Secretion of the arthrodial membrane gland of a harvester (Arachnida: Opiliones): Antimicrobial activity.

Because of the exoskeleton, arthropods must have flexible areas to be able to move. Such regions are called arthrodial membranes and are particularly vulnerable to bacteria and fungi. Here, we analyzed the secretion in the glands underneath it in a Neotropical harvester Mischonyx squalidus (Arachnida: Opiliones) and tested whether it has antiseptical properties. Wepuncturedthemembrane,collectedand quantified ina spectrophotometer. We also fractionated and analyzed the samples in reversed-phase high-performance liquid chromatography (RP-HPLC) and then incubated the treated fractions and determined growth inhibition by measuring absorbance. The secretions resulted in 100 fractions, among which two had activity against the Gram-positive bacteria Micrococcus luteus and against the yeast Candida albicans. The low concentrations at which the secretions were active are relevant from a biotechnological point of view. For the organism, the secretions possibly prevent infections, including when they are attacked in these regions by predators that pick that spot to bite.

Garlic: An Alternative Treatment for Group B Streptococcus.

Prenatal screening in pregnant women between 35 and 37 weeks of gestation and intrapartum antibiotic prophylaxis has successfully reduced the incidence of neonatal morbidity and mortality related to Streptococcus agalactiae. However, the contamination rates of newborns are still considerable. In traditional and folk medicines, it has been observed that garlic has been effective in treating S. agalactiae infection. The aim of this study was to isolate and identify the active compounds from garlic that have antimicrobial activity against S. agalactiae. In order to do this, SP80 (Sep-Pak 80%) obtained from crude garlic extract (CGE) was fractionated by reverse-phase ultrafast liquid chromatography with UV (RP-UFLC-UV) using a Shim-pack PREP-ODS column. All fractions obtained were tested using a microbial growth inhibition test against the S. agalactiae strain (ATCC 12386). Five clinical isolates were used to confirm the action of the fractions with antimicrobial activity, and the bacterial growth curve was determined. Identification of the antimicrobial compounds was carried out through liquid chromatography coupled with mass spectrometry (LC/MS) and nuclear magnetic resonance (NMR). The active compounds found to exhibit antimicrobial activity were Ƴ-glutamyl-S-allyl-cysteine (fraction 18), Ƴ-glutamyl-phenylalanine (fraction 20), and the two stereoisomers (E and Z) of ajoene (fraction 42). The MICs of these fractions were 5.41 mg/ml, 4.60 mg/ml, and 0.16 mg/ml, respectively, and they inhibited the growth of the clinical isolates tested. Antimicrobial compounds from garlic may be a promising source in the search for new drugs against S. agalactiae. IMPORTANCE Invasive disease due to group B streptococcal (GBS) infection results in a wide spectrum of clinical disease in neonates. Maternal colonization by GBS is the primary risk factor for disease. The strategy recommended by the Centers for Disease Control to reduce neonatal GBS infection is the culture-based screening of all pregnant women at 35 to 37 weeks of gestation and intrapartum antibiotic prophylaxis (IAP). However, indiscriminate use of antibiotics favors the selection and spread of resistant bacteria. The global scenario of antibacterial resistance has been of great concern for public health, and natural products can be a source of new substances to help us grapple with this problem.

In silico bioprospecting of receptors associated with the mechanism of action of Rondonin, an antifungal peptide from spider Acanthoscurria rondoniae haemolymph

Multiple drug-resistant fungal species are associated with the development of diseases. Thus, more efcient drugs for the treatment of these aetiological agents are needed. Rondonin is a peptide isolated from the haemolymph of the spider Acanthoscurria rondoniae. Previous studies have shown that this peptide has antifungal activity against Candida sp. and Trichosporon sp. strains, acting on their genetic material. However, the molecular targets involved in its biological activity have not yet been described. Bioinformatics tools were used to determine the possible targets involved in the biological activity of Rondonin. The PharmMapper server was used to search for microorganismal targets of Rondonin. The PatchDock server was used to perform the molecular docking. UCSF Chimera software was used to evaluate these intermolecular interactions. In addition, the I-TASSER server was used to predict the target ligand sites. Then, these predictions were contrasted with the sites previously described in the literature. Molecular dynamics simulations were conducted for two promising complexes identifed from the docking analysis. Rondonin demonstrated consistency with the ligand sites of the following targets: outer membrane proteins F (id: 1MPF) and A (id: 1QJP), which are responsible for facilitating the passage of small molecules through the plasma membrane; the subunit of the favoprotein fumarate reductase (id: 1D4E), which is involved in the metabolism of nitrogenous bases; and the ATP-dependent Holliday DNA helicase junction (id: 1IN4), which is associated with histone proteins that package genetic material. Additionally, the molecular dynamics results indicated the stability of the interaction of Rondonin with 1MPF and 1IN4 during a 10 ns simulation. These interactions corroborate with previous in vitro studies on Rondonin, which acts on fungal genetic material without causing plasma membrane rupture. Therefore, the bioprospecting methods used in this research were considered satisfactory since they were consistent with previous results obtained via in vitro experimentation.

