Biology subjects

Mendonca, R. Z.

Publications and source records attributed to Mendonca, R. Z..

9 recordsLinked to original sources

bioRxiv2024

Antiviral action of different molecules obtained from invertebrates against coronavirus

The few availability of antivirals for new strains of highly pathogenic viruses has become a serious public health problem that leads to the death of thousands of people annually. For this reason, the search for new products against these agents has become an urgent need. Many studies have been carried out with this aim. Among the multiple sources of research for new antibiotics and antivirals, bioprospecting for molecules obtained from invertebrates, or their products, has become an increasingly frequent option. Arthropods appeared on the planet around 350 million years ago and have been one of the beings with the greatest adaptability and resistance. Invertebrates have been found in all known ecosystems. Their survival for so long, in such different environments, is an indication that they have a very efficient protection system against environmental infections, despite not having a developed immune system like mammals. Historically, products obtained mainly from bees, such as honey and propolis, have been shown to be of great pharmacologica l importance, being used as antimicrobials, anti-inflammatory, antitumor, healing and several other functions. However, these molecules have also been obtained from other invertebra tes, such as caterpillars and spiders. Previous studies by our group have demonstrated an intense antiviral and antimicrobial activity of these materials. In this study, we identified, isolated and characterized compounds with potent antiviral effect against avian Coronavirus in propolis from Scaptotrigona aff postica, hemolymph of Lonomia obliqua and from mygalin, an acylpolyamine, isolated from hemocytes of spider Acanthoscurria gomesiana. The antiviral assay was carried out by reducing infectious foci in cultures of infected cells and treated with these differents substances obtained from invertebrates. Propolis and crude hemolymph reduced avian coronavirus by an average of 256 x when used at a concentration of 5% v/v and an average reduction of 8x when 160{micro}M of Mygalin was used. Propolis purified and sinthetic hemolymph reduced the virus titer by an average 64 fold. The virus reduction with synthetic mygalin, at a concentration of 26 uM, was average of 16 times. The antiviral responses of the 3 substances were dose dependent. By the other hand, the virus titer reduction was 2 times more intense when the substances were added 1 hour before cell infection with the virus. The chemical characterization of the elements present in the extracts was carried out by liquid chromatography.

microbiology↗

bioRxiv2023

Shotgun proteomic analysis of the caterpillar Lonomia obliqua (Lepitoptera, Saturniidae) hemolymph and effects in rat hippocampal neurons culture

Study of substances with potentially neuroprotective has been one of the research focus on drugs development. Toxic proteins of Lonomia obliqua caterpillars, which have caused several accidents in southern Brazil, were identified in the hemolymph with anti-apoptotic activity. This study aims the evaluation of the protein profile and the hemolymph effect on cell viability of rats primary cultured hippocampal neurons after apoptosis induction. Semi-quantitative shotgun proteomics approach was used to evaluate the protein profile of 3 caterpillars lots of different origin. Were identified a total of 76 proteins, 71 in hemolymph and 40 in fractions. Antiviral protein predominated in crude hemolymph, following by serine proteases, hemolins and protease inhibitors. In fractions were identified hemolins, serine proteases and protease inhibitors. The treatment of rats primary cultured hippocampal neurons with the chromatographic fraction at concentration of 0.05 and 0.10% (v/v) for 24 hours, with subsequently apoptosis induction was able to maintain cell viability significantly higher than positive control. Hemolymph protein composition can show qualitative and quantitative variations intra species when compared different origins animals and consequently exposed to various environmental factors. The results shown on this study may contribute to the identification of proteins with potential use as neuroprotective in degenerative conditions.

biochemistry↗

bioRxiv2023

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 and isolate proteins from the hemolymph of caterpillars of the Megalopygidae family with pharmacological and biotechnological interest. Two species of this 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 100M. By acting on the mitochondrial pathway of death by apoptosis, a pathway that can cause disorders and diseases neurodegenerative such as Parkinsons and Alzheimers diseases, substances present in the hemolymph of these and others caterpillars could be good candidates in studies for the treatment of these diseases.

cell biology↗

bioRxiv2022

Antiviral action of aqueous extracts of propolis from Scaptotrigona aff. postica against Zica, Chikungunya, and Mayaro virus

