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La citometría de flujo es una tecnología que ha favorecido el rápido avance de muchas y muy diversas áreas de la ciencia, ya que permite la medición simultánea de múltiples características de cada una de las partículas o células individuales que se encuentran en una muestra mientras pasan a gran velocidad a través de una zona iluminada por uno o varios láseres. La información obtenida incluye datos sobre el tamaño y la complejidad interna, así como otros parámetros inherentes a cada una de las partículas presentes en la muestra, los cuales son captados por el equipo como señales luminosas. Las partículas más comúnmente analizadas en los citómetros de flujo son células, así que puede analizarse la expresión de moléculas tanto en su superficie como en su interior, la viabilidad, la funcionalidad, la proliferación celular, el contenido de ADN y la producción de citocinas entre muchas otras. Estas determinaciones pueden realizarse gracias a la utilización de anticuerpos acoplados a fluorocromos o bien, al uso de moléculas cuya fluorescencia depende de la característica que se quiera evaluar. Algunos citómetros de flujo son además clasificadores (“sorters”), lo que implica que el equipo puede separar físicamente las células que presentan las características de interés y además, es factible que una vez que han sido purificadas, éstas puedan emplearse en posteriores experimentos. En esta revisión se concentran los fundamentos de la citometría de flujo y sus principales aplicaciones, las cuales ofrecen una gran ventana de oportunidad en el ámbito veterinario, tanto en investigación como en la clínica.

Leishmaniasis is a neglected vector-borne disease; there are different manifestations of the diseases and species involved, and cutaneous leishmaniasis caused by

The biological activity of essential oils and their major components is well documented. Essential oils such as oregano and cinnamon are known for their effect against bacteria, fungi, and even viruses. The mechanism of action is proposed to be related to membrane and external cell structures, including cell walls. This study aimed to evaluate the biological activity of seven essential oils and eight of their major components against Gram-negative and Gram-positive bacteria, filamentous fungi, and protozoans. The antimicrobial activity was evaluated by determination of the Minimal Inhibitory Concentration for Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella Typhimurium, Shigella sonnei, Aspergillus niger, Aspergillus ochraceus, Alternaria alternata, and Fusarium oxysporium, the half-maximal inhibitory concentration (IC50) for Trypanosoma cruzi and Leishmania mexicana, and the median lethal dose (LD50) for Giardia lamblia. Results showed that oregano essential oil showed the best antibacterial activity (66–100 µg/mL), while cinnamon essential oil had the best fungicidal activity (66–116 µg/mL), and both showed excellent antiprotozoal activity (22–108 µg/mL). Regarding the major components, thymol and carvacrol were also good antimicrobials (23–200 µg/mL), and cinnamaldehyde was an antifungal compound (41–75 µg/mL). The major components were grouped according to their chemical structure as phenylpropanoids, terpenoids, and terpinenes. The statistical analysis of the grouped data demonstrated that protozoans were more susceptible to the essential oils, followed by fungi, Gram-positive bacteria, and Gram-negative bacteria. The analysis for the major components showed that the most resistant microbial group was fungi, which was followed by bacteria, and protozoans were also more susceptible. Principal Component Analysis for the essential oils demonstrated the relationship between the biological activity and the microbial group tested, with the first three components explaining 94.3% of the data variability. The chemical structure of the major components was also related to the biological activity presented against the microbial groups tested, where the three first principal components accounted for 91.9% of the variability. The external structures and the characteristics of the cell membranes in the different microbial groups are determinant for their susceptibility to essential oils and their major components

