Osmar Nascimento Silva

• PhD
• Professor (Assistant) at Evangelical University of Goias

Profiling the variability related to the estrous cycle is essential for assessing depressive-like behavior and screening drugs. This study compares circulating plasma corticosterone levels [CORT] and behavioral alterations in mice exposed to sucrose preference, forced swimming, and tail suspension tests (SPT, FST, and TST, respectively). While SPT...

Background The synthetic antimicrobial peptide, PaDBS1R1, has been reported as a powerful anti-Klebsiella pneumoniae antimicrobial. However, there is only scarce knowledge about whether K. pneumoniae could develop resistance against PaDBS1R1 and which resistance mechanisms could be involved. Objectives Identify via label-free shotgun proteomics th...

Citation: Fajemiroye, J.O.; Moreira, A.L.E.; Ito, C.R.M.; Costa, E.A.; Queiroz, R.M.; Ihayi, O.J.; Moreira, C.V.; Costa, R.F.; Teixeira, C.C.; Bortolini, M.J.S.; et al. Advancing Syphilis Research: Exploring New Frontiers in Immunology and Pharmacological Interventions. Abstract: In recent years, the global resurgence of syphilis has posed signific...

Syphilis continues to be a significant global health concern, and understanding the latest advancements in immunology and pharmacological treatment is crucial for effective disease management. This review article provides an in-depth exploration of these advancements, aiming to contribute to the growing body of knowledge on syphilis research. The e...

The pandemic caused by the Coronavirus 19 (Coronavirus disease 2019, COVID-19) killed countless people in 2020 and it arrived in Brazil in mid-February from the same year. It spread quickly, through its facilitated form of transmission by droplets of saliva, coughing, sneezing and contaminated surfaces. Several studies have indicated that male peop...

A Bioeletricidade Pode Revolucionar a Medicina

Trimetozine is used to be indicated for the treatment of mental illnesses, particularly anxiety. The present study provides data on the pharmacological profile of trimetozine derivative morpholine (3,5-di-tert-butyl-4-hydroxyphenyl) methanone (LQFM289) which was designed from molecular hybridization of trimetozine lead compound and 2,6-di-tert-buty...

Bacterial resistance is a threat to health worldwide, mainly due to reduced effective treatment. In this context, the search for strategies to control such infections and suppress antimicrobial resistance is necessary. One of the strategies that has been used is combination therapy. In the present work, we investigated the in vitro efficacy of the...

The gonorrhoea caused by the bacterium Neisseria gonorrhoeae remains a major global public health problem with high morbidity. Gonorrhoea can affect both women and men, being more prevalent in sexually active young individuals. Even after infection from N. gonorrhoeae, many patients may remain asymptomatic, making the diagnosis and adequate treatme...

O presente artigo tem como objetivo analisar a importância do letramento digital na formação dos professores no processo de ensino-aprendizagem. Para tanto, fizemos uma pesquisa bibliográfica, exploratória-descritiva. Observamos que o novo movimento de letramento está baseado na pedagogia crítica e fundamentos filosóficos do letramento crítico e re...

The discovery of antibiotics was a revolutionary feat that provided countless health benefits. The identification of penicillin by Alexander Fleming initiated the era of antibiotics, represented by constant discoveries that enabled effective treatments for the different classes of diseases caused by bacteria. However, the indiscriminate use of thes...

A tuberculose (TB) é uma das mais antigas doenças infecciosas da humanidade e, embora passível de tratamento efetivo, continua sendo um importante problema de saúde pública mundial, em virtude da ampla dispersão geográfica, emergência de casos multirresistentes e coinfecção com HIV. Este estudo busca traçar o perfil epidemiológico, através de uma a...

Forensic Science compounds many study areas in context of solving crimes, one of which is the forensic microbiology. Combined with genomic approaches, microbiology has shown strong performance in studies regarding the relationship between microorganisms present on human skin and environment. The Human Microbiome Project (HMP) has contributed signif...

Objectives In order to evaluate host defense peptides (HDPs) HHC-10 and synoeca-MP activity in in vitro osteoclastogenesis process and in vivo induced apical periodontitis, testing the effect of molecules in the inflammatory response and in apical periodontitis size/volume after root canal treatment. Materials and methods In vitro osteoclastogenes...

