Bioguided isolation, characterization and media optimization for production of Lysolipins by actinomycete as antimicrobial compound against Xanthomonas citri subsp. citri.

Citrus Canker disease is one of the most important disease in citrus production worldwide caused by gram-negative bacterial pathogen Xanthomonas citri subsp. citri, leading to great economic losses. Currently, a spray of copper-based bactericides is the primary measure for citrus canker management. However, these measures can lead to the contamination of soil by metal contamination, but also the development of copper-resistant Xanthomonas populations. Considering the need to discovery new alternatives to control the citrus canker disease, actinomycetes isolated from the Brazilian Caatinga biome and their crude extracts were tested against different strains of Xanthomonas citri subsp. citri. Streptomyces sp. Caat 1-54 crude extract showed the highest antibiotic activity against Xcc. The crude extract dereplication was performed by LC-MS/MS. Through bioassay-guided fractionation strategy, the antimicrobial activity was assigned to Lysolipins, showing a MIC around 0.4-0.8 µg/mL. Growth media optimization using statistical experimental design increased the Lysolipins production in three-fold production. The preventive and curative effects of the optimized crude extract obtained by experimental design of Caat-1-54 against citrus canker were evaluated in potted 'Pera' sweet orange nursery trees. Caat 1-54 extract was effective in preventing new infections by Xcc on leaves but was not able to reduce Xcc population in pre-established citrus canker lesions. Streptomyces sp. Caat 1-54 extract is a promising, environmentally-friendly source of antimicrobial compound to protect citrus trees against citrus canker.

Metabolic Profile in Plasma AND CSF of LEVODOPA-induced Dyskinesia in Parkinson's Disease: Focus on Neuroinflammation.

The existence of few biomarkers and the lack of a better understanding of the pathophysiology of levodopa-induced dyskinesia (LID) in Parkinson's disease (PD) require new approaches, as the metabolomic analysis, for discoveries. We aimed to identify a metabolic profile associated with LID in patients with PD in an original cohort and to confirm the results in an external cohort (BioFIND). In the original cohort, plasma and CSF were collected from 20 healthy controls, 23 patients with PD without LID, and 24 patients with PD with LID. LC-MS/MS and metabolomics data analysis were used to perform untargeted metabolomics. Untargeted metabolomics data from the BioFIND cohort were analyzed. We identified a metabolic profile associated with LID in PD, composed of multiple metabolic pathways. In particular, the dysregulation of the glycosphingolipid metabolic pathway was more related to LID and was strongly associated with the severity of dyskinetic movements. Furthermore, bile acid biosynthesis metabolites simultaneously found in plasma and CSF have distinguished patients with LID from other participants. Data from the BioFIND cohort confirmed dysregulation in plasma metabolites from the bile acid biosynthesis pathway. There is a distinct metabolic profile associated with LID in PD, both in plasma and CSF, which may be associated with the dysregulation of lipid metabolism and neuroinflammation.

Targeted analysis of eicosanoids derived from cytochrome P450 pathway by high-resolution multiple-reaction monitoring mass spectrometry.

Cytochrome P450 (CYP450) pathway is one of the critical enzymatic via eicosanoid biosynthesis. Nevertheless, their metabolites are far less explored. This pathway plays a crucial role in converting arachidonic acid to hydroxyeicosatetraenoic (HETEs), epoxyeicosatrienoic (EETs), dihydroxyeicosatetraenoic acids (DiHETEs), and dihydroxyeicosatrienoic acids (DiHETrEs), which mediate several physiological and pathological functions. However, CYP450-derived eicosanoids are structurally complex, making those analyses a challenge in lipidomics studies. Herein, a high-resolution multiple-reaction monitoring (MRMHR ) method has been proposed as a powerful tool for the simultaneous analysis of CYP450-eicosanoids on different biological samples. The developed liquid chromatography (LC)-MRMHR method was partially validated according to the Food and Drug Administration (FDA) criteria, demonstrating adequate specificity, linearity, precision, and accuracy. Besides, several biological samples were analyzed to guarantee the feasibility of the method. The proposed strategy may improve the understanding of CYP450-derived eicosanoids in biological systems, which could be fundamental to reveal new aspects of those in physiologic and pathologic conditions.

