Spinal alarmin HMGB1 and the activation of TLR4 lead to chronic stress-induced nociceptive hypersensitivity in rodents.

Chronic stress affects millions of people around the world, and it can trigger different behavioral disorders like nociceptive hypersensitivity and anxiety, among others. However, the mechanisms underlaying these chronic stress-induced behavioral disorders have not been yet elucidated. This study was designed to understand the role of high-mobility group box-1 (HMGB1) and toll-like receptor 4 (TLR4) in chronic stress-induced nociceptive hypersensitivity. Chronic restraint stress induced bilateral tactile allodynia, anxiety-like behaviors, phosphorylation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (p38MAPK) and activation of spinal microglia. Moreover, chronic stress enhanced HMGB1 and TLR4 protein expression at the dorsal root ganglion, but not at the spinal cord. Intrathecal injection of HMGB1 or TLR4 antagonists reduced tactile allodynia and anxiety-like behaviors induced by chronic stress. Additionally, deletion of TLR4 diminished the establishment of chronic stress-induced tactile allodynia in male and female mice. Lastly, the antiallodynic effect of HMGB1 and TLR4 antagonists were similar in stressed male and female rats and mice. Our results suggest that chronic restraint stress induces nociceptive hypersensitivity, anxiety-like behaviors, and up-regulation of spinal HMGB1 and TLR4 expression. Blockade of HMGB1 and TLR4 reverses chronic restraint stress-induced nociceptive hypersensitivity and anxiety-like behaviors and restores altered HMGB1 and TLR4 expression. The antiallodynic effects of HMGB1 and TLR4 blockers in this model are sex independent. TLR4 could be a potential pharmacological target for the treatment of the nociceptive hypersensitivity associated with widespread chronic pain.

An Updated View of the Trypanosoma cruzi Life Cycle: Intervention Points for an Effective Treatment.

Chagas disease (CD) is a parasitic, systemic, chronic, and often fatal illness caused by infection with the protozoan Trypanosoma cruzi. The World Health Organization classifies CD as the most prevalent of poverty-promoting neglected tropical diseases, the most important parasitic one, and the third most infectious disease in Latin America. Currently, CD is a global public health issue that affects 6-8 million people. However, the current approved treatments are limited to two nitroheterocyclic drugs developed more than 50 years ago. Many efforts have been made in recent decades to find new therapies, but our limited understanding of the infection process, pathology development, and long-term nature of this disease has made it impossible to develop new drugs, effective treatment, or vaccines. This Review aims to provide a comprehensive update on our understanding of the current life cycle, new morphological forms, and genetic diversity of T. cruzi, as well as identify intervention points in the life cycle where new drugs and treatments could achieve a parasitic cure.

Survival and Detection of Bivalve Transmissible Neoplasia from the Soft-Shell Clam Mya arenaria (MarBTN) in Seawater.

Many pathogens can cause cancer, but cancer itself does not normally act as an infectious agent. However, transmissible cancers have been found in a few cases in nature: in Tasmanian devils, dogs, and several bivalve species. The transmissible cancers in dogs and devils are known to spread through direct physical contact, but the exact route of transmission of bivalve transmissible neoplasia (BTN) has not yet been confirmed. It has been hypothesized that cancer cells from bivalves could be released by diseased animals and spread through the water column to infect/engraft into other animals. To test the feasibility of this proposed mechanism of transmission, we tested the ability of BTN cells from the soft-shell clam (Mya arenaria BTN, or MarBTN) to survive in artificial seawater. We found that MarBTN cells are highly sensitive to salinity, with acute toxicity at salinity levels lower than those found in the native marine environment. BTN cells also survive longer at lower temperatures, with 50% of cells surviving greater than 12 days in seawater at 10 °C, and more than 19 days at 4 °C. With one clam donor, living cells were observed for more than eight weeks at 4 °C. We also used qPCR of environmental DNA (eDNA) to detect the presence of MarBTN-specific DNA in the environment. We observed release of MarBTN-specific DNA into the water of laboratory aquaria containing highly MarBTN-diseased clams, and we detected MarBTN-specific DNA in seawater samples collected from MarBTN-endemic areas in Maine, although the copy numbers detected in environmental samples were much lower than those found in aquaria. Overall, these data show that MarBTN cells can survive well in seawater, and they are released into the water by diseased animals. These findings support the hypothesis that BTN is spread from animal-to-animal by free cells through seawater.

