Hélcio Silva dos Santos

State University of Vale do Acaraú · Química

Objectives Malaria continues to be the primary cause of mortality worldwide, and timely recognition and prompt intervention are crucial in mitigating adverse consequences. This review article aims to examine the effectiveness and structural characteristics of quinoline-based compounds as antimalarial agents. It specifically focuses on their therape...

Leishmaniasis is a neglected disease in tropical and subtropical regions caused by obligate intracellular parasitic protozoa of the genus Leishmania ssp, which can infect humans and animals. In the search for new drugs to treat leishmaniasis, natural compounds have emerged as therapeutic alternatives, such as carvacrol and coumarins, which are cons...

Ischemia/reperfusion injury (I/R) is a leading cause of acute kidney injury (AKI) in conditions like kidney transplants, cardiac surgeries, and nephrectomy, contributing to high global mortality and morbidity. This study aimed to analyze the protective effects of 2′-hydroxychalcones in treating I/R-induced AKI by targeting key pathological pathways...

Small ruminant farming in developing countries is hindered by gastrointestinal nematodes, such as Haemonchus contortus causing anemia, leading to weight loss and reduced productivity. The excessive use of synthetic anthelmintics has driven resistance. Therefore, natural compounds are being investigated as alternative control strategies. Hence, the...

This study investigated the anxiolytic, anticonvulsant and memory preservation effects of the flavonoid robinin. The compound, administered at doses of 4, 20 and 40 mg/kg, did not show toxicity after 96 hours of monitoring. In behavioral experiments with zebrafish, robinin did not cause significant changes in motor functions, but it impairs locomot...

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi and transmitted mainly by triatomine insects, represents a significant challenge to public health, especially in impoverished regions. Current treatments, such as benznidazole and nifurtimox, have limitations, including serious side effects and reduced efficacy in the chronic phase....

Background/Objectives: The work investigates the effect of the estragole complex encapsulated in beta-cyclodextrin (ES/β-CD) in modulating bacterial resistance, specifically in Staphylococcus aureus strains expressing NorA and MepA efflux pumps. Efflux pumps are mechanisms that bacteria use to resist antibiotics by expelling them from the cell. Met...

Bacterial resistance has become a global concern for public health agencies. Various resistance mechanisms found in Staphylococcus aureus strains grant this bacterium resistance to a wide range of antibiotics, contributing to the rise in human mortality worldwide. Resistance mediated by efflux pumps is one of the most prevalent mechanisms in multi-...

(1) Background: Lippia sidoides Cham is a Brazilian aromatic plant rich in phenolic compounds. In traditional medicine, its leaves are used to treat diseases of the Central Nervous System such as stress and anxiety. This study evaluates the capacity of the aqueous extract of L. sidoides as an anticonvulsant, anticholinesterase and antihemolytic age...

The desire for products that are healthier, safer, and better for the environment is on the rise in society. Chalcones are aromatic ketones with anxiolytic and antimicrobial properties. The limited solubility, bioavailability, and long-term stability of chalcones hinder their application. Nanoemulsions can be used as a drug transport system to addr...

Background/Objectives: Nanoemulsions (NEs) possess properties that enhance the solubility, bioavailability and therapeutic efficacy of drugs. Chalcones are compounds known for their antifungal properties. In this study, we evaluated different emulsification techniques to create alginate nanoemulsions containing chalcone (1E,4E)-1,5-bis (4-methoxyph...

The investigation of new drugs is slow and costly. Drug repositioning, like with Hydralazine (HDZ), an old antihypertensive, can accelerate the process. HDZ and its hydrazonic derivatives exhibit diverse biological activities, promising for new drugs. This review explores HDZ's repositioning potential and its derivatives' applications in various bi...

This study investigated the anxiolytic and anticonvulsant effects and safety profile of limonene enantiomers and their oxidized derivatives. The toxicity test was performed by monitoring the animals for 96 hours, with no deaths or significant toxicity observed up to the highest dose, which allowed the determination of the LD50. Doses of 4, 20 and 4...

The compilation of ligand and structure-based molecular modeling methods has become an important practice in virtual screening applied to drug discovery. This systematic review addresses and ranks various virtual screening strategies to drive the selection of the optimal method for studies that have as their starting point a multi-ligand investigat...

Antimicrobials fight microorganisms, preventing and treating infectious diseases. However, antimicrobial resistance (AMR) is a growing concern due to the inappropriate and excessive use of these drugs. Several mechanisms can lead to resistance, including efflux pumps such as the NorA pump in Staphylococcus aureus, which reduces the effectiveness of...