Dengue is a worldwide expanding threat caused by dengue virus (DENV) infection. To date, no specific treatment or effective vaccine is available. Antibodies produced by plasma cells (PCs) might be involved concomitantly in protection and severe dengue immunopathology. Although a massive appearance of PCs has been reported during acute DENV infection in humans, this response has been poorly characterized. Here, we show the dynamic of PC generation in immune-competent mice cutaneously inoculated with DENV compared with two control experimental groups: mice inoculated with inactivated DENV or with PBS. We found that PC numbers increased significantly in the skin-draining lymph node (DLN), peaking at day 10 and abruptly decreasing by day 14 after DENV inoculation. Class-switched IgG+ PCs appeared from day 7 and dominated the response, while in contrast, the frequency of IgM+ PCs decreased from day 7 onwards. Even though the kinetic of the response was similar between DENV- and iDENV-inoculated mice, the intensity of the response was significantly different. Interestingly, we demonstrated a similar PC response to virus antigens (E and prM) by ELISPOT. In situ characterization showed that PCs were distributed in the medullary cords and in close proximity to germinal centers (GCs), suggesting both an extrafollicular and a GC origin. Proliferating PCs (Ki-67+) were found as early as 3-day postinoculation, and in-depth analysis showed that these PCs were in active phases of cell cycle during the kinetic. Finally, we found a progressive appearance of high-affinity neutralizing DENV-specific IgG further supporting GC involvement. Of note, these antibodies seem to be highly cross-reactive, as a large proportion recognizes Zika virus (ZIKV). The strong PC response to skin-inoculated DENV in this work resembles the findings already described in humans. We consider that this study contributes to the understanding of the in vivo biology of the humoral immune response to DENV in an immunocompetent murine model.

Cyrtocarpa procera is a plant used in traditional Mexican medicine to treat different gastrointestinal problems. Here, we investigated the effects of a C. procera methanolic extract in DSS-induced colitis mice. Ulcerative colitis (UC) was induced by administering 4% DSS in drinking water to female BALB/c mice. Compared to untreated mice with UC, the treatment group receiving the C. procera extract presented less severe UC symptoms of diarrhea, bleeding, and weight loss. Additionally, colon shortening was significantly reduced, and at the microscopic level, only minor damage was observed. Levels of proinflammatory cytokines such as TNF-α, IL-1β, and IFNγ in serum as well as the MPO activity in the colon were significantly reduced in the C. procera methanolic extract-treated group. Moreover, the extract of C. procera reduced oxidative stress during UC, preventing the deterioration of the activity of antioxidant enzymes such as SOD, CAT, and GPx. Additionally, the extract decreased lipid peroxidation damage and its final products, such as malondialdehyde (MDA). In agreement with this, in vitro assays with the C. procera extract displayed good antioxidant capacity, probably due to the presence of polyphenolic compounds, in particular the flavonoids that were identified, such as chrysin, naringenin, kaempferol, and catechin, which have been reported to have anti-inflammatory and antioxidant activities. Therefore, the improvement of UC by the C. procera methanolic extract may be related to the action mechanisms of these compounds.

Dengue is a global health problem without current specific treatment nor safe vaccines available. While severe dengue is related to pre-existing non-neutralizing dengue virus (DENV) antibodies, the role of T cells in protection or pathology is unclear. Using cutaneous DENV infection in immunocompetent mice we previously showed the generation of PNA+ germinal centers (GCs), now we assessed the activation and proliferation of B and T cells in draining lymph nodes (DLNs). We found a drastic remodelling of DLN compartments from 7 to 14 days post-infection (dpi) with greatly enlarged B cell follicles, occupying almost half of the DLN area compared to ~24% in naive conditions. Enormous clusters of proliferating (Ki-67+) cells inside B follicles were found 14 dpi, representing ~33% of B cells in DLNs but only ~2% in non-infected mice. Inside GCs, we noticed an important recruitment of tingle body macrophages removing apoptotic cells. In contrast, the percentage of paracortex area and total T cells decreased by 14–16 dpi, compared to controls. Scattered randomly distributed Ki-67+ T cells were found, similar to non-infected mice. CD69 expression by CD4+ and CD8+ T cells was minor, while it was remarkable in B cells, representing 1764.7% of change from basal levels 3 dpi. The apparent lack of T cell responses cannot be attributed to apoptosis since no significant differences were observed compared to non-infected mice. This study shows massive B cell activation and proliferation in DLNs upon DENV infection. In contrast, we found very poor, almost absent CD4+ and CD8+ T cell responses.