Library of Selenocyanate and Diselenide Derivatives as In Vivo Antichagasic Compounds Targeting Trypanosoma cruzi Mitochondrion.

Chagas disease is usually caused by tropical infection with the insect-transmitted protozoan Trypanosoma cruzi. Currently, Chagas disease is a major public health concern worldwide due to globalization, and there are no treatments neither vaccines because of the long-term nature of the disease and its complex pathology. Current treatments are limited to two obsolete drugs, benznidazole and nifurtimox, which lead to serious drawbacks. Taking into account the urgent need for strict research efforts to find new therapies, here, we describe the in vitro and in vivo trypanocidal activity of a library of selected forty-eight selenocyanate and diselenide derivatives that exhibited leishmanicidal properties. The inclusion of selenium, an essential trace element, was due to the well-known extensive pharmacological activities for selenium compounds including parasitic diseases as T. cruzi. Here we present compound 8 as a potential compound that exhibits a better profile than benznidazole both in vitro and in vivo. It shows a fast-acting behaviour that could be attributed to its mode of action: it acts in a mitochondrion-dependent manner, causing cell death by bioenergetic collapse. This finding provides a step forward for the development of a new antichagasic agent.

Selenium Derivatives as Promising Therapy for Chagas Disease: In Vitro and In Vivo Studies.

Chagas disease is a tropical infection caused by the protozoan parasite Trypanosoma cruzi and a global public health concern. It is a paradigmatic example of a chronic disease without an effective treatment. Current treatments targeting T. cruzi are limited to two obsolete nitroheterocyclic drugs, benznidazole and nifurtimox, which lead to serious drawbacks. Hence, new, more effective, safer, and affordable drugs are urgently needed. Selenium and their derivatives have emerged as an interesting strategy for the treatment of different prozotoan diseases, such as African trypanosomiasis, leishmaniasis, and malaria. In the case of Chagas disease, diverse selenium scaffolds have been reported with antichagasic activity in vitro and in vivo. On the basis of these premises, we describe the in vitro and in vivo trypanocidal activity of 41 selenocompounds against the three morphological forms of different T. cruzi strains. For the most active selenocompounds, their effect on the metabolic and mitochondrial levels and superoxide dismutase enzyme inhibition capacity were measured in order to determine the possible mechanism of action. Derivative 26, with a selenocyanate motif, fulfills the most stringent in vitro requirements for potential antichagasic agents and exhibits a better profile than benznidazole in vivo. This finding provides a step forward for the development of a new antichagasic agent.

In Vivo Biological Evaluation of a Synthetic Royleanone Derivative as a Promising Fast-Acting Trypanocidal Agent by Inducing Mitochondrial-Dependent Necrosis.

The life-long and life-threatening Chagas disease is one of the most neglected tropical diseases caused by the protozoan parasite Trypanosoma cruzi. It is a major public health problem in Latin America, as six to seven million people are infected, being the principal cause of mortality in many endemic regions. Moreover, Chagas disease has become widespread due to migrant populations. Additionally, there are no vaccines nor effective treatments to fight the disease because of its long-term nature and complex pathology. Therefore, these facts emphasize how crucial the international effort for the development of new treatments against Chagas disease is. Here, we present the in vitro and in vivo trypanocidal activity of some oxygenated abietane diterpenoids and related compounds. The 1,4-benzoquinone 15, not yet reported, was identified as a fast-acting trypanocidal drug with efficacy against different strains in vitro and higher activity and lower toxicity than benznidazole in both phases of murine Chagas disease. The mode of action was also evaluated, suggesting that quinone 15 kills T. cruzi by inducing mitochondrion-dependent necrosis through a bioenergetics collapse caused by a mitochondrial membrane depolarization and iron-containing superoxide dismutase inhibition. Therefore, the abietane 1,4-benzoquinone 15 can be considered as a new candidate molecule for the development of an appropriate and commercially accessible anti-Chagas drug.

