Immature Stages, Natural History and Population Biology of Opoptera syme (Hübner, 1821), (Lepidoptera: Nymphalidae: Satyrinae) from Southeastern Brazil.

The present study describes the immature stages of Opoptera syme (Hübner, [1821]) using SEM and Micro-CT to generate 2D and 3D models to study the morphology and chaetotaxy, and present information on the natural history, behavior, and population biology. In laboratory, eggs were laid singly, and the isolated larvae passed through six to seven instars. Host plant in the study site is unknown, but larvae are known to feed on bamboos; in laboratory, larvae accepted the ornamental bamboo Bambusa textilis McClure, 1940. Adults are diurnal and univoltine, flying from December to April (the austral summer). The present study adds information to the biology and natural history of Brassolini, an iconic and still poorly known tribe of Neotropical butterflies.

Insights about resveratrol analogs against trypanothione reductase of Leishmania braziliensis: Molecular modeling, computational docking and in vitro antileishmanial studies.

In this work, we combined molecular modeling, computational docking and in vitro analysis to explore the antileishmanial effect of some resveratrol analogs (ResAn), focusing on their pro-oxidant effect. The molecular target was the trypanothione reductase of Leishmania braziliensis (LbTryR), an essential component of the antioxidant defenses in trypanosomatid parasites. Three-dimensional structures of LbTryR were modeled and molecular docking studies of ResAn1-5 compounds showed the following affinity: ResAn1 > ResAn2 > ResAn4 > ResAn5 > ResAn3. Positive correlation was observed between these compounds' affinity to the LbTryR and the IC50 values against Leishmania sp (ResAn1 < ResAn2 < ResAn4), which allows for TryR being considered an important target for them. As the compound ResAn1 showed the best antileishmanial activity, and docking studies showed its high affinity for NADP binding site (NS) of TryR, plus having been able to induce ROS production in L. braziliensis promastigotes treated, ResAn1 probably occupies NS interfering in the electron transfer processes responsible for the catalytic reaction. The in silico prediction of ADMET properties suggests that ResAn1 may be a promising drug candidate with properties to cross biological membranes and high gastrointestinal absorption, not violating Lipinski's rules. Ultimately, the antileishmanial effect of ResAn can be associated with a pro-oxidant effect which, in turn, can be exploited as an antimicrobial agent. Communicated by Ramaswamy H. Sarma.

Beta Lapachone blocks the cell cycle and induces apoptosis in canine osteosarcoma cells / Beta Lapachona bloqueia o ciclo celular e induz apoptose em células de osteossarcoma canino

Osteosarcoma is a malignant tumor of primitive bone cells with a high incidence in dogs and humans. The need for more effective drugs with less adverse consequences has pushed the development of chemotherapeutic agents from plants and other natural sources. The aim of this study was to verify the cytotoxic effects of beta-lapachone, a compound present in the sawdust of Tabebuia sp. (popularly known as ipê) wood, on canine osteosarcoma cells subcultured and treated in different concentrations (0.1µm, 0.3µm e 1.0µm) and exposure times (24h, 48h e 72h). Results were obtained through Trypan blue dye exclusion, tetrazolium reducing method, cell survival assay, Annexin V-FITC and Propidium Iodine labeling, JC-1 dye labeling and cell cycle kinetics e analysis. The group treated with 0.3µm beta-lapachone presented higher decrease in cell viability (80.27%, 24h, 47.41%, 48h and 35.19%, 72h) and greater progression of cytotoxicity (19.73%, 24h, 52.59%, 48h and 64.81%, 72h). The lower IC50 (0.180µm) was verified in the group treated for 72 hours. Cell growth after treatment decreased as concentration and time of exposure increased, with 0.50% survival fraction at the concentration of 1.0µm. Initial apoptosis was the most frequent type of cell death in all groups, reaching bottom in the 24-hour group treated with 0.1µm (4.26%) and peaking in the 72-hour group treated with 1.0µm (85.89%). Mitochondrial depolarization demonstrated a dose-dependent phenomenon, indicating the intrinsic apoptosis. Cell growth inhibition by blocking cell cycle in the G0/G1 phase related to the exposure the time. β-lapachone is cytotoxic for canine osteosarcoma cells, induces apoptosis and promotes cell cycle arrest in G0/G1 phase.(AU)