In silico prospection of receptors associated with the biological activity of U1-SCTRX-lg1a: an antimicrobial peptide isolated from the venom of Loxosceles gaucho

The emergence of antibiotic-resistant pathogens generates impairment to human health. U1-SCTRX-lg1a is a peptide isolated from a phospholipase D extracted from the spider venom of Loxosceles gaucho with antimicrobial activity against Gram-negative bacteria (between 1.15 and 4.6 μM). The aim of this study was to suggest potential receptors associated with the antimicrobial activity of U1-SCTRX-lg1a using in silico bioinformatics tools. The search for potential targets of U1-SCRTX-lg1a was performed using the PharmMapper server. Molecular docking between U1-SCRTX-lg1a and the receptor was performed using PatchDock software. The prediction of ligand sites for each receptor was conducted using the PDBSum server. Chimera 1.6 software was used to perform molecular dynamics simulations only for the best dock score receptor. In addition, U1-SCRTX-lg1a and native ligand interactions were compared using AutoDock Vina software. Finally, predicted interactions were compared with the ligand site previously described in the literature. The bioprospecting of U1-SCRTX-lg1a resulted in the identification of three hundred (300) diverse targets (Table S1), forty-nine (49) of which were intracellular proteins originating from Gram-negative microorganisms (Table S2). Docking results indicate Scores (10,702 to 6066), Areas (1498.70 to 728.40) and ACEs (417.90 to – 152.8) values. Among these, NAD + NH3-dependent synthetase (PDB ID: 1wxi) showed a dock score of 9742, area of 1223.6 and ACE of 38.38 in addition to presenting a Normalized Fit score of 8812 on PharmMapper server. Analysis of the interaction of ligands and receptors suggests that the peptide derived from brown spider venom can interact with residues SER48 and THR160. Furthermore, the C terminus (– 7.0 score) has greater affinity for the receptor than the N terminus (– 7.7 score). The molecular dynamics assay shown that free energy value for the protein complex of – 214,890.21 kJ/mol, whereas with rigid docking, this value was – 29.952.8 sugerindo that after the molecular dynamics simulation, the complex exhibits a more favorable energy value compared to the previous state. The in silico bioprospecting of receptors suggests that U1-SCRTX-lg1a may interfere with NAD + production in Escherichia coli, a Gram-negative bacterium, altering the homeostasis of the microorganism and impairing growth.

Impact of mygalin on inflammatory response induced by toll-like receptor 2 agonists and IFN-γ activation

Several natural products are being studied to identify new bioactive molecules with therapeutic potential for infections, immune modulation, and other pathologies. TLRs are a family of receptors that play a crucial role in the immune system, constituting the first line of immune defense. They recognize specific products derived from microorganisms that activate multiple pathways and transcription factors in target cells, which are vital for producing immune mediators. Mygalin is a synthetic acylpolyamine derived from hemocytes of the spider Acanthoscurria gomesiana. This molecule negatively regulates macrophage response to LPS stimulation by interacting with MD2 in the TLR4/MD2 complex. Here, we investigated the activity of Mygalin mediated by TLR2 agonists in cells treated with Pam3CSK4 (TLR2/1), Pam2CSK4, Zymosan (TLR2/6), and IFN-γ. Our data showed that Mygalin significantly inhibited stimulation with agonists and IFN-γ, reducing NO and IL-6 synthesis, regardless of the stimulation. There was also a significant reduction in the phosphorylation of proteins NF-κB p65 and STAT-1 in cells treated with Pam3CSK4. Molecular docking assays determined the molecular structure of Mygalin and agonists Pam3CSK4, Pam2CSK4, and Zymosan, as well as their interaction and free energy with the heterodimeric complexes TLR2/1 and TLR2/6. Mygalin interacted with the TLR1 and TLR2 dimer pathway through direct interaction with the agonists, and the ligand-binding domain was similar in both complexes. However, the binding of Mygalin was different from that of the agonists, since the interaction energy with the receptors was lower than with the agonists for their receptors. In conclusion, this study showed the great potential of Mygalin as a potent natural inhibitor of TLR2/1 and TLR2/6 and a suppressor of the inflammatory response induced by TLR2 agonists, in part due to its ability to interact with the heterodimeric complexes.

