Própolis vermelha e ação antifúngica: potencialidades e desafios / Red própolis and antifungal activity: potentialities and challenges / Propóleo rojo y acción antifúngica: potencialidades y desafíos

Introdução: a própolis é uma composição resinosa produzida por abelhas e utilizada em suas colmeias contra microrganismos. Existem diversos tipos desse composto, sendo o de coloração vermelha o último espécime relatado na literatura. Assim, dentre suas aplicabilidades, a atividade antifúngica da própolis vermelha tem sido explorada com vistas a ampliar sua ação terapêutica. Objetivo: explorar estudos acerca da ação antifúngica da própolis vermelha, identificando suas potencialidades e desafios. Metodologia: foi realizada uma revisão integrativa nas bases de dados bibliográficos MEDLINE (via PubMed), SciELO e Google Acadêmico, complementada por uma diligência nas bases de ensaios clínicos ReBEC e Clinical Trials. Em seguida todos os estudos selecionados foram explorados para obtenção do cenário atual sobre o tema. Resultados: foram incluídos 08 estudos, sendo 01 deles um ensaio clínico. Os estudos comprovam a ação antifúngica da própolis vermelha, principalmente contra Candida spp. e Paracoccidioides brasiliensis, e evidenciam a maior potência fungicida deste composto em detrimento de outros tipos de própolis. Conclusão: a ação antifúngica da própolis vermelha mostra-se uma potencialidade em diversos estudos. Entretanto, o volume de pesquisas científicas relativas a esse tema é insuficiente e a complexidade desse composto configura-se como um desafio à sua aplicabilidade.

Introduction: propolis is a resinous composition produced by compounds and used in their hives against microorganisms. There are several types of this compound, the red one is the last specimen reported in the literature. Thus, among its applicability, the antifungal activity of red propolis has been explored as a path to expand its therapeutic action. Objective: to explore studies about the antifungal action of red propolis, identifying its potentialities and challenges. Methodology: Na integrative review was carried out in the bibliographic databases MEDLINE (via PubMed), SciELO and Google Scholar, complemented by a diligence in ReBEC and Clinical Trials databases. Then, all selected studies were explorers to obtain the current scenario on the subject. Results: 08 studies were included, which 01 of them was a clinical trial. Studies prove the antifungal action of red propolis, mainly against Candida spp. and Paracoccidioides brasiliensis, and show the greater fungicidal power of this compound compared to other types of propolis. Conclusion: the antifungal action of red propolis shows potential in several studies. However, the volume of scientific research on this theme is insufficient and the complexity of this compound represents a challenge to its applicability.

Introducción: el propóleo es una composición resinosa producida por las abejas y utilizada en sus colmenas contra los microorganismos. Existen varios tipos de este compuesto, siendo el rojo el último ejemplar reportado en la literatura. Así, entre sus posibilidades de aplicación, se ha explorado la actividad antifúngica del propóleo rojo con vistas a ampliar su acción terapéutica. Objetivo: explorar estudios sobre la acción antifúngica del propóleo rojo, identificando sus potencialidades y desafíos. Metodología: Se realizó una revisión en las bases de datos bibliográficas MEDLINE (vía PubMed), SciELO y Google Scholar, complementada con una diligencia en las bases de datos de ensayos clínicos ReBEC y Clinical Trials. Luego se exploraron todos los estudios seleccionados para obtener el escenario actual sobre el tema. Resultados: Se incluyeron 08 estudios, 01 de los cuales fue un ensayo clínico. Los estudios demuestran la acción antifúngica del propóleo rojo, principalmente contra Candida spp. y Paracoccidioides brasiliensis, y muestran el mayor poder fungicida de este compuesto en detrimento de otros tipos de propóleos. Conclusión: la acción antifúngica del propóleo rojo muestra potencial en varios estudios. Sin embargo, el volumen de investigación científica sobre este tema es insuficiente y la complejidad de este compuesto representa un desafío para su aplicabilidad.

Phytochemical profile, evaluation of antimicrobial and antioxidant activity in vitro of the hydroalcoholic extract of two species of the genus Cyperus (Cyperaceae)

Abstract Several factors contribute to the resistance of some pathogenic microorganisms and this fact requires the search for new therapeutic alternatives. The genus Cyperus (family Cyperaceae) groups species that present chemical compounds of pharmacological interest, mainly with antimicrobial action. Thus, the present work was carried out to investigate the antimicrobial activities, antioxidants and the phytochemical profile of Cyperus articulatus L. and Cyperus iria L. Hydroalcoholic extracts (1:1, v:v) of the aerial and underground parts of these species were used to analyze the total phenol content and to evaluate the in vitro antioxidant activity against the DPPH (2,2-diphenyl-1-picrylhydrazyl). The ethyl acetate and chloroform phases resulting from liquid-liquid partitioning of C. articulatus and C. iria extracts were evaluated in antimicrobial assays and subject to high performance liquid chromatography (HPLC-DAD) analysis. The chromatograms obtained by HPLC-DAD allowed us to identify four compounds: chlorogenic acid, catechin, quercetin, and quercitrin. The hydroalcoholic extracts of C. articulatus and C. iria showed a weak antioxidant activity with IC50 of 395.57 and 321.33 µg/mL (aerial parts), and 1,114.01 and 436.82 µg/mL (underground parts), respectively. Regarding antimicrobial activity, the chloroform phase of C. iria showed the best result at the concentration of only 31.2 µg/mL against the pathogens Candida albicans and Staphylococcus aureus. The ethyl acetate phases of the aerial parts of C. articulatus and C. iria did not show antimicrobial activity