Investigation of the Involvement of the Endocannabinoid System in TENS-Induced Antinociception.

Transcutaneous electrical nerve stimulation (TENS) promotes antinociception by activating the descending pain modulation pathway and consequently releasing endogenous analgesic substances. In addition, recent studies have shown that the endocannabinoid system controls pain. Thus, the present study investigated the involvement of the endocannabinoid system in TENS-induced antinociception of cancer pain using a cancer pain model induced by intraplantar (i.pl.) injections of Ehrlich tumor cells in male Swiss mice. Low- and high-frequency TENS was applied for 20 minutes to the mice's paws, and to investigate the involvement of the endocannabinoid system were used the N-(peperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pitazole-3-carboixamide (AM251), a cannabinoid CB1 receptor antagonist and (5Z,8Z,11Z,14Z)-5,8,11,14-eicosatetraenyl-methylester phosphonofluoridic acid (MAFP), an inhibitor of the endocannabinoid metabolizing enzyme fatty acid amide hydrolase, injected by via i.pl., intrathecal (i.t.), and intradorsolateral periaqueductal gray matter (i.dl.PAG). Furthermore, liquid chromatography-tandem mass spectrometry, western blot, and immunofluorescence assays were used to evaluate the endocannabinoid anandamide levels, cannabinoid CB1 receptor protein levels, and cannabinoid CB1 receptor immunoreactivity, respectively. Low- and high-frequency TENS reduced the mechanical allodynia induced by Ehrlich tumor cells and this effect was reversed by AM251 and potentiated by MAFP at the peripheral and central levels. In addition, TENS increased the endocannabinoid anandamide levels and the cannabinoid CB1 receptor protein levels and immunoreactivity in the paw, spinal cord, and dorsolateral periaqueductal gray matter. These results suggest that low- and high-frequency TENS is effective in controlling cancer pain, and the endocannabinoid system is involved in this effect at both the peripheral and central levels. PERSPECTIVE: TENS is a nonpharmacological strategy that may be used to control cancer pain. Identification of a new mechanism involved in its analgesic effect could lead to the development of clinical studies as well as an increase in its application, lessening the need for pharmacological treatments.

Involvement of Spinal Cannabinoid CB2 Receptors in Exercise-Induced Antinociception.

Muscle pain affects approximately 11-24% of the global population. Several studies have shown that exercise is a non-pharmacological therapy to pain control. It has been suggested that the endocannabinoid system is involved in this antinociceptive effect. However, the participation of this pathway is unclear. The present study aimed to investigate whether spinal cannabinoid CB2 receptors participate in the exercise-induced antinociception. The inflammatory muscle pain model was induced by the intramuscular injection of carrageenan. Tactile allodynia and thermal hyperalgesia were determined with the von Frey filaments and hot-plate tests. C57BL/6J female mice underwent a swimming training protocol that lasted 3 weeks. This protocol of exercise reduced carrageenan-induced tactile allodynia and thermal hyperalgesia and this effect was prevented by the cannabinoid CB2 receptors inverse agonist AM630 and potentiated by MAFP (inhibitor of the enzyme that metabolizes endocannabinoids) and minocycline (microglia inhibitor). In addition, exercise increased the endocannabinoid anandamide levels and cannabinoid CB2 receptors expression whereas it reduced Iba1 (microglial marker) protein expression as well as pro-inflammatory cytokines (TNF-α and IL-1ß) in the spinal cord of mice with inflammatory muscle pain. Swimming training also reduced muscle temperature of carrageen-treated animals. The present study suggests that activation of spinal cannabinoid CB2 receptors and reduction of activated microglia are involved in exercise-induced antinociception.

Amblyomma sculptum Salivary PGE2 Modulates the Dendritic Cell-Rickettsia rickettsii Interactions in vitro and in vivo.