Antiviral action of aqueous extracts of propolis from Scaptotrigona aff. postica (Hymenoptera; Apidae) against Zica, Chikungunya, and Mayaro virus

The limited availability of antivirals for new highly pathogenic strains of virus has become a serious public health. Therefore, news products against these pathogens has become an urgent necessity. Among the multiple sources for news antibiotics and antivirals, insect exudates or their products has become an increasingly frequent option. Insects emerged 350 million years ago and have showed a high adaptability and resistance to the most varied biomes. Their survival for so long, in such diferent environments, is an indication that they have a very efcient protection against environmental infections, despite not having a developed immune system like mammals. Since the ancient civilizations, the products obtained from the bee have been of great pharmacological importance, being used as antimicrobial, anti-infammatory, antitumor and several other functions. Investigations of biological activity of propolis have been carried out, mainly in the species Apis mellifera, and its product have showed activity against some important viruses. However, for the Meliponini species, known as stingless bees, there are few studies, either on their chemical composition or on their biological activities. The importance of studying these bees is because they come from regions with native forests, and therefore with many species of plants not yet studied, in addition to which they are regions still free of pesticides, which guarantees a greater fdelity of the obtained data. Previous studies by our group with crude hydroalcoholic extract of propolis demonstrated an intense antiviral activity against Herpes, infuenza, and rubella viruses. In this work, we chose to use aqueous extracts, which eliminates the presence of other compounds besides those originally present in propolis, in addition to extracting substances diferent from those obtained in alcoholic extracts. Therefore, this study aimed to identify, isolate and characterize compounds with antiviral efects from aqueous propolis extracts from Scaptotrigona af postica, in emerging viruses such as zicavirus, chikungunya, and mayaro virus. The evaluation of the antiviral activity of the crude and purifed material was performed by reducing infectious foci in VERO cell cultures. The results obtained with crude propolis, indicate a high reduction of zica virus (64×) and mayaro (128×) when was used 10% v/v of propolis. The reduction of chikungunya virus was of 256 fold, even when was used 5% v/v of propolis. The chemical characterization of the compounds present in the extracts was performed by high-pressure liquid chromatography. Through the purifcation of propolis by HPLC and mass spectrometry, it was possible to identify and isolate a peak with antiviral activity. This substance showed activity against all viruses tested. When purifed fraction was used, the reduction observed was of 16 fold for zicavirus, 32 fold for mayaro virus and 512 fold for chikungunya virus. Likewise, it was observed that the antiviral response was concentration dependent, being more intense when propolis was added 2 h after the viral infection. Now we are carrying out the chemical characterization of the purifed compounds that showed antiviral action.

Proteins with anti-apoptotic action in the hemolymph of caterpillars of the Megalopygidae family acts by maintaining the structure of the cellular cytoskeleton

