Mycobacterium bovis BCG expressing the proteins CP40 or CP09720 of Corynebacterium pseudotuberculosis promotes protection in mice after challenge

In this study, we assessed the survival and immune response of mice vaccinated with recombinant Mycobacterium bovis BCG Pasteur that expressed the CP40 or CP09720 proteins after the mice were challenged with a C. pseudotuberculosis MIC-6 virulent strain. Six groups of mice (n = 10 mice per group) were immunised with a sterile 0.9% saline solution (G1), 106 CFU of M. bovis BCG Pasteur (G2), 106 CFU of M. bovis BCG/cp40 (G3), 106 CFU of M. bovis BCG/cp09720 (G4), M. bovis BCG/cp40 boosted with rCP40 (G5), and M. bovis BCG/cp09720 boosted with rCP09720 (G6). The highest survival rate of 90% was observed in the G5 group, followed by 80% in the G6 group and 70% in the G3 and G4 groups. Moreover, a significantly greater induction of IFN-γ and IL-10 was found in the G3 group and higher IL-17 levels were recorded in the G5 group compared to their levels in the control group (G1) (p < 0.05). A specific humoral immune response (total IgG) was found in the G5 and G6 groups on day 42 compared to the level of response in the G1 group. These results indicated that the vector vaccine elicited significantly greater survival of mice in all experimental groups after a strong virulent challenge and induced a strong immune response.

Reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay as a rapid molecular diagnostic tool for COVID-19 in healthcare workers

In December 2019, the Chinese Center for Disease Control (CDC of China) reported an outbreak of pneumonia in the city of Wuhan (Hubei province, China) that haunted the world, resulting in a global pandemic. This outbreak was caused by a betacoronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several of these cases have been observed in healthcare professionals working in hospitals and providing care on the pandemic's frontline. In the present study, nasopharyngeal swab samples of healthcare workers were used to assess the performance of the reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay and subsequently compared with the real-time reverse-transcription quantitative PCR (RT-qPCR) method. Thus, in this study, we validated a method for detecting SARS-CoV-2 based on RT-LAMP that can be used to diagnose these workers. The methodology used was based on analyzing the sensitivity, specificity, evaluation of the detection limit, and cross-reaction with other respiratory viruses. The agreement was estimated using a dispersion diagram designed using the Bland-Altman method. A total of 100 clinical specimens of nasopharyngeal swabs were collected from symptomatic and asymptomatic healthcare workers in Pelotas, Brazil, during the SARS-CoV-2 outbreak. RT-LAMP assay, it was possible to detect SARS-CoV-2 in 96.7% of the healthcare professionals tested using the E gene and N gene primers approximately and 100% for the gene of human β-actin. The observed agreement was considered excellent for the primer set of the E and N genes (k = 0.957 and k = 0.896), respectively. The sensitivity of the RT-LAMP assay was positive for the primer set of the E gene, detected to approximately 2 copies per reaction. For the primer set of the N gene, the assay was possible to verify an LoD of approximately 253 copies per reaction. After executing the RT-LAMP assay, no positive reactions were observed for any of the virus respiratory tested. Therefore, we conclude that RT-LAMP is effective for rapid molecular diagnosis during the COVID-19 outbreak period in healthcare professionals.

Komagataella pastoris KM71H Mitigates Depressive-Like Phenotype, Preserving Intestinal Barrier Integrity and Modulating the Gut Microbiota in Mice

The role of intestinal microbiota in the genesis of mental health has received considerable attention in recent years, given that probiotics are considered promising therapeutic agents against major depressive disorder. Komagataella pastoris KM71H is a yeast with probiotic properties and antidepressant-like effects in animal models of depression. Hence, we evaluated the antidepressant-like effects of K. pastoris KM71H in a model of antibiotic-induced intestinal dysbiosis in male Swiss mice. The mice received clindamycin (200 μg, intraperitoneal) and, after 24 h, were treated with K. pastoris KM71H at a dose of 8 log CFU/animal by intragastric administration (ig) or PBS (vehicle, ig) for 14 consecutive days. Afterward, the animals were subjected to behavioral tests and biochemical analyses. Our results showed that K. pastoris KM71H administration decreased the immobility time in the tail suspension test and increased grooming activity duration in the splash test in antibiotic-treated mice, thereby characterizing its antidepressant-like effect. We observed that these effects of K. pastoris KM71H were accompanied by the modulation of the intestinal microbiota, preservation of intestinal barrier integrity, and restoration of the mRNA levels of occludin, zonula occludens-1, zonula occludens-2, and toll-like receptor-4 in the small intestine, and interleukin-1β in the hippocampi of mice. Our findings provide solid evidence to support the development of K. pastoris KM71H as a new probiotic with antidepressant-like effects.

