Accuracy of the Verbal Autopsy questionnaire in the diagnosis of COVID-19 deaths in a Brazilian capital.

The Verbal Autopsy (VA) is a questionnaire about the circumstances surrounding a death. It was widely used in Brazil to assist in postmortem diagnoses and investigate excess mortality during the Coronavirus Disease 2019 (COVID-19) pandemic. This study aimed to determine the accuracy of investigating acute respiratory distress syndrome (ARDS) using VA. This is a cross-sectional study with prospective data collected from January 2020 to August 2021 at the Death Verification Service of Sao Luis city, Brazil. VA was performed for suspected COVID-19 deaths, and one day of the week was randomly chosen to collect samples from patients without suspected COVID-19. Two swabs were collected after death and subjected to reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2 detection. Of the 250 cases included, the VA questionnaire identified COVID-19-related ARDS in 67.2% (52.98% were positive for COVID-19). The sensitivity of the VA questionnaire was 0.53 (0.45-0.61), the specificity was 0.75 (0.64-0.84), the positive predictive value was 0.81 (0.72-0.88), and the negative predictive value was 0.44 (0.36-0.53). The VA had a lower-than-expected accuracy for detecting COVID-19 deaths; however, because it is an easily accessible and cost-effective tool, it can be combined with more accurate methods to improve its performance.

Validation of NUTRIFICO Mnemonic as a Nutritional Approach and Breaking Dismal News in Palliative Care / Validação do Mnemônico NUTRIFICO como Abordagem Nutricional e Comunicação de Notícias Difíceis em Cuidados Paliativos / Validación del Mneumónico NUTRIFICO como Enfoque Nutricional y Comunicación de Noticias Difíciles en Cuidados Paliativos

A assistência nutricional em cuidados paliativos possui papel preventivo e visa assegurar as necessidades nutricionais do paciente na tentativa de auxiliar o controle dos sintomas, manter a hidratação satisfatória, ressignificar a alimentação, reduzir a ansiedade, retardar o desenvolvimento da caquexia, preservar o peso e a composição nutricional. Objetivo: Desenvolver e validar o mnemônico NUTRIFICO como abordagem de assistência nutricional e comunicação de notícias difíceis em cuidados paliativos. Método: Pesquisa de desenvolvimento e validação de conteúdo que utilizou a técnica Delphi com a aplicação do delineamento misto com abordagens qualitativas e quantitativas para a coleta e análise dos dados. Os participantes, nutricionistas com atuação em cuidados paliativos e/ou formação na área, foram recrutados por amostragem do tipo bola de neve. O percentual de concordância mínimo definido para validação foi de 80% pela escala Likert de cinco pontos. Resultados: Quarenta participantes, incluindo oito "sementes", foram convidados a participar do estudo. Destes, 16 assinaram o Termo de Consentimento Livre e Esclarecido (TCLE). A análise de conteúdo seguiu duas rodadas Delphi e foi obtida uma taxa de concordância superior a 80% entre os participantes para todos os componentes. A versão final do mnemônico NUTRIFICO resultou em dois princípios-chave, oito componentes e 12 recomendações. Conclusão: O mnemônico NUTRIFICO foi considerado válido quanto ao conteúdo e, portanto, pertinente à aplicação na abordagem nutricional e comunicação de notícias difíceis em cuidados paliativos.

Nutritional assistance in palliative care has a preventive role and seeks to ensure the patient's nutritional needs in an attempt to help to control the symptoms, maintain satisfactory hydration, reframe food, reduce anxiety, delay the development of cachexia, preserve weight and nutritional composition. Objective: To develop and validate the NUTRIFICO mnemonic as an approach to nutritional assistance and communication of dismal news in palliative care. Method: Research development and validation of content utilizing the Delphi technique with the application of a mixed design with qualitative and quantitative approaches for data collection and analysis. The participants, nutritionists with experience in palliative care and/or training in the area, were recruited by sampling using the snowball method. The minimum agreement percentage defined for validation was 80% on the five-point Likert scale. Results: Forty participants were invited to participate in the study, including eight "seeds" and 16 signed the Informed Consent Form (ICF). The content analysis followed two Delphi rounds, an agreement rate greater than 80% was obtained among participants for all the components. The final version of the NUTRIFICO mnemonic presented two key principles, eight components and twelve recommendations. Conclusion: The mnemonic NUTRIFICO was validated in terms of content and relevant for the application in the nutritional approach and communication of dismal news in palliative care