Early plants began colonizing earth about 450 million years ago. During the process of coevolution, their metabolic cellular pathways produced a myriad of natural chemicals, many of which remain uncharacterized biologically. Popular preparations containing some of these molecules have been used medicinally for thousands of years. In Brazilian folk...

COVID-19 was characterized as a pandemic regarding its rapid international spread and severity on March 2020. The Coronaviridae family receives this name regarding the organization of the spike glycoprotein located in the envelope, which resembles a stellar corona when observed under a microscope. Coronaviruses undergo frequent mutations in their g...

Dental pulp is a specialized tissue able to respond to infectious processes. Nevertheless, infection progress and root canal colonization trigger an immune-inflammatory response in tooth-surrounding tissues, leading to apical periodontitis and bone tissue destruction, further contributing to tooth loss. In order to shed some light on the effects of...

Significance Novel antibiotics are urgently needed to treat the ever-increasing number of drug-resistant infections. Venoms constitute a treasure trove of novel potential medicines. Here, we converted a peptide derived from venom into potent antimicrobials capable of resolving otherwise lethal infections in mice. We demonstrate that the peptide act...

Background: Gastric ulcer has been a major cause of morbidity and mortality worldwide, and it has been linked to factors such as nutritional deficiency, smoking, stress, and continuous intake of non-steroidal anti-inflammatory drugs (NSAIDs). The search for new anti-ulcer therapeutic agents has been the subject of several studies. Recently, the ga...

Antimicrobial resistance is considered a health issue worldwide. This public health problem underscores the importance of searching for new antimicrobial molecules with different mechanisms of action. Leaf transcriptomes were used to search and develop synthetic antimicrobial peptides derived from mRNA sequences. The in silico search for new AMPs f...

Mastoparan-L (mast-L) is a cell-penetrating tetradecapeptide and stimulator of monoamine exocytosis. In the present study, we evaluated the anxiolytic-like effect of mast-L. Preliminary pharmacological tests were conducted to determine the most appropriate route of administration, extrapolate dose and detect potential toxic effects of this peptide....

Tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC) interactions with the allergenic milk protein casein (CAS) were here evaluated simulating food conditions. The antibiotics assessed interact with CAS through static quenching and form non-fluorescent complexes. At 30ºC, the binding constant (Kb) varied from 0.05 to 1.23 × 10⁶ M⁻¹...

Biofilm formation is an important virulence factor that allows microorganisms to resist host responses and conventional antimicrobial agents. These characteristics constitute the chronic picture of infections associated with biofilms. Therefore, prevention and/or treatment of this type of infection becomes extremely important. In this regard, new s...

The search for new drugs remains an important focus for the safe and effective treatment of cardiovascular diseases. Previous evidence has shown that choline analogs can offer therapeutic benefit for cardiovascular complications. The current study investigates the effects of 2-(4-((1-phenyl-1H-pyrazol-4-yl)methyl)piperazin-1-yl)ethan-1-ol (LQFM032)...

Biofilm-related infections represent an enormous clinical challenge nowadays. In this context, diverse studies are underway to develop effective antimicrobial agents targeting bacterial biofilms. Here, we describe the antibacterial and anti-biofilm activities of a short, cationic peptide named R5F5, obtained from sliding-window analysis based on a...

Over the years, pain has contributed to low life quality, poor health, and economic loss. Opioids are very effective analgesic drugs for treating mild, moderate, or severe pain. Therapeutic application of opioids has been limited by short and long-term side effects. These side effects and opioid-overuse crisis has intensified interest in the search...

Background Cancer is a major cause of mortality and morbidity and given the limitations of many current cancer drugs, there is great need to discover and develop novel treatments. An alternative to the conventional drug discovery path is to exploit new classes of natural compounds such as cyclotides. This peptide family is characterized by linked C...

Infections caused by Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa foremost among them, constitute a major worldwide health problem. Bioinformatics methodologies are being used to rationally design new antimicrobial peptides, a potential alternative for treating these infections. One of the algorithms used to develop antimicro...

