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.

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.

Hypoglycemic and hepatoprotective effects in adult zebrafish (Danio rerio) of fisetinidol isolated from Bauhinia pentandra: In vivo and in silico assays.

Diabetes mellitus is a chronic metabolic disorder that has been increasing drastically around the worldwide. It is important to emphasize that although many drugs are commercially available to treat diabetes, many of them have shown a number of adverse effects. Therefore, search for new antidiabetic agents is of great interest, and natural products, especially those obtained from plants sources, may be an alternative to available drugs. This study reports the in vivo and in silico evaluation of the hypoglycemic activity of fisetinidol. The conformational analysis confirmed that the fisetinidol compound possesses two valleys in the potential energy curve, showing a stable conformer on the global minimum of the PES defined by the dihedral angle θ (C6-C7-O-H) at 179.9°, whose energy is equal to zero. In addition, fisetinidol has shown promise in glycemic control and oxidative stress caused by hyperglycemia induced by high sucrose concentration, causing hypoglycemic and hepatoprotective effects in adult zebrafish. ADMET studies showed that fisetinidol has high passive permeability, low clearance and low toxic risk by ingestion, and computational studies demonstrated that fisetinidol complexes in the same region as metformin and α-acarbose, which constitutes a strong indication that fisetinidol has the same inhibitory mechanisms of α-acarbose and metformin.Communicated by Ramaswamy H. Sarma.

Codium isthmocladum lectin 1 (CiL-1): Interaction with N-glycans explains antinociceptive and anti-inflammatory activities in adult zebrafish (Danio rerio).

Inflammation and oxidative stress are processes associated with different human diseases. They are treated using drugs that have several side effects. Seaweed are sources of potentially relevant natural compounds for use as treatment of these disorders. Lectins are able to reversibly interact with complex carbohydrates and modulate cell membrane glycosylated receptors through this interaction. This study aimed to determine the antinociceptive and anti-inflammatory potential of CiL-1 in adult zebrafish by modulation of TRPA1 through lectin-glycan binding. Possible neuromodulation by TRPA1 channel was also evaluated by camphor pretreatment. CiL-1 was efficacious at all tested doses, revealing anti-nociceptive and anti-inflammatory effects in adult zebrafish. This galactose-binding lectin was also able to reduce the content of ROS in brain and liver. In silico analyses showed CiL-1 interactions with both ligands tested. LacNac2 presents the most favorable binding energy with the protein. The interaction occurs at 4 subsites as an extended conformation at the site. LacNac2-Sia had a less favorable curved-shape interaction energy. Based on the predictions made for the oligosaccharides, a tetra-antenate putative glycan was schematically constructed, illustrating an interaction between TRPA1 N-glycan and CiL-1. This binding seems to be related to CiL-1 anti-inflammatory activity as result of receptor modulation.

Antinociceptive, anti-inflammatory and hypoglycemic activities of the ethanolic Turnera subulata Sm. flower extract in adult zebrafish (Danio rerio).

Turnera subulata Sm. belongs to the family Turneraceae and is found in Brazil. The present study evaluated the antinociceptive, anti-inflammatory, and hypoglycemic potential of T. subulata flower extract (EtFloTsu) in zebrafish (Danio rerio). The total phenol and flavonoid contents of EtFloTsu were determined and identified using the Folin Ciocalteu reagent and aluminum chloride (AlCl3), respectively. The constituents of the extract were identified by HPLC-DAD, and the in vitro antioxidant activity (DPPH) was determined, toxicity in brine shrimp, and acute toxicity of 96 h in adult zebrafish. In addition, adult zebrafish (n = 6/fish) were treated orally with EtFloTsu (4, 20, or 40 mg/kg; vo) and subjected to formalin-induced nociception tests (with its possible mechanism of action with camphor), carrageenan-induced inflammation, and D-glucose-induced hyperglycemia (111 mM). Oxidative stress in the liver and brain tissues was assessed. EtFloTsu showed high levels of phenolic and flavonoid compounds with antioxidant activity. The phytochemicals chlorogenic acid, luteolin-7-o-glucoside, vitexin, and apigenin-7-o-glucoside were also identified in EtFloTsu. The synergism between these constituents was possibly responsible for the antinociceptive (via TRPA1), anti-inflammatory, and hypoglycemic effects of EtFloTsu in adult zebrafish, without causing toxicity in animals. Therefore, T. subulata flowers have therapeutic agents that could treat pain, inflammation, diabetes, and related complications.Communicated by Ramaswamy H. Sarma.

