Naphth[1,2-d]imidazoles Bioactive from ß-Lapachone: Fluorescent Probes and Cytotoxic Agents to Cancer Cells.

Theranostics combines therapeutic and imaging diagnostic techniques that are extremely dependent on the action of imaging agent, transporter of therapeutic molecules, and specific target ligand, in which fluorescent probes can act as diagnostic agents. In particular, naphthoimidazoles are potential bioactive heterocycle compounds to be used in several biomedical applications. With this aim, a group of seven naphth[1,2-d]imidazole compounds were synthesized from ß-lapachone. Their optical properties and their cytotoxic activity against cancer cells and their compounds were evaluated and confirmed promising values for molar absorptivity coefficients (on the order of 103 to 104), intense fluorescence emissions in the blue region, and large Stokes shifts (20-103 nm). Furthermore, the probes were also selective for analyzed cancer cells (leukemic cells (HL-60). The naphth[1,2-d]imidazoles showed IC50 between 8.71 and 29.92 µM against HL-60 cells. For HCT-116 cells, values for IC50 between 21.12 and 62.11 µM were observed. The selective cytotoxicity towards cancer cells and the fluorescence of the synthesized naphth[1,2-d]imidazoles are promising responses that make possible the application of these components in antitumor theranostic systems.

Involvement of MT2 receptors in protective effects of melatonin against cisplatin-induced gastrointestinal damage in mice

Abstract Melatonin (MLT) reportedly reduces side effects associated with certain antineoplastic agents. Accordingly, we investigated the effect of MLT on cisplatin (CP)-induced gastric emptying (GE) delay. Mice were intraperitoneally pretreated with vehicle (ethanol 5%; control group), MLT (5, 10, or 20 mg/kg), or N-acetylcysteine (NAC; 150 mg/kg), followed by CP treatment (5 mg/kg). Pharmacological modulation was analyzed using relevant receptor antagonists (luzindole: non-selective MT1/MT2 antagonist; 5 mg/kg or 4-P-PDOT: selective MT2 antagonist; 4 mg/kg) before treatment with MLT plus CP. All treatments were performed once daily for three days. GE was assessed using phenol red. Gut morphology was examined using scanning electron microscopy and optical microscopy. Compared with the control, CP decreased GE. Pretreatment with NAC and MLT (5 and 10 mg/kg) did not prevent CP-induced gastric dysmotility; however, pretreatment with 20 mg/kg MLT prevented this effect. In addition, luzindole and 4-P-PDOT suppressed MLT-mediated gastroprotection against cytotoxic effects of CP. CP caused degeneration of the gut mucosa, which was attenuated by MLT treatment. Thus, 20 mg/kg MLT prevented the GE delay and decreased CP-induced adverse effects on the gut mucosa. In addition, the gastroprotective activity was mediated via the MT2 receptor.

A Short Review on the Electrochemical Performance of Hierarchical and Nitrogen-Doped Activated Biocarbon-Based Electrodes for Supercapacitors.

Cheap and efficient carbon electrodes (CEs) for energy storage systems (ESS) such as supercapacitors (SCs) and batteries are an increasing priority issue, among other things, due to a globally increasing share of intermittent electricity production (solar and wind) and electrification of transport. The increasing consumption of portable and non-portable electronic devices justifies research that enables environmentally and economically sustainable production (materials, processing techniques, and product design) of products with a high electrochemical performance at an acceptable cost. Among all the currently explored CEs materials, biomass-based activated carbons (AC) present enormous potential due to their availability and low-cost, easy processing methods, physicochemical stability, and methods for self-doping. Nitrogen doping methods in CEs for SCs have been demonstrated to enhance its conductivities, surface wettability, and induced pseudocapacitance effect, thereby delivering improved energy/power densities with versatile properties. Herein, a short review is presented, focusing on the different types of natural carbon sources for preparing CEs towards the fabrication of SCs with high electrochemical performance. The influences of ACs' pore characteristics (micro and mesoporosity) and nitrogen doping on the overall electrochemical performance (EP) are addressed.

Antimicrobial activity of polypyrrole nanoparticles and aqueous extract of Moringa oleifera against Staphylococcus spp. carriers of multi-drug efflux system genes isolated from dairy farms.

Our objectives were to identify genes of the multi-drug efflux system and to evaluate the antimicrobial activities of polypyrrole nanoparticles (PPy-NPs) and aqueous extract of Moringa oleifera against Staphylococcus spp. isolated from dairy farms in Northeast Brazil. Initially, 162 Staphylococcus spp. isolates were subjected to in vitro antimicrobial sensitivity tests. Of these, 35 presented antimicrobial multi-drug resistance phenotypes. These 35 isolates were then referred for the detection of norA, norB, norC, msrA, mgrA, tet-38, and lmrS genes, all of which feature in multi-drug efflux systems. In the isolates carrying the genes, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PPy-NPs and Moringa oleifera aqueous extract were determined. In the molecular analysis of the 35 isolates norA, norC, tet-38, and msrA genes were detected and for the other genes norB, lmrS and mgrA there was no amplification. Antimicrobial activity was verified of PPy-NPs and aqueous extract of Moringa oleifera in Staphylococcus spp. carrying multi-drug efflux system genes. We concluded that there are multi-drug efflux system genes present in the Staphylococcus spp. from the agricultural environment in Northeast Brazil, and that aqueous extract of Moringa oleifera and PPy-NPs show bactericidal activity against these isolates.