Brazil has a very large biological variety, which is an almost inexhaustible source of substances of pharmacological and biotechnological interest. Several studies have demonstrated the presence of bioactive peptides in insect hemolymph and their potential use as therapeutic agents. However, few data are available regarding molecules extracted from insects with anti-apoptotic action. The objective of this work was to identify the presence of proteins from the hemolymph of caterpillars of the Megalopygidae family with pharmacological and biotechnological interest. This study provides preliminary and innovative information on a new substance that inhibits cellular apoptopsis and stabilizes the tested cells, impacting the cytoskeleton, maintaining cellular structure and its functions. To this, two species of Megalopygidae family were studied, Podalia sp. and Megalopyge albicolis. Cytotoxicity tests on Vero and Sf-9 cells revealed that the hemolymph of both caterpillars was cytotoxic only at concentrations greater than 5%v/v. In the anti-apoptotic activity assays, it was verified that the supplementation of cell cultures with only 1% of hemolymph v/v is sufficient to inhibit cell death by apoptosis induced by different inducers such as terbutyl, actinomycin D, hydrogen peroxide, or even by nutrient depletion. For this study, cells were stained with trypan blue, crystal violet, and fluorescent markers to cytoskeleton (actin and tubulin), mitochondria membrane electric potential (JC-1), and apoptosis marker (acridine orange and ethidium). The protein responsible for anti-apoptotic action was isolated through gel filtration chromatography, using an AKTA purifier high-resolution liquid chromatography system. The hemolymph was fractionated into 3 pools for Podalia sp. and 6 pools for M. abicolis. In the antiapoptotic tests, semi-purified hemolymph from both caterpillars showed anti-apoptotic effect in VERO and SF-9 cells, pre-treated with only 1% v/v of hemolymph and induced to death by different and apoptotic inductors. Was observed that the molecule with anti-apoptotic effect is present in pool 3 in both hemolymphs. This protector effect blocked and attenuated the disruption of the cytoskeleton (actin filaments), being that the protective effect also was observed on the integrity of the mitochondrial membrane of SF-9 cells pre-treated with both hemolymphs and treated with the apoptosis inducer Terbutil at concentrations of 25 to 100 µM. By acting on the mitochondrial pathway of death by apoptosis, and by maintaining the structure of the cytoskeleton and cellular functions, pathway that can cause disorders and diseases neurodegenerative, the substances present in the hemolymph of these and other caterpillars could be good candidates in studies for the treatment of neurodegenerative diseases such as Parkinson’s disease and Alzheimer’s.

Mygalin, an Acanthoscurria gomesiana spider‐derived synthetic, modulates haloperidol-induced cataleptic state in mice

Background: Haloperidol (HAL) is an antipsychotic used in the treatment of schizophrenia. However, adverse effects are observed in the extrapyramidal tracts due to its systemic action. Natural compounds are among the treatment alternatives widely available in Brazilian biodiversity. Mygalin (MY), a polyamine that was synthesized from a natural molecule present in the hemolymph of the Acanthoscurria gomesian spider, may present an interesting approach. Aims: This study aimed to evaluate the effect of MY in mice subjected to HAL-induced catalepsy. Methods: Male Swiss mice were used. Catalepsy was induced by intraperitoneal administration of HAL (0.5 mg/kg − 1 mL/Kg) diluted in physiological saline. To assess the MY effects on catalepsy, mice were assigned to 4 groups: (1) physiological saline (NaCl 0.9 %); (2) MY at 0.002 mg/Kg; (3) MY at 0.02 mg/Kg; (4) MY at 0.2 mg/Kg. MY or saline was administered intraperitoneally (IP) 10 min b HAL before saline. Catalepsy was evaluated using the bar test at 15, 30, 60, 90, and 120 min after the IP administration of HAL. Results: The latency time in the bar test 15, 30, 60, and 90 min increased (p < 0.05) after IP administration of HAL compared to the control group. Catalepsy was attenuated 15, 30, 90, and 120 min (p < 0.05) after the IP-administration of MY at 0.2 mg/Kg; while MY at 0.02 mg/Kg attenuated catalepsy 15 min after the HAL treatment. Our findings showed that MY attenuates the HAL-induced cataleptic state in mice.

In silico bioprospecting of receptors for Doderlin: an antimicrobial peptide isolated from Lactobacillus acidophilus

The emergence of resistant bacteria strains against traditional antibiotics and treatments increases each year. Doderlin is a cationic and amphiphilic peptide active against gram-positive, negative and yeast stains. The aim of the present work was prospect potentials receptors associated of antimicrobial activity of Doderlin using in silico bioinformatics tools. To search for potential targets of Doderlin, PharmMapper software was used. Molecular docking between Doderlin and the receptor was performed by PatchDock. Additional interaction and ligand site prediction for each receptor was performed by I-TASSER software. Those PDB Id, 1XDJ (score: 11,746), 1JMH (score: 11,046), 1YR3 (score: 10,578), 1NG3 (score: 10,082) showed highest dock score. Doderlin was found to predicted/real sites co-localize with 1XDJ and 1JMH, enzymes accountable for nitrogenic bases synthesis. The resulting receptor bioprospecting is highly correlated and suggests that Doderlin might act by interfering with DNA metabolism/production of bacteria, altering microorganism homeostasis and growth impairment.