Propolis in Oral Healthcare: Antibacterial Activity of a Composite Resin Enriched With Brazilian Red Propolis.

The aim of this study was to obtain a Brazilian red propolis (BRP) enriched composite resin and to perform the characterization of its antibacterial activity, mechanical, and physical-chemical properties. Brazilian red propolis ethyl acetate extract (EABRP) was characterized by LC-ESI-Orbitrap-FTMS, UPLC-DAD, antibacterial activity, total flavonoids content, and radical scavenging capacity. BRP was incorporated to a commercial composite resin (RC) to obtain BRP enriched composite at 0.1, 0.15 and 0.25% (RP10, RP15 and RP25, respectively). The antibacterial activity RPs was evaluated against Streptococcus mutans by contact direct test and expressed by antibacterial ratio. The RPs were characterized as its cytotoxicity against 3T3 fibroblasts, flexural strength (FS), Knoop microhardness (KHN), post-cure depth (CD), degree of conversion (DC%), water sorption (Wsp), water solubility (Wsl), average roughness (Ra), and thermal analysis. Were identified 50 chemical compounds from BRP extract by LC-ESI-Orbitrap-FTMS. EABRP was bacteriostatic and bactericide at 125 and 500 µg/ml, respectively. The RP25 exhibited antibacterial ratio of 90.76% after 1 h of direct contact with S. mutans (p < 0.0001) while RC no showed significative antibacterial activity (p = 0.1865), both compared with cell control group. RPs and RC no showed cytotoxicity. RPs exhibited CD from 2.74 to 4.48 mm, DC% from 80.70 to 83.96%, Wsp from 17.15 to 21.67 µg/mm3, Wsl from 3.66 to 4.20 µg/mm3, Ra from 14.48 to 20.76 nm. RPs showed thermal resistance between 448-455°C. The results support that propolis can be used on development of modified composite resins that show antibacterial activity and that have compatible mechanical and physical-chemical properties to the indicate for composite resins.

Layered double hydroxides for controlled fluoride release.

This study aims to develop a nano-sized fluoridated layered double hydroxide (LDH)-based release system via hydrothermal treatment for the controlled delivery of fluoride (F-) ions in the oral environment. The synthesis of conventional LDH-type (C-LDH) precursor nanomaterials was conducted using a co-precipitation method at constant pH, and the nanoparticulate-LDH (N-LDH) was synthesized by a hydrothermal procedure. Fluoride LDH (F-LDH) products were obtained through indirect synthesis using the precursor ion-exchange technique by varying the agitation time (2 and 24 h) and temperature (25 and 40 °C) to produce 12 material samples. The materials were characterized by energy dispersive x-ray, hexamethyldisilazane, digital radiography x-ray, Fourier-transform infrared, thermogravimetric analysis, and scanning electron microscopy. Additionally, the F-release kinetic profile was evaluated for 21 d in neutral and acid media with mathematical model analysis. Products with varying F-quantities were obtained, revealing specific release profiles. In general, there was a higher F-release in the acid medium, with emphasis on F-LDH-8. Fluoride-LDH and controlled fluoride delivery was successfully obtained, proving the potential of these nanomaterials as alternative anti-caries agents.

Polyphenols and Brazilian red propolis incorporated into a total-etching adhesive system help in maintaining bonding durability.

OBJECTIVES: The aim of this study was to evaluate the degree of conversion and bond strength of a commercial dental adhesive modified by the incorporation of quercetin, resveratrol (RES), and Brazilian red propolis (BRP). METHODS: BRP markers were identified using ultra-performance liquid chromatography coupled with a diode array detector, and the antioxidant activity (AAO) of the three substances was analyzed. Single Bond 2 adhesive (3M ESPE) was modified by adding BRP, quercetin, and RES, separately, at 20 µg/mL, 250 µg/mL, and 500 µg/mL, respectively. The degree of conversion (DC) was measured using near-infrared spectroscopy 24 h after photopolymerization. Measurements of the resin-dentin microtensile bond strength (µTBS) were carried out after 1 day and 1 year. Student's t test and ANOVA with Tukey's test were used for data analysis (α = 0.05). RESULTS: The markers daidzein, liquiritigenin, pinobanksin, isoliquiritigenin, formononetin, pinocembrin, and biochanin A were found in the ethanolic extract of BRP. Quercetin, RES, and BRP showed high AAO. The DC of the tested adhesives remained adequate for this category of material, with a slight increase in the DC of adhesives with quercetin and BRP (P > 0.05). Comparisons between µTBS measurements made at 1 day and 1 year showed that, contrary to the control group, µTBS values for all modified adhesives were maintained after 1 year in distilled water (P > 0.05). CONCLUSIONS: These findings suggest that quercetin, RES, or BRP might be useful in adhesive dentistry to help improve hybrid layer resistance. CLINICAL SIGNIFICANCE: Dentin bonding agents with quercetin, RES, and BRP have potential to increase the longevity of composite restorations.