Ursolic and oleanolic acids are natural isomeric triterpenes known for their anticancer activity. Here, we investigated the effect of triterpenes on the viability of A549 human lung cancer cells and the role of autophagy in their activity. The induction of autophagy, the mitochondrial changes and signaling pathway stimulated by triterpenes were systematically explored by confocal microscopy and western blotting. Ursolic and oleanolic acids induce autophagy in A549 cells. Ursolic acid activates AKT/mTOR pathways and oleanolic acid triggers a pathway independent on AKT. Both acids promote many mitochondrial changes, suggesting that mitochondria are targets of autophagy in a process known as mitophagy. The PINK1/Parkin axis is a pathway usually associated with mitophagy, however, the mitophagy induced by ursolic or oleanolic acid is just dependent on PINK1. Moreover, both acids induce an ROS production. The blockage of autophagy with wortmannin is responsible for a decrease of mitochondrial membrane potential (&Delta, &psi, ) and cell death. The wortmannin treatment causes an over-increase of p62 and Nrf2 proteins promote a detoxifying effect to rescue cells from the death conducted by ROS. In conclusion, the mitophagy and p62 protein play an important function as a survival mechanism in A549 cells and could be target to therapeutic control.

Mariano García-Martínez,1,2 Luis Vázquez-Flores,1,2 Violeta D Álvarez-Jiménez,1,3 Jessica Castañeda-Casimiro,1 Miguel Ibáñez-Hernández,4 Luvia Enid Sánchez-Torres,1 Jorge Barrios-Payán,5 Dulce Mata-Espinosa,5 Sergio Estrada-Parra,1 Rommel Chacón-Salinas,1 Jeanet Serafín-López,1 Isabel Wong-Baeza,1 Rogelio Hernández-Pando,5 Iris Estrada-García11Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas (ENCB), Instituto Politécnico Nacional (IPN), Mexico City, Mexico; 2Posgrado en Inmunología, Escuela Nacional de Ciencias Biológicas (ENCB), Instituto Politécnico Nacional (IPN), Mexico City, Mexico; 3Laboratorio de Biología Molecular y Bioseguridad Nivel 3, Centro Médico Naval (CEMENAV), Secretaría de Marina Armada de México (Semar), Mexico City, Mexico; 4Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas (ENCB), Instituto Politécnico Nacional (IPN), Mexico City, Mexico; 5Sección de Patología Experimental, Departamento de Patología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, MexicoCorrespondence: Iris Estrada-GarcíaDepartamento de Inmunología, Escuela Nacional de Ciencias Biológicas (ENCB), Instituto Politécnico Nacional (IPN), Prolongación de Carpio y Plan de Ayala s/n, Col. Santo Tomás, Ciudad de México 11340, MéxicoTel +52 555 729 6000 x 62507Fax +52 555 729 6000 x 62369Email iestrada5@hotmail.comBackground: Tuberculosis is the leading cause of death by an infectious microorganism worldwide. Conventional treatment lasts at least six months and has adverse effects; therefore, it is important to find therapeutic alternatives that reduce the bacterial load and may reduce the treatment duration. The immune response against tuberculosis can be modulated by several mechanisms, including extracellular vesicles (EVs), which are nano-sized membrane-bound structures that constitute an efficient communication mechanism among immune cells.Methods: The EVs released by the J774A.1 mouse macrophage cell line, both spontaneously (S-EV) and after infection with Mycobacterium tuberculosis H37Rv (Mtb-EV), were purified by ultra-centrifugation and size-exclusion chromatography. The size distribution and chemical composition of these EVs were evaluated, and their effect on the bacterial load and the production of cytokines was determined in both in vitro and in vivo models of M. tuberculosis infection.Results: Mtb-EV are larger than S-EV, they contain M. tuberculosis-specific antigens (not detected in EVs released from M. fortuitum-infected J774A.1 cells) and are rich in phosphatidylserine, present in their outer membrane layer. S-EV, but not Mtb-EV, reduced the bacterial load and the production of MCP-1 and TNF-α in M. tuberculosis-infected macrophages, and these effects were reversed when phosphatidylserine was blocked with annexin V. Both S-EV and Mtb-EV significantly reduced the lung bacterial load in mice infected with M. tuberculosis after 60days of treatment, but they had no effect on survival or on the lung pneumonic area of these mice.Conclusion: J774A.1 macrophages infected with M. tuberculosis H37Rv released EVs that differed in size and phosphatidylserine content from spontaneously released EVs, and these EVs also had different biological effects: S-EV reduced the mycobacterial load and the cytokine production in vitro (through a phosphatidylserine-dependent mechanism), while both EVs reduced the lung bacterial load in vivo. These results are the basis for further experiments to evaluate whether EVs improve the efficiency of the conventional treatment for tuberculosis.Keywords: tuberculosis, extracellular vesicles, phosphatidylserine, macrophages, lung disease