Molecular hybridization strategy for tuning bioactive peptide function

The physicochemical and structural properties of antimicrobial peptides (AMPs) determine their mechanism of action and biological function. However, the development of AMPs as therapeutic drugs has been traditionally limited by their toxicity for human cells. Tuning the physicochemical properties of such molecules may abolish toxicity and yield synthetic molecules displaying optimal safety profiles and enhanced antimicrobial activity. Here, natural peptides were modified to improve their activity by the hybridization of sequences from two different active peptide sequences. Hybrid AMPs (hAMPs) were generated by combining the amphipathic faces of the highly toxic peptide VmCT1, derived from scorpion venom, with parts of four other naturally occurring peptides having high antimicrobial activity and low toxicity against human cells. This strategy led to the design of seven synthetic bioactive variants, all of which preserved their structure and presented increased antimicrobial activity (3.1–128 μmol L−1). Five of the peptides (three being hAMPs) presented high antiplasmodial at 0.8 μmol L−1, and virtually no undesired toxic effects against red blood cells. In sum, we demonstrate that peptide hybridization is an effective strategy for redirecting biological activity to generate novel bioactive molecules with desired properties.

Doderlin: isolation and characterization of a broad-spectrum antimicrobial peptide from Lactobacillus acidophilus

Lactobacillus acidophilus are Gram-positive bacteria distributed in diverse environments, and as a component of the normal microbiota of gastrointestinal and urogenital tract, they are relevant for human beings. Classified as lactic acid bacteria, due to the production of lactic acid, Lactobacillus can also produce antimicrobial peptides (AMPs), which is a compound synthesized by all forms of life aiming for protecting themselves from threats and to increase their competitivity to survive in a specific environment. AMPs are molecules capable of inhibiting the growth of microorganisms and, due to the indiscriminate use of conventional antibiotics and the emergence of multi-resistant bacteria, they have become an alternative, not only for treating multi-resistant infections, but also for the identification of probiotic products and food conservation. Considering the rampant rise of bacterial resistance to classical antimicrobials, the present study aimed to isolate and characterize AMPs from L. acidophilus extracts. Lactobacillus acid extract was pre-fractionated on disposable cartridges, followed by a high-performance liquid chromatography (HPLC). The collected fractions were evaluated in a liquid growth inhibition assay allowing to identify eight fractions with antimicrobial activity, and one of them showed antimicrobial activity against Candida albicans and, for this reason, was further characterized by mass spectrometry (MS). A peptide with a molecular mass of 1788.01 Da, showing the primary sequence NEPTHLLKAFSKAGFQ, as determined by MS, was named as Doderlin. Interestingly, antimicrobial molecules isolated from L. acidophilus have already been described previously, but few reports describe AMPs effective against C. albicans as the one reported here. We show here that this newly discovered molecule has a biological property with potential to be used in pharmaceutical and food companies, in the fight against contamination and/or for treating infections caused by microorganisms, respectively.

In silico and In Vitro approach for evaluation of the anti-inflammatory and antioxidant potential of mygalin

There is a great interest in describing new molecules to be used as therapeutic targets in various diseases, particularly those that play a role in inflammatory responses and infection control. Mygalin is a synthetic analogue of spermidine, and previous studies have demonstrated its bactericidal effect against Escherichia coli, as well as its ability to modulate the inflammatory response of macrophages against lipopolysaccharide (LPS). However, the mechanisms through which mygalin regulates this inflammatory response remain poorly characterized. A set of platforms using molecular docking analysis was employed to analyze various properties of mygalin, including toxicity, biodistribution, absorption, and the prediction of its anti-inflammatory properties. In in vitro assays, we evaluated the potential of mygalin to interact with products of the inflammatory response, such as reactive oxygen species (ROS) and antioxidant activity, using the BMDM cell. The in silico analyses indicated that mygalin is not toxic, and can interact with proteins from the kinase group, and enzymes and receptors in eukaryotic cells. Molecular docking analysis showed interactions with key amino acid residues of COX-2, iNOS and 5-LOX enzymes. In vitro, assays demonstrated a significant reduction in the expression of iNOS and COX-2 induced by LPS, along with a decrease in the oxidative stress caused by the treatment with PMA, all without altering cell viability. Mygalin exhibited robust antioxidant activity in DPPH assays, regardless of the dose used, and inhibited heat-induced hemolysis. These studies suggest that mygalin holds promise for further investigation as a new molecule with anti-inflammatory and antioxidant properties.