Bioprospection of the trichomonacidal activity of lipid extracts derived from marine macroalgae Gigartina skottsbergii

Algal extracts are sources of bioactive substances with applications in the development of novel alternative drugs against several diseases, including trichomoniasis sexually transmitted infection caused by Trichomonas vaginalis. Factors such as clinical failures and resistant strains limit the success of the existing drugs available for treating this disease. Therefore, searching for viable alternatives to these drugs is essential for the treatment of this disease. The present study was conducted for, in vitro and in silico characterization of extracts obtained from marine macroalgae Gigartina skottsbergii at stages gametophidic, cystocarpic, and tetrasporophidic. In addition, antiparasitic activity of these extracts against the ATCC 30236 isolate of T. vaginalis, their cytotoxicity, and gene expression of trophozoites after treatment were evaluated. The minimum inhibitory concentration and 50% inhibition concentration were determined for each extract. Results: In vitro analysis of the extracts' anti-T. vaginalis activity revealed an inhibitory effect of 100%, 89.61%, and 86.95% for Gigartina skottsbergii at stages gametophidic, cystocarpic, and tetrasporophidic, respectively, at 100 μg/mL. In silico analysis revealed the interactions between constituents of the extracts and enzymes from T. vaginalis, with significant free energy values obtained for the binding. None of the extract concentrations exhibited cytotoxic effects on VERO cell line compared to control, while cytotoxicity on HMVII vaginal epithelial cells line was observed at 100 μg/mL (30% inhibition). Gene expression analysis revealed differences in the expression profile of T. vaginalis enzymes between the extract-treated and control groups. According to these results, Gigartina skottsbergii extracts exhibited satisfactory antiparasitic activity.

Effect of QTC-4-MeOBnE Treatment on Memory, Neurodegeneration, and Neurogenesis in a Streptozotocin-Induced Mouse Model of Alzheimer's Disease

Growing evidence suggests that drugs targeting neurogenesis and myelinization could be novel therapeutic targets against Alzheimer's disease (AD). Intracerebroventricular (icv) injection of streptozotocin (STZ) induces neurodegeneration through multiple mechanisms ultimately resulting in reduced adult neurogenesis. Previously, the multitarget compound QTC-4-MeOBnE (1-(7-chloroquinolin-4-yl)-N-(4-methoxybenzyl)-5-methyl-1H-1,2,3-triazole-4-carboxamide) demonstrated beneficial effects in preclinical models of AD. Here we investigated its pharmacokinetics profile and the effect on memory impairments and neurodegeneration induced by STZ. Two icv injections of STZ resulted in significant cognitive and memory impairments, assessed by novel object recognition, Y-maze, social recognition, and step-down passive avoidance paradigms. These deficits were reversed in STZ-injected mice treated with QTC-4-MeOBnE. This effect was associated with reversion of neuronal loss in hippocampal dentate gyrus, reduced oxidative stress, and amelioration of synaptic function trough Na⁺/K⁺ ATPase and acetylcholinesterase activities. Furthermore, brains from QTC-4-MeOBnE-treated mice had a significant increase in adult neurogenesis and remyelination through Prox1/NeuroD1 and Wnt/β-catenin pathways. Overall, our findings support the potential anti-AD effect of QTC-4-MeOBnE through multiple pathways, all of which have been involved in the onset and progression of the disease.