Staphylococcal cassette chromosome mec elements from Staphylococcus intermedius group (SIG) isolates from dogs in a center for veterinary diagnostics in Brazil / Cassetes cromossômicos estafilocócicos mec de isolados do grupo Staphylococcus intermedius (GSI) de cães em um centro veterinário de diagnósticos no Brasil

ABSTRACT: Methicillin resistance in the Staphylococcus intermedius group (SIG) has emerged in small animal practice. Methicillin-resistant SIG (MRSIG) members have been implicated as causes of infections in both companion animals and humans. Staphylococcal cassette chromosome mec (SCCmec) elements carry the mecA/C genes, which encode for the transpeptidase PBP2a (PBP2') responsible for β-lactam antibiotic resistance in staphylococci. This study examined the SCCmec types of MRSIG isolates from different clinical specimens of dogs that exhibited methicillin MIC ≥ 0.5 μg/mL by an automated identification and susceptibility system in a Center for Veterinary Diagnostics in São Paulo, Brazil. Susceptibility to methicillin was determined by broth microdilution testing, and Oxoid® M.I.C.Evaluator® strips. PBP2a production was detected using a latex agglutination assay. SCCmec typing was performed according to the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) guidelines. SCCmec type II (2A), SCCmec type III (3A), composite SCC structures consisting of a class A mec gene complex in addition to multiple ccr gene complexes, and non-typable SCCmec elements were reported in these MRSIG isolates. SCCmec type variants differing from those so far acknowledged by IWG-SCC were found, indicating new rearrangements in the genetic context of mecA in these canine MRSIG isolates.

RESUMO: A resistência à meticilina no grupo Staphylococcus intermedius (GSI) tem aumentado na clínica de pequenos animais. Membros GSI resistentes à meticilina (GSIRM) têm sido causas de infecções tanto em animais de companhia e humanos. Cassetes cromossômicos estafilocócicos mec (SCCmec) carregam os genes mecA/C, que codificam a transpeptidase PBP2a (PBP2') responsável pela resistência aos antibióticos β-lactâmicos em estafilococos. Nosso objetivo foi investigar os elementos SCCmec de GSIRM isolados de diferentes amostras clínicas de cães que exibiram CIM de meticilina ≥ 0,5 μg/mL por meio de um sistema automatizado em um Centro Veterinário de Diagnósticos em São Paulo, Brasil. A sensibilidade à meticilina foi determinada por meio do teste de microdiluição em caldo e fitas Oxoid® M.I.C.Evaluator®. A produção de PBP2a foi detectada usando um ensaio de aglutinação de látex. A tipagem dos elementos SCCmec foi realizada de acordo com as diretrizes do International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC). SCCmec tipo II (2A), SCCmec tipo III (3A), SCC compostos de um complexo mec de classe A com múltiplos complexos ccr, e elementos SCCmec não tipáveis foram encontrados nesses isolados GSIRM. Variantes que diferem dos elementos SCCmec reconhecidos até o momento pelo IWG-SCC foram encontradas, indicando novos rearranjos no contexto genético de mecA nesses isolados GSIRM caninos.

Layered double hydroxides for controlled fluoride release

Abstract This study aims to develop a nano-sized fluoridated layered double hydroxide (LDH)-based release system via hydrothermal treatment for the controlled delivery of fluoride (F-) ions in the oral environment. The synthesis of conventional LDH-type (C-LDH) precursor nanomaterials was conducted using a co-precipitation method at constant pH, and the nanoparticulate-LDH (N-LDH) was synthesized by a hydrothermal procedure. Fluoride LDH (F-LDH) products were obtained through indirect synthesis using the precursor ion-exchange technique by varying the agitation time (2 and 24 h) and temperature (25 and 40 °C) to produce 12 material samples. The materials were characterized by energy dispersive x-ray, hexamethyldisilazane, digital radiography x-ray, Fourier-transform infrared, thermogravimetric analysis, and scanning electron microscopy. Additionally, the F-release kinetic profile was evaluated for 21 d in neutral and acid media with mathematical model analysis. Products with varying F-quantities were obtained, revealing specific release profiles. In general, there was a higher F-release in the acid medium, with emphasis on F-LDH-8. Fluoride-LDH and controlled fluoride delivery was successfully obtained, proving the potential of these nanomaterials as alternative anti-caries agents.