A randomized multicenter clinical trial to evaluate the efficacy of melatonin in the prophylaxis of SARS-CoV-2 infection in high-risk contacts (MeCOVID Trial): A structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: Primary objective: to evaluate the efficacy of melatonin as a prophylactic treatment on prevention of symptomatic SARS-CoV-2 infection among healthcare workers at high risk of SARS-CoV-2 exposure. Secondary objectives: To evaluate the efficacy of melatonin as a prophylactic treatment on prevention of asymptomatic SARS-CoV-2 infection.To evaluate the efficacy of melatonin to prevent the development of severe COVID-19 in the participants enrolled in this study who develop SARS-CoV-2 infection along the trial.To evaluate the duration of COVID-19 symptoms in participants receiving melatonin before the infection.To evaluate seroconversion timing post-symptom onset. Exploratory objectives:To compare severity of COVID-19 between men and women.To evaluate the influence of sleep and diet on prevention from SARS-CoV-2 infection.To evaluate the effect of melatonin on the incidence and characteristics of lymphopenia and increase of inflammatory cytokines related to COVID-19. TRIAL DESIGN: This is a two-arm parallel randomised double-blind controlled trial to evaluate the efficacy of melatonin versus placebo in the prophylaxis of coronavirus disease 2019 among healthcare workers. PARTICIPANTS: Inclusion Criteria: Male or female participants ≥ 18 and ≤ 80 years of age.Healthcare workers from the public and private Spanish hospital network at risk of SARS-CoV 2 infection.Not having a previous COVID19 diagnosis.Understanding the purpose of the trial and not having taken any pre-exposure prophylaxis (PrEP) including HIV PrEP from March 1st 2020 until study enrolment.Having a negative SARS-CoV 2 reverse-transcription PCR (RT-PCR) result or a negative serologic rapid test (IgM/IgG) result before randomization.Premenopausal women must have a negative urinary pregnancy test in the 7 days before starting the trial treatment.Premenopausal women and males with premenopausal couples must commit to using a high efficiency anticonceptive method. EXCLUSION CRITERIA: HIV infection.Active hepatitis B infection.Renal failure (CrCl < 60 mL/min/1.73 m2) or need for hemodialysis.Osteoporosis.Myasthenia gravis.Pre-existent maculopathy.Retinitis pigmentosa.Bradycardia (less than 50 bpm).Weight less than 40 Kg.Participant with any immunosuppressive condition or hematological disease.Treatment with drugs that may prolong QT in the last month before randomization for more than 7 days including: azithromycin, chlorpromazine, cisapride, clarithromycin, domperidone, droperidol, erythromycin, halofantrine, haloperidol, lumefantrine, mefloquine, methadone, pentamidine, procainamide, quinidine, quinine, sotalol, sparfloxacin, thioridazine, amiodarone.Hereditary intolerance to galactose, Lapp lactase deficiency or glucose or galactose malabsorption.Treatment with fluvoxamine.Treatment with benzodiazepines or benzodiazepine analogues such as zolpidem, zopiclone or zaleplon.Pregnancy.Breastfeeding.History of potentially immune derived diseases such as: lupus, Crohn's disease, ulcerative colitis, vasculitis or rheumatoid arthritis.Insulin-dependent diabetes mellitus.Known history of hypersensitivity to the study drug or any of its components.Patients that should not be included in the study at the judgment of the research team. Participants will be recruited from the following eight hospitals in Madrid, Spain: Hospital Universitario La Paz, Hospital Ramón y Cajal, Hospital Infanta Sofía, Hospital 12 de Octubre, Hospital Clínico San Carlos, Hospital Central de la defensa Gómez Ulla,Hospital de La Princesa and Hospital Infanta Leonor. INTERVENTION AND COMPARATOR: Experimental: Melatonin (Circadin®, Exeltis Healthcare, Spain): 2 mg of melatonin orally before bedtime for 12 weeks. Comparator: Identical looking placebo (Laboratorios Liconsa, Spain) orally before bedtime for 12 weeks. MAIN OUTCOMES: Number of SARS-CoV-2 (COVID-19) symptomatic infections confirmed by polymerase chain reaction (PCR) test or serologic test or according to each centre diagnosis protocol. Primary outcome will be measured until the end of treatment for each participant (until the date of the last dose taken by each patient). RANDOMISATION: Patients who meet all inclusion and no exclusion criteria will be randomised, stratified by centres, sex and age (<50 and ≥ 50 years old). The randomisation sequence was created using SAS version 9.4 statistical software (procedure 'PROC PLAN') with a 1:1 allocation. No randomisation seed was specified. The randomisation seed was generated taking the hour of the computer where the program was executed. Randomization will be done centrally through the electronic system RedCAP® in order to conceal the sequence until interventions are assigned BLINDING (MASKING): Participants, caregivers, and those assessing the outcomes are blinded to group assignment. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): A total of 450 participants are planned to be enrolled in this clinical trial, 225 in the experimental arm and 225 in the placebo arm. TRIAL STATUS: Protocol version 3.0, 17th of April 2020. Recruitment ongoing. First participant was recruited on the 21st of April 2020. The final participant is anticipated to be recruited on the 31st of May 2020. As of May 18th, 2020, a total of 312 participants have been enrolled (154 at Hospital La Paz, 85 at Hospital Infanta Sofía and 73 at Hospital 12 de Octubre). TRIAL REGISTRATION: EU Clinical Trials Register: 2020-001530-35; Date of trial registration: 13th of April 2020; https://www.clinicaltrialsregister.eu/ctr-search/trial/2020-001530-35/ES FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Insights into Chagas treatment based on the potential of bacteriocin AS-48.

