Effect of the Combination of Synthetic Anthelmintics with Carvacryl Acetate in Emulsions with and without a Sodium Alginate Matrix on Haemonchus contortus.

The present study aimed to evaluate the effect of nanoemulsions using combined synthetic anthelmintics, thiabendazole (TBZ), levamisole (LEV), and ivermectin (IVM), with carvacryl acetate (CA) against Haemonchus contortus, and also tested the presence and absence of alginate (ALG). The anthelmintic effect of the CA/TBZ nanoemulsion was evaluated in the egg hatch test (EHT). The effects of CA/IVM and CA/LEV nanoemulsions were evaluated in the larval development test (LDT). The emulsions CA/TBZ/ALG and CA/TBZ showed a multimodal profile, with most particles on the nanometric scale. The encapsulation efficiency in CA/TBZ/ALG was 80.25%, and that in CA/LEV/ALG was 89.73%. In the EHT, CA/TBZ and CA/TBZ/ALG showed mean combination indices (CIs) of 0.55 and 0.36, respectively, demonstrating synergism in both. In LDT, CA/IVM had an average CI of 0.75, and CA/LEV and CA/LEV/ALG showed CI values of 0.4 and 0.93, respectively. It was concluded that CA/TBZ showed a synergistic interaction, and CA/TBZ/ALG showed an enhanced effect. In addition, the matrix brought stability to the product, encouraging its improvement to obtain higher efficacy.

Structure-based virtual screening of mangiferin derivatives with antidiabetic action: a molecular docking and dynamics study and MPO-based drug-likeness approach.

Extracts from Mangifera indica leaves and its main component, mangiferin, have proven antidiabetic activity. In this study, mangiferin and its natural derivatives Homomangiferin (HMF), Isomangiferin (IMF), Neomangiferin (NMF), Glucomangiferin (GMF), Mangiferin 6'-gallate (MFG), and Norathyriol (NRT) were compared regarding their action on Diabetes mellitus (DM), employing docking and molecular dynamics (MD) simulations to analyze interactions with the aldose reductase enzyme, the precursor to the conversion of glucose into sorbitol. Notably, HMF showed significant affinity to residues in the active site of the enzyme, including Trp 79, His 110, Trp 111, Phe 122, and Phe 300, with an energy of - 7.2 kcal/mol, observed in the molecular docking simulations. MD reinforced the formation of stable complexes for HMF and MFG with the aldose reductase, with interaction potential energies (IPE) in the order of - 300.812 ± 52 kJ/mol and - 304.812 ± 52 kJ/mol, respectively. The drug-likeness assessment, by multiparameter optimization (MPO), highlighted that HMF and IMF have similarities with polyphenols and glycosidic flavonoids recently patented as antidiabetics, revealing that high polarity (TPSA > 180 Å2) is a favorable property for subcutaneous administration, especially because of the gradual passive cell permeability values in biological tissues, with Papp values estimated at < 10 × 10-6 cm/s. These compounds are metabolically stable against metabolic enzymes, resulting in a low toxic incidence by metabolic activation, corroborating with a lethal dose (LD50) greater than 2000 mg/kg. In this way, HMF showed a systematic alignment between predicted pharmacokinetics and pharmacodynamics, characterizing it as the most favorable substance for inhibiting aldose reductase. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-03978-9.

Potential of the Blue Calm® food supplement in the treatment of alcohol withdrawal-induced anxiety in adult zebrafish (Danio rerio).