Vibrio parahaemolyticus is a serious pathogen that affects aquaculture. Nonetheless, to the best of our knowledge, no studies have focused on its immunological implications in Totoaba macdonaldi. Thus, the early immune response to V. parahaemolyticus in juveniles of totoaba was studied at 24 h post-infection with an in vivo study. In addition, changes in cellular innate immune parameters - phagocytosis, respiratory burst activity and viability (annexin V/propidium iodide) - were evaluated in vitro in head-kidney, spleen and thymus leukocytes at 6 and 24 h after bacterial stimulation by flow cytometry. Simultaneously, the expression levels of two immune-relevant genes (IL-1β and IL-8) were measured by using real time PCR. During in vivo study, mRNA transcripts of IL-1β were highly expressed in spleen, thymus and intestine and down-regulated in liver after 24 h post-infection. IL-8 gene expression was upregulated in spleen, intestine and liver compared to that of non-infected fish and down-regulated in thymus after 24 h post-infection. Generally, the results showed a significant decrease in cellular immune responses during the infection, principally in phagocytic ability and respiratory burst. The survival or viability of stimulated leukocytes was significantly reduced causing necrosis and apoptosis, indicating a robust killing response by V. parahaemolyticus. Finally the in vitro analysis showed that transcript levels of IL-1β and IL-8 were up-regulated during stimulation with V. parahaemolyticus in head-kidney, spleen and intestine and down-regulated in thymus at any time of the experiment. Although V. parahaemolyticus has been reported to be an important pathogen for many aquatic organisms, to our knowledge this might be the first report of early-immune response in juvenile totoaba and these immune parameters may be reliable indicators and can be useful in the health control of this species.

The larvicidal activity of essential oils cinnamon (Cinnamomum verum J. Presl), Mexican lime (Citrus aurantifolia Swingle) cumin (Cuminum cyminum Linnaeus), clove (Syzygium aromaticum (L.) Merr. & L.M.Perry), laurel (Laurus nobilis Linnaeus), Mexican oregano (Lippia berlandieri Schauer) and anise (Pimpinella anisum Linnaeus)) and their major components are tested against larvae and pupae of Culex quinquefasciatus Say. Third instar larvae and pupae are used for determination of lethality and mortality. Essential oils with more than 90% mortality after a 30-min treatment are evaluated at different time intervals. Of the essential oils tested, anise and Mexican oregano are effective against larvae, with a median lethal concentration (LC50) of 4.7 and 6.5 µg/mL, respectively. Anise essential oil and t-anethole are effective against pupae, with LC50 values of 102 and 48.7 µg/mL, respectively. Oregano essential oil and carvacrol also have relevant activities. A kinetic analysis of the larvicidal activity, the oviposition deterrent effect and assays of the effects of the binary mixtures of chemical components are undertaken. Results show that anethole has synergistic effects with other constituents. This same effect is observed for carvacrol and thymol. Limonene shows antagonistic effect with β-pinene. The high larvicidal and pupaecidal activities of essential oils and its components demonstrate that they can be potential substitutes for chemical compounds used in mosquitoes control programs.