Accuracy of the Verbal Autopsy questionnaire in the diagnosis of COVID-19 deaths in a Brazilian capital

ABSTRACT The Verbal Autopsy (VA) is a questionnaire about the circumstances surrounding a death. It was widely used in Brazil to assist in postmortem diagnoses and investigate excess mortality during the Coronavirus Disease 2019 (COVID-19) pandemic. This study aimed to determine the accuracy of investigating acute respiratory distress syndrome (ARDS) using VA. This is a cross-sectional study with prospective data collected from January 2020 to August 2021 at the Death Verification Service of Sao Luis city, Brazil. VA was performed for suspected COVID-19 deaths, and one day of the week was randomly chosen to collect samples from patients without suspected COVID-19. Two swabs were collected after death and subjected to reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2 detection. Of the 250 cases included, the VA questionnaire identified COVID-19-related ARDS in 67.2% (52.98% were positive for COVID-19). The sensitivity of the VA questionnaire was 0.53 (0.45-0.61), the specificity was 0.75 (0.64-0.84), the positive predictive value was 0.81 (0.72-0.88), and the negative predictive value was 0.44 (0.36-0.53). The VA had a lower-than-expected accuracy for detecting COVID-19 deaths; however, because it is an easily accessible and cost-effective tool, it can be combined with more accurate methods to improve its performance.

In vitro activity of the novel Fe-cyclam complex against clinical multidrug-resistant bacterial isolates from Brazil.

Aim: To evaluate the effect of a new Fe-cyclam complex on pathogenic bacterial species, including multidrug-resistant clinical specimens. Materials & methods: The complex [Fe(cyclam)ox]PF6 (D2) was tested in cytotoxicity and MIC tests. Clinical and reference strains of Gram-negative and Gram-positive bacteria were used. Considering Staphylococcus aureus strains, the profile of antimicrobial susceptibility and time-kill kinetics for D2 was performed. An in silico analysis for D2 was also performed. Results: D2 showed broad bacterial activity, mainly against specimens of Cutibacterium acnes, S. aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. Low cytotoxicity in human cells was demonstrated. Conclusion: The tested compound proved to be a promising agent against resistant bacterial infections.

A Metformin-Ferulic Acid Salt with Improved Biopharmaceutical Parameters.

Though ferulic acid presents great hypoglycemic potential, it possesses limited aqueous solubility, and low oral bioavailability. When associated with metformin, the first-choice drug in Type 2 diabetes treatment, FA demonstrates synergistic hypoglycemic effects, however, it also causes certain undesirable dose-related effects. This study aimed to develop a new ferulic acid - metformin multicomponent system, and incorporate it into a solid dosage form with improved biopharmaceutical parameters. A novel metformin: ferulate (1:1) salt (MFS) was produced, which was properly characterized using differing analytical techniques, including single crystal analysis. Also during the course of the study, a new polymorph of the metformin free base was observed. The MFS was obtained using solvent evaporation methods, which achieved high yields in reproducible process, as well as a 740-fold increase in ferulic acid aqueous solubility. The MFS tablets developed met quality control requirements for this dosage form, as well as revealing excellent performance in vitro dissolution tests, presenting dissolution efficiency values of 95.4 ± 0.5%. Additionally, physicochemical instability was not observed in a study at 40 °C for 3 months for both MFS powder and its tablet form. The MFS product developed is a promising candidate for further Type 2 diabetes clinical study.

Atestado odontológico falso e seu real enquadramento no Código Penal brasileiro / False certificate in Dentistry and its real framework in the Brazilian Penal Code