Alcohol use disorder (AUD) is characterized by a set of behavioral, cognitive, nutritional, and physiological phenomena derived from the uncontrolled use of alcoholic beverages. There are cases in which AUD is associated with anxiety disorder, and when untreated, it requires careful pharmacotherapy. Blue Calm® (BC) is a food supplement indicated to aid restorative sleep, which has traces of medicinal plant extracts, as well as myo-inositol, magnesium bisglycinate, taurine, and L-tryptophan as its main chemical constituents. In this context, this study aimed to evaluate the potential of the BC in the treatment alcohol withdrawal-induced anxiety in adult zebrafish (aZF). Initially, BC was submitted to antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl radical. Subsequently, the aZF (n = 6/group) were treated with BC (0.1 or 1 or 10 mg/mL; 20 µL; p.o.), and the sedative effect and acute toxicity (96 h) were evaluated. Then, the anxiolytic-like effect and the possible GABAergic mechanism were analyzed through the Light & Dark Test. Finally, BC action was evaluated for treating alcohol withdrawal-induced anxiety in aZF. Molecular docking was performed to evaluate the interaction of the major chemical constituents of BC with the GABAA receptor. BC showed antioxidant potential, a sedative effect, was not toxic, and all doses of BC had an anxiolytic-like effect and showed potential for the treatment of alcohol withdrawal-induced anxiety in aZF. In addition to the anxiolytic action, the main chemical constituents of BC were confirmed in the molecular docking, thus suggesting that BC is an anxiolytic that modulates the GABAergic system and has pharmacological potential for the treatment of alcohol withdrawal-induced anxiety.

Chemical Characterization, Phenolic Compounds Quantification, and Assessment of Antioxidant and Anti-Acetylcholinesterase Activities of Byrsonima sericea DC fruits.

Byrsonima sericea is a species native to Brazil that is widely used in traditional medicine. The seed ethanol extract (SEE) had the highest content of total phenols (179.35 mg GAE g-1 extract) and flavonoids (10.42 mg QE g-1 extract) and was the most active in relation to antioxidant activity (DPPH: IC50 =4.25 µg mL-1 and ABTS: IC50 =4.82 µg mL-1 ). The peel/pulp ethanol extract (PEE) had the best anticholinesterase activity (IC50 =6.02 µg mL-1 ). Chromatographic investigation identified gallic acid, isoquercitrin, quercetin and amentoflavone in SEE, and gallic acid, isoquercitrin, quercetin and rutin in PEE. Six fatty acid methyl esters and seven triterpenes were identified, highlighting oleic acid in the seed hexane extract (61.85 %) and in the peel/pulp hexane extract (52.61 %), and betulin in the peel/pulp hexane extract (5.25 %). The substances and biological activities identified in B. sericea characterize this fruit as a functional food for future studies.

Byrsonima sericea Ethanol Extract Protected PC12 Cells from the Oxidative Stress and Apoptosis Induced by 6-Hydroxydopamine.

Parkinson's disease is characterized by the progressive loss of dopaminergic neurons in the nigrostriatal pathway and oxidative stress is one of the main mechanisms that lead to neuronal death in this disease. Previous studies have shown antioxidant activity from the leaves of Byrsonima sericea, a plant of the Malpighiaceae family. This study aimed to evaluate the cytoprotective activity of the B. sericea ethanolic extract (BSEE) against the cytotoxicity induced by 6-hydroxydopamine (6-OHDA) in PC12 cells, an in vitro model of parkinsonism. The identification of phenolic compounds in the extract by HPLC-DAD revealed the presence of geraniin, rutin, isoquercetin, kaempferol 3-O-ß-rutinoside, and quercetin. The BSEE (75-300 µg/mL) protected PC12 cells from toxicity induced by 6-OHDA (25 µg/mL), protected cell membrane integrity and showed antioxidant activity. BSEE was able to decrease nitrite levels, glutathione depletion, and protect cells from 6-OHDA-induced apoptosis. Thus, we suggest that the BSEE can be explored as a possible cytoprotective agent for Parkinson's disease due to its high antioxidant capacity and anti-apoptotic action.

Combinations of amitraz with essential oils from Lippia sidoides and Thymus vulgaris, thymol and thymol acetate for Rhipicephalus microplus control: studies under laboratory and field conditions.