The limited availability of antivirals for new highly pathogenic strains of virus has become a serious public health problem that kills thousands of people annually. For this reason, the search for new products against these agents has become an urgent necessity. Many studies have been carried out with this aim. Among the multiple sources of research for new antibiotics and antivirals, bioprospecting from insect exudates or their products has become an increasingly frequent option. Insects appeared on the planet about 350 million years ago and have been one of the beings with greater adaptability and resistance to the most varied biomes. Insects have been found in all known ecosystems. Their survival for so long, in such different environments, is an indication that they have a very efficient protection system against environmental infections, despite not having a developed immune system like mammals. Historically, since the ancient civilizations of Egypt and Rome, the products obtained from the bee, such as honey and propolis, have been of great pharmacological importance, being used as antimicrobial, anti-inflammatory, antitumor, healing several other functions. Investigations on the chemical composition and biological activity of propolis have been carried out, mainly in the species Apis mellifera, and this product has shown activity against some important viruses, such as poliovirus, influenza, HIV, hepatitis, and others. 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 fidelity of the obtained data. Previous studies by our group with crude hydroalcoholic extract of propolis demonstrated an intense antiviral activity against Herpes, influenza, and rubella viruses. All studies carried out with propolis are done with alcoholic extracts. 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 different from those obtained in alcoholic extracts, which makes this work unprecedented. Therefore, this study aimed to identify, isolate and characterize compounds with antiviral effects from aqueous propolis extracts from Scaptotrigona aff postica, in emerging viruses such as zicavirus, chikungunya, and Mayaro. The evaluation of the antiviral activity of the crude and purified material was performed by reducing infectious foci in cultures of infected cells treated with propolis extracts in infected cultures and treated or not treated with propolis. The chemical characterization of the elements present in the extracts was performed by high pressure liquid chromatography. The results obtained indicate a high reduction of Zicavirus (64x) and Mayaro (256x) when was used 10% v/v of propolis and 256 x for chikungunya virus when was used 5% v/v of propolis. When compared to infected-only cultures. Even when was used 2% v/v of propolis, was observed a reduction of 128 fold in Mayaro virus replication. When purified fraction was used, the reduction observed was of 16 fold for Zicavirus, 32 fold for Mayaro virus and 125 fold for chikungunya virus. Likewise, it was observed that the antiviral response was dose-dependent, being more intense when propolis was added 2 hours after the viral infection. At the moment we are carrying out the chemical characterization of the purified compounds that showed antiviral action.

microbiology↗

bioRxiv2022

How a tarantula can help treat infections: Avicularia juruensis theraphotoxins that also act as antimicrobials.

Short abstractConsidering that there are still many species little-studied, this work aimed to analyze the venom of the spider Avicularia juruensis searching for antimicrobial peptides. Using reverse-phase high-performance liquid chromatography, microbial growth inhibition assay, transcriptomics, and proteomics approaches we identified three antimicrobial peptides: Avilin, Juruin_2, and Juruenine. All of them showed similarities with neurotoxins that act on ion channels and, probably, they have the ICK motif. The study of animal venoms is of great importance to carry out the characterization of unknown components and that may have a biotechnological application, in special venoms from spiders that are from less studied families. Spiders are the most successful group of venomous animals, comprising more than 50,350 species distributed in all terrestrial habitats. One strategy that facility their broad distribution is the production of elaborate venoms, which are composed of inorganic salts, organic molecules with low molecular mass, free amino acids, small polypeptides, linear peptides, nucleotides, disulfide-rich peptides, enzymes, and high molecular mass proteins. Considering that there are still many species little-studied, this work aimed to analyze the venom of the mygalomorph spider Avicularia juruensis searching for new antimicrobial peptides. Using reverse-phase high-performance liquid chromatography, microbial growth inhibition assay, transcriptomics, and proteomics approaches we identified three antimicrobial peptides that were named Avilin, Juruin_2, and Juruenine. All of them showed similarities with neurotoxins that act on ion channels and, probably, they have the ICK motif in their structure. The ICK fold seems to be conserved in several venomous animal lineages and presents elevated functional diversity, as well as gives stability to the toxins. The study of animal venoms is of great importance to carry out the characterization of unknown components and that may have a biotechnological application (like the antimicrobial peptides), in special venoms from spiders that are from less studied families.

microbiology↗

bioRxiv2022

"The anti-apoptotic effect of Lonomia obliqua hemolymph is associated with the mitochondria pathway"