O atestado odontológico compreende um tipo de documento emitido pelo profissional que expressa a veracidade de um fato relacionado ao paciente constatado durante a prática clínica. O objetivo deste artigo foi apontar e analisar o tipo de crime que incorre o cirurgião-dentista que emite atestado falso. Trata-se de uma pesquisa transversal com abordagem descritiva realizada por meio do levantamento das provas de concursos públicos realizados no Brasil para o cargo de Perito Odontolegista ou nomenclatura correspondente. Foram considerados os concursos realizados nas unidades federativas do Brasil sem distinção quanto ao ano, sendo que a coleta das informações se deu nos meses de janeiro a abril de 2023. Conclui-se que, apesar de ocorrerem discrepâncias de interpretação muito pontuais na literatura odontológica quanto ao condizer entre os Artigos 299 e 302 do Código Penal Brasileiro, não há possibilidade legal de o cirurgião-dentista ser sujeito ativo do crime de falsidade de atestado médico, por ser crime próprio do profissional médico

The dental certificate comprises a kind of document issued by the professional that expresses the veracity of a fact related to the patient verified during clinical practice. The aim of this article was to point out and analyze the type of crime incurred by dentists who issue false certificates. This is a cross-sectional research with a descriptive approach carried out through the survey of public tenders held in Brazil for the position of Forensic Odontologist or corresponding nomenclature. It was considered the contests held in the Brazilian Federative Units without distinction to the year, and the information collection was performed from January to April 2023. It can be concluded that, although there are few interpretation discrepancies in the dental literature regarding articles 299 and 302 of the Brazilian Penal Code, there is no legal possibility for the dentist to be an active subject of the crime of falsity of medical certificate, as it is a crime specific to the professional medical doctor

Quantum Biochemistry Screening and In Vitro Evaluation of Leishmania Metalloproteinase Inhibitors.

Leishmanolysin, also known as major promastigote protease (PSP) or gp63, is the most abundant surface glycoprotein of Leishmania spp., and has been extensively studied and recognized as the main parasite virulence factor. Characterized as a metalloprotease, gp63 can be powerfully inactivated in the presence of a metal chelator. In this study, we first used the structural parameters of a 7-hydroxycoumarin derivative, L1 compound, to evaluate the theoretical-computational experiments against gp63, comparing it with an available metal chelator already described. The methodology followed was (i) analysis of the three-dimensional structure of gp63 as well as its active site, and searching the literature and molecular databases for possible inhibitors; (ii) molecular docking simulations and investigation of the interactions in the generated protein-ligand complexes; and (iii) the individual energy of the gp63 amino acids that interacted most with the ligands of interest was quantified by ab initio calculations using Molecular Fraction with Conjugated Caps (MFCC). MFCC still allowed the final quantum balance calculations of the protein interaction to be obtained with each inhibitor candidate binder. L1 obtained the best energy quantum balance result with -2 eV, followed by DETC (-1.4 eV), doxycycline (-1.3 eV), and 4-terpineol (-0.6 eV), and showed evidence of covalent binding in the enzyme active site. In vitro experiments confirmed L1 as highly effective against L. amazonensis parasites. The compound also exhibited a low cytotoxicity profile against mammalian RAW and 3T3 cells lines, presenting a selective index of 149.19 and 380.64 µM, respectively. L1 induced promastigote forms' death by necrosis and the ultrastructural analysis revealed disruption in membrane integrity. Furthermore, leakage of the contents and destruction of the parasite were confirmed by Spectroscopy Dispersion analysis. These results together suggested L1 has a potential effect against L. amazonensis, the etiologic agent of diffuse leishmaniasis, and the only one that currently does not have a satisfactory treatment.

Silver Nanoparticles Containing Fucoidan Synthesized by Green Method Have Anti-Trypanosoma cruzi Activity.

The brown seaweed Spatoglossum schröederi synthesizes three bioactive fucoidans, the most abundant of which is fucan A. This fucoidan was extracted and its identity was confirmed by chemical analysis, Fourier-transform infrared spectroscopy (FTIR), and agarose gel electrophoresis. Thereafter, silver nanoparticles containing fucan A (AgFuc) were produced using an environmentally friendly synthesis method. AgFuc synthesis was analyzed via UV-vis spectroscopy and FTIR, which confirmed the presence of both silver and fucan A in the AgFuc product. Dynamic light scattering (DLS), X-ray diffraction, scanning electron microscopy, and atomic force microscopy revealed that the AgFuc particles were ~180.0 nm in size and spherical in shape. DLS further demonstrated that AgFuc was stable for five months. Coupled plasma optical emission spectrometry showed that the AgFuc particles contained 5% silver and 95% sugar. AgFuc was shown to be more effective in inhibiting the ability of parasites to reduce MTT than fucan A or silver, regardless of treatment time. In addition, AgFuc induced the death of ~60% of parasites by necrosis and ~17% by apoptosis. Therefore, AgFuc induces damage to the parasites' mitochondria, which suggests that it is an anti-Trypanosoma cruzi agent. This is the first study to analyze silver nanoparticles containing fucan as an anti-Trypanosoma cruzi agent. Our data indicate that AgFuc nanoparticles have potential therapeutic applications, which should be determined via preclinical in vitro and in vivo studies.