Virulence, agr groups, antimicrobial resistance and epidemiology of Staphylococcus aureus isolated from bovine subclinical mastitis / Virulência, grupos agr, resistência a antimicrobianos e epidemiologia de isolados de Staphylococcus aureus obtidos de vacas com mastite

Fifty-two Staphylococcus aureus recovered from papillary ostium and milk samples collected from cows with subclinical mastitis and milking environments in three small dairy herds located in southeastern Brazil were subjected to PCR identification based on the thermonuclease (nuc) gene. All the strains were submitted to in vitro antimicrobial susceptibility testing, and we investigated the sequence types (STs), agr groups (I-IV), virulence genes encoding for Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMMs), biofilm-associated proteins, bi-component toxins, pyrogenic toxin superantigens, and enterotoxins. Screening for oxacillin resistance (2-6 µg/ml oxacillin), beta-lactamase activity assays, and PCR for the mecA/mecC genes detected 26 methicillin-susceptible S. aureus(MSSA) and 26 mec-independent oxacillin-nonsusceptible S. aureus (MIONSA). While MSSA isolates were found to be susceptible to all antimicrobial agents tested, or only resistant to penicillin and ampicillin, MIONSA isolates were multidrug-resistant. ST126-agr group II MSSA isolates were prevalent in milk (n=14) and carried a broad set of virulence genes (clfA, clfB, eno, fnbA, fiB, icaA, icaD, lukED, hla, and hlb), as well as the ST126-agr group II MIONSA isolated from milking liners (n=1), which also carried the eta gene. ST1-agr group III MIONSA isolates (n=4) were found in papillary ostium and milk, but most MIONSA isolates (n=21), which were identified in both papillary ostium and milking liners, were agr-negative and assigned to ST126. The agr-negative and agr group III lineages showed a low potential for virulence. Studies on the characterization of bovine-associated MSSA/MIONSA are essential to reduce S. aureus mastitis to prevent economic losses in dairy production and also to monitor the zoonotic potential of these pathogens associated with invasive infections and treatment failures in healthcare.

Cinquenta e dois isolados de Staphylococcus aureus obtidos de amostras colhidas do óstio papilar, do leite de vacas com mastite subclínica e do ambiente de ordenha em três fazendas de rebanhos leiteiros localizadas no sudeste do Brasil foram identificados por PCR para o gene da termonuclease (nuc). Todos os isolados foram testados para sensibilidade a antimicrobianos e foram investigados os sequence types (STs), grupos agr (I-IV) e genes de virulência que codificam Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMMs), proteínas associadas a biofilme, toxinas bi-componentes, toxinas pirogênicas com propriedades de superantígenos e enterotoxinas. Triagem para detecção de resistência à oxacilina (2-6 µg/ml oxacilina), ensaios de atividade de enzimas beta-lactamases e PCR para os genes mecA/mecC detectaram 26 estirpes de S. aureus sensíveis à meticilina (methicillin-susceptible S. aureus, MSSA) e 26 estirpes de S. aureus mec-negativas não sensíveis à meticilina (mec-independent oxacillin-nonsusceptible S. aureus, MIONSA). Enquanto os isolados MSSA foram sensíveis a todos os agentes antimicrobianos testados, ou apenas resistentes à penicilina e ampicilina, os isolados MIONSA foram multirresistentes. MSSA ST126-agr grupo II foram prevalentes no leite (n= 14) e apresentaram um amplo conjunto de genes de virulência (clfA, clfB, eno, fnbA, fiB, icaA, icaD, lukED, hla e hlb), assim como o isolado MIONSA ST126-agr grupo II proveniente de um insuflador (n= 1), o qual também apresentou o gene eta. MIONSA ST1-agr grupo III (n= 4) foram identificados no óstio papilar e leite, mas a maioria dos isolados MIONSA (n= 21), encontrados em óstios papilares e insufladores, foram agr-negativos e pertenceram ao ST126. As linhagens agr-negativas e agr grupo III apresentaram baixo potencial de virulência. Estudos sobre a caracterização de MSSA/MIONSA associados a bovinos são essenciais para a redução da mastite causada por S. aureus e de perdas econômicas na produção leiteira e, também, para o monitoramento do potencial zoonótico desses patógenos associados a infecções invasivas e falhas de tratamento em ambientes hospitalares.

Inhibition of matrix metalloproteinases: a troubleshooting for dentin adhesion.