The apoptosis death is a very important factors in production processes that limited the industrial production of some proteins of economic interest. However, one of the forms to increase the cellular productivity would be inhibit or attenuate the cellular death. Recently we have demonstrated the presence of a potent anti-apoptotic protein in Lonomia obliqua hemolymph which extends the cell culture viability through apoptosis prevention. By the other side, has been reported that mitochondria have one important action in the apoptosis control process, being that mitochondria membrane permeabilization (MMP) can be an important stage in this process. MMP associated or not with the loss of the electrochemical potential of the mitochondria and alteration of the matrix is responsible for the inter membranes protein release (e.g. cytochrome c, the AIF, etc) of cytosol. The result obtained showed that the addition of a protein from Lonomia obliqua hemolymph in the culture lead to a prolongation of the cellular life (3-4 days) and the cells leading a high electrochemical potential of the mitochondria. This protein can has its action in mitochondria membrane, avoiding the loss of the membrane permeability and the Cytochrome-C release. As positive control, apoptosis death in these cultures was induced by 50 m of t-BHP or 600 m of H202. The presence of apoptosis was characterized by flow citometry, microscopy electronic and agarose gel electrophoresis. The potential electrochemical of the mitochondria was determined by JC-1, Hoechst 33324 and DIOC6. Cytochrome C was identified in cytosol by an anti-cytochrome antibody.

cell biology↗

bioRxiv2022

Antiviral activity of the hemolymph of Podalia sp and M. albicolis (Lepidoptera: Megalopigydae)

Potent antiviral activity against measles, influenza, picornavirus and herpes simplex viruses was observed in the hemolymph of Podalia sp and M. Albicolis (Lepidoptera: Megalopigydae). The antiviral proteins responsible for this activity were isolated by gel filtration chromatography using a gel filtration column system (Superdex 75) and further fractionated using a Resource-Q ion exchange column system. Experiments with the semi-purified protein led to a 128-fold reduction in picornavirus production, 64-fold reduction in measles virus production and a 32-fold reduction in influenza virus replication. qPCR showed a significantly lower level of herpes virus transcription. In addition no citotoxicity and genotoxicity effect was observed for Vero cells, suggesting a very interesting potential antiviral activity.

microbiology↗

bioRxiv2021

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

Stingless bees belonging to the Meliponinae subfamily, are known as meliponines. Scaptotrigona affinis postica Latreille, 1807 from northeast of Brazil is popularly known as tubi in Maranhao State. Scaptotrigona, which is widely distributed in neotropical regions, includes species that build their hives in pre-existing cavities. Flavones di-C-glycosides, and the pyrrolizidine alkaloid 7-(3-methoxy-2-methylbutyryl)-9-echimidinylretronecine were reported previously in propolis from S. postica. Fractions 40 AEP and 40 MEP from ethanolic extract were analyzed by LC-MS. The chromatographic profile of fractions 40 AEP and 40 MEP revealed the presence of many pyrrolizidine alkaloids, among them, lithosenine (14), lithosenine arabinoside (19), 7-angeloyl-9-(2,3- dihydroxybutyryl) retronecine (1), 7-(2-methylbutyryl) retronecine (3), 9-sarracinoylretronecine (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 3-O-methyl mangiferin (17). Fractions 40 AEP and 40 MEP showed antimicrobial activity against Gram negative bacteria, including Escherichia coli D31-streptomycin resistant. Cell viability was expressed in terms of the relative absorbance of treated and untreated cells (control). There was no statistical difference between treated and untreated cells.

microbiology↗

bioRxiv2021

Evaluation of genotoxic and cytogenetic effects of saponins and aluminum hydroxide adjuvant on viral vaccine

Bovine papillomavirus (BPV) is the etiological agent of bovine papillomatosis, infectious disease characterized by the presence of benign tumors that can progress to malignancy. The phylogenetic classification of the PVs is performed based on the sequence homology of the Open Reading Frame L1, the most conserved among different viral serotypes. Given the immunogenicity of saponins, it,s has been used as a candidate as adjuvant use. For this reason, the safety of using saponin as an adjuvant has to be better determined to human or veterinary vaccine use. So, this study aimed to evaluate the mutagenic and genotoxic effect of saponins in comparison with the adjuvant widely used aluminum hydroxide using an isolated and purified L1 protein from BPV as model. In this study, genomic lesions, which after processed without repair can result in mutations, were detected by comet assay. Possible damages to genetic material caused by structural chromosomal changes (clastogenesis), as well as chromosomal losses (aneugenesis) were evaluated by the micronucleus test. Both tests were done on polychromatic erythrocytes and Vero cells. The evaluation of apoptosis and necrosis of treated Vero cells was made by Annexin V / PI staining and flow cytometry. The two vaccine products (L1 +Saponin and L1 + Aluminum Hydroxide) showed damages compatible with the positive control in the comet assay and both slightly elevated the micronucleus levels, in the Cell Viability Assay the results with Aluminum Hydroxide were satisfactory, characterizing Aluminum Hydroxide as a safer adjuvant according to the proposed tests, better than the saponins. Some fractions of the saponin extract separated by High Performance Liquid Chromatography were evaluated against genotoxic activity by comet assay, and their identities were confirmed by similarity to the reference standard by mass spectrometry.

microbiology↗