Resumen Más de la mitad de la población humana está expuesta a contraer infecciones transmitidas por mosquitos. El cambio climático y la aparición de cepas resistentes a los insecticidas tradicionalmente utilizados han motivado la búsqueda de nuevos agentes capaces de controlar las poblaciones de mosquitos. Los aceites esenciales han resultado ser eficaces agentes repelentes y larvicidas. El objetivo de este trabajo fue revisar las investigaciones llevadas a cabo en los últimos años sobre la actividad larvicida de los aceites esenciales y sus componentes contra mosquitos de los géneros Aedes, Anopheles y Culex, así como los últimos reportes sobre su posible mecanismo de acción. Abstract More than half of the human population is exposed to mosquito-borne infections. Climate change and the emergence of strains resistant to traditionally used insecticides have motivated the search of new agents for mosquito population control. Essential oils have been effective repellents and larvicidal agents. The aim of this work was to review research studies conducted in recent years on the larvicidal activity of essential oils and their components against Aedes, Anopheles and Culex mosquitoes, as well as the latest reports about their possible mechanism of action.

Background In order to develop new larvicidal agents derived from phytochemicals, the larvicidal activity of fifty molecules that are constituent of essential oils was evaluated against Culex quinquefasciatus Say. Terpenes, terpenoids and phenylpropanoids molecules were included in the in vitro evaluation, and QSAR models using genetic algorithms were built to identify molecular and structural properties of biological interest. Further, to obtain structural details on the possible mechanism of action, selected compounds were submitted to docking studies on sterol carrier protein-2 (SCP-2) as possible target. Results Results showed high larvicidal activity of carvacrol and thymol on the third and fourth larval stage with a median lethal concentration (LC50) of 5.5 and 11.1 µg/mL respectively. Myrcene and carvacrol were highly toxic for pupae, with LC50 values of 31.8 and 53.2 µg/mL. Structure–activity models showed that the structural property π-bonds is the largest contributor of larvicidal activity while ketone groups should be avoided. Similarly, property–activity models attributed to the molecular descriptor LogP the most contribution to larvicidal activity, followed by the absolute total charge (Qtot) and molar refractivity (AMR). The models were statistically significant; thus the information contributes to the design of new larvicidal agents. Docking studies show that all molecules tested have the ability to interact with the SCP-2 protein, wherein α-humulene and β-caryophyllene were the compounds with higher binding energy. Conclusions The description of the molecular properties and the structural characteristics responsible for larvicidal activity of the tested compounds were used for the development of mathematical models of structure–activity relationship. The identification of molecular and structural descriptors, as well as studies of molecular docking on the SCP-2 protein, provide insight on the mechanism of action of the active molecules, and the information can be used for the design of new structures for synthesis as potential new larvicidal agents. Electronic supplementary material The online version of this article (10.1186/s13065-018-0425-2) contains supplementary material, which is available to authorized users.

Colonization of epithelium by microorganisms leads to inflammatory responses. In some cases an anti-apoptotic response involving the cellular inhibitor of apoptosis protein-2 (cIAP-2) also occurs. Although strong expression of cIAP-2 has been observed in lesional skin from psoriatic patients and in HaCaT keratinocytes treated with peptidoglycan (PGN) from Staphylococcus aureus, anti-apoptotic responses induced in the skin by cIAP-2 have seldom been studied. In this study, the effect of PGN on TNF-α-induced apoptotic HaCaT keratinocytes was assessed. Morphological analysis, quantification of cells with DNA fragmentation and active caspase-3 detection was performed to assess apoptotic cell death. Greater LL-37 and cIAP-2 production was found in keratinocytes stimulated with PGN than in non-treated cells (P < 0.05). In comparison with cells treated with TNF-α only, a significant reduction in apoptotic cell death was observed when HaCaT were pretreated with PGN before inducing apoptosis with TNF-α (P < 0.05). In addition, an inhibitor of cIAP-2 activity (LCL161) stopped the PGN effect. These findings show that PGN from S. aureus has an anti-apoptotic effect in keratinocytes mediated by cIAP-2 production, suggesting that this anti-apoptotic activity could favor proliferation of keratinocytes in psoriasis.

Los cambios socioeconómicos y las intervenciones sanitarias han mejorado la salud de la población mundial en las últimas décadas. Sin embargo, han empezado a presentarse modificaciones en la distribución de ciertas enfermedades debidas, principalmente, a lo que se conoce como cambio climático y que es una consecuencia más del deterioro del medio ambiente. Una de las preocupaciones derivadas de lo anterior es la redistribución o nueva geolocalización de las enfermedades transmitidas por vectores (ETV), ya que los vectores que las transmiten están encontrando nuevos nichos ecológicos en los cuales establecerse y multiplicarse. El objetivo de la presente revisión fue conjuntar la evidencia científica en torno al cambio climático y sus efectos en las ETV.