Chagas disease caused by the protozoan parasite Trypanosoma cruzi represents a significant public health problem in Latin America, affecting around 8 million cases worldwide. Nowadays is urgent the identification of new antichagasic agents as the only therapeutic options available, Nifurtimox and Benznidazole, are in use for >40 years, and present high toxicity, limited efficacy and frequent treatment failures in the chronic phase of the disease. Recently, it has been described the antiparasitic effect of AS-48, a bacteriocin produced by Enterococcus faecalis, against Trypanosoma brucei and Leishmania spp. In this work, we have demonstrated the in vitro potential of the AS-48 bacteriocin against T. cruzi. Interesting, AS-48 was more effective against the three morphological forms of different T. cruzi strains, and displayed lower cytotoxicity than the reference drug Benznidazole. In addition, AS-48 combines the criteria established as a potential antichagasic agent, resulting in a promising therapeutic alternative. According to the action mechanism, AS-48 trypanocidal activity could be explained in a mitochondrion-dependent manner through a reactive oxygen species production and mitochondrial depolarization, causing a fast and severe bioenergetic collapse.

In vitro anti-leishmania evaluation of nickel complexes with a triazolopyrimidine derivative against Leishmania infantum and Leishmania braziliensis.

Studies on the anti-proliferative activity in vitro of seven ternary nickel (II) complexes with a triazolopyrimidine derivative and different aliphatic or aromatic amines as auxiliary ligands against promastigote and amastigote forms of Leishmania infantum and Leishmania braziliensis have been carried out. These compounds are not toxic for the host cells and two of them are effective at lower concentrations than the reference drug used in the present study (Glucantime). In general, the in vitro growth rate of Leishmania spp. was reduced, its capacity to infect cells was negatively affected and the multiplication of the amastigotes decreased. Ultrastructural analysis and metabolism excretion studies were executed in order to propose a possible mechanism for the action of the assayed compounds. Our results show that the potential mechanism is at the level of organelles membranes, either by direct action on the microtubules or by their disorganization, leading to vacuolization, degradation and ultimately cell death.

In vitro and in vivo trypanocidal evaluation of nickel complexes with an azapurine derivative against Trypanosoma cruzi.

Seven ternary nickel(II) complexes (three previously described and four firstly described here) with an azapurine derivative (the anionic form of 4,6-dimethyl-1,2,3-triazolo[4,5-d]pyrimidin-5,7-dione) have been synthesized and spectroscopically characterized, and the crystal structures of three of them have been solved by X-ray diffraction. Studies in vitro and in vivo on the antiproliferative activity of these complexes against Trypanosoma cruzi (epimastigote, amastigote, and trypomastigote forms) have been carried out, displaying in some cases significantly higher antitrypanosomatid activity and lower toxicity than the reference drug for Chagas' disease, benznidazole (N-benzyl-2-(2-nitro-1H-imidazol-1-yl)acetamide). Ultrastructural analysis and metabolism excretion studies were also executed in order to propose a possible mechanism of action for the assayed drugs.

Antileishmaniasis activity of flavonoids from Consolida oliveriana.

A set of flavonoids from Consolida oliveriana, kaempferol (1), quercetin (2), trifolin (3), and acetyl hyperoside (5) and their O-acetyl derivatives (1a, 2a, 3a), and octa-O-acetylhyperoside (4) showed leishmanicidal activity against promastigote as well as amastigote forms of Leishmania spp. The cellular proliferation, metabolic, and ultrastructural studies showed that the acetylated compounds 2a, 3a, and 4 were highly active against Leishmania (V.) peruviana, while 2a as well as 4 were effective against Leishmania (V.) braziliensis. These compounds were not cytotoxic and are effective at similar concentrations up to or lower than the reference drugs (pentostam and glucantim).