Faced with the global health threat of increasing resistance to antibiotics, researchers are exploring interventions that target bacterial virulence factors. Quorum sensing is a particularly attractive target because several bacterial virulence factors are controlled by this mechanism. Furthermore, attacking the quorum-sensing signaling network is...

Background: Arginine is considered a semi-essential amino acid in healthy adults and the elderly. This amino acid seems to improve the immune system, stimulate cell growth and differentiation, and increase endothelial permeability, among other effects. For those reasons, it has been theorized that arginine supplementation may be used as an adjuvant...

Bacterial resistance has become a problem of great concern all over the world. Gram-negative bacteria, including the Enterobacteriaceae family and Pseudomonas and Acinetobacter species, are among the leading causes of healthcare-associated infections. The rate of antibiotic resistance among these pathogens has increased dramatically in recent years...

The extraction and purification of parigidin-br3, a cyclotide analogue belonging to the "bracelet" subfamily, from Palicourea rigida leaves is discussed. Unlike conventional cyclotides, parigidin-br3 has free N-and C-termini, as identified by MALDI-TOF/TOF analysis and confirmed by gene structure elucidation, and is one of a small number of acyclot...

Since the early 19th century, it has been known that host-defense peptides (HDPs) have a crucial role in innate host defense. Subsequent work has demonstrated their role in adaptive immunity as well as their involvement in different inflammatory diseases, autoimmune diseases, and cancer. In addition to these multiple functional activities, several...

Protease inhibitors have a broad biotechnological application ranging from medical drugs to anti-microbial agents. The Inga laurina trypsin inhibitor (ILTI) previously showed a great in vitro inhibitory effect under the adherence of Staphylococcus species, being a strong candidate for use as an anti-biofilm agent. Nevertheless, this is found in sma...

The use of central venous catheters (CVC) is highly associated with nosocomial blood infections and its use largely requires a systematic assessment of benefits and risks. Bacterial contamination of these tubes is frequent and may result in development of microbial consortia also known as biofilm. The woven nature of biofilm provides a practical de...

Objective: To evaluate the antinociceptive and anti-inflammatory activities and the toxic effects of Rhipicephalus microplus saliva for elucidating the modulation mechanism between arthropod saliva and host. Methods: For saliva collection, engorged ticks were obtained from a controlled bovine infestation and collected by natural fall. The ticks wer...

Amniotic membrane (AM) is frequently used in ophthalmologic surgery for rapid ocular surface reconstruction. Sometimes it may create a major problem with associated infections after biofilm formation over the membrane. To overcome this problem, AM was coated with the antimicrobial peptide clavanin A. The antifungal activity of clavanin A in the nat...

Antimicrobial peptides (AMPs) have evolved through billions of years as part of our innate immune system. These agents are produced by various cells throughout the human body and play important roles in our ability to respond to infections. In this review, we outline evidence linking AMP expression with a range of inflammatory and autoimmune human...

In recent years, the number of people suffering from cancer and multi-resistant infections has increased, such that both diseases are already seen as current and future major causes of death. Moreover, chronic infections are one of the main causes of cancer, due to the instability in the immune system that allows cancer cells to proliferate. Likewi...

Mastoparans, a class of peptides found in wasp venom, have significant effects following a sting as well as useful applications in clinical practice. Among these is their potential use in the control of micro-organisms that cause infectious diseases with a significant impact on society. Thus, the present study describes the isolation and identifica...

The extraction and purification of parigidin-br3, a cyclotide analogue belonging to the "bracelet" subfamily, from Palicourea rigida leaves is discussed. Unlike conventional cyclotides, parigidin-br3 has free N- and C-termini, as identified by MALDI-TOF/TOF analysis and confirmed by gene structure elucidation, and is one of a small number of acyclo...

Objectives The purpose of this study was to evaluate the effect of type 2 diabetes mellitus (T2DM) on salivary function impairments according to glycemic control status and subsequently compare the concentration of chromogranin A (CHGA) with its genetic profile. Materials and methods Thirty-six patients with controlled T2DM, 36 with poorly controll...