TanP: A Multifunctional Anionic Peptide From Tityus stigmurus Scorpion Venom.

Anionic peptides of scorpions are molecules rich in aspartic and/or glutamic acid residues and correspond to a class of peptides without disulfide bonds that are still little explored. TanP is a linear anionic peptide (50 amino acid residues and net charge -20) present in the venom gland of the scorpion, Tityus stigmurus, with chelating properties for Cu2+ ion and immunomodulatory properties. The therapeutic application of chelating molecules is related to cases of acute or chronic intoxication by metals, neurodegenerative diseases, hematological diseases, healing of skin wounds, cardiovascular diseases, and cancer. In this approach, the chelating activity of TanP was evaluated in relation to new metal ions (Fe2+ and Zn2+) of biological importance, as well as its antioxidant, hemostatic, immunomodulatory, and healing potential, aiming to expand the biological and biotechnological potential of this peptide. TanP (25 µM) was able to form stable complexes with Fe2+ in a ratio of 1:5 (TanP: Fe2+). Theoretical results suggest that TanP can work as a sensor to identify and quantify Fe2+ ions. The fluorescence intensity of TanP (1.12 µM) decreased significantly after the addition of Fe2+, obtaining the highest ratio 1: 7.4 (TanP: Fe2+) that led to the lowest fluorescence intensity. For Zn2+, no relevant spectral change was noted. TanP (50 µM) showed a maximum of 3% of hemolytic activity, demonstrating biocompatibility, as well as exhibiting a 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity of above 70% at all the concentrations tested (1-25 µM), and 89.7% iron-chelating activity at 25 µM and 96% hydroxyl radical-scavenging activity at 73.6 µM. In addition, TanP (12.5 and 25 µM) revealed an anticoagulant effect, prolonging the clotting time in prothrombin time and activated partial thromboplastin time assays, with no fibrinogenolytic activity. TanP (12.5 and 25 µM) induced the release of TNF-α by murine macrophages, in the absence of lipopolysaccharides, with a concentration-dependent increase and also stimulated the migration of 3T3 cells in the in vitro healing assay. Thus, TanP revealed a multifunctional potential, being useful as a prototype for the development of new therapeutic and biotechnological agents.

Gallic Acid-Laminarin Conjugate Is a Better Antioxidant than Sulfated or Carboxylated Laminarin.

A 12.4 kDa laminarin (LM) composed of ß(1→3)-glucan with ß(1→6)-branches was extracted from brown seaweed Lobophora variegata and modified via carboxylation using dielectric barrier discharge (LMC), conjugation with gallic acid (LMG), and sulfation (LMS). Analyses of the chemical composition of LMC, LMG, and LMS yielded 11.7% carboxyl groups, 1.5% gallic acid, and 1.4% sulfate content, respectively. Antioxidant activities of native and modified laminarins were assessed using six different in vitro methods. Sulfation stopped the antioxidant activities of LM. On the other hand, carboxylation improved cooper chelation (1.2 times). LMG was found to be a more efficient antioxidant agent than LM in terms of copper chelation (1.3 times), reducing power (1.3 times), and total antioxidant capacity (80 times). Gallic acid conjugation was further confirmed using Fourier transform infrared spectroscopy (FT-IR) and one- and two-dimensional NMR spectroscopy analyses. LMG also did not induce cell death or affect the cell cycle of Madin-Darby canine kidney (MDCK) cells. On the contrary, LMG protected MDCK cells from H2O2-induced oxidative damage. Taken together, these results show that LMG has the potent antioxidant capacity, and, therefore, potential applications in pharmacological and functional food products.