Anxiety and epilepsy are common worldwide and represent a primary global health concern. Fisetin, a flavonoid isolated from Bauhinia pentandra, has a wide range of biological activities may be a promising alternative to combat diseases related to the central nervous system (CNS). The present study aimed to investigate the anxiolytic and anticonvuls...

Background: Ascorbic acid (AA), uric acid (UA), and dopamine (DA) play crucial roles in human metabolism. These substances coexist in biological fluids, and their levels are directly associated with various pathologies. A significant problem encountered in the direct and simultaneous electrochemical detection of AA, UA, and DA is that these species...

Antimicrobial resistance is a global health issue, in which microorganisms develop resistance to antimicrobial drugs, making infections more difficult to treat. This threatens the effectiveness of standard medical treatments and necessitates the urgent development of new strategies to combat resistant microbes. Studies have increasingly explored na...

Parkinson’s disease (PD) is a debilitating condition that can cause locomotor problems in affected patients, such as tremors and body rigidity. PD therapy often includes the use of monoamine oxidase B (MAOB) inhibitors, particularly phenylhalogen compounds and coumarin-based semi-synthetic compounds. The objective of this study was to analyze the s...

The study focuses on the anxiolytic potential of chalcone (2E,4E)‐1‐(2‐hydroxyphenyl)‐5‐phenylpenta‐2,4‐dien‐1‐one (CHALCNM) in adult zebrafish. Successfully synthesized in 58% yield, CHALCNM demonstrated no toxicity after 96 h of exposure. In behavioral tests, CHALCNM (40 mg/kg) reduced locomotor activity and promoted less anxious behavior in zebr...

This study aims to evaluate the antitrypanosomiasis activity of a synthetic dichloro-substituted aminochalcone via in vitro assays against infected cell cultures, as well as a theoretical characterization of pharmacokinetics and pharmacodynamics against the protein targets of the evolutionary cycle of T. cruzi. The in vitro evaluation of parasite p...

A Educação Ambiental (EA) é uma instituição histórica que se estabeleceu ao longo dos anos para promover alternativas sustentáveis e amenizar os problemas enfrentados pela população. Com base no exposto, este trabalho teve como objetivo realizar uma pesquisa exploratória de caráter bibliográfico, do tipo Revisão de Literatura, desenvolvida com base...

This is the first study to analyze the anti‐inflammatory and antinociceptive effect of withanicandrin, isolated from Datura Ferox leaves, and the possible mechanism of action involved in adult zebrafish (ZFa). To this end, the animals were treated intraperitoneally (i.p.) with withanicandrin (4; 20 and 40 mg/kg; 20 μL) and subjected to locomotor ac...

Ultramodern analytical techniques must also be hyphenated with cheaper and less complex techniques such as UV-visible spectrophotometry to confirm the formation of organic synthesis products. Here, the synthesis of 4 compounds (HC4ATIOF, HFEC, HCPA4NO2, and HICNM) from a clinically approved antitubercular drug, the Isoniazid, was preliminarily veri...

Table of Contents, Issue 2, Volume 12, Journal of Renewable Materials

According to The World Alzheimer Report 2023 by Alzheimer’s Disease International (ADI) estimates that 33 to 38.5 million people worldwide suffer from Alzheimer’s Disease (AD). A crucial hallmark associated with this disease is associated with the deficiency of the brain neurotransmitter acetylcholine, due to an affected acetylcholinesterase (AChE)...

The Enterobacteriaceae family is recognized as a primary group of Gram-negative pathogens responsible for foodborne illnesses and is frequently associated with antibiotic resistance. The present study explores the natural-based compound trans-cinnamaldehyde (TC) against drug-resistant Enterobacteriaceae and its synergism with gentamicin (GEN) to ad...

Griffinia gardneriana Ravenna, Griffinia liboniana Morren and Griffinia nocturna Ravenna (Amarillydaceae) are bulbous plants found in tropical regions of Brazil. Our work aimed to determine the alkaloid profiles of Griffinia spp. and evaluate their anxiolytic potential through in vivo and in silico assays. The plants grown in greenhouses were dried...

The xanthone Lichenxanthone did not show toxic effects (LC50 > 1.0 mg/mL). Lichenxanthone prevented nociceptive behavior induced by acidic saline, and its analgesic effect was blocked by amiloride, highlighting the involvement of neuromodulation of acid‐sensitive ion channels (ASICs). In the analysis of anti‐inflammatory activity, concentrations of...