Matrix metalloproteinases (MMPs) are enzymes that can degrade collagen in hybrid layer and reduce the longevity of adhesive restorations. As scientific understanding of the MMPs has advanced, useful strategies focusing on preventing these enzymes' actions by MMP inhibitors have quickly developed in many medical fields. However, in restorative dentistry, it is still not well established. This paper is an overview of the strategies to inhibit MMPs that can achieve a long-lasting material-tooth adhesion. Literature search was performed comprehensively using the electronic databases: PubMed, ScienceDirect and Scopus including articles from May 2007 to December 2019 and the main search terms were "matrix metalloproteinases", "collagen", and "dentin" and "hybrid layer". MMPs typical structure consists of several distinct domains. MMP inhibitors can be divided into 2 main groups: synthetic (synthetic-peptides, non-peptide molecules and compounds, tetracyclines, metallic ions, and others) and natural bioactive inhibitors mainly flavonoids. Selective inhibitors of MMPs promise to be the future for specific targeting of preventing dentin proteolysis. The knowledge about MMPs functionality should be considered to synthesize drugs capable to efficiently and selectively block MMPs chemical routes targeting their inactivation in order to overcome the current limitations of the therapeutic use of MMPs inhibitors, i.e., easy clinical application and long-lasting effect.

FOODS, NUTRACEUTICALS AND MEDICINAL PLANTS USED AS COMPLEMENTARY PRACTICE IN FACING UP THE CORONAVIRUS (COVID-19) SYMPTOMS: A REVIEW / ALIMENTOS, NUTRACÊUTICOS E PLANTAS MEDICINAIS UTILIZADOS COMO PRÁTICA COMPLEMENTAR NO ENFRENTAMENTO DOS SINTOMAS DO CORONAVÍRUS (COVID-19): UMA REVISÃO

The present prospective work of scientific articles related to foods and natural products with anti-Covid activity in databases in order to present a scientific community, to governments and society as main foods, nutraceuticals and medicinal plants as strategies used by countries during the COVID-19 pandemic. A review of articles on food, medicinal plants and biotechnology was carried out in databases of scientific articles such as: CAPES journals, PubMed, Elsevier's Science Direct, Willey on library library, Taylor & Francis Springer-Nature database, BMC, Hindawi, Scielo, ACS - American Chemical Society, Google Scholar, in addition to the Patent Database "The LENS" and "Questel-Orbit". Foods used in daily life such as garlic, ginger, turmeric, sour orange, vegetables, lactobacilli demonstrate proven anti-virus action. Medicinal plants used by Traditional Chinese, Korean and Indian Medicine also demonstrate anti-Covid activity and used during the coronavirus outbreak. Some medicinal plants, green propolis extract, red propolis extract, royal gelly, polen, honey have also been cited as anti-covid, natural anti-inflammatory and immunomodulatory products.

O presente trabalho prospectou artigos científicos relacionadas à alimentos e produtos naturais com atividade anti-Covid com o intuito de apresentar, à comunidade científica, aos governos e à sociedade, dados sobre as principais estratégias nutracêuticas, biotecnológicas e plantas medicinais utilizadas em alguns países durante o enfrentamento da pandemia COVID-19. A revisão de artigos sobre alimentos, plantas medicinais e produtos biotecnológicos foi realizada nas bases de dados periódicos da CAPES, PubMed, Science Direct, Willey on line library, Springer-Nature, Taylor & Francis, BMC, Hindawi, Scielo, ACS ­ American Chemical Society, Google acadêmico, "The LENS" e Questel-Orbit. Alimentos de uso frequente como alho, gengibre, cúrcuma, laranja azeda, vegetais e lactobacilos demonstraram ação anti-coronavirus comprovada. Foram descritos usos de plantas medicinais da Medicina tradicional Chinesa, Coreana, Indiana bastante utilizadas durante a pandemia. Algumas plantas medicinais e nutracêuticos como: extrato de própolis verde e extrato de própolis vermelha brasileiras, geleia real, pólen e mel também foram citados como produtos anti-covid, antiinflamatórios naturais e imunomodulatórios.

Comprehensive multivariate correlations between climatic effect, metabolite-profile, antioxidant capacity and antibacterial activity of Brazilian red propolis metabolites during seasonal study.

The standardization of apiceutical products like as propolis extracts has been widely debated worldwide and variations in the propolis chemical composition are still very relevant topics for use-standardized of different propolis-type as medication by much of the world's population. The present manuscript discuss important issues related to the climate effect and variations in propolis metabolite-profiling changes, antioxidant capacity and variations of the antibacterial activity of the Brazilian red propolis metabolites using comprehensive multivariate correlations. It was observed the increasing of guttiferones concentrations during the intense drought period and drastic decreasing in rainy period. The climate variation induced the high concentration of flavonoids in rainy period with pronounced dropped in some rainy months. The Pearson´s analysis demonstrated correlation between IC50 from DPPH and guttiferones and flavonoids concentrations. The PCA-X and Hotelling T2 test showed outliers during the months with lowest concentrations of formononetin and isoliquiritigenin was observed in antibacterial tests. The PLS-DA, OPLS-DA and VIP analysis demonstrate guttiferone E, guttiferone B, liquiritigenin, naringenin are considered important substances responsible by anti-staphylococcal activity in red propolis composition during the rainy season and drought period, but a synergistic effect with other flavonoids and isoflavonoids are not ruled out.

Characterization and Stability of the Antimony-Quercetin Complex.