Copper (II) complexes of [1,2,4]triazolo [1,5-a]pyrimidine derivatives as potential anti-parasitic agents.

Anti-proliferative effects are described for newly synthesised copper (II) complexes of two triazolo-pyrimidine derivatives (1,2,4-triazolo-[1,5-a]pyrimidine, tp, and 5,7-dimethyl 1,2,4-triazolo-[1,5-a]pyrimidine, dmtp) against to Trypanosoma cruzi and Leishmania (Viannia) peruviana. Of the compounds assayed, those that presented the ligand tp and auxiliary ligand 1,10-phenanthroline (C24b, C49) were most highly active against to T. cruzi with IC(50) within the range of the reference drug benznidazole. These compounds, together with C35 were the most effective against L. (V.) peruviana with an IC(50) greater than that presented by reference drugs (Pentostam and Glucantim). These compounds were not toxic to the host cell. IC(25) diminished the infection capacity and severely reduced the multiplication of intracellular forms of T. cruzi, and L. (V.) peruviana. In the case of T. Cruzi, the transformation to trypomastigote was seriously depressed. Copper (II) complexes C24b, C49 and C35, acted on the energy metabolism of the parasites at the level of the NAD(+)/NADH balance and at the level of the organelle membranes, causing degradation and cell death.

Detección de parásitos intestinales en agua y alimentos de Trujillo, Perú / Detection of water-borne and food-borne intestinal Parasites of Trujillo, Peru

Detectamos distintas especies de parásitos intestinales, tanto protozoos como helmintos, presentes en muestras de agua provenientes de acequias y pozos (Giardia lamblia, Blastocystis hominis, Entamoeba coli, Cyclospora cayetanensis, Cryptosporidium spp. y Balantidium coli), así como en alimentos crudos y cocidos (Giardia lamblia, Cyclospora cayetanensis., Endolimax nana, Iodamoeba butschlii y Blastocystis hominis Fasciola hepatica y Ascaris lumbricoides) recolectadas en varios distritos de la provincia de Trujillo, Perú.

We report the detection of different intestinal parasites, protozoan and helminthes, in samples of water from ditches and wells (Giardia lamblia, Blastocystis hominis, Entamoeba coli, Cyclospora cayetanensis, Cryptosporidium spp. y Balantidium coli), as well as in raw and cooked foods (Giardia lamblia, Cyclospora cayetanensis., Endolimax nana, Iodamoeba butschlii y Blastocystis hominis Fasciola hepatica y Ascaris lumbricoides) collected in several districts of the province of Trujillo, Peru.

Cytotoxicity of three new triazolo-pyrimidine derivatives against the plant trypanosomatid: Phytomonas sp. isolated from Euphorbia characias.

There is no effective chemotherapy against diseases caused by Phytomonas sp., a plant trypanosomatid responsible for economic losses in major crops. We tested three triazolo-pyrimidine complexes [two with Pt(II), and another with Ru(III)] against promastigotes of Phytomonas sp. isolated from Euphorbia characias. The incorporation of radiolabelled precursors, ultrastructural alterations and changes in the pattern of metabolite excretion were examined. Different degrees of toxicity were found for each complex: the platinum compound showed an inhibition effect on nucleic acid synthesis, provoking alterations on the levels of mitochondria, nucleus and glycosomes. These results, together with others reported previously in our laboratory about the activity of pyrimidine derivatives, reflect the potential of these compounds as agents in the treatment of Phytomonas sp.

Cytotoxicity of three new triazolo-pyrimidine derivatives against the plant trypanosomatid: Phytomonas sp. isolated from Euphorbia characias

There is no effective chemotherapy against diseases caused by Phytomonas sp., a plant trypanosomatid responsible for economic losses in major crops. We tested three triazolo-pyrimidine complexes [two with Pt(II), and another with Ru(III)] against promastigotes of Phytomonas sp. isolated from Euphorbia characias. The incorporation of radiolabelled precursors, ultrastructural alterations and changes in the pattern of metabolite excretion were examined. Different degrees of toxicity were found for each complex: the platinun compound showed an inhibition effect on nucleic acid synthesis, provoking alterations on the levels of mitochondria, nucleus and glycosomes. These results, together with others reported previously in our laboratory about the activity of pyrimidine derivatives, reflect the potential of these compounds as agents in the treatment of Phytomonas sp.