Background: Staphylococcus aureus is a human pathogen responsible for high mortality rates. The development of new antimicrobials is urgent. Materials & methods: The authors evaluated the activity of hydralazine along with its synergism with other drugs and action on biofilms. With regard to action mechanisms, the authors evaluated cell viability,...

The Piper genus, known for its pharmacological potential, comprises 2,263 species primarily found in tropical regions. Despite recent advancements in pain therapies, the demand for more effective and well‐tolerated analgesics and anti‐inflammatories, particularly for chronic pain, remains. This study assessed the effects of essential oils from Pipe...

Background: Infections caused by multi-resistant microorganisms are a public health issue. Synthetic products have been studied as a therapeutic alternative for these cases, with the aim of antibacterial activity or enhancing existing antibiotics. Methods: This study aimed to evaluate the antibacterial activity upon modifying antibiotic actions and...

Aim: Our objective was to investigate the trypanocidal effect of the chalcone (2 E,4 E)-1-(2-hydroxy-3,4,6-trimethoxyphenyl)-5-phenylpenta-2,4-dien-1-one (CPNC). Material & methods: Cytotoxicity toward LLC-MK2 host cells was assessed by MTT assay, and the effect on Trypanosoma cruzi life forms (epimastigotes, trypomastigotes and amastigotes) was ev...

As the spread of bacterial resistance to clinically available antibiotics has become a global public health problem, the scientific community has intensified its studies in the search for natural compounds and their derivatives to combat bacterial resistance. In this work, a circadian study of the essential oil extracted from the leaves of Croton p...

Treatment of cutaneous leishmaniasis depends on drugs that potentially cause serious side effects and resistance. Thus, topical therapies are attractive alternatives to the drugs currently used. 3β, 6β, 16β-trihydroxylup-20 (29)-ene is a lupane triterpene isolated from Combretum leprosum Mart. leaves (CLF-1), with reports of in vitro antileishmania...

Salmonellosis has a high power of dissemination and dispersion of strains resistant to conventional antimicrobials, which constitutes a public health problem. Nanoemulsions can enhance the efficacy of antimicrobials compared to conventional drug administration, with reduced side effects and prolonged release. The aim of this study is to produce nan...

Tetragonisca angustula (Latreille, 1811) is an indigenous neotropical stingless bee, popularly known as "Jataí", with a wide distribution in the Brazilian territory. T. angustula produces other derivatives such as propolis, geopropolis, fermented (saburá pollen), cerumen and resins, which are important in folk medicine. In this review, the objectiv...

Diabetes mellitus is a medical condition characterized by elevated blood glucose levels, known as hyperglycemia, which can damage other organs of the human body through metabolic alterations. Pectin, a naturally occurring polysaccharide, is present in the cell walls of plants and is composed of a polymer chain of galacturonic acid with additional s...

Background: Anxiety disorders represent the complex interaction between biological, psychological, temperamental, and environmental factors; drugs available to treat anxiety such as benzodiazepines (BZDs) are associated with several unwanted side effects. Although there are useful treatments, there is still a need for more effective anxiolytics wi...

A Educação Ambiental na macrorregião do Jaguaribe aponta a necessidade de vincular a pesquisa científica a prática docente para a produção de estratégias, ferramentas e ações voltadas a conscientização sobre as questões ambientais nas escolas estadual e municipal. As atividades da extensão retrataram as necessidades de ações criativas e inovações p...

A Educação Ambiental na macrorregião do Jaguaribe aponta a necessidade de vincular a pesquisa científica a prática docente para a produção de estratégias, ferramentas e ações voltadas a conscientização sobre as questões ambientais nas escolas estadual e municipal. As atividades da extensão retrataram as necessidades de ações criativas e inovações p...

Introduction. Antibiotic resistance is a major threat to public health, particularly with methicillin-resistant Staphylococcus aureus (MRSA) being a leading cause of antimicrobial resistance. To combat this problem, drug repurposing offers a promising solution for the discovery of new antibacterial agents. Hypothesis. Menadione exhibits antibacteri...

Background: Thiadiazines are heterocyclic compounds that contain two nitrogen atoms and one sulfur atom in their structure. These synthetic molecules have several relevant pharmacological activities, such as antifungal, antibacterial, and antiparasitic. Objectives: The present study aimed to evaluate the possible in vitro and in silico interacti...

Background: Clove volatile oil (CVO) and its major compound, eugenol (EUG), have anxiolytic effects, but their clinical use has been impaired due to their low bioavailability. Thus, their encapsulation in nanosystems can be an alternative to overcome these limitations. Objectives: This work aims to prepare, characterize and study the anxiolytic...