This study aimed to assess the effect of combining amitraz with essential oils (EOs) from Thymus vulgaris and Lippia sidoides, as well as the monoterpenes thymol and thymol acetate, on Rhipicephalus microplus in laboratory conditions, and to select the most effective combination for testing in field conditions. The chemical analysis showed that EOs were mainly composed of monoterpenes, with thymol and p-cymene as the major compounds. In larval (LIT) and adult (AIT) immersion tests using different concentrations of the oils and terpenes mixed with amitraz, the results showed that both EOs and thymol improved the efficacy of amitraz against larvae and engorged females of R. microplus, whereas thymol acetate only enhanced activity against larvae. The most favorable outcome was obtained with the EO of L. sidoides combined with amitraz, resulting in 99 % and 100 % efficacy against larvae and engorged females, respectively. Furthermore, the combination of amitraz with thymol showed presented an efficacy of 94 % and 91 % against larvae and engorged females, respectively. Thus, for the other tests, the combination of thymol + amitraz was chosen due to the ease of working with pure thymol in bioassays, and easier standardization. The immersion test (thymol + amitraz) with semi-engorged females showed 100 % efficacy for the combination of thymol + amitraz, while in tests with different solvents (thymol + amitraz), ethanol being the most effective solvent among those tested (ethanol, Triton, and Tween), resulting in 95 % efficacy on engorged females. In the field test, in treatments with amitraz and thymol + amitraz, efficacy of 54 % and 74 % was observed on day + 3 and 33 % and 43 % on day + 7, respectively. Assessing the reproductive biology of females recovered from animals treated with amitraz or amitraz + thymol, in day + 7, efficacies of 33 % and 52 %, respectively, were observed. EOs from T. vulgaris and L. sidoides and thymol improved the acaricidal activity of amitraz on larvae and engorged females of R. microplus under laboratory conditions, while thymol acetate only enhanced activity against larvae. Thymol increased the efficacy of amitraz under field conditions, however for the development of a commercially available acaricide to R. microplus control, additional studies are needed to increase the efficacy. Further research is needed (by changing concentrations, adding other compounds and/or developing formulations) to increase acaricidal efficacy and develop new effective products to combat R. microplus infestations in cattle.

In vitro antiviral effect of ethanolic extracts from Azadirachta indica and Melia azedarach against goat lentivirus in colostrum and milk.

This study aimed to evaluate, in vitro, the use of leaf extracts of Azadirachta indica (A. indica) and Melia azedarach (M. azedarach) as antivirals against caprine lentivirus (CLV) in colostrum and milk of goat nannies. These were collected from eight individuals and infected with the standard strain of CLV. Samples were then subdivided into aliquots and treated with 150 µg/mL of crude extract, and with ethyl acetate and methanol fractions for 30, 60, and 90 min. Next, somatic cells from colostrum and milk were co-cultured with cells from the ovine third eyelid. After this step, viral titers of the supernatants collected from treatments with greater efficacy in co-culture were assessed. The organic ethyl acetate fractions of both plants at 90 min possibly inhibited the viral activity of CLV by up to a thousandfold in colostrum. In milk, this inhibition was up to 800 times for the respective Meliaceae. In conclusion, the ethanolic fraction of ethyl acetate from both plants demonstrated efficacy against CLV in samples from colostrum and milk when subjected to treatment, which was more effective in colostrum.

Chemical Composition Determination and Evaluation of the Antimicrobial Activity of Essential Oil from Croton blanchetianus (Euphorbiaceae) against Clinically Relevant Bacteria.

In this study, the chemical composition of the essential oil (EO) extracted from Croton blanchetianus Baill leaves was identified, and antimicrobial and antibiofilm activities against Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli strains were determined. Moreover, the effects of EO in combination with ampicillin and tetracycline were investigated. Thirty-four components, mainly mono-and sesquiterpenes that represented 94.05 % of the chemical composition, were identified in the EO. The EO showed bacteriostatic and bactericidal activities against all strains tested. Furthermore, the EO showed a synergistic effect with ampicillin and tetracycline. EO significantly inhibited biofilm formation and reduced the number of viable cells in biofilms. The EO may be a promising natural product for preventing bacterial biofilm infections.

In vitro anthelmintic activity of Lippia alba essential oil chemotypes against Haemonchus contortus.