Antibiotic-resistant infections are predicted to kill 10 million people per year by 2050, costing the global economy $100 trillion. Therefore, there is an urgent need to develop alternative technologies. We have engineered a synthetic peptide called clavanin-MO, derived from a marine tunicate antimicrobial peptide, which exhibits potent antimicrobi...

Enterobacter cloacae is a Gram-negative bacterium associated with high morbidity and mortality in intensive care patients due to its resistance to multiple antibiotics. Currently, therapy against multi-resistant bacteria consists of using colistin, in spite of its toxic effects at higher concentrations. In this context, colistin-resistant E. cloaca...

Clavanins is a class of peptides (23aa) histidine-rich, free of post-translational modifications. Clavanins have been studied largely for their ability to disrupt bacterial membranes. In the present study, the interaction of clavanin A with membranes was assessed by dynamic light scattering, zeta potential and permeabilization assays. We observed t...

Here, the purification, biochemical and biological properties of a trypsin inhibitor from Inga vera seeds (IVTI) are described. Partial amino acid sequence of IVTI showed that it belongs to the MEROPS I03 Kunitz inhibitor family. Moreover, it is composed of a single 20 kDa polypeptide chain with one disulfide bridge and was capable of inhibiting bo...

Proteínas consistem em um dos mais importantes componentes básicos da vida. Uma proteína pode apresentar inúmeros níveis estruturais e desempenhar milhares de funções. Esse fato se reflete na enorme diversidade dos organismos e suas funções, muitas das quais ainda não são entendidas completamente. O estudo da química de proteínas será explorado de...

Objectives: To appraise the salivary and plasma levels of Chromogranin A (ChgA) in controlled and poorly controlled type 2 diabetes mellitus patients compared with age-matched controls. The secondary purposes were to compare the ChgA genetic profile, the salivary flow rate and the periodontal status among groups. Methods: A case-control epidemiolog...

Staphylococcus aureus is a virulent pathogen that is responsible for a wide range of superficial and invasive infections. Its resistance to existing antimicrobial drugs is a global problem and the development of novel antimicrobial agents is crucial. Antimicrobial peptides (AMPs) from natural resources offer potential as new treatments against Stap...

The rapid increase in the incidence of multi-drug-resistant infections today has led to enormous interest in antimicrobial peptides (AMPs) as suitable compounds for developing unusual antibiotics. In this study clavanin A, an antimicrobial peptide, previously isolated from the marine tunicate Styela clava, was selected as a purposeful molecule that...

The main bacterium associated with skin infection is Staphylococcus aureus, occurring especially in infections acquired via surgical wounds, commonly leading to lethal hospital-acquired infections, emphasizing the importance of identifying new antimicrobial compounds. Among them, cyclotides have gained interest due to their high stability and multi...

Controlling human pathogenic bacteria is a worldwide problem due to increasing bacterial resistance. This has prompted a number of studies investigating peptides isolated from marine animals as a possible alternative for control of human pathogen infections. Clavanins are antimicrobial peptides isolated from the marine tunicate Styela clava, showin...

Workflow for clavanin A nonoencapsulation and further morphological and functional characterization. Abbreviations: FITC, fluorescein isothiocyanate; IL, interleukin; TNF, tumor necrosis factor.

Atomic force microscopy analysis of methacrylate nanoparticles for particles obtained using 3:1 (w:w) of polymer (Eudragit® L100-55) and copolymer (Eudragit® RS30D), showing trimodal Gaussian distribution for diameter (69 and 260 nm), with majority showing 120 nm.

Hemolytic activity analysis. Notes: Free peptide (Cl) was compared with nanostructures clavanin A (NCl) and free structure (N), which does not contain the peptide. For bioassays 12 μg of nanostructured peptide was used. C+ correspond to positive control by using 100% Triton X-100. C− correspond to negative control that was saline solution. Abbrevia...

Dynamic light scattering analysis of methacrylate nanoparticles was obtained by use of 3:1 ratios of polymer (Eudragit® L100-55) and copolymer (Eudragit® RS30D). (A) A unimodal Gaussian distribution showing nanoparticles of approximately 372 nm. (B) Experiment showing nanoparticles with −7.16 mV zeta potential.

