalcone 2 also had its anxiolytic action reversed by the antagonist granisetron, indicating the participation of serotonergic receptors 5HTR3A/3B in the anxiolytic effect. In addition, molecular docking results showed that chalcones have a higher affinity for the GABAA receptor than DZP and binding in the same region of the DZP binding site, indicating a similar effect to the drug. Furthermore, the interaction of chalcones with GABAA and 5-HT3A receptors demonstrates the anxiolytic effect potential of these molecules.Communicated by Ramaswamy H. Sarma.