The aim of the present study was to evaluate the effects of the essential oils of Lippia alba chemotypes carvone and citral on H. contortus. Chemical characterization was performed by means of gas chromatography coupled to mass spectrometry (GC/MS). The anthelmintic effects of the essential oils were assessed through the egg hatch test (EHT) and the adult worm motility test (AWMT) using a multidrug-resistant H. contortus Kokstad isolate. Confocal laser scanning microscopy (CLSM) of eggs and adults of H. contortus and scanning electron microscopy (SEM) of adults were performed after treatment with oils for qualitative observations of their effects. The carvone chemotype of L. alba (LaCV) presented 70% carvone, and the citral chemotype of L. alba (LaCT) presented 29.4% geranial and 20.4% neral, respectively. In the EHT, the EC50 values of LaCV and LaCT were 0.2 and 0.3 mg/mL, respectively. In AWMT, after 12 h of exposure to 2 mg/mL LaCV and 2 mg/mL LaCT, 100% of adult nematodes were immobile. CLSM showed changes in larval motility inside the egg caused by LaCV, while LaCT promoted changes in larval formation. In adults exposed to both chemotypes, alterations in the anterior portion of the oesophagus were observed. In SEM, morphological changes were observed in the buccal capsule and in the medial portion of H. contortus adults. It is concluded that the two essential oils of L. alba, the chemotypes carvone and citral, caused morphological changes and inhibited the hatching of eggs and the motility of adult H. contortus nematodes.

Antioxidant and anticholinesterase activities of amentoflavone isolated from Ouratea fieldingiana (Gardner) Engl. through in vitro and chemical-quantum studies.

Ouratea fieldingiana, popularly known as batiputá, is a tree species easily found in the coastal part of northeastern Brazil. Its leaves are rich in biflavonoids, its major compound being amentoflavone. Biflavonoids are well studied due to their high antioxidant capacity. Alzheimer's disease (AD) is a disease characterized by the progressive loss of neurons. Currently, the pharmacological treatment of AD has four drugs: donepezil, galantamine, rivastigmine and memantine. Where these drugs, with the exception of memantine, are inhibitors of acetylcholinesterase, thus inhibiting the enzyme that destroys acetylcholine, thus increasing the availability of this neurotransmitter. This article aims to determine in vitro and in silico the antioxidant and anticholinesterase action of amentoflavone isolated from the leaves of Ouratea fieldingiana. The antioxidant capacity of amentoflavone was evaluated using the DPPH* free radical scavenging method, with an IC50 of 5.73 ± 0.08 µg/mL. The antiradical properties of the molecule were also studied in silico through several HAT, SET-PT and SPLET mechanisms via DFT M06-2X/6-311++G(d,p). It was found that in the hydrogen atom transfer mechanism (HAT) the best trend was obtained as an anti-radical mechanism. Amentoflavone has the ability to inhibit acetylcholinesterase when tested in vitro, having an IC50 of 8.68 ± 0.73 µg/mL, corroborating its effect in the in silico test, presenting four strong covalent hydrogen bonds for having a bond length up to 2.5 Å. Thus, amentoflavone is an important target for further testing against Alzheimer's disease. Communicated by Ramaswamy H. Sarma.

HIF1 inhibition of the biflavonoids against pancreas cancer: drug-likeness, bioavailability, ADMET, PASS, molecular docking, molecular dynamics, and MM/GBSA calculations.

Pancreatic cancer is an aggressive disease with a high death rate and is difficult to treat. This disease, in the most cases, is asymptomatic until it progresses to an advanced stage. Therefore, the search for bioactive molecules is urgent to combat pancreatic cancer. Then, this work analyzed the interaction potential of agathisflavone and amentoflavone molecules against the HIF1 target using the ADMET, molecular docking, and molecular dynamics simulations. More recent drug-likeness filters that combine physicochemical and physiological parameters have shown that high polar surface area (TPSA > 75 Å2) drives biflavonoids out of the toxic drug space of Pfizer dataset. Regarding the pharmacokinetic descriptors, it was possible to notice that Amentoflavone showed a better order of passive cell permeability (Papp = 8 × 10-6 cm/s) and better metabolic stability, biotransformed by aromatic hydroxylation reactions by the CYP3A4 isoenzyme on the human liver, that favor its hepatic clearance. The molecular docking and molecular dynamics simulations indicated the high interaction potential and stability between the ligands analyzed (highlighted the amentoflavone molecule), respectively. The MM/GBSA calculations showed that the amentoflavone ligand registered the highest ΔG binding value of -32.6957 kcal/mol with the HIF1 target. Then, this molecule may be used as a potential inhibitor of pancreatic cancer. In this perspective, the present work represents an initial step in the virtual bioprospecting a pharmacological tool for treating of pancreatic cancer.Communicated by Ramaswamy H. Sarma.