In vitro algicidal effect of polypyrrole on Prototheca species isolates from bovine mastitisAlgicidal activity of polypyrrole on Prototheca spp.

Algae of the genus Prototheca are microorganisms involved in the occurrence of diseases in humans and animals. In bovine species, Prototheca spp. cause environmental mastitis, productive losses in dairy herds, mainly leading to the discard of infected cows. Currently, there are no effective anti-Prototheca spp. drugs to combat this infection. Thus, the search for an efficacious therapy for Prototheca spp. infections have become essential. Highly soluble polypyrrole (Ppy) is a molecule with known antimicrobial activity. This study aimed to characterize Prototheca spp. isolates from bovine mastitis as well as to evaluate the susceptibility profile and to verify the morphological alterations on Prototheca spp. isolates treated with Ppy. In this research, 36 Brazilian isolates of Prototheca spp. were characterized by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) assay for the mitochondrial cytB gene. Additionally, Ppy algicidal activity against these isolates of Prototheca spp. was assessed by minimal microbicidal concentration method in microplates. Further, scanning electron microscopy (SEM) was performed in order to verify the morphological alterations on Prototheca spp. isolates in response to Ppy. The isolates were characterized as belonging to Prototheca zopfii genotype 2 (35/36) and Prototheca blaschkeae (1/36). Ppy had an algicidal effect on all isolates tested at concentrations ranging from 15.625 µg ml-1 to 62.5 µg ml-1. SEM showed changes on planktonic and sessile P. zopfii, including a decrease of the number of cells with the presence of an amorphous substance involving the cells. The algicidal activity of Ppy suggests the therapeutic potential of this molecule in the prevention and treatment of Prototheca spp. in bovine mastitis.

Soluções de óxido de zinco e de nitrato de prata como alternativa para antissepsia de tetos de bovinos (teste in situ) / Solutions of Zinc oxide and silver nitrate as an alternative to bovine udder antisepsis

Este trabalho teve como objetivo analisar o potencial das soluções de óxido de zinco e de nitrato de prata como alternativa para antissepsia de tetos de bovinos (in situ), considerando a escassez de literatura a respeito do uso destes compostos na profilaxia de mastites. Primeiramente foram realizados ensaios de microdiluição e CBM (Concentração Bactericida Mínima) a fim de verificar a atividade antimicrobiana das soluções de óxido de zinco e de nitrato de prata sobre 30 isolados de Staphylococcus spp., obtidos de casos de mastite. Todos os isolados apresentaram sensibilidade às duas soluções testadas, mas a solução de nitrato de prata apresentou menores valores de CBMs (3,05 a 97,65 µg/mL), quando comparada as CBMs da solução de óxido de zinco (97,65 a 6.250 µg/mL). Posteriormente, foram conduzidos os ensaios de antissepsia dos tetos (in situ) através da imersão dos mesmos nas soluções antimicrobianas testadas. Para isso, foram utilizados 40 tetos (n=40) oriundos de vacas abatidas, os quais foram divididos em 4 grupos de 10 tetos, destinados ao teste das solução de óxido de zinco a 3% (30mg/mL), de nitrato e prata 1% (10mg/mL) e seus respectivos controles. Os tetos foram submetidos à contagem de microrganismos mesófilos na superfície dos tetos (UFC/cm2) antes e após a imersão nas soluções testadas. Como resultado, todas as soluções (de óxido de zinco e de nitrato de prata) apresentaram significativa redução de UFC/cm2 até aos 60 minutos após a imersão (M 0' a M 60'). A solução de nitrato de prata apresentou redução de UFC/cm2 significativamente maior, quando comparado ao grupo testado com solução de óxido de zinco. Tais resultados validam o potencial das soluções de óxido de zinco e nitrato de prata para utilização no pré e pós-dipping em vacas leiteiras.(AU)

This study aimed to analyze the zinc oxide and silver nitrate solutions as an alternative antiseptic for cow teats (in situ), considering the lack in the literature about these compounds uses in mastitis prophylaxis. First microdilution tests med and MBC (Minimal Bactericidal Concentration were perfor in order to determine the antimicrobial activity of zinc oxide and silver nitrate solutions over 30 Staphylococcus spp. isolates, obtained from cows with mastitis. All strains tested showed sensitivity to both solutions, but the silver nitrate solution had lower MBC values (3,05 to 97,65ug/ml) compared with zinc oxide solution MBCs (97,65 to 6,250 ug/ml). Subsequently, the antiseptic teat tests were conducted (in situ) by immersing the teats in same antimicrobial solutions tested in the first experiment. Therefore, 40 teats were used (n = 40) originating from slaughtered cows were divided into 4 groups of 10 teats, to test test zinc oxide 3% (30mg/mL) and silver nitrate 1% (10mg/mL) solutions and their respective controls. The teats were submitted to mesophilic count on the teat surface (CFU/cm2) before and after immersion in tested solutions. As a result, all the solutions (zinc oxide and silver nitrate) had a significant reduction in CFU/cm2 until 60 minutes after immersion (M 0' to 60 M'). Silver nitrate solution showed a reduction of CFU/cm2 significantly higher compared to the group treated with zinc oxide solution. These results validate the potential use of zinc oxide and silver nitrate solutions in dairy cows as a pre- and post-dipping antiseptic.(AU)