Purpose: Quercetin is a flavonoid known for its therapeutic properties and for forming complexes. Although the antimony-quercetin (SbQ) complex has been produced before, no previous exploration of its characteristics has been published in literature. Thus, this study aimed to characterize this complex, assess its stability and investigate its complexation site through its antibacterial activity. Methods: The SbQ complex was synthetized using Sb(III) potassium tartrate trihydrate and quercetin anhydrous (1:1) (v/v) as a solution and dried using three methods: rotaevaporation, lyophilization and spray drying. The material, in solution, was analyzed by UV-vis and fluorimetry; and, in the powder, by X-ray diffraction (XRD), both scanning electronic and fluorescence microscopy and infrared spectroscopy (FT-IR). Antimicrobial activity was evaluated via broth microdilution. Results: UV-vis exhibited a shoulder peak at 291 nm indicating metal chelation at C-ring of quercetin and confirmed 1:1 stoichiometry. Spectrofluorimetry showed an increase of intensity with the complex formation with an emission band (525 nm). After drying, XRD and SEM indicated loss of crystallinity and a difference in shape and size of the complex compared to its precursors. FT-IR suggested by a shift of frequency of the carbonyl group (1661 cm-1) that the quercetin bond to antimony by the C-3, followed by positions C-5 and C-4 carbonyl, which has been confirmed by MIC through the structure-activity relationship of the antibacterial activity of quercetin. Conclusion: These results provided a characterization of SbQ complex with the confirmation of its binding site, working as a guide for future studies involving this complex.

Recent advances in layered double hydroxides applied to photoprotection.

Layered double hydroxides have received more attention from researchers due to their range of applications, ease of synthesis and low cost of production. With broader knowledge about solar radiation effects on the body, the use of sunscreens has become even more important. The ability of some nanostructures, such as layered double hydroxides, to act as matrices has made it possible to obtain improvements in photoprotective formulations, with solutions to problems caused by radiation and sunscreens. This review article brings together the most recent advances of these clays, the layered double hydroxides, applied to photoprotection.

Recent advances in layered double hydroxides applied to photoprotection / Recentes avanços dos hidróxidos duplos lamelares aplicados à fotoproteção

ABSTRACT Layered double hydroxides have received more attention from researchers due to their range of applications, ease of synthesis and low cost of production. With broader knowledge about solar radiation effects on the body, the use of sunscreens has become even more important. The ability of some nanostructures, such as layered double hydroxides, to act as matrices has made it possible to obtain improvements in photoprotective formulations, with solutions to problems caused by radiation and sunscreens. This review article brings together the most recent advances of these clays, the layered double hydroxides, applied to photoprotection.

RESUMO Os hidróxidos duplos lamelares vêm ganhando maior atenção de pesquisadores, em decorrência da gama de aplicações, da facilidade de síntese e do baixo custo de produção. Com o crescente conhecimento sobre diversos efeitos da radiação solar sobre o organismo, a utilização de fotoprotetores tem se tornado indispensável. A capacidade de nanoestruturas, como os hidróxidos duplos lamelares, atuarem como matrizes possibilitou melhorias nas formulações fotoprotetoras, tendo em vista os problemas provocados pela radiação, bem como por alguns filtros solares. Este artigo de revisão reúne os avanços mais recentes destas argilas, os hidróxidos duplos lamelares, aplicados à fotoproteção.

Lipase Activity in the Larval Midgut of Rhynchophorus palmarum: Biochemical Characterization and the Effects of Reducing Agents.

Lipases have key roles in insect lipid acquisition, storage, and mobilization and are also fundamental to many physiological processes in insects. Lipids are an important component of insect diets, where they are hydrolyzed in the midgut lumen, absorbed, and used for the synthesis of complex lipids. The South American palm weevil Rhynchophorus palmarum is one of the most important pests on commercial palm plantations. However, there are few studies about lipid digestion for this insect. In this work, we have described the biochemical characterization of the lipase activity in the posterior midgut of the R. palmarum palm weevil. Lipase activity was highest between the temperatures of 37 °C and 45 °C and at pH 6.5. Lipase activity was also sensitive to variations in salt and calcium concentrations. Lipases have been described structurally as enzymes with the Ser-His-Asp Catalytic Triad, containing an active serine. The serine protease inhibitor PMSF (phenylmethane sulfonyl fluoride) inhibited the lipases from R. palmarum, demonstrating the importance of a serine residue for this activity. The ability of the lipases to hydrolyze p-Nitrophenyl esters with different chain lengths has revealed the activities of a broad range of substrates. The lipase activities of R. palmarum increased in the presence of reduced glutathione (GSH) and dithiothreitol (DTT), while in the presence of oxidized glutathione (GSSG), activities were drastically reduced. To our knowledge, this study has provided the first information about lipase activity in the R. palmarum palm weevil.

Chemical and microbiological characterization of tinctures and microcapsules loaded with Brazilian red propolis extract.