Amblyomma sculptum is an important vector of Rickettsia rickettsii, causative agent of Rocky Mountain spotted fever and the most lethal tick-borne pathogen affecting humans. To feed on the vertebrate host's blood, A. sculptum secretes a salivary mixture, which may interact with skin resident dendritic cells (DCs) and modulate their function. The present work was aimed at depicting the A. sculptum saliva-host DC network and the biochemical nature of the immunomodulatory component(s) involved in this interface. A. sculptum saliva inhibits the production of inflammatory cytokines by murine DCs stimulated with LPS. The fractionation of the low molecular weight salivary content by reversed-phase chromatography revealed active fractions eluting from 49 to 55% of the acetonitrile gradient. Previous studies suggested that this pattern of elution matches with that observed for prostaglandin E2 (PGE2) and the molecular identity of this lipid mediator was unambiguously confirmed by a new high-resolution mass spectrometry methodology. A productive infection of murine DCs by R. rickettsii was demonstrated for the first time leading to proinflammatory cytokine production that was inhibited by both A. sculptum saliva and PGE2, a result also achieved with human DCs. The adoptive transfer of murine DCs incubated with R. rickettsii followed by treatment with A. sculptum saliva or PGE2 did not change the cytokine profile associated to cellular recall responses while IgG2a-specific antibodies were decreased in the serum of these mice. Together, these findings emphasize the role of PGE2 as a universal immunomodulator of tick saliva. In addition, it contributes to new approaches to explore R. rickettsii-DC interactions both in vitro and in vivo.

High-resolution multiple reaction monitoring method for quantification of steroidal hormones in plasma.

Multiple reaction monitoring (MRM) is one of the most powerful modes of analysis in liquid chromatographic tandem mass spectrometry for quantification of low-concentration metabolites in biological samples. The advances in mass spectrometry enabled the development of high-resolution multiple reaction monitoring (MRMHR ) and became suitable for the more specific analysis of target analytes. This is important for lipidomic studies and contributes in the medical and pharmaceutical fields, primarily in investigating alterations in cells or fluids relevant to various diseases. Therefore, this work proposes the development of the MRMHR method for quantification of circulating steroids. We focused on the determination of corticosterone, 11-dehydrocorticosterone (11-DHC), cortisol, cortisone, aldosterone, and progesterone concentration in serum, by using 129sv male mice exposed to chronic unpredictable stress to validate the quantification. The method was conducted according to the ANVISA normative, adopting a coefficient of variation, as well as relative standard deviation and relative error lower than 15% in linearity, intraday and interday precision, and accuracy. For cortisol, corticosterone, and their inert metabolites (cortisone and 11-DHC), the lower limit of quantification was 3.9 ng· mL-1 , while that for progesterone and aldosterone was 7.8 and 15.6 ng· mL-1 , respectively. MRMHR analysis showed that animals submitted to stressors have 4.5 times more corticosterone in their serum than nonstressed mice. However, 11-DHC concentration does not vary significantly in response to stress for these animals. The results indicate that the method can be applied for quantification of steroids in several biological samples, such as human plasma.

Comprehensive high-resolution multiple-reaction monitoring mass spectrometry for targeted eicosanoid assays.

Eicosanoids comprise a class of bioactive lipids derived from a unique group of essential fatty acids that mediate a variety of important physiological functions. Owing to the structural diversity of these lipids, their analysis in biological samples is often a major challenge. Advancements in mass spectrometric have been helpful for the characterization and quantification of these molecular lipid species in complex matrices. However, there are technical limitations to this approach, including low-abundant and/or poorly ionizable lipids. Using high-resolution multiple-reaction monitoring (MRMHR), we were able to develop a targeted bioanalytical method for eicosanoid quantification. For this, we optimized the LC-MS/MS conditions and evaluated several parameters, including linearity, limits of quantification, matrix effects and recovery yields. For validation purposes, we looked at the method's precision and accuracy. A library of high-resolution fragmentation spectra for eicosanoids was developed. Our comprehensive dataset meets benchmark standards for targeted analysis, having been derived using best-practice workflows and rigorous quality assessments. As such, our method has applications for determining complex eicosanoid profiles in the biomedical field.