Evaluation of antioxidant activity and toxicity of sulfur- or selenium-containing 4-(arylchalcogenyl)-1H-pyrazoles

Pyrazoles represent a significant class of heterocyclic compounds that exhibit pharmacological properties. The present study aimed to investigate the antioxidant potential of pyrazol derivative compounds in brain of mice in vitro and the effect of pyrazol derivative compounds in the oxidative damage and toxicity parameters in mouse brain and plasma of mice. The compounds tested were 3,5-dimethyl-1-phenyl-4-(phenylselanyl)-1H-pyrazol (1a), 3,5-dimethyl-4-(phenylselanyl)-1H-pyrazole (2a), 4-((4-methoxyphenyl)selanyl)-3,5-dimethyl-1-phenyl-1H-pyrazole (3a), 4-((4-chlorophenyl)selanyl)-3,5-dimethyl-1-phenyl-1H-pyrazole (4a), 3,5-dimethyl-1-phenyl-4-(phenylthio)-1H-pyrazole (1b), 3,5-dimethyl-4-(phenylthio)-1H-pyrazole (2b), 4-((4-methoxyphenyl)thio)-3,5-dimethyl-1-phenyl-1H-pyrazole (3b), 4-((4-chlorophenyl)thio)-3,5-dimethyl-1-phenyl-1H-pyrazole (4b), and 3,5-dimethyl-1-phenyl-1H-pyrazole (1c). In vitro, 4-(arylcalcogenyl)-1H-pyrazoles, at low molecular range, reduced lipid peroxidation and reactive species in mouse brain homogenates. The compounds also presented ferric-reducing ability as well nitric oxide-scavenging activity. Especially compounds 1a, 1b, and 1c presented efficiency to 1,1-diphenyl-2-picryl-hydrazyl-scavenging activity. Compounds 1b and 1c presented 2,20 -azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)-scavenging activity. In vivo assays demonstrated that compounds 1a, 1b, and 1c (300 mg/kg, intragastric, a single administration) did not cause alteration in the of δ-aminolevulinic acid dehydratase activity, an enzyme that exhibits high sensibility to prooxidants situations, in the brain, liver, and kidney of mice. Compound 1c reduced per se the lipid peroxidation in liver and brain of mice. Toxicological assays demonstrate that compounds 1a, 1b, and 1c did not present toxicity in the aspartate aminotransferase, alanine aminotransferase, urea, and creatinine levels in the plasma. In conclusion, the results demonstrated the antioxidant action of pyrazol derivative compounds in in vitro assays. Furthermore, the results showed low toxicity of compounds in in vivo assays.

Evaluation of the effect of synthetic compounds derived from azidothymidine on MDA-MB-231 type breast cancer cells

The present study aimed to investigate the effect of AZT derivates containing tellurium (Te) on human breast cancer cell lines and the mechanisms underlying cell death. The inhibitory effect of AZT and its derivatives (7m and 7r) was determined by the MTT assay (6.25, 12.5, 25, 50 and 100 μM in 24 and 48 h time points), meanwhile the induction of apoptosis and the cell cycle phases was investigated by flow cytometry. The MTT assay showed that AZT derivatives decreased the rate of cell proliferation at concentrations of 12.5 μM, while commercial AZT showed low antitumor potential. In flow cytometric analysis, we demonstrate that the AZT derivatives do not induce apoptosis at the concentration tested and promote the cell cycle arrest in the S phase. Besides, predicted absorption, distribution, metabolization, excretion and toxicity analysis suggest that the compounds possess a good pharmacokinetic profile and possibly less toxicity when compared to conventional AZT. These compounds containing tellurium in their formulation are potential therapeutic agents for breast cancer.