Amphipterygium adstringensis an endemic species in Mexico commonly known as “cuachalalate.” Healers to treat gastritis, gastric ulcers, and gastrointestinal cancer have traditionally used the bark. We investigated the effects of alcoholic extract ofA. adstringens(AaEE) in DSS-induced colitis in mice. The protective effect of AaEE was determined at 200 mg/kg by oral gavage for 10 days. We determine the effect of AaEE on clinical features (disease activity index), antioxidants, anti-inflammatory, and immunomodulatory activities in relation to the activity of SOD, CAT, and GPx, levels of proinflammatory cytokines, and changes both macroscopic and microscopic of the colonic mucosa. AaEE significantly reduced the inflammation of colon and significantly increased SOD and GPx activities. AaEE also significantly decreased TNF-α, IFN-γ, and IL-1βcytokine levels compared to DSS-treated mice and reduced both infiltration of inflammatory cells and the mucosal damage in colon. The results suggested the protective potential of AaEE in DSS-induced colitis and this might be attributed to its phytochemicals compounds that have been found to induce a wide spectrum of activities such as reduction in oxidative stress, suppression of inflammation, modulating numerous signal transduction pathways, and induction of apoptosis. The findings of this study suggest that AaEE has substantial potential for the treatment of inflammatory colitis.

In this study, we investigated the cytotoxic effect of perezone, a constituent isolated from the roots of Perezia spp. and of its synthetic isomer isoperezone on the K562 human leukemia cell line. Perezone showed greater cytotoxic effect than isoperezone but both compounds were found to induce cytotoxicity trough a caspase-dependent and a caspase-independent mechanisms; important changes in their light scattering properties, phosphatidylserine translocation and mitochondrial membrane potential disruption were detected by cytometry. The mechanism of death induction of each compound showed interesting concentration-dependent differences. Neither compound induced the apoptosis inducing factor.

Type 1 diabetes (T1D) is an autoimmune disease that is characterized by the specific destruction of insulin-producing pancreatic β cells. Invariant natural killer T (iNKT) cells have been associated with development of T1D. Class I MHC-restricted T cell-associated molecule (CRTAM) is expressed on activated iNKT, CD8(+), and CD4(+) T cells, and it is associated with the pro-inflammatory profiles of these cells. Crtam gene expression in CD3(+) lymphocytes from non-obese diabetic (NOD) mice is associated with T1D onset. However, expression of CRTAM on T cells from patients with T1D has not yet been evaluated. We compared iNKT cell (CD3(+)Vα24(+)Vβ11(+)) numbers and CRTAM expression in a Mexican population with recent-onset T1D and their first-degree relatives with control families. Remarkably, we found lower iNKT cell numbers in T1D families, and we identified two iNKT cell populations in some of the families. One iNKT cell population expressed high iTCR levels (iNKT(hi)), whereas another expressed low levels (iNKT(lo)) and also expressed CRTAM. These findings support a probable genetic determinant of iNKT cell numbers and a possible role for these cells in T1D development. This study also suggests that CRTAM identifies recently activated iNKT lymphocytes.