Metabolic profile of pitaya (Hylocereus polyrhizus (F.A.C. Weber) Britton & Rose) by UPLC-QTOF-MSE and assessment of its toxicity and anxiolytic-like effect in adult zebrafish.

Pitaya is a Cactacea with potential for economic exploitation, due to its high commercial value and its functional components - such betalains, oligosaccharides and phenolic compounds. Although the biological activities of pitaya have been studied using in vivo and in vitro models (anti-inflammatory and antiproliferative activities, as example), its anxiolytic-like effect is still unexplored. Therefore, the aim of this work was to perform a characterization of pulp and peel of pitaya (Hylocereus polyrhizus (F.A.C. Weber) Britton & Rose) using UPLC-QTOF-MSE, and to assess its toxicity and anxiolytic-like effect in adult zebrafish (Danio rerio). The results showed 16 and 15 compounds (in pulp and peel, respectively), including maltotriose, quercetin-3-O-hexoside, and betalains, putatively identified by UPLC-QTOF-MSE. Thus, pitaya pulp and peel showed no toxicity in both models tested (Vero cell lines and zebrafish model, LC50 ˃ 1 mg/mL); and a significant anxiolytic activity, since the treated fish reduced the permanence in the clear zone (Light & Dark Test) compared to that in the control, exhibiting anxiolytic-simile effect of diazepam. However, these effects were reduced by pre-treatment with the flumazenil suggesting that the pulp and peel of pitaya are anxiolytics agents mediated via the GABAergic system. These findings suggested that H. polyrizhus has the potential of developing an alternative plant-derived anxiolytic therapy. In addition, pitaya peel (which is a waste in the food industry) should be regarded as a valuable product, which has the potential as an economic value-added ingredient for anxiety disorders.

Serratia marcescens resistance profile and its susceptibility to photodynamic antimicrobial chemotherapy.

BACKGROUND: Some authors have reported the antimicrobial action of photodynamic antimicrobial chemotherapy (PACT) on bacteria related to nosocomial infections but there are few studies evaluating PACT on Serratia marcescens grown as planktonic cultures or as biofilms. The purpose of this study was to analyze the S. marcescens resistance profile and its susceptibility to PACT. METHODS: Initially, 55 S. marcescens strains isolated from environmental, oral and extra-oral infections were tested by antimicrobial resistance to cefotaxime (CTX), imipenem (IPM), ciprofloxacin (CIP), tobramycin (TOB) and doxycycline (DOX) using E-test(®). Following, isolates grown as planktonic cultures or biofilms were submitted to PACT using the association of a light-emitting diode and toluidine blue (TBO). The E-test(®) results demonstrated intermediated sensitive strains to CTX, IMP, TOB, and DOX; and resistant strains to CTX, TOB, DOX and CIP. Also, CTX and IMP demonstrated variation when CLSI 2007 and CLSI 2015 were compared. RESULTS: Planktonic cultures and biofilms submitted to PACT demonstrated counts varying from 10(11) to 10(7) for planktonic cultures and 10(10) to 10(7) for biofilms. There were no statistical differences in the results when planktonic cultures and biofilms were compared. CONCLUSIONS: Increase in the profile of S. marcescens resistance was observed when CLSI 2007 and CLSI 2015 were compared. Also, IMP remains as the drug with lower rate of resistance. Additionally, both S. marcescens planktonic cultures and early biofilms are susceptible to PACT under tested conditions.

Real time PCR and importance of housekeepings genes for normalization and quantification of mRNA expression in different tissues

The aim of this review was to evaluate the importance of the real-time PCR (qRT-PCR) as a technique for mRNA expression analysis in different tissues. Real-time PCR is widely used for quantification of mRNA levels and is a fundamental tool for basic research, molecular medicine and biotechnology.Genes of references are expressed in a wide variety of tissues and cells with minimal variations in their expression levels, and thus are used to normalize data of mRNA quantification. Software programs, such as geNorm, BestKeeper and NormFinder, have been developed to perform the normalization of data, which help to choose the most stable reference gene. Several genes, such as GAPDH, β-actin, β-tubulin, PGK, UBQ, RPL-19 and 18S rRNA have been suggested as standards in PCR studies, but these genes can have variation in their expression in different tissues, reinforcing the idea that there is no ideal reference gene.