Amblyomma sculptum salivary PGE2 modulates the dendritic cell-Rickettsia rickettsii interactions in vitro and in vivo

Amblyomma sculptum is an important vector of Rickettsia rickettsii, causative agent of Rocky Mountain spotted fever and the most lethal tick-borne pathogen affecting humans. To feed on the vertebrate host’s blood, A. sculptum secretes a salivary mixture, which may interact with skin resident dendritic cells (DCs) and modulate their function. The present work was aimed at depicting the A. sculptum saliva-host DC network and the biochemical nature of the immunomodulatory component(s) involved in this interface. A. sculptum saliva inhibits the production of inflammatory cytokines by murine DCs stimulated with LPS. The fractionation of the low molecular weight salivary content by reversed-phase chromatography revealed active fractions eluting from 49 to 55% of the acetonitrile gradient. Previous studies suggested that this pattern of elution matches with that observed for prostaglandin E2 (PGE2) and the molecular identity of this lipid mediator was unambiguously confirmed by a new high-resolution mass spectrometry methodology. A productive infection of murine DCs by R. rickettsii was demonstrated for the first time leading to proinflammatory cytokine production that was inhibited by both A. sculptum saliva and PGE2, a result also achieved with human DCs. The adoptive transfer of murine DCs incubated with R. rickettsii followed by treatment with A. sculptum saliva or PGE2 did not change the cytokine profile associated to cellular recall responses while IgG2a-specific antibodies were decreased in the serum of these mice. Together, these findings emphasize the role of PGE2 as a universal immunomodulator of tick saliva. In addition, it contributes to new approaches to explore R. rickettsii-DC interactions both in vitro and in vivo.

Jacobsen catalyst as a cytochrome P450 biomimetic model for the metabolism of monensin A.

Monensin A is a commercially important natural product isolated from Streptomyces cinnamonensins that is primarily employed to treat coccidiosis. Monensin A selectively complexes and transports sodium cations across lipid membranes and displays a variety of biological properties. In this study, we evaluated the Jacobsen catalyst as a cytochrome P450 biomimetic model to investigate the oxidation of monensin A. Mass spectrometry analysis of the products from these model systems revealed the formation of two products: 3-O-demethyl monensin A and 12-hydroxy monensin A, which are the same ones found in in vivo models. Monensin A and products obtained in biomimetic model were tested in a mitochondrial toxicity model assessment and an antimicrobial bioassay against Staphylococcus aureus, S. aureus methicillin-resistant, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. Our results demonstrated the toxicological effects of monensin A in isolated rat liver mitochondria but not its products, showing that the metabolism of monensin A is a detoxification metabolism. In addition, the antimicrobial bioassay showed that monensin A and its products possessed activity against Gram-positive microorganisms but not for Gram-negative microorganisms. The results revealed the potential of application of this biomimetic chemical model in the synthesis of drug metabolites, providing metabolites for biological tests and other purposes.

Amblyomma sculptum salivary PGE2 modulates the dendritic cell-Rickettsia rickettsii interactions in vitro and in vivo

Amblyomma sculptum is an important vector of Rickettsia rickettsii, causative agent of Rocky Mountain spotted fever and the most lethal tick-borne pathogen affecting humans. To feed on the vertebrate host’s blood, A. sculptum secretes a salivary mixture, which may interact with skin resident dendritic cells (DCs) and modulate their function. The present work was aimed at depicting the A. sculptum saliva-host DC network and the biochemical nature of the immunomodulatory component(s) involved in this interface. A. sculptum saliva inhibits the production of inflammatory cytokines by murine DCs stimulated with LPS. The fractionation of the low molecular weight salivary content by reversed-phase chromatography revealed active fractions eluting from 49 to 55% of the acetonitrile gradient. Previous studies suggested that this pattern of elution matches with that observed for prostaglandin E2 (PGE2) and the molecular identity of this lipid mediator was unambiguously confirmed by a new high-resolution mass spectrometry methodology. A productive infection of murine DCs by R. rickettsii was demonstrated for the first time leading to proinflammatory cytokine production that was inhibited by both A. sculptum saliva and PGE2, a result also achieved with human DCs. The adoptive transfer of murine DCs incubated with R. rickettsii followed by treatment with A. sculptum saliva or PGE2 did not change the cytokine profile associated to cellular recall responses while IgG2a-specific antibodies were decreased in the serum of these mice. Together, these findings emphasize the role of PGE2 as a universal immunomodulator of tick saliva. In addition, it contributes to new approaches to explore R. rickettsii-DC interactions both in vitro and in vivo.