Chitosan-Based Nanoparticles for Cardanol-Sustained Delivery System.

Cardanol, principal constituent of the technical cashew nut shell liquid, has applications as antioxidant and antibacterial, and these properties may be enhanced through encapsulation. In the present study, we isolated and purified cardanol, and nanoparticles (NPs) were produced by polyelectrolyte complexation using polysaccharide systems with chitosan, sodium alginate, and non-toxic Arabic gum, because they are biocompatible, biodegradable, and stable. We characterized the NPs for morphological, physicochemical, and antioxidant activity. The micrographs obtained revealed spherical and nanometric morphology, with 70% of the distribution ranging from 34 to 300 nm, presenting a bimodal distribution. The study of the spectra in the infrared region suggested the existence of physicochemical interactions and cross-links between the biopolymers involved in the encapsulated NPs. Furthermore, the NPs showed better antioxidant potential when compared to pure cardanol. Thus, the encapsulation of cardanol may be an effective method to maintain its properties, promote better protection of the active ingredient, minimize side effects, and can target its activities in specific locations, by inhibiting free radicals in various sectors such as pharmaceutical, nutraceutical, and biomedical.

Chemical Profile and Evaluation of the Antioxidant and Anti-Acetylcholinesterase Activities of Annona squamosa L. (Annonaceae) Extracts.

This study presents the chemical profile of extracts from the pulp and seed of Annona squamosa L., as well as the evaluation of their antioxidant and acetylcholinesterase inhibition activities. In the chemical prospection, qualitative assays were performed, and the contents of total phenols, flavonoids, vitamin C, and carotenoids were quantified. For the compounds identification, analyses of the extracts were performed by liquid chromatography coupled to mass spectrometry. Antioxidant evaluation was performed using the DPPH, ABTS, Fe3+ reduction, 2-DR protection, and ß-carotene protection methods. The assay for inhibition of acetylcholinesterase activity was determined using the method described by Ellman. The secondary metabolites identified were anthocyanidins, flavones, flavonols, and alkaloids. Phenol analysis showed a higher quantitative value of total phenols and flavonoids for the seed extract, and the vitamin C content was higher in the pulp extract. There was no significant difference in relation to the carotenoids quantification. The best results obtained for antioxidant activity, for both seed and pulp extracts, were with the ABTS method with IC50 of 0.14 ± 0.02 and 0.38 ± 0.02 mg/mL, respectively. Compared to A. squamosa seed extract, the pulp extract demonstrates higher AChE inhibitory activity with IC50 of 18.82 ± 0.17 µg/mL. A. squamosa is a nutritious food source. The continuity of the studies is fundamental to relate the consumption of this food and its effects on neurodegenerative diseases.

Chemical Composition, Larvicidal Activity, and Enzyme Inhibition of the Essential Oil of Lippia grata Schauer from the Caatinga Biome against Dengue Vectors.

Insect resistance and environmental pollution are among the drawbacks of continuous use of synthetic insecticides against the vectors of dengue, Aedesaegypti and Aedes albopictus. The objective of this study was to analyze the composition of the essential oil of Lippia grata Schauer collected from plants, in three periods of the year, to compare the larvicidal activity and enzymatic inhibition of the dengue vectors. The oilsanalyzed by gas chromatography coupled to mass spectrometry (GC-MS), presented thymol and 1,8-cineole, as the main constituents, in all three periods. This composition was different from that found in previous studies of the species from different places, thus, suggesting a new chemotype of Lippia grata. Larvicidal tests were performed at concentrations of 100, 75, 50, 25, and 12.5 µg.mL-1 and the essential oil from the rainy season showed the best results, with LC50 of 22.79 µg.mL-1 and 35.36 µg.mL-1 against Ae. aegypti and Ae. albopictus, respectively; this result was better than other reports. In the rainy period, however, there was a greater variety of components, which led to a better larvicidal effect, possibly due to synergistic action with minor constituents. Total proteins, amylases, and acetylcholinesterase of both species were inhibited by the oils.