Morphology of the arthrodial membrane gland in a Neotropical harvester (Arachnida: Opiliones)

We describe a gland in the arthrodial membrane of the coxa-trochanter articulation in the fourth pair of legs in the Neotropical harvester Mischonyx squalidus Bertkau, 1880. Externally the glandular area has a rough appearance with pores on its surface, with folds of the arthrodial membrane. Internally, its secretory cells have spherical secretory vesicles, smooth endoplasmic reticulum, mitochondria and ducts that exit from the cells and cross the arthrodial membrane. Histochemical tests indicate the presence of proteins and neutral glycoproteins. The function of the gland might be to produce lubricating products that allow better movement of the coxa-trochanter region.

Acanthoscurria gomesiana spider-derived Mygalin in the prelimbic prefrontal cortex modulates neuropathic pain and depression comorbid

Depression has a high rate of comorbidity with neuropathic pain. This study aims to investigate the effect of Mygalin, an acylpolyamine synthesized from a natural molecule in the hemolymph of the Acanthoscurria gomesiana spider, injected into the prelimbic (PrL) region of the medial prefrontal cortex on chronic neuropathic pain and depression comorbidity in rats. To investigate that comorbidity, neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve in male Wistar rats. The biotinylated biodextran amine (BDA) bidirectional neural tract tracer was microinjected into the PrL cortex to study brain connections. Rodents were further subjected to von Frey (mechanical allodynia), acetone (cold allodynia), and forced swim (depressive-like behavior) tests. BDA neural tract tracer-labeled perikarya were found in the dorsal columns of the periaqueductal gray matter (dPAG) and the dorsal raphe nucleus (DRN). Neuronal activity of DRN neurons decreased in CCI rats. However, PrL cortex treatment with Mygalin increased the number of spikes on DRN neurons. Mygalin treatment in the PrL cortex decreased both mechanical and cold allodynia and immobility behavior in CCI rats. PrL cortex treatment with N-methyl-D-aspartate (NMDA) receptor receptors attenuated the analgesic and antidepressive effects caused by Mygalin. The PrL cortex is connected with the dPAG and DRN, and Mygalin administration into the PrL increased the activity of DRN neurons. Mygalin in the PrL cortex produced antinociceptive and antidepressive-like effects, and the NMDA agonist reversed these effects.

Bioactive properties of persea lingue ness (Lauraceae) fruit and leaf extracts

Persea lingue Ness is a tree species that lives mainly in temperate forests of south-central Chile. Its leaves are used in ethnomedicine, the fruit is a drupe similar to that of the avocado and has not been studied. The aim of this study was to determine the cytotoxicity in leukemia cell and antibacterial activity, along with some chemical content characteristics of P. lingue fruit and leaf extracts. The antibacterial activity was determined by the inhibition of bacterial growth in liquid medium assay against Gram-positive and Gram-negative bacteria. The leukemia cell lines Kasumi-1 and Jurkat were used to evaluate the cytotoxic activity by using propidium iodide and AlamarBlue assays. Total phenolic, flavonoid, condensed tannin, alkaloid and lipid contents were evaluated in the fruit and in the leaf extracts. The antioxidant activity of both extracts were also elavaluated. Leaf extract presented the highest content of total phenols, condensed tannins and flavonoids, and also the highest antioxidant activity. While the fruit extract has a higher amount of lipids and alkaloids and the high antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus megaterium and Micrococcus luteus. The leaf extract only showed activity against M. luteus. Concerning the cytotoxic activity, only the fruit extract showed cytotoxicity against the cell lines Jurkat and Kasumi-1. P. lingue fruit extract is a potential source of biologically active molecules for the development of new drugs to be used in some types of leukemia, as well as antibacterial agent.