This work presents the synthesis of 12 phenol and chromone derivatives, prepared by the analogs, and the possibility of conducting an in silico study of its derivatives as a therapeutic alternative to combat the SARS-CoV-2, pathogen responsible for COVID-19 pandemic, using its S-glycoprotein as a macromolecular target. After the initial screening f...

Este estudo trata-se de uma revisão integrativa de literatura que teve como objetivo avaliar a atividade antimicrobiana e moduladora da resistência de derivados da hidrazina (hidrazona e isoniazida) em cepas multirresistentes de S. aureus. A resistência antimicrobiana é considerada uma das 10 maiores ameaças mundiais pela Organização Mundial de Saú...

Background: The bacterium Staphylococcus aureus has stood out for presenting a high adaptability, acquiring resistance to multiple drugs. The search for natural or synthetic compounds with antibacterial properties capable of reversing the resistance of S. aureus is the main challenge to be overcome today. Natural products such as chalcones are sub...

Severe Acute Respiratory Syndrome caused by a coronavirus is a recent viral infection. There is no scientific evidence or clinical trials to indicate that possible therapies have demonstrated results in suspected or confirmed patients. This work aims to perform a virtual screening of 1430 ligands through molecular docking and to evaluate the possib...

Unlabelled: Diabetes is a disease linked to pathologies, such as chronic inflammation, neuropathy, and pain. The synthesis by the Claisen-Schmidt condensation reaction aims to obtain medium to high yield chalconic derivatives. Studies for the synthesis of new chalcone molecules aim at the structural manipulation of aromatic rings, as well as the r...

Essential oils extracted from many plant species have different biological activities, among which microbial activity stands out. Species of the genus Piper have antimicrobial potential against different species of bacteria and fungi. In this sense, the present study aimed to determine the chemical composition of the essential oil from the leaves o...

Chalcones have an open chain flavonoid structure that can be obtained from natural sources or by synthesis and are widely distributed in fruits, vegetables, and tea. They have a simple and easy to handle structure due to the α-β-unsaturated bridge responsible for most biological activities. The facility to synthesize chalcones combined with its eff...

poster

Tinnitus is a syndrome that affects the human auditory system and is characterized by a perception of sounds in the absence of acoustic stimuli, or in total silence. Research indicates that muscarinic acetylcholine receptors (mAChRs), especially the M1 type, have a fundamental role in the alterations of auditory perceptions of tinnitus. Here, a ser...

Species belonging to the genus Lippia are used worldwide as foods, beverages, and seasonings. Studies have demonstrated that these species have antioxidant, sedative, analgesic, anti-inflammatory, and antipyretic activities. This work aimed to evaluate the antibacterial activity and anxiolytic effect by different pathways of essential oils and etha...

General anxiety disorders are among the most prevalent mental health problems worldwide. The emergence and development of anxiety disorders can be due to genetic (30–50%) or non-genetic (50–70%) factors. Despite medical progress, available pharmacotherapies are sometimes ineffective or can cause undesirable side effects. Thus, it becomes necessary...

Anxiety-related mental health problems are estimated at 3.6% globally, benzodiazepines (BZDs) are the class of drugs indicated for the treatment of anxiety, including lorazepam and diazepam. However, concerns have been raised about the short- and long-term risks associated with BZDs. Therefore, despite anxiolytic and antidepressant drugs, there is...

Antimicrobial resistance is a natural phenomenon and is becoming a huge global public health problem, since some microorganisms not respond to the treatment of several classes of antibiotics. The objective of the present study was to evaluate the antibacterial, antibiofilm, and synergistic effect of triterpene 3β,6β,16β-trihydroxyilup-20(29)-ene (C...

The increased resistance of microorganisms to antimicrobial drugs makes it necessary to search for new active compounds, such as chalcones. Their simple chemical structure makes them molecules easy to synthesize. Therefore, the aim of this study was to evaluate the antimicrobial and potentiating activity of antibiotics and antifungals by synthetic...

Rauvolfia species are well-known as producers of bioactive monoterpene indole alkaloids (MIAs) which exhibit a broad spectrum of biological activities. A new vobasine-sarpagan-type bisindole alkaloid (1) along with six known monomeric indoles (2, 3/4, 5, and 6/7) were isolated from the ethanol extract from the roots of Rauvolfia ligustrina. The str...

About 6.5 million people are infected with Chagas disease (CD) globally, and WHO estimates that $ > million people worldwide suffer from ChHD. Sudden cardiac death (SCD) represents one of the leading causes of death worldwide and affects approximately 65% of ChHD patients at a rate of 24 per 1000 patient-years, much greater than the SCD rate in the...