Xyloglucan-based hybrid nanocomposite with potential for biomedical applications.

Natural polymer-based hybrid nanocomposites have been proposed as one of the most promising tools for biomedical applications, including disease treatment and diagnosis procedures. Xyloglucan nanocapsules can simultaneously load magnetic iron oxide nanoparticles and bioactive for a specific tissue, reducing the processes of degradation and metabolic inactivation of molecules with biological activity. In this work, magnetic nanocapsules of xyloglucan loaded with hydrophilic sulfated quercetin (MNXQ_SO3) were successfully synthesized by inverse miniemulsion process through interfacial polymerization. The polymeric shell formation of nanocapsules was evidenced by Fourier Transform Infrared spectroscopy and Transmission Electron Microscopy. The ferrofluid (Fe3O4@PAAS) incorporated into the xyloglucan nanocapsules was synthesized by hydrothermal method, using polyacrylic acid sodium salt as coating. Dynamic Light Scattering technique confirmed the nanomeric dimensions (202.3 nm) and the good colloidal stability (-40.2 mV) of MNXQ_SO3. The saturation magnetization analyses pointed out the superparamagnetic behavior of Fe3O4@PAAS (48 emu/g) and MNXQ_SO3 (4.2 emu/g). MNXQ_SO3 was able to modify the release profile of sulfated quercetin (67%) when compared to the free bioactive (100%), exhibiting a release profile compatible with the zero-order kinetic model. The results showed that the development of MNXQ_SO3 presents a new perspective for biomedical applications, including studies of targeted drug delivery.

Anacardic Acid Complexes as Possible Agents Against Alzheimer's Disease Through Their Antioxidant, In vitro, and In silico Anticholinesterase and Ansiolic Actions.

The frequency of Alzheimer's disease (AD) is growing rapidly with longer life expectancy and the consequent increase of people with a high risk of neurodegenerative diseases. Anacardic acid (AA) has several pharmacological actions, such as antioxidants, anticholinesterase, and anti-inflammatory, which are related to the protection against aging disorders. Also, the metals copper and zinc are co-factors of antioxidant enzymes that can be associated with AA to improve brain-protective action. This study aimed to evaluate the potential of AA metal complexes using copper and zinc chelators to produce potential agents against Alzheimer's disease. For this purpose, Cu and Zn were linked to AA in the ratio of 1:1 in a basic medium. The complexes' formation was confirmed by ultraviolet and visible spectroscopy. The toxicity was evaluated in the zebrafish model, and other information related to AD was obtained using the zebrafish model of anxiety. AA-Zn and AA-Cu complexes showed better antioxidant action than free AA. In the anti-AChE activity, AA was like the AA-Cu complex. In models using adult zebrafish, no toxicity for AA complexes was found, and in the locomotor model, AA-Cu demonstrated possible anxiolytic action. In in silico experiments comparing AA and AA-Cu complex, the coupling energy with the enzyme was lower for the AA-Cu complex, showing better interaction, and also the distances of the active site amino acids with this complex were lower, similar to galantamine, the standard anti-AChE inhibitor. Thus, AA-Cu showed interesting results for more detailed study in experiments related to Alzheimer's disease.

Anti-acetylcholinesterase and toxicity against Artemia salina of chitosan microparticles loaded with essential oils of Cymbopogon flexuosus, Pelargonium x ssp and Copaifera officinalis.

Essential oils (EOs) are bioactive compounds with therapeutic potential for use as alternatives or as support to conventional treatments. However, EOs present limitations, such as sensibility to environmental factors, which can be overcome through microencapsulation. The objective of this study was to produce, by spray drying, chitosan microparticles (CMs) loaded with EO of Lemongrass (Cymbopogon flexuosus), Geranium (Pelargonium x ssp) and Copaiba (Copaifera officinalis). Physicochemical and biological characterization of these microparticles showed that CMs presented spherical morphology, had an average size range of 2-3 µm with positive zeta potential (ZP) values, and enhanced thermal stability, compared to free EO. The encapsulation efficiency (EE) ranged from 4.8-58.6%, depending on the oil's properties. In vitro EO release from CMs was determined at different pHs, with 94% release observed in acid media. All microparticles were non-hemolytic at concentrations of up to 0.1 mg·mL-1. EOs and CMs presented acetylcholinesterase (AChE) inhibition activity (IC 50 ranged from 11.92 to 28.18 µg·mL-1). Geranium and Copaiba EOs presented higher toxicity against Artemia salina, and greater inhibition of acetylcholinesterase, indicating potential bioactivity for Alzheimer's disease (AD). Our findings demonstrate that CM systems may show promise for the controlled release of these EOs.