Bioactive properties of Persea lingue Ness (Lauraceae) fruit and leaf extracts / Propriedades bioativas de extratos de folhas e frutos de Persea lingue Ness (Lauraceae)

Persea lingue Ness is a tree species that lives mainly in temperate forests of south-central Chile. Its leaves are used in ethnomedicine, the fruit is a drupe similar to that of the avocado and has not been studied. The aim of this study was to determine the cytotoxicity in leukemia cell and antibacterial activity, along with some chemical content characteristics of P. lingue fruit and leaf extracts. The antibacterial activity was determined by the inhibition of bacterial growth in liquid medium assay against Gram-positive and Gram-negative bacteria. The leukemia cell lines Kasumi-1 and Jurkat were used to evaluate the cytotoxic activity by using propidium iodide and AlamarBlue assays. Total phenolic, flavonoid, condensed tannin, alkaloid and lipid contents were evaluated in the fruit and in the leaf extracts. The antioxidant activity of both extracts were also elavaluated. Leaf extract presented the highest content of total phenols, condensed tannins and flavonoids, and also the highest antioxidant activity. While the fruit extract has a higher amount of lipids and alkaloids and the high antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus megaterium and Micrococcus luteus. The leaf extract only showed activity against M. luteus. Concerning the cytotoxic activity, only the fruit extract showed cytotoxicity against the cell lines Jurkat and Kasumi-1. P. lingue fruit extract is a potential source of biologically active molecules for the development of new drugs to be used in some types of leukemia, as well as antibacterial agent.

Persea lingue Ness é uma árvore que vive principalmente na floresta temperada do centro-sul do Chile. As folhas são usadas na etnomedicina. O fruto é uma drupa similar ao abacate e que nunca foi pesquisada anteriormente. O objetivo deste estudo foi o de avaliar a citotoxicidade em células leucêmicas e as atividades antibacterianas, assim como algumas características químicas do extrato de fruto e da folha do P. lingue. As atividades antibacterianas foram determinadas pelo método da inibição do crescimento bacteriano em meio líquido empregando-se bactérias Gram-positivas e Gram-negativas. As linhagens celulares leucêmicas, Kasumi-1 e Jurkat foram usadas para avaliar a atividade citotóxica em ensaios empregando-se iodeto de propídio e AlamarBlue. Foram avaliados os teores totais de fenóis, flavonóides, taninos condensados, alcalóides e lipídeos presentes nos extratos das folhas e dos frutos. As atividades antioxidantes de ambos os extratos também foram avaliadas. O extrato das folhas foi o que apresentou o maior conteúdo de fenóis, taninos condensados e flavonóides totais e a maior atividade antioxidante. Já o extrato de fruto apresentou a maior quantidade de lipídios e alcaloides e a melhor atividade antibacteriana contra Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus megaterium e Micrococcus luteus. Já o extrato das folhas apresentou apenas atividade contra M. luteus. Em relação à atividade citotóxica, apenas o extrato do fruto apresentou citotoxicidade contra as linhagens celulares Jurkat e Kasumi-1. Em resumo, o extrato do fruto de P. lingue é uma potencial fonte de moléculas com atividade biológica para o desenvolvimento de novos fármacos a serem utilizados em alguns tipos de leucemia, bem como agente antibacteriano.

Morphology of the arthrodial membrane gland in a Neotropical harvester (Arachnida: Opiliones)

We describe a gland in the arthrodial membrane of the coxa-trochanter articulation in the fourth pair of legs in the Neotropical harvester Mischonyx squalidus Bertkau, 1880. Externally the glandular area has a rough appearance with pores on its surface, with folds of the arthrodial membrane. Internally, its secretory cells have spherical secretory vesicles, smooth endoplasmic reticulum, mitochondria and ducts that exit from the cells and cross the arthrodial membrane. Histochemical tests indicate the presence of proteins and neutral glycoproteins. The function of the gland might be to produce lubricating products that allow better movement of the coxa-trochanter region.