Peptide rational design was used here to guide the creation of two novel short β-lactamase inhibitors, here named dBLIP-1 and -2, with length of five amino acid residues. Molecular modeling associated with peptide synthesis improved bactericidal efficacy in addition to amoxicillin, ampicillin and cefotaxime. Docked structures were consistent with c...

Bacterial infectious diseases are currently a serious health problem, especially in patients compromised by illness or those receiving immune-suppressant drugs. In this context, it is not only essential to improve the understanding of infectious mechanisms and host response but also to discover novel therapies with extreme urgency. Probiotics and a...

Antimicrobial peptides (AMPs) are multifunctional compounds that may show antimicrobial and immunomodulatory activities. With the rapid increase in the incidence of multidrug-resistant bacteria, there is an enormous interest in AMPs as templates for the production of new antibiotics. However, there are concerns that the therapeutic administration o...

Healthcare-associated infection represents a frequent cause of mortality that increases hospital costs. Due to increasing microbial resistance to antibiotics, it is necessary to search for alternative therapies. Consequently, novel alternatives for the control of resistant microorganisms have been studied. Among them, plant antimicrobial protein pr...

A large number of peptides isolated from different plant species seem to play an important role in plant defense against fungi. The antifungal activities of these compounds have been associated with interaction with components from walls, membranes, or nuclei of fungal cells. According to this view, antifungal peptides may cause physiological, morp...

Despite all the dental information acquired over centuries and the importance of proteome research, the cross-link between these two areas only emerged around mid-nineties. Proteomic tools can help dentistry in the identification of risk factors, early diagnosis, prevention, and systematic control that will promote the evolution of treatment in all...

Inhibitors of peptidases isolated from leguminous seeds have been studied for their pharmacological properties. The present study focused on purification, biochemical characterization and anti-inflammatory and anticoagulant evaluation of a novel Kunitz trypsin inhibitor from Erythrina velutina seeds (EvTI). Trypsin inhibitors were purified by ammon...

Cytotoxicity of trypsin inhibitor purified from seeds of Erythrina velutina (EvTI) and flow cytometry of human peripheral blood in the presence and absence of EvTI. A. Human peripheral blood in the absence of EvTI, andin the presence of EvTI (2.6×10−8 to 1.3×10−6 mol.L−1). Analysis of cytotoxic effects on peripheral blood EvTI total. Absence of inh...

Evaluation of antibacterial activity of trypsin inhibitor purified from seeds of Erythrina velutina (EvTI). A) Effect of different concentrations of EvTI on the growth of Escherichia coli. B) Effect of different concentrations on the growth of Staphylococcus aureus. EvTI of 2.0×10−7 mol.L−1 to 5.3×10−6 mol.L−1. The bacterial culture in PBS represen...

Stability of EvTI purified from Erythrina velutina seeds as a function of pH and temperature. A. Stability at pH variation. B. Thermal stability. EvTI (2.6×10−7 mol.L−1) was pre-incubated for 30 min at different temperatures or pH at 37°C. The inhibitory activity on trypsin (13×10−6 mol.L−1) was determined by using BApNA (1,25.10−3 mol.L−1) as subs...

Exercise is recognized to prevent and attenuate several metabolic and cardiovascular disorders. Obesity is commonly related to cardiovascular diseases, frequently resulting in heart failure and death. To elucidate the effects of acute exercise in heart tissue from obese animals, twelve-week-old C57BL6/J obese (ob/ob) and non-obese (ob/OB) mice were...

A large number of peptides isolated from different plant species seem to play an important role in plant defense against fungi. The antifungal activities of these compounds have been associated with interaction with components from walls, membranes, or nuclei of fungal cells. According to this view, antifungal peptides may cause physiological, morp...

In several organisms, the first barrier against microbial infections consists of antimicrobial peptides (AMPs) which are molecules that act as components of the innate immune system. Recent studies have demonstrated that AMPs can perform various functions in different tissues or physiological conditions. In this view, this study was carried out in...

Envenomation by snakes of the genus Bothrops is characterized by local pain, systemic bleeding, tachycardia, acute renal failure, as well as swelling and redness caused by the enzymatic and proteolytic action of venom. The toxicological and histological effects of the venom of Bothrops itapetiningae, one of the smallest pit vipers in Brazil, were c...