O osteossarcoma é o tumor maligno das células ósseas primitivas, com alta incidência em cães e humanos. A necessidade de medicamentos mais efetivos, com menor consequência adversa, tem gerado esforços para o desenvolvimento de agentes quimioterápicos compostos por plantas e outras fontes naturais. O objetivo deste estudo foi verificar os efeitos citotóxicos da beta lapachona, um composto presente na serragem da madeira do ipê, sobre células de osteossarcoma canino subcultivadas e submetidas ao tratamento, de acordo com as diferentes concentrações (0.1µm, 0.3µm e 1.0µm) e tempo de exposição (24h, 48h e 72h). Os resultados foram obtidos por meio dos métodos de exclusão do corante azul de Tripan e de redução do tetrazólio, além dos ensaios de sobrevivência celular, de dupla marcação com Anexina V-FITC e Iodeto de Propídio, de marcação com o corante JC-1 e pela análise da cinética do ciclo celular. O grupo tratado com 0.3µm de beta lapachona apresentou melhor regressão da viabilidade celular (80,27%, 24h; 47,41%, 48h e 35,19%, 72h) e maior progressão da citotoxicidade (19,73%, 24h; 52,59%, 48h e 64,81%, 72h). O menor IC50 (0.180µm) ocorreu no grupo tratado por 72 horas. O crescimento celular após o tratamento foi menor, de acordo com o aumento da concentração e tempo de exposição, apresentando 0,50% de fração de sobrevivência na concentração de 1.0µm. A apoptose inicial foi o tipo de morte celular mais frequente em todos os grupos, menor no grupo de 24 horas tratado com 0.1µm (4,26%) e maior no grupo de 72 horas tratado com 1.0µm (85,89%). A despolarização mitocondrial ocorreu de maneira dose dependente, indicando a ocorrência de apoptose intrínseca. A β lapachona possui efeitos citotóxicos em células de osteossarcoma canino, induz apoptose e promove o bloqueio do ciclo celular na fase G0/G1.(AU)

Distinct purinergic signaling pathways in prepubescent mouse spermatogonia.

Spermatogenesis ranks among the most complex, yet least understood, developmental processes. The physiological principles that control male germ cell development in mammals are notoriously difficult to unravel, given the intricate anatomy and complex endo- and paracrinology of the testis. Accordingly, we lack a conceptual understanding of the basic signaling mechanisms within the testis, which control the seminiferous epithelial cycle and thus govern spermatogenesis. Here, we address paracrine signal transduction in undifferentiated male germ cells from an electrophysiological perspective. We identify distinct purinergic signaling pathways in prepubescent mouse spermatogonia, both in vitro and in situ. ATP-a dynamic, widespread, and evolutionary conserved mediator of cell to cell communication in various developmental contexts-activates at least two different spermatogonial purinoceptor isoforms. Both receptors operate within nonoverlapping stimulus concentration ranges, display distinct response kinetics and, in the juvenile seminiferous cord, are uniquely expressed in spermatogonia. We further find that spermatogonia express Ca(2+)-activated large-conductance K(+) channels that appear to function as a safeguard against prolonged ATP-dependent depolarization. Quantitative purine measurements additionally suggest testicular ATP-induced ATP release, a mechanism that could increase the paracrine radius of initially localized signaling events. Moreover, we establish a novel seminiferous tubule slice preparation that allows targeted electrophysiological recordings from identified testicular cell types in an intact epithelial environment. This unique approach not only confirms our in vitro findings, but also supports the notion of purinergic signaling during the early stages of spermatogenesis.

Effect of 3-alkylpyridine marine alkaloid analogues in Leishmania species related to American cutaneous leishmaniasis.

A series of oxygenated analogues of marine 3-alkylpyridine alkaloids were synthesized, and their leishmanicidal activity was assayed. All compounds were prepared from 3-pyridinepropanol in few steps and in good yields. The key step for the synthesis of these compounds was a classic Williamson etherification under phase-transfer conditions. Besides toxicity in peritoneal macrophages, the compounds exhibited a significant leishmanicidal activity. Of twelve compounds tested, five showed a strong leishmanicidal activity against promastigote forms of Leishmania amazonensis and L. braziliensis with IC50 below 10 µm. Compounds 11, 14, 15, and 16 showed a strong leishmanicidal activity on intracellular amastigotes (IC50 values of 2.78; 0.27; 1.03, and 1.33 µm, respectively), which is unlikely to be owing to the activation of nitric oxide production by macrophages.

Synthesis of 4-aminoquinoline analogues and their platinum(II) complexes as new antileishmanial and antitubercular agents.

A series of 4-amino-7-chloroquinoline derivatives were synthesized by the reaction of 4,7-dichloro-quinoline with the corresponding diamine and then with propargyl bromide. In addition, platinum(II) complexes were obtained by reacting some of the organic derivatives with K(2)PtCl(4). Several of the synthesized compounds displayed antituberculosis activities. Compound 3 was 47.5 times more active than amphotericin B against Leishmania chagasi (IC(50)=0.04 µg/mL). Compounds 5, 6, 7, 9, 10, 11 and 13 presented promising results against Mycobacterium tuberculosis, with MIC values ranging from 12.5 to 15.6 µg/mL, comparable to the "first and second line" drugs used to treat tuberculosis.

Synthesis, cytotoxicity, and antileishmanial activity of N,N'-disubstituted ethylenediamine and imidazolidine derivatives.

This paper describes the preparation of N,N'-disubstituted ethylenediamine and imidazolidine derivatives and their in vitro biological activities against Leishmania species. Of the nine synthesized compounds, five displayed a good activity in both L. amazonensis and L. major promastigotes. The compounds 1,2-Bis(p-methoxybenzyl) ethylenediamine (4) and 1,3-Bis(p-methoxybenzyl)imidazolidines (5) showed the best activity on intracellular amastigotes, with IC50 values of 2.0 and 9.4 microgram/mL, respectively. In addition, none of compounds were cytotoxic against mammalian cells. The leishmanicidal activity can be related with inhibition of polyamine synthesis and cellular penetration within biological membranes.

Synthesis, cytotoxicity and antileishmanial activity of some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines.

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3). Hydrolysis of the methyl ester adduct (5) yielded the free acid (6). The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.