Antimicrobial activity of flavonoids glycosides and pyrrolizidine alkaloids from propolis of Scaptotrigona aff. postica

Stingless bees, or simply meliponines, are a large group of bees (about 550 described species), comprising the tribe Meliponini. They belong in the family Apidae, and are closely related to Apis mellifera. Scaptotrigona affinis postica Latreille, 1807 from northeast of Brazil is popularly known as “tubi” in Maranhão State. Flavones di-C-glycosides, and the pyrrolizidine alkaloid 3-methoxy-7-(2-methylbutyryl)-9-echimidinyl retronecine (7) were reported previously in propolis from S. postica and detected only in samples collected in October, November and December. The presence of pyrrolizidine alkaloids and their N-oxides were reported in honey and pollen. In the present study, the preparative liquid chromatography in reversed-phase column from ethanolic extract of propolis allowed the separation of fractions 40AEP and 40 MEP, which were analyzed by LC-MS. Many pyrrolizidine alkaloids, among them, lithosenine (14), lithosenine arabinoside (19), 7-angeloyl-9-(2,3- dihydroxybutyryl) retronecine (1), 7-(2- methylbutyryl) retronecine (3), 9-sarracinoyl retronecine (13) and viridinatine (8), besides the flavonoids schaftoside (15), aromadendrin-7-O-methyl ether (12), 7- methoxy-5,6,3’,4’,5’,6’-hexahydroxy-flavone-3-O-glucuronide (11), mangiferin (10) and mangiferin-O-methyl ether (17) were detected in these fractions. Fraction 40MEP showed antibacterial effect against gram positive and gram negative bacterial pathogens with MIC ranging from 62.5 μg/mL to 200 μg/mL, while fractions 40AEP and 40MEP showed antimicrobial activity against gram negative bacteria, including Escherichia coli D31- streptomycin resistant. The cells were treated with 40MEP and 40AEP at a concentration of 200 μg/mL and were not observed statistical difference between treated and untreated cells.

Multiomics profiling of toxins in the venom of the Amazonian spider Acanthoscurria juruenicola

Acanthoscurria juruenicola is an Amazonian spider described for the first time almost a century ago. However, little is known about their venom composition. Here, we present a multiomics characterization of A. juruenicola venom by a combination of transcriptomics, proteomics, and peptidomics approaches. Transcriptomics of female venom glands resulted in 93,979 unique assembled mRNA transcript encoding proteins. A total of 92 proteins were identified in the venom by mass spectrometry, including 14 mature cysteine-rich peptides (CRPs). Quantitative analysis showed that CRPs, cysteine-rich secretory proteins, metalloproteases, carbonic anhydrases, and hyaluronidase comprise >90% of the venom proteome. Relative quantification of venom toxins was performed by DIA and DDA, revealing converging profiles of female and male specimens by both methods. Biochemical assays confirmed the presence of active hyaluronidases, phospholipases, and proteases in the venom. Moreover, the venom promoted in vivo paralytic activities in crickets, consistent with the high concentration of CRPs. Overall, we report a comprehensive analysis of the arsenal of toxins of A. juruenicola and highlight their potential biotechnological and pharmacological applications. Mass spectrometry data were deposited to the ProteomeXchange Consortium via the PRIDE repository with the dataset identifier PXD013149 and via the MassIVE repository with the dataset identifier MSV000087777.

Hemoglobin reassembly of antimicrobial fragments from the midgut of triatoma infestans

Hemoglobin is one of the most important molecules of the human body. Beyond its physiological activity, hemoglobins are able to inhibit the growth of several microorganisms. Since 1999, studies have reported that antimicrobial peptides can be produced by blood-feeding insects through hemoglobin digestion, and it has been reported that Triatoma infestans can generate an antimicrobial fragment from human fibrinopeptide. Thus T. infestans intestinal content was analyzed through Reverse Phase High Performance Liquid Chromatography (RP-HPLC), the eluted fractions were tested against Micrococcus luteus, Escherichia coli and Staphylococcus aureus, and the active fractions submitted to mass spectrometry. The data obtained were compared to hemoglobin databases to verify the presence of hemoglobin-derived fragments. Ten fractions eluted from chromatography presented antimicrobial activity, and when analyzed through mass spectrometry revealed the presence of 8 murine hemoglobin a-chain fragments and 24 fragments from murine hemoglobin ß fragments. Through the compilation of the fragments is possible to obtain over 67% coverage of both sequences. Part of the amino acid sequences corresponds to the sequences already identified on other intestinal contents of arthropods, and are highly conserved between the blood of other wild animals that are the most common intermediate hosts of Chagas’ disease in Brazil and some of the main natural blood source for triatomines.