Dose-response effect of crude extracts produced by actinobacteria on in vitro rumen fermentation / Padrão dose-resposta de extratos brutos produzidos por actinobactérias sobre a fermentação ruminal in vitro

Actinobacteria have been researched as a source that produces crude extracts, which contain bioactive compounds able to act as antimicrobial agents. The present investigation evaluated the dose-response effect of two crude extracts, obtained at Caatinga rhizosphere (Caat) and Rhizophora mangle (AMC), on in vitro ruminal fermentation by:cumulative gas production, digestibility of dry (IVDMD) and organic matter (IVOMD), and short-chain fatty acids concentration (SCFA). Three multiparous Holstein dairy cows with ruminal fistula were used as the inoculum donors and fed a basal diet consisting of corn silage, soybean meal, urea, ground corn and mineral supplement. Ruminal fluid samples were incubated in glass bottles with 1 g of the dried and milled diet, a buffer solution, and the crude extracts evaluated in four doses (0.3, 0.6, 0.9 and 1.20 mg/10 mL inoculum) in a randomized block design, and the donators were considered as blocks with random effects. Additionally, negative controls were used. The results were expressed as average values based on triplicate analyses. Decreased cumulative gas production was observed according to linear dose response at 24, 48 and 72 h of incubation with the addition of Caat extract. The IVOMD showed a linear decrease at 72 h of incubation with dose Caat inclusion. Furthermore, the inclusion of Caat extract linearly reduced butyric and isovaleric acid concentrations, as well as acetate:propionate ratio. Finally, the Caat inclusion increased the propionic acid concentration in comparison to AMC extract. However, the inclusion of AMC extract did not affect any of the analyzed variables at the used doses. The Caat extract could be used as a modulator of in vitro ruminal fermentation, since it reduced acetate:propionate ratio and cumulative gas production.(AU)

As actinobactérias têm sido pesquisadas como fonte produtoras de extratos brutos que contêm compostos bioativos capazes de atuar como agentes antimicrobianos. O presente trabalho investigou o efeito dose-resposta de dois extratos brutos, AMC e Caat, na fermentação ruminal in vitro por: produção cumulativa de gás, digestibilidade in vitro da matéria seca (IVDMD) e matéria orgânica (IVOMD) e concentração de ácidos graxos de cadeia curta (SCFA). Três vacas leiteiras da raça Holandesa, multíparas e portadoras de fístula ruminal foram utilizadas como doadoras de inóculo ruminal e foram alimentadas com uma dieta basal composta por silagem de milho, farelo de soja, ureia, milho moído e suplemento mineral. As amostras de inóculo ruminal foram incubadas em garrafas de vidro com 1 g da dieta seca e moída, solução tampão e os extratos brutos avaliados em quatro doses (0,3, 0,6, 0,9 e 1,20 mg/10 mL de inóculo) em delineamento em blocos casualizados, sendo as doadoras consideradas os blocos como efeito aleatório. Além disso, foram utilizados controles negativos para a correção da produção de gás. Os resultados foram expressos como valores médios com base em análises triplicadas. A diminuição da produção cumulativa de gás foi observada de acordo com a dose em resposta linear às 24, 48 e 72 h de incubação com a adição de extrato de Caat. A IVOMD mostrou uma diminuição linear com 72 h de incubação com inclusão de Caat. Além disso, a inclusão do Caat reduziu linearmente as concentrações de ácido butírico e isovalérico, bem como a proporção de acetato/propionato. Diferentemente, a inclusão do extrato de AMC não afetou nenhuma das variáveis analisadas nas doses utilizadas. O extrato de Caat pode ser usado como um modulador da fermentação ruminal in vitro, uma vez que reduziu a proporção de acetato/propionato e a produção de gás acumulada. (AU)