The antimicrobial peptides (AMPs) are evolutionarily ancient molecules that act as components of the innate immune system. Recently, it was demonstrated that a single AMP can perform various functions; this ability is known as "peptide promiscuity." However, little is known about promiscuity in plant AMPs without disulfide bonds. This study was car...

Recently, defense peptides that are able to act against several targets have been characterized. The present work focuses on structural and functional evaluation of the peptide analogue Pa-MAP, previously isolated as an antifreeze peptide from Pleuronectes americanus. Pa-MAP showed activities against different targets such as tumoral cells in cultu...

Titration curve of Pa-MAP in with sodium hydroxide. Experiment was performed with 0.27 mM of Pa-MAP titrated with 1 mM sodium hydroxide. (TIF)

A remarkable and intriguing challenge for the modern medicine consists in the development of alternative therapies to avoid the problem of microbial resistance. The cationic antimicrobial peptides present a promise to be used to develop more efficient drugs applied to human health. The in silico analysis of genomic databases is a strategy utilized...

Antimicrobial peptides (AMPs) are compounds that act in a wide range of physiological defensive mechanisms developed to counteract bacteria, fungi, parasites and viruses. These molecules have become increasingly important as a consequence of remarkable microorganism resistance to common antibiotics. This report shows Escherichia coli expressing the...

In recent decades the activity of conventional antibiotics against pathogenic bacteria has decreased due to the development of resistance. This phenomenon has generated the socalled ‘superbugs’, which are multi-resistant bacteria. In this context, antimicrobial peptides (AMP) appear as an alternative to control them. AMPs have been found in several...

Healthcare-associated infections (HAIs) are causes of mortality and morbidity worldwide. The prevalence of bacterial resistance to common antibiotics has increased in recent years, highlighting the need to develop novel alternatives for controlling these pathogens. Pitviper venoms are composed of a multifaceted mixture of peptides, proteins and ino...

De novo sequencing of peptides generated by mass spectrometer LIFT analysis. (A) BmLAO-f1, (B) BmLAO-f2 and (C) BmLAO-f3 peptides were sequenced through PepSeq. (TIF)

Antimicrobial peptides have been found in mollusks and other sea animals. In this report, a crude extract of the marine snail Cenchritis muricatus was evaluated against human pathogens responsible for multiple deleterious effects and diseases. A peptide of 1485.26 Da was purified by reversed-phase HPLC and functionally characterized. This trypsiniz...

In the last few years, the number of bacteria with enhanced resistance to conventional antibiotics has dramatically increased. Most of such bacteria belong to regular microbial flora, becoming a real challenge, especially for immune-depressed patients. Since the treatment is sometimes extremely expensive, and in some circumstances completely ineffi...

Storage proteins perform essential roles in plant survival, acting as molecular reserves important for plant growth and maintenance, as well as being involved in defense mechanisms by virtue of their properties as insecticidal and antimicrobial proteins. These proteins accumulate in storage vacuoles inside plant cells, and, in response to determine...

Bacterial infections directly affect the world's population, and this situation has been aggravated by indiscriminate use of antimicrobial agents, which can generate resistant microorganisms. In this report, an initial screening of proteins with antibacterial activity from corms of 15 species of the Xanthosoma genus was conducted. Since Xanthosoma...

The "aroeira" (Myracrodruon urundeuva Allemão) is a tropical tree with limited geographic distribution in South America, being found in drier formations such as the Cerrado and Caatinga. Empirically it is used with antiseptic, antiinflammatory, antiulcer, antidiarrhoeal and others. In this study we used mature leaves and expanded from the third and...

Eugenia dysenterica is a plant typically found in the Cerrado biome and commonly used in popular medicine due to its pharmacological properties, which include antidiarrheal, skin healing, and antimicrobial activities. The effects of ethanolic extract, aqueous extract and infusion of E. dysenterica leaves on intestinal motility and antidiarrheal act...

Plant antibacterial peptides have been isolated from a wide variety of species. They consist of several protein groups with different features, such as the overall charge of the molecule, the content of disulphide bonds, and structural stability under environmental stress. Although the three-dimensional structures of several classes of plant peptid...