The aim of this study was to characterize tinctures and microcapsules loaded with an ethanol extract of red propolis through chemical, physicochemical and microbiological assays in order to establish quality control tools for nutraceutical preparations of red propolis. The markers (isoflavonoids, chalcones, pterocarpans, flavones, phenolic acids, terpenes and guttiferones) present in the tinctures A and B were identified and confirmed using LC/ESI/FTMS/Orbitrap. Four compositions (A, B, C and D) were prepared to contain B tincture of the red propolis with some pharmaceutical excipients and submitted to two drying processes, i. e. spray-drying and freeze-drying to obtain microcapsules loaded with the red propolis extract. The tinctures and microcapsules of the red propolis were submitted to the total flavonoid content and antioxidant activity tests. The antibacterial activity and minimum inhibitory concentration (MIC) were tested using Staphylococcus aureus ATCC 25293 and Pseudomonas aeruginosa ATCC 27853 strains. The tinctures and microcapsules presented high flavonoid quantities from 20.50 to 40.79 mg/100 mg of the microcapsules. The antioxidant activity and IC50 were determined for the tinctures A and B (IC50: 6.95 µg/mL and 7.48 µg/mL), the spray-dried microcapsules (IC50: 8.89-15.63 µg/mL) and the freeze-dried microcapsules (IC50: 11.83-23.36 µg/mL). The tinctures and microcapsules were proved to be bioactive against gram-positive and gram-negative bacteria with inhibition halos superior to 10 mm at concentration of 200 µg/mL and MIC values of 135.87-271.74 µg/mL using gram-positive strain and 271.74-543.48 µg/mL using gram-negative strain. The tinctures and microcapsules of the red propolis have a potential application for nutraceutical products.

Polymeric Nanoparticles of Brazilian Red Propolis Extract: Preparation, Characterization, Antioxidant and Leishmanicidal Activity.

The ever-increasing demand for natural products and biotechnology derived from bees and ultra-modernization of various analytical devices has facilitated the rational and planned development of biotechnology products with a focus on human health to treat chronic and neglected diseases. The aim of the present study was to prepare and characterize polymeric nanoparticles loaded with Brazilian red propolis extract and evaluate the cytotoxic activity of "multiple-constituent extract in co-delivery system" for antileishmanial therapies. The polymeric nanoparticles loaded with red propolis extract were prepared with a combination of poly-ε-caprolactone and pluronic using nanoprecipitation method and characterized by different analytical techniques, antioxidant and leishmanicidal assay. The red propolis nanoparticles in aqueous medium presented particle size (200-280 nm) in nanometric scale and zeta analysis (-20 to -26 mV) revealed stability of the nanoparticles without aggregation phenomenon during 1 month. After freeze-drying method using cryoprotectant (sodium starch glycolate), it was possible to observe particles with smooth and spherical shape and apparent size of 200 to 400 nm. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermal analysis revealed the encapsulation of the flavonoids from the red propolis extract into the polymeric matrix. Ultra performance liquid chromatography coupled with diode array detector (UPLC-DAD) identified the flavonoids liquiritigenin, pinobanksin, isoliquiritigenin, formononetin and biochanin A in ethanolic extract of propolis (EEP) and nanoparticles of red propolis extract (NRPE). The efficiency of encapsulation was determinate, and median values (75.0 %) were calculated using UPLC-DAD. 2,2-Diphenyl-1-picryhydrazyl method showed antioxidant activity to EEP and red propolis nanoparticles. Compared to negative control, EEP and NRPE exhibited leishmanicidal activity with an IC50 value of ≅38.0 µg/mL and 31.3 µg/mL, 47.2 µg/mL, 154.2µg/mL and 193.2 µg/mL for NRPE A1, NRPE A2, NRPE A3 and NRPE A4, respectively. Nanoparticles loaded with red propolis extract in co-delivery system and EEP presented cytotoxic activity on Leishmania (V.) braziliensis. Red propolis extract loaded in nanoparticles has shown to be potential candidates as intermediate products for preparation of various pharmaceutical dosage forms containing red propolis extract in the therapy against negligible diseases such as leishmaniasis. Graphical Abstract Some biochemical mechanisms of cellular debridement of Leishmania (V.) braziliensis species by the flavonoids of red propolis extract (EEP) or NRPE loaded with red propolis extract.

Brazilian red propolis: phytochemical screening, antioxidant activity and effect against cancer cells.