Compounds isolated from Bixa orellana: evidence-based advances to treat infectious diseases / Compuestos aislados de Bixa orellana: avances basados en la evidencia para tratar enfermedades infecciosas

SUMMARY Bixa orellana L. is a native plant from Brazil, but it is also present in other tropical countries such as Peru, Colombia, Ecuador, Mexico, Indonesia, India and East Africa. It is popularly known as Urucum in Brazil. This review shows the potential of bioactive compounds derived from B. orellana to treat infectious diseases due their antimicrobial and antioxidant properties. This plant is also related as an antiinflammatory agent for treatment of pulmonary diseases, or even as eye drops for redness. Its leaves are used for treatment of snakebite, diarrhea, gonorrhea, hepatitis, gastritis, diuretic, antipyretic, and for skin disease. This popular knowledge has encouraged the identification of bioactive compounds in this plant. Compounds as β-cryptoxanthin, geranylgeraniol, lutein, procyanidin B2, procyanidin B3, ellagi tannin isomer and ellagic acid deoxyhexose have been described. These compounds inhibited pathogenic microorganisms such as bacteria, fungi, protozoan and viruses. In addition, some compounds with anti-inflammatory and antioxidant activities were also described. In this sense, B. orellana is a promising source of compounds that could be applied in antimicrobial therapy. This review work may help in the understanding and incentive of new research for antimicrobial discoveries using different B. orellana compounds.

RESUMEN Bixa orellana L. es una planta nativa de Brasil, pero también está presente en otros países tropicales como Perú, Colombia, Ecuador, México, Indonesia, India y África Oriental. Es conocida popularmente como Urucum en Brasil. Esta revisión expone el potencial de los compuestos bioactivos derivados de B. orellana para tratar enfermedades debido a sus propiedades antimicrobianas y antioxidantes. Esta planta también está relacionada como un agente antiinflamatorio para el tratamiento de enfermedades pulmonares e incluso como gotas para los ojos para el enrojecimiento. Sus hojas se utilizan para el tratamiento de la mordedura de serpiente, diarrea, gonorrea, hepatitis, gastritis, diuréticos, antipiréticos y para enfermedades de la piel. Ese conocimiento popular ha fomentado la identificación de compuestos bioactivos en esa planta. Los compuestos β-criptoxantina, geranilgeraniol, luteína, procianidina B2, procianidina B3, isómero elagitanino y ácido elágico desoxihexosa inhibieron microorganismos patógenos como bacterias, hongos, protozoos y virus. En ese sentido, B. orellana es una fuente prometedora de compuestos que podrían aplicarse en la terapia antimicrobiana. Este trabajo de revisión puede ayudar a comprender e incentivar nuevas investigaciones para los descubrimientos de antimicrobianos que utilizan diferentes compuestos de B. orellana.

Green Synthesis of Antileishmanial and Antifungal Silver Nanoparticles Using Corn Cob Xylan as a Reducing and Stabilizing Agent.

Corn cob is an agricultural byproduct that produces an estimated waste burden in the thousands of tons annually, but it is also a good source of xylan, an important bioactive polysaccharide. Silver nanoparticles containing xylan (nanoxylan) were produced using an environmentally friendly synthesis method. To do this, we extracted xylan from corn cobs using an ultrasound technique, which was confirmed by both chemical and NMR analyses. This xylan contained xylose, glucose, arabinose, galactose, mannose, and glucuronic acid in a molar ratio of 50:21:14:9:2.5:2.5, respectively. Nanoxylan synthesis was analyzed using UV-vis spectroscopy at kmax = 469 nm and Fourier transform infrared spectroscopy (FT-IR), which confirmed the presence of both silver and xylan in the nanoxylan product. Dynamic light scattering (DLS) and atomic force microscopy (AFM) revealed that the nanoxylan particles were ~102.0 nm in size and spherical in shape, respectively. DLS also demonstrated that nanoxylan was stable for 12 months and coupled plasma optical emission spectrometry (ICP-OES) showed that the nanoxylan particles were 19% silver. Nanoxylan reduced Leishmania amazonensis promastigote viability with a half maximal inhibitory concentration (IC50) value of 25 µg/mL, while xylan alone showed no effective. Additionally, nanoxylan exhibited antifungal activity against Candida albicans (MIC = 7.5 µg/mL), C. parapsilosis (MIC = 7.5 µg/mL), and Cryptococcus neoformans (MIC = 7.5 µg/mL). Taken together, these data suggest that it is possible to synthesize silver nanoparticles using xylan and that these nanoxylan exert improved antileishmanial and antifungal activities when compared to the untreated polysaccharide or silver nitrate used for their synthesis. Thus, nanoxylan may represent a promising new class of antiparasitic agents for use in the treatment of these microorganisms.

