Chronic exposure to aluminium (Al) can contribute to the progression of several neurological and neurodegenerative diseases. Al is a metal that promotes oxidative damage leading to neuronal death in ...different brain regions with behavior, cognition, and memory deficits. Chrysin is a flavonoid found mainly in honey, passion fruit, and propolis with antioxidant, anti-inflammatory, and cytoprotective properties. In this study, we used an integrated approach of in vitro and in vivo studies to evaluate the antioxidant and neuroprotective effects of chrysin against the neurotoxicity elicited by aluminium chloride (AlCl3). In in vitro studies, chrysin (5 μM) showed the ability to counteract the early oxidative stress elicited by tert-butyl hydroperoxide, an oxidant that mimics the lipid peroxidation and Fenton reaction in presence of AlCl3 as well as the late necrotic death triggered by AlCl3 in neuronal SH-SY5Y cells. In vivo studies in a mouse model of neurotoxicity induced by chronic exposure to AlCl3 (100 mg/kg/day) for ninety days then corroborated the antioxidant and neuroprotective effect of chrysin (10, 30, and 100 mg/kg/day) using the oral route. In particular, chrysin reduced the cognitive impairment induced by AlCl3 as well as normalized the acetylcholinesterase and butyrylcholinesterase activities in the hippocampus. In parallel, chrysin counteracted the oxidative damage, in terms of lipid peroxidation, protein carbonylation, catalase, and superoxide dismutase impairment, in the brain cortex and hippocampus. Lastly, necrotic cells frequency in the same brain regions was also decreased by chrysin. These results highlight the ability of chrysin to prevent the neurotoxic effects associated with chronic exposure to Al and suggest its potential use as a food supplement for brain health.
The PsdRSAB and ApsRSAB detoxification modules, together with the antimicrobial peptides (AMPs)-resistance determinants Dlt system and MprF protein, play major roles in the response to AMPs in ...Lacticaseibacillus paracasei BL23. Sensitivity assays with a collection of mutants showed that the PsdAB ABC transporter and the Dlt system are the main subtilin resistance determinants. Quantification of the transcriptional response to subtilin indicate that this response is exclusively regulated by the two paralogous systems PsdRSAB and ApsRSAB. Remarkably, a cross-regulation of the derAB, mprF and dlt-operon genes-usually under control of ApsR-by PsdR in response to subtilin was unveiled. The high similarity of the predicted structures of both response regulators (RR), and of the RR-binding sites support this possibility, which we experimentally verified by protein-DNA binding studies. ApsR-P shows a preferential binding in the order P
> P
> P
> P
. However, PsdR-P bound with similar apparent affinity constants to the four promoters. This supports the cross-regulation of derAB, mprF and the dlt-operon by PsdR. The possibility of cross-regulation at the level of RR-promoter interaction allows some regulatory overlap with two RRs controlling the expression of systems involved in maintenance of critical cell membrane functions in response to lantibiotics.
Abstract In vitro grown plants may have abnormal structural and physiological features. However, the type of the sealing material used in tissue culture may minimize such abnormalities. This study ...evaluates the influence of the type of sealing of test tubes on the anatomical and ultrastructural features of leaves of Aechemea bromeliifolia (Rudge) Baker (Bromeliaceae), an ornamental bromeliad native to Brazil, grown in vitro. Three types of sealing were used: rigid polypropylene cap (PC), polyvinyl chloride film (PVC), and PC coupled with a microporous membrane (PM). Seedlings germinated in a greenhouse were also studied for comparison. Plants grown in test tubes sealed with PM were more similar to those from the greenhouse, as far as the pattern of stomatal opening, the presence of starch grains, and the organization of the internal membrane system of the chloroplasts is concerned. Plants cultivated in test tubes sealed with PC had higher stomatal density and the chloroplasts had large areas without thylakoids in the stroma. Plants grown in test tubes sealed with PVC had few or no starch grains. These results suggest that microporous membrane used coupled with PC sealing provided natural ventilation, thus contributing to a better plant development.
Resumo Plantas desenvolvidas in vitro podem apresentar características estruturais e fisiológicas pouco funcionais. Contudo, o tipo de vedação dos recipientes utilizados na cultura de tecidos pode minimizar tais características. Este estudo avaliou a influência do tipo de vedação dos tubos de ensaio sobre a anatomia e a ultraestrutura das folhas de Aechmea bromeliifolia (Rudge) Baker (Bromeliaceae), uma bromélia ornamental nativa do Brasil, desenvolvidas in vitro. Foram utilizados três tipos de vedação: tampa rígida de polipropileno (PC), filme de policloreto de vinila (PVC) e PC coberta com uma membrana microporosa (PM). Para efeitos de comparação, plantas provenientes de sementes germinadas em telado também foram estudadas. As plantas desenvolvidas em tubos vedados com PM se assemelharam mais às desenvolvidas em telado, quanto à abertura dos estômatos, a presença de grãos de amido e a organização do sistema interno de membranas dos cloroplastos. Nas plantas cultivadas em tubos vedados com PC, houve maior densidade estomática e os cloroplastos ficaram com grandes áreas sem tilacóides no estroma. Na condição PVC, pouco ou nenhum grão de amido foi encontrado. Esses resultados sugerem que a membrana microporosa, adicionada ao orifício da PC, proporcionou uma vedação com ventilação natural, contribuindo para o melhor desenvolvimento das plantas.
Spontaneous swallowing contributes to airway protection and depends on the activation of brainstem reflex circuits in the central pattern generator (CPG). We studied the effect of age and gender on ...spontaneous swallowing frequency (SSF) in healthy volunteers and assessed basal SSF and TRPV1 stimulation effect on SSF in patients with post-stroke oropharyngeal dysphagia (OD). The effect of age and gender on SSF was examined on 141 healthy adult volunteers (HV) divided into three groups: GI-18-39 yr, GII-40-59 yr, and GIII->60 yr. OD was assessed by the Volume-Viscosity Swallowing Test (VVST). The effect of sensory stimulation with capsaicin 10
M (TRPV1 agonist) was evaluated in 17 patients with post-stroke OD, using the SSF. SSF was recorded in all participants during 10 min using surface electromyography (sEMG) of the suprahyoid muscles and an omnidirectional accelerometer placed over the cricothyroid cartilage. SSF was significantly reduced in GII (0.73 ± 0.50 swallows/min;
= 0.0385) and GIII (0.50 ± 0.31 swallows/min;
< 0.0001) compared to GI (1.03 ± 0.62 swallows/min), and there was a moderate significant correlation between age and SFF (r = -0.3810;
< 0.0001). No effect of gender on SSF was observed. Capsaicin caused a strong and significant increase in SSF after the TRPV1 stimulation when comparing to basal condition (pre-capsaicin: 0.41 ± 0.32 swallows/min vs post-capsaicin: 0.81 ± 0.51 swallow/min;
= 0.0003). OD in patients with post-stroke OD and acute stimulation with TRPV1 agonists caused a significant increase in SSF, further suggesting the potential role of pharmacological stimulation of sensory pathways as a therapeutic strategy for CPG activation in patients with OD.
Abstract Background Alexithymia has been described as an important dimension in several medical diseases. Systemic lupus erythematosus (SLE) is a chronic condition characterized by unpredictable ...clinical manifestations. Our aim is to reveal which factors (psychological factors and quality of life dimensions) are associated with alexithymia in SLE patients. Methods Fifty-three sequential SLE patients (ACR criteria) and 41 asthma patients were studied by means of validated scales for alexithymia (Toronto Alexithymia Scale), psychopathology (Brief Symptom Inventory, Hospital Anxiety and Depression Scale), personