Toxicity and sublethal effects of phthalides analogs to Rhyzopertha dominica

Phthalides and their precursors have demonstrated a large variety of biological activities. Eighteen phthalides were synthesized and tested on the stored grain pest Rhyzopertha dominica. In the screening bioassay, compounds rac‐(2R,2aS,4R,4aS,6aR,6bS,7R)‐7‐bromohexahydro‐2,4‐methano‐1,6‐dioxacyclopenta[cd]pentalen‐5(2H)‐one (15) and rac‐(3R,3aR,4R,7S,7aS)‐3‐(propan‐2‐yloxy)hexahydro‐4,7‐methano‐2‐benzofuran‐1(3H)‐one (17) showed mortality similar to the commercial insecticide, Bifenthrin® (≥90 %). The time (LT50) and dose (LD50) necessary to kill 50 % of the R. dominica population were determined for the most efficacious phthalides 15 and 17. Compound 15 presented the lowest LD50 (1.97 μg g−1), being four times more toxic than Bifenthrin® (LD50=9.11 μg g−1). Both compounds presented an LT50 value equal to 24 h. When applied at a sublethal dose, both phthalides (especially compound 15), reduced the emergence of the first progeny of R. dominica. These findings highlight the potential of phthalides 15 and 17 as precursors for the development of insecticides for R. dominica control

An investigation into the stability of an oregano essential oil emulsion for the preparation of microparticles using spray drying.

The objective of this study was to evaluate the viscosity, zeta potential and soluble and total solids of the emulsion and microparticles of oregano essential oil (Origanum vulgare) using gum arabic as a coating agent and to analyze the morphology of the microparticles produced by the spray drying method. The rheological analysis showed a viscosity for emulsion of 36.23 ± 0.59 mPas and for microparticles of 20.13 ± 0.15 mPa.s. The zeta potential of the emulsion was - 6.67 ± 0.32 mV and of the oregano oil microparticles -16.47 ± 0.70 mV. Soluble solids showed Brix° of 8.44 ± 0.13 and 0.98 ± 0.36 and total solids 8.95 ± 0.42 and 1.03 ± 0.02 % for emulsion and microparticles, respectively. The morphology of the microparticles presented irregular spherical shapes and agglomeration

Puerpério na atenção primária: Foco no aleitamento materno e depressão pós-parto / Puerperum in primary care: Focus on breastfeeding and postpartum depression

O puerpério é uma das áreas prioritárias para atuação da Saúde da Família, englobando o puerpério imediato, tardio e remoto. Atualmente, a terceira maior causa de morbidade do mundo é a depressão, e as gestantes e puérperas são um grupo de alto risco de desenvolver este quadro. Este estudo visou elucidar a área de pesquisa de depressão pós-parto e aleitamento materno, evidenciando a construção do conhecimento com base nas políticas públicas nacionais. Foi realizado levantamento bibliográfico com os descritores associados “aleitamento materno”, “depressão pós-parto” e “puerpério pós-parto”, sendo analisadas 101 publicações. Quando abordado fator de proteção contra o risco de desenvolvimento de depressão pós-parto, 93% dos artigos evidenciaram significância estatística do aleitamento materno exclusivo como fator de proteção. A maioria dos artigos afirmam que mulheres jovens, de minoria étnicas, e solteiras possuem maiores chances de desenvolvimento de depressão pós-parto assim como interrupção do aleitamento exclusivo em relação as mulheres em união estável. Dessa forma, mostra-se necessário o aprofundamento das discussões acerca do cuidado na atenção primária e no período puerperal, evidenciando as relações existentes entre o aleitamento materno e a depressão pós-parto

Alginate/Polypyrrole Hydrogels as Potential Extraction Phase for Determination of Atrazine, Caffeine, and Progesterone in Aqueous Samples

Hydrogels are smart-swelling 3D structures capable of incorporating/expelling water while maintaining their structures. When combined with electroactive materials, such as conducting polymers, the resulting composite may present tunable properties. Herein, the preparation and characterization of alginate-polypyrrole composite hydrogels is described using chemical polymerization to form polypyrrole inside and around alginate beads, employing two simple protocols. These materials were qualitatively tested as extraction phases, using the solid-phase extraction technique, for the pre-concentration of contaminants of emerging concern (atrazine, caffeine, and progesterone). Compared to alginate alone, the composite materials showed a modified extraction capacity, especially for the extraction of progesterone. It was shown that the alginate matrix also contributes to the extraction, not only acting as a support but also as an active extraction media, evidencing a good combination of materials

Alginate/Polypyrrole Hydrogels as Potential Extraction Phase for Determination of Atrazine, Caffeine, and Progesterone in Aqueous Samples

Hydrogels are smart-swelling 3D structures capable of incorporating/expelling water while maintaining their structures. When combined with electroactive materials, such as conducting polymers, the resulting composite may present tunable properties. Herein, the preparation and characterization of alginate-polypyrrole composite hydrogels is described using chemical polymerization to form polypyrrole inside and around alginate beads, employing two simple protocols. These materials were qualitatively tested as extraction phases, using the solid-phase extraction technique, for the pre-concentration of contaminants of emerging concern (atrazine, caffeine, and progesterone). Compared to alginate alone, the composite materials showed a modified extraction capacity, especially for the extraction of progesterone. It was shown that the alginate matrix also contributes to the extraction, not only acting as a support but also as an active extraction media, evidencing a good combination of materials

Catalase protects Aedes aegypti from oxidative stress and increases midgut infection prevalence of Dengue but not Zika.

BACKGROUND:Digestion of blood in the midgut of Aedes aegypti results in the release of pro-oxidant molecules that can be toxic to the mosquito. We hypothesized that after a blood meal, the antioxidant capacity of the midgut is increased to protect cells against oxidative stress. Concomitantly, pathogens present in the blood ingested by mosquitoes, such as the arboviruses Dengue and Zika, also have to overcome the same oxidative challenge, and the antioxidant program induced by the insect is likely to influence infection status of the mosquito and its vectorial competence. METHODOLOGY/PRINCIPAL FINDINGS:We found that blood-induced catalase mRNA and activity in the midgut peaked 24 h after feeding and returned to basal levels after the completion of digestion. RNAi-mediated silencing of catalase (AAEL013407-RB) reduced enzyme activity in the midgut epithelia, increased H2O2 leakage and decreased fecundity and lifespan when mosquitoes were fed H2O2. When infected with Dengue 4 and Zika virus, catalase-silenced mosquitoes showed no alteration in infection intensity (number of plaque forming units/midgut) 7 days after the infectious meal. However, catalase knockdown reduced Dengue 4, but not Zika, infection prevalence (percent of infected midguts). CONCLUSION/SIGNIFICANCE:Here, we showed that blood ingestion triggers an antioxidant response in the midgut through the induction of catalase. This protection facilitates the establishment of Dengue virus in the midgut. Importantly, this mechanism appears to be specific for Dengue because catalase silencing did not change Zika virus prevalence. In summary, our data suggest that redox balance in the midgut modulates mosquito vectorial competence to arboviral infections

Catalase knockdown in the midgut.

<p>(A) Two-day-old females were injected with dsRNA against catalase (dsCat) or an unrelated control gene (dsLac). Two days after the dsRNA injection, a group of mosquitoes were fed blood, while others were fed exclusively with sugar. Twenty-four hours later, RNA was extracted for qPCR analysis. (B) Catalase activity in the epithelia was measured 24 h after a blood meal in dsRNA-treated mosquitoes. (C) Hydrogen peroxide leakage was measured in the midgut epithelia of SF mosquitoes injected with dsCat or dsLacZ. (A) *** <i>p <</i> 0.001 (t-test). (B) **** <i>p <</i> 0.0001 (t-test). (C) * <i>p</i> = 0.0404 (t-test).</p

The Aedes aegypti peritrophic matrix controls arbovirus vector competence through HPx1, a heme-induced peroxidase.

Aedes aegypti mosquitoes are the main vectors of arboviruses. The peritrophic matrix (PM) is an extracellular layer that surrounds the blood bolus. It acts as an immune barrier that prevents direct contact of bacteria with midgut epithelial cells during blood digestion. Here, we describe a heme-dependent peroxidase, hereafter referred to as heme peroxidase 1 (HPx1). HPx1 promotes PM assembly and antioxidant ability, modulating vector competence. Mechanistically, the heme presence in a blood meal induces HPx1 transcriptional activation mediated by the E75 transcription factor. HPx1 knockdown increases midgut reactive oxygen species (ROS) production by the DUOX NADPH oxidase. Elevated ROS levels reduce microbiota growth while enhancing epithelial mitosis, a response to tissue damage. However, simultaneous HPx1 and DUOX silencing was not able to rescue bacterial population growth, as explained by increased expression of antimicrobial peptides (AMPs), which occurred only after double knockdown. This result revealed hierarchical activation of ROS and AMPs to control microbiota. HPx1 knockdown produced a 100-fold decrease in Zika and dengue 2 midgut infection, demonstrating the essential role of the mosquito PM in the modulation of arbovirus vector competence. Our data show that the PM connects blood digestion to midgut immunological sensing of the microbiota and viral infections