A divergent mode of activation of a nitrosyl iron complex with unusual antiangiogenic activity.

Nitric oxide (NO) and nitroxyl (HNO) have gained broad attention due to their roles in several physiological and pathophysiological processes. Remarkably, these sibling species can exhibit opposing effects including the promotion of angiogenic activity by NO compared to HNO, which blocks neovascularization. While many NO donors have been developed over the years, interest in HNO has led to the recent emergence of new donors. However, in both cases there is an expressive lack of iron-based compounds. Herein, we explored the novel chemical reactivity and stability of the trans-[Fe(cyclam)(NO)Cl]Cl2 (cyclam = 1,4,8,11-tetraazacyclotetradecane) complex. Interestingly, the half-life (t1/2) for NO release was 1.8 min upon light irradiation, vs 5.4 h upon thermal activation at 37 °C. Importantly, spectroscopic evidence supported the generation of HNO rather than NO induced by glutathione. Moreover, we observed significant inhibition of NO donor- or hypoxia-induced HIF-1α (hypoxia-inducible factor 1α) accumulation in breast cancer cells, as well as reduced vascular tube formation by endothelial cells pretreated with the trans-[Fe(cyclam)(NO)Cl]Cl2 complex. Together, these studies provide the first example of an iron-nitrosyl complex with anti-angiogenic activity as well as the potential dual activity of this compound as a NO/HNO releasing agent, which warrants further pharmacological investigation.

Effect of Gold Nanoparticle on 5-Fluorouracil-Induced Experimental Oral Mucositis in Hamsters.

BACKGROUND: Oral mucositis (OM) is a severe inflammation of the oral mucosal cells associated with chemotherapy and/or radiotherapy-induced toxicity, resulting in epithelial ulcers and higher risk of death from sepsis. The aim of the present study was to evaluate the nanoparticle (AuNp) effect on OM induced in hamsters. MATERIALS AND METHODS: 5-fluorouracil (5FU) was used on the first and second day of the experimental model in Golden sirian hamsters, and on the fourth day, mechanical trauma was applied to induce OM. The animals were divided into groups, i.e., polyvinylpyrrolidone (PVP), mechanical trauma (MT), 5FU, and groups treated with gold nanoparticles (AuNps) (62.5, 125, and 250 µg/kg). On the 10th day, animals were euthanized for macroscopic, histopathological, immunohistochemical, western blot, quantitative polymerase chain reaction (qRT-PCR), and AuNp quantification. RESULTS: AuNp (250 µg/kg) reduced TNF-α, IL-1ß, COX-2, NF-κB, TGF-ß, and SMAD 2/3; increased glutathione levels; decreased the expression of Kelch ECH-associated protein 1 (KEAP1); and induced heme oxygenase 1 (HMOX-1) and NAD (P) H quinone oxidoreductase 1 (NQO1) genes. CONCLUSIONS: AuNp (250 µg/kg) prevented 5-FU-induced OM in hamsters and improved the parameters of inflammation and oxidative stress.

Synthesis of Silver Nanoparticle Employing Corn Cob Xylan as a Reducing Agent with Anti-Trypanosoma cruzi Activity.

BACKGROUND: Chagas disease, also known as American Trypanosomiasis, is caused by the protozoan Trypanosoma cruzi. It is occurring in Americas, including USA and Canada, and Europe and its current treatment involves the use of two drugs as follows: benznidazole (BNZ) and nifurtimox, which present high toxicity and low efficacy during the chronic phase of the disease, thus promoting the search for more effective therapeutic alternatives. Amongst them xylan, a bioactive polysaccharide, extracted from corn cob. METHODS: Ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy (FITR), Raman spectroscopy, energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy, atomic force microscopy, plasma optical emission spectroscopy (ICP-OES), dynamic light scattering (DLS) have been used to characterize the silver-xylan nanoparticles (NX). Their cytotoxicity was evaluated with 3-bromo(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) test. MTT and flow cytometry were used to ascertain the anti-Trypanosoma cruzi activity. RESULTS: UV-Vis spectroscopy gave plasmon resonance ranging between 400 and 450 nm while FITC and Raman spectroscopy proved nano interface functionalized with xylan. ICP-OES data showed NX with xylan (81%) and silver (19%). EDS showed NX consisting of carbon (59.4%), oxygen (26.2%) and silver (4.8%) main elements. Spherical NX of 55 nm average size has been depicted with SEM and AFM, while DLS showed 102 ± 1.7 nm NX. The NX displayed negligible cytotoxicity (2000 µg/mL). NX (100 µg/mL) was more effective, regardless of experiment time, in affecting the ability of parasites to reduce MTT than BZN (100 µg/mL). In addition, NX (100 µg/mL) induced death of 95% of parasites by necrosis. CONCLUSION: This is the first time silver nanoparticles are presented as an anti-Trypanosoma cruzi agent and the data point to the potential application of NX to new preclinical studies in vitro and in vivo.

Bioinspired oxidation in cytochrome P450 of isomers orientin and isoorientin using Salen complexes.

RATIONALE: Orientin and isoorientin are C-glycosidic flavonoids, considered as markers of some plant species such as Passiflora edulis var. flavicarpa Degener, and reported in the literature to have pharmacological properties. In order to evaluate and characterize the in vitro metabolism of these flavonoids, phase I biotransformation reactions were simulated using Salen complexes. METHODS: These flavonoids were oxidized separately in biomimetic reactions in different proportions, using one oxidant, m-chloroperbenzoic acid or iodosylbenzene, and one catalyst, the Jacobsen catalyst or [Mn(3-MeOSalen)Cl]. The [Mn(3-MeOSalen)Cl] catalyst was synthesized and characterized using spectrometric techniques. The oxidation potentials of the catalysts were compared. All reactions were monitored and analyzed using ultrahigh-performance liquid chromatography diode-array detection (UHPLC-DAD) and high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). RESULTS: The analysis by UHPLC-DAD and HPLC/MS/MS showed that isoorientin produces more products than orientin and that [Mn(3-MeOSalen)Cl] produces more products than the Jacobsen catalyst. In addition, [Mn(3-MeOSalen)Cl], which has a higher oxidation potential, formed products with the addition of one or two atoms of oxygen, while the Jacobsen catalyst formed compounds with only one added oxygen atom. The products with the addition of one oxygen atom were mainly epoxides, while those with two added oxygens formed an epoxide in the C-ring and incorporated the other oxygen into the glycosidic moiety. CONCLUSIONS: The formation of epoxides is common in biomimetic reactions and they may represent a safety risk in medicinal products due to their high reactivity. This study may serve as a basis for subsequent pharmacological and toxicological studies that investigate the presence of these compounds as phase I metabolites, and ensure the safe use of plant products containing orientin as a chemical marker.

Caulerpa Cupressoides Var. Flabellata.

Green seaweeds are rich sources of sulfated polysaccharides (SPs) with potential biomedical and nutraceutical applications. The aim of this work was to evaluate the immunostimulatory activity of SPs from the seaweed, Caulerpa cupressoides var. flabellata on murine RAW 264.7 macrophages. SPs were evaluated for their ability to modify cell viability and to stimulate the production of inflammatory mediators, such as nitric oxide (NO), intracellular reactive oxygen species (ROS), and cytokines. Additionally, their effect on inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) gene expression was investigated. The results showed that SPs were not cytotoxic and were able to increase in the production of NO, ROS and the cytokines, tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). It was also observed that treatment with SPs increased iNOS and COX-2 gene expression. Together, these results indicate that C. cupressoides var. flabellata SPs have strong immunostimulatory activity, with potential biomedical applications.

A vanillin-based copper(ii) metal complex with a DNA-mediated apoptotic activity.

Vanillin (vanH) is the major component of vanilla and one of the most widely used flavoring agents. In this work the complex [Cu(phen)(van)2] was prepared and characterized by structural (X-ray), spectroscopic (IR, UV-Vis, EPR) and electrochemical techniques. This compound showed an octahedral geometry with an unusual arrangement of the vanillin ligands, where the methoxy groups of the vanillinate ions are coordinated opposite to each other. The compound promoted DNA cleavage in the presence of glutathione (GSH) and H2O2. At 40 µmol L-1 of complex with GSH (10 mmol L-1), there is a complete cleavage of DNA to nicked form II, while only at 10 µmol L-1 of this complex with H2O2 (1 mmol L-1) an extensive cleavage leading to form III took place. Additionally, we have evidences of superoxide generation upon reaction with GSH. Therefore, DNA fragmentation occurs likely through an oxidative pathway. MTT assays indicated that the complex is highly cytotoxic against three distinct cell lines: B16-F10 (IC50 = 3.39 ± 0.61 µmol L-1), HUH-7 (IC50 = 4.22 ± 0.31 µmol L-1) and 786-0 (IC50 = 10.38 ± 0.91 µmol L-1). Flow cytometry studies conducted with 786-0 cell line indicated cell death might occur by apoptosis. Cell cycle progression evaluated at 5 and 10 µmol L-1 resulted in a clear increase of 786-0 cells at G1 phase and depletion of G2/M, while higher doses showed an expressive increase of sub-G1 phase. Altogether, these results pointed out to a promising biological activity and potential as an anti-cancer agent.

Chitosan Membrane Modified With a New Zinc(II)-Vanillin Complex Improves Skin Wound Healing in Diabetic Rats.

The treatment of chronic wounds is considered a public health problem. When the condition affects at-risk groups such as those with diabetics, it becomes a great clinical challenge. In this work, we evaluated the healing effects of a new zinc complex, [Zn(phen)(van)2], identified as ZPV, which was synthesized, characterized and associated with chitosan (CS) membranes and tested on cutaneous wounds of diabetic rats. Chitosan membranes were modified by Schiff base reaction with the complex under two experimental conditions (14 and 21 days), resulting in membranes with concentrations of complex equal to 0.736 µmol cm-2 (CS-ZPV1) and 1.22 µmol cm-2 (CS-ZPV2). Release assays in aqueous medium indicated that the membranes release the complex gradually when exposed to an aqueous medium. Diabetes was inducted in Wistar rats using 40 mg/kg (i.v.) streptozotocin. On the 7th day after diabetic induction, a circular excision on the skin (1.0 cm) was performed with a punch. The lesions were treated with the pure chitosan membrane and the membrane associated with the zinc-vanillin complex in two different doses. Skin samples were subjected to macroscopic and histopathological analyses, cytokine (TNF-α, IL-1ß, and IL-10) quantification and reverse transcriptase polymerase chain reaction (TGF-ß and VEGF) assays. The analyses showed a decrease in wound size, reepithelialization, angiogenic stimulus, collagen deposition, and reduced levels of TNF-α and IL-1ß as well as increased IL-10 and gene expression of TGF-ß and VEGF. The evaluated parameters suggest that CS-ZPV in the two concentrations tested may be effective in the treatment of chronic wounds.

Structure and in vitro activities of a Copper II-chelating anionic peptide from the venom of the scorpion Tityus stigmurus.

Anionic Peptides are molecules rich in aspartic acid (Asp) and/or glutamic acid (Glu) residues in the primary structure. This work presents, for the first time, structural characterization and biological activity assays of an anionic peptide from the venom of the scorpion Tityus stigmurus, named TanP. The three-dimensional structure of TanP was obtained by computational modeling and refined by molecular dynamic (MD) simulations. Furthermore, we have performed circular dichroism (CD) analysis to predict TanP secondary structure, and UV-vis spectroscopy to evaluate its chelating activity. CD indicated predominance of random coil conformation in aqueous medium, as well as changes in structure depending on pH and temperature. TanP has chelating activity on copper ions, which modified the peptide's secondary structure. These results were corroborated by MD data. The molar ratio of binding (TanP:copper) depends on the concentration of peptide: at lower TanP concentration, the molar ratio was 1:5 (TanP:Cu2+), whereas in concentrated TanP solution, the molar ratio was 1:3 (TanP:Cu2+). TanP was not cytotoxic to non-neoplastic or cancer cell lines, and showed an ability to inhibit the in vitro release of nitric oxide by LPS-stimulated macrophages. Altogether, the results suggest TanP is a promising peptide for therapeutic application as a chelating agent.