QTC-4-MeOBnE Rescues Scopolamine-Induced Memory Deficits in Mice by Targeting Oxidative Stress, Neuronal Plasticity, and Apoptosis

Cognitive decline and memory impairment induced by disruption of cholinergic neurons and oxidative brain damage are among the earliest pathological hallmark signatures of Alzheimer's disease. Scopolamine is a postsynaptic muscarinic receptor blocker which causes impairment of cholinergic transmission resulting in cognitive deficits. Herein we investigated the effect of QTC-4-MeOBnE (1-(7-chloroquinolin-4-yl)-N-(4-methoxybenzyl)-5-methyl-1H-1,2,3-triazole-4-carboxamide) on memory impairments in mice chronically treated with scopolamine and the molecular mechanisms involved. Administration of scopolamine (1 mg/kg) for 15 days resulted in significant impairments in working and short-term memory in mice, as assessed by the novel object recognition and the Y-maze paradigms. However, both deficits were prevented if mice receiving the scopolamine were also treated with QTC-4-MeOBnE. This effect was associated with an increase in antioxidant enzymes (superoxide dismutase and catalase), a reduction in lipid peroxidation, and an increase in Nrf2 expression. Moreover, brains from QTC-4-MeOBnE treated mice had a significant decrease in acetylcholinesterase activity and glycogen synthase kinase-3β levels but an increase in brain-derived neurotrophic factor and Bcl-2 expression levels. Taken together our findings demonstrate that the beneficial effect of QTC-4-MeOBnE in a mouse model of scopolamine-induced memory impairment is mediated via the involvement of different molecular pathways including oxidative stress, neuroplasticity, neuronal vulnerability, and apoptosis. Our study provides further evidence on the promising therapeutic potential of QTC-4-MeOBnE as a multifactorial disease modifying drug in AD and related dementing disorders.

Antinociceptive and anti-inflammatory effects of 1,2-bis-(4 methoxyphenylselanyl) styrene in mice: involvement of the serotonergic system

BACKGROUND

Pain is one of the most prevalent, costly and disabling conditions that reduces quality of life. Although there are many analgesics available, there is some concern regarding their efficacy, safety and side effects. Organic selenium compounds are attractive targets of various research groups due to their pharmacological properties.

OBJECTIVES

The aim of this study was to evaluate the antinociceptive and anti-inflammatory activity of 1,2-bis-(4-methoxyphenylselanyl) styrene (BMOSE) in mice, as well as to investigate the mechanism involved in the antinociceptive effect.

METHODS

The animals were submitted to the formalin and glutamate tests. The assessment of the possible involvement of the serotonergic system in BMOSE antinociceptive activity was performed using the glutamate test. Also, we investigated the possible toxicity of the compound.

KEY FINDINGS

1,2-bis-(4-methoxyphenylselanyl) styrene (0.1-50 mg/kg, i.g.) was efficient in avoiding nociception induced by glutamate and formalin and also reduced paw oedema. The possible involvement of 5-HT₃ serotoninergic receptor antagonist ondansetron blocked the antinociceptive effect of BMOSE. The acute toxicity assays did not show any toxicity related to the administration of BMOSE (200 mg/kg).

CONCLUSIONS

It is possible to conclude that BMOSE has both antinociceptive and anti-inflammatory activity, and the serotoninergic system, more specifically, the 5-HT₃ receptor, is involved in the effect.

Evaluation of Se-phenyl-thiazolidine-4-carboselenoate protective activity against oxidative and behavioral stress in the maniac model induced by ouabain in male rats

This study investigates Se-phenyl-thiazolidine-4-carboselenoate (Se-PTC) protective activity against oxidative and behavioral stress in the model of mania induced by ouabain (OUA) in male rats. The compound used was Se-PTC (50mg/kg) and the positive control LiCl (45mg/kg) was administered for intragastric route (i.g.) 30min prior to administration of OUA (10^-5M). OUA was dissolved in artificial cerebrospinal fluid (aCSF) and administered at the 5μl through an intracerebroventricular (i.c.v) cannula. The pretreatment with Se-PTC was effective in preventing the increase in locomotor activity induced by OUA, however the positive control LiCl is capable to block crossing augmentation induced by OUA. Na⁺/K⁺-ATPase activity was significantly reduced in OUA group and the Se-PTC to normalize Na^+/K^+-ATPase activity. Pretreatment with Se-PTC protect against the increase in catalase activity and thiobarbituric acid reactive species (TBARS) content in the brain caused by OUA. Therefore, Se-PTC is effective against OUA-induced hyperactivity and alterations in brain oxidative status of rats.