BACKGROUND: The implementation of new public healthcare models that stimulate the use of natural products from traditional medicine, as a so-called integrated medicine, refers to an approach that use best of both conventional medicine and traditional medicine. Propolis is a widely used natural product by different ancient cultures and known to exhibit biological activities beneficial for health. The large number of studies conducted with propolis had shown that its chemical composition differs as a function of the climate, plant diversity and bee species and plays an important role on its therapeutic properties. The aim of this study was to analyse the phytochemical profile of the ethanolic extract of red propolis (EEP) and its fractionation, antioxidant action of EEP and its fractions hexane, cloroform and ethyl acetate and cytotoxic activity of EEP on human tumour cell lines SF-295 (glioblastoma), OVCAR-8 (ovary) and HCT-116 (colon). METHODS: EEP was obtained by maceration with absolute ethanol, then it was concentrated in rotaevaporator up to complete evaporation of the solvent. The crude extract was fractionated with hexane, ethyl acetate, chloroform and methanol and they were subjected to phytochemical screening and total phenolic compounds. Antioxidant activity of EEP and fractions was done by means of the 2,2-diphenyl-1-picryhydrazyl (DPPH) method. Biomarkers of red propolis were identified by LC-Orbitrap-FTMS. To assess cytotoxic activity of the extract, cells were exposed to EEP over 72 h. Cell viability was assessed by means of MTT assay. The percentage of cell growth inhibition (IC50) was analysed by means of non-linear regression, and the absorbance values of the various investigated concentrations were subjected to one-factor analysis of variance (ANOVA) followed by Tukey's or Tamhane's tests (α = 0.05). RESULTS: The results obtained using phytochemical screening and LC-Orbitrap-FTMS indicated the presence of phlobaphene tannins, catechins, chalcones, aurones, flavonones, flavonols, xanthones, pentacyclic triterpenoids and guttiferones in Brazilian red propolis. EEP and its hexane, chloroform and ethyl acetate fractions obtained by liquid-liquid partitioning exhibited satisfactory antioxidant percentages. EEP (IC50 < 34.27 µg/mL) exhibited high levels of cytotoxicity on all human tumour cell lines tested when compared to negative control. CONCLUSIONS: C-Orbitrap-FTMS was useful to establish the chemical profile of the red propolis. Brazilian red propolis has antioxidant properties and decreases substantially the percentage of cell survival of human tumour cells; thus, it has potential to serve as an anticancer drug.

Short-term stability studies of ampicillin and cephalexin in aqueous solution and human plasma: Application of least squares method in Arrhenius equation.

A limited number of studies with application of the Arrhenius equation have been reported to drugs and biopharmaceuticals in biological fluids at frozen temperatures. This paper describes stability studies of ampicillin and cephalexin in aqueous solution and human plasma applying the Arrhenius law for determination of adequate temperature and time of storage of these drugs using appropriate statistical analysis. Stability studies of the beta-lactams in human plasma were conducted at temperatures of 20°C, 2°C, -20°C and also during four cycles of freeze-thawing. Chromatographic separation was achieved using a Shimpak C(18) column, acetonitrile as organic modifier and detection at 215nm. LC-UV-MS/MS was used to demonstrate the conversion of ampicillin into two diastereomeric forms of ampicilloic acid. Stability studies demonstrated degradation greater than 10% for ampicillin in human plasma at 20°C, 2°C and -20°C after 15h, 2.7days, 11days and for cephalexin at the same temperatures after 14h, 3.4days and 19days, respectively, and after the fourth cycle of freezing-thawing. The Arrhenius plot showed good prediction for the ideal temperature and time of storage for ampicillin (52days) and cephalexin (151days) at a temperature of -40°C, but statistical analysis (least squares method) must be applied to avoid incorrect extrapolations and estimated values out uncertainty limits.

Correlation of thermal analysis and pyrolysis coupled to GC-MS in the characterization of tacrolimus.

In recent years, thermal analysis has assumed major role in the pharmaceutical industry because it can be used to evaluate the stability both in the control of raw materials and the finished product, having employment potential in the development and characterization of new products and assessment processes. Tacrolimus (TCR) is a macrolide lactone with potent immunosuppressive activity. The purpose of this study was to characterize tacrolimus raw material using Thermal analysis and Pyrolysis coupled to Gas chromatography-Mass spectrometry (Pyr-GC-MS). It was analyzed four samples of tacrolimus named TCR A, B, C and D. Thermal analysis experiments was performed in Shimadzu equipment, under nitrogen and synthetic air atmosphere in different heating rate. Pyrolysis analysis was conducted in isothermal conditions of 300°C and 400°C coupled to GC-MS, in which the mass spectrometer was operated in scan mode to detect ions in the range of mass of m/z 25-900. The thermal studies by DSC, DTA and DSC-Photovisual showed desolvation process for all tacrolimus raw materials and TG-dynamical demonstrated two pseudo-polymorphic forms (monohydrate and sesquihydrate) of tacrolimus. It was observed good correlation between the stoichiometric mass losses of the TG-dynamical and identification of product ion in Pyr-GC/MS technique. It was possible to correlate the five pyrolytic product ions with the Ozawa kinetic analysis from the thermal decomposition of TG-dynamical. The thermal studies (DSC, DSC-Photovisual, DTA and TG-dynamical) were applied in the thermal characterization of the raw materials of tacrolimus which showed pseudo-polymorphic forms, which must be monitored by pharmaceutical industry, avoiding future problems in pharmaceutical process, chemical stability and bioavailability of the tacrolimus product.