Astronium fraxinifolium Schott Exerts Leishmanicidal Activity by Providing a Classically Polarized Profile in Infected Macrophages.

BACKGROUND: Leishmania braziliensis is prevalent in Latin American countries, including Brazil. It causes cutaneous and mucocutaneous leishmaniasis, leading to high morbidity, and has a low cure rate. Treatment is based on pentavalent antimonials; nonetheless, there are problems related to high toxicity, high cost, and parasitic resistance. Discovery of new leishmanicidal drugs without these limitations and that stimulate the cellular immune response is necessary. PURPOSE: The present work evaluates whether Astronium fraxinifolium Schott exerts leishmanicidal activity against L. braziliensis by providing a classically polarized profile in infected macrophages. METHODS: For the evaluation of the A. fraxinifolium Schott leishmanicidal activity, amastigote cell death was demonstrated in infected RAW 267.4 macrophages treated with an ethanolic extract from the plant sapwood (EEAF). For the evaluation of the EEAF capacity in providing a classically polarized profile in infected macrophages, the following analyses were done: detection of LAMP-1 protein by the baculovirus technology, measurement of superoxide anion by the NBT testing, quantification of TNF-α, IL-12p40, IL-10, IL-4, and TGF-ß by sandwich-type enzyme immune assays, and iNOS and COX-2 expression by RT-PCR technique. RESULTS: The EEAF significantly reduced amastigote counts inside the cells. Vacuoles were visualized in infected and treated cells before and after May-Grünwald-Giemsa staining. A strong LAMP-1 protein fluorescence revealed phagosome maturation in infected cells treated with the EEAF. No production of superoxide was visualized in infected cells treated with the plant material. Nonetheless, high levels of TNF-α, IL-12p40, and IL-10 were found in cell supernatants, but reduced levels of TGF-ß and no IL-4 production. We identified augmented mRNA expression for COX-2, but no expression of iNOS mRNA. CONCLUSION: Our results demonstrated that A. fraxinifolium induced a classically polarized profile in infected macrophages but also provided a less harmful environment by stimulating the production of certain anti-inflammatory mediators, such as IL-10.

Synthesis of Quercetin-Metal Complexes, In Vitro and In Silico Anticholinesterase and Antioxidant Evaluation, and In Vivo Toxicological and Anxiolitic Activities.

The level of acetylcholine, a neurotransmitter essential for processing memory and learning, is lower in the brains of patients with Alzheimer's disease due to the higher concentration of the enzyme acetylcholinesterase. The main compounds used for Alzheimer's treatment are acetylcholinesterase inhibitors. Quercetin coordination complexes with the metal ions Cu+2, Zn+2, Ni+2, Co+2, and Fe+2 were synthesized to investigate their potential use against Alzheimer's disease, by evaluating the inhibition of acetylcholinesterase in vitro and in silico, as well as the antioxidant activity, toxicity, and anxiolytic action in the zebrafish (Danio rerio) model. The organic complexes were characterized by UV-Vis and FT-IR. The spectral information suggested that coordination of metals occurs with the carbonyl group and OH linked to the C-3 carbon of quercetin. The quercetin-Fe (QFe) complex presented the best antioxidant and antiacetylcholinesterase actions, and these results were confirmed by molecular docking. In the toxicity and locomotor evaluation, the quercetin molecules and the synthesized complexes, mainly QCu and QZn derivatives, showed the highest degree of inhibition of the fish's locomotor activity, suggesting a possible anxiolytic action. Then, quercetin complexes with metals, mainly with Fe+2, represent valuable compounds and deserve more investigation as promising agents against Alzheimer's disease.