Background Essential oils and their constituents are commonly known for their antibacterial, antifungal and antiparasitic activity, and there are also reports on the antimycobacterial properties, but more experimental data are needed for the description of the mechanism of action or structural (and molecular) properties related to the antimicrobial activity. Methods Twenty-five constituents of essential oils were evaluated against Mycobacterium tuberculosis H37Rv and Mycobacterium bovis AN5 by the Alamar Blue technique. Twenty compounds were modeled using in silico techniques descriptor generation and subsequent QSAR model building using genetic algorithms. The p-cymene, menthol, carvacrol and thymol were studied at the quantum mechanical level through the mapping of HOMO and LUMO orbitals. The cytotoxic activity against macrophages (J774A) was also evaluated for these four compounds using the Alamar Blue technique. Results All compounds tested showed to be active antimicrobials against M. tuberculosis. Carvacrol and thymol were the most active terpenes, with MIC values of 2.02 and 0.78 μg/mL respectively. Cinnamaldehyde and cinnamic acid were the most active phenylpropanes with MIC values of 3.12 and 8.16 μg/mL respectively. The QSAR models included the octanol-water partition (LogP) ratio as the molecular property that contributes the most to the antimycobacterial activity and the phenolic group (nArOH) as the major structural element. Conclusions The description of the molecular properties and the structural characteristics responsible for antimycobacterial activity of the compounds tested, were used for the development of mathematical models that describe structure-activity relationship. The identification of molecular and structural descriptors provide insight into the mechanisms of action of the active molecules, and all this information can be used for the design of new structures that could be synthetized as potential new antimycobacterial agents.

Chagas disease or American trypanosomiasis is a worldwide public health problem. In this work, we evaluated 26 new propyl and isopropyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives as potential trypanocidal agents. Additionally, molecular docking and enzymatic assays on trypanothione reductase (TR) were performed to provide a basis for their potential mechanism of action. Seven compounds showed better trypanocidal activity on epimastigotes than the reference drugs, and only four displayed activity on trypomastigotes; T-085 was the lead compound with an IC50 = 59.9 and 73.02 µM on NINOA and INC-5 strain, respectively. An in silico analysis proposed compound T-085 as a potential TR inhibitor with better affinity than the natural substrate. Enzymatic analysis revealed that T-085 inhibits parasite TR non-competitively. Compound T-085 carries a carbonyl, a CF3, and an isopropyl carboxylate group at 2-, 3- and 7-position, respectively. These results suggest the chemical structure of this compound as a good starting point for the design and synthesis of novel trypanocidal derivatives with higher TR inhibitory potency and lower toxicity.

Recently it was discovered that neutrophils can generate extracellular fibers called NET (neutrophil extracellular traps), which are composed of a skeleton of DNA “decorated” with many cytoplasmic –including enzymes– and nuclear components.The NET are a physical barrier that prevent the spread of microorganisms and facilitate the cell death by promoting a high local concentration of antimicrobial molecules. On the other hand, the fibrous structure limits the damage to the tissue where they are generated by restricting the range of molecules that are released by the neutrophil. This paper describes this new form of cell death and the implications this may have on different diseases.

Neutrophils are one the earliest, crucial innate defenses against innumerable pathogens. Their main microbicidal activities include phagocytosis and degranulation, with many pharmacologically active molecules contributing to inflammation. Recently, a novel antimicrobial mechanism was discovered; the Neutrophil Extracelullar Traps (NETs) formed by extrusion of DNA and associated molecules (histones, elastase, antimicrobial peptides, among others) which trap and kill microorganisms. Since NETs were recently described, research has focused on their induction and microbicidal properties, and recently on disease involvement. However, the functional consequences of NETs interacting with other immune cells, either resident or recruited during early inflammation, have not been assessed. We therefore investigated the consequences of exposing two major APCs, macrophages (Mfs) and conventional Dendritic Cells (cDCs) to NETs. Our data revealed that at early times (30 min), both Antigen Presenting Cells (APCs) showed induction of important costimulatory molecules (CD80, CD86). Unexpectedly, however, at later times (6 and 24 hours) NETs apparently triggered a cell death process in these APCs by a caspase- and Apoptosis induced factor (AIF)-dependent pathway, suggesting mitochondrial damage. By rhodamine-123 labelling we found that in both APCs, relatively prolonged exposure to NETs or their components importantly decreased the mitochondrial membrane potential. Ultrastructural analysis confirmed mitochondrial alterations in both APCs. Our results would suggest that early in inflammation, NETs can activate the two main APCs (Mfs and cDCs), but as the process continues, NETs can then initiate apoptosis of these cells through mitochondrial harm. Conceivable, this “late” induction of cell death in these two APCs might start limiting an ongoing inflammatory process to control it. Electronic supplementary material The online version of this article (doi:10.1186/s40064-015-0932-8) contains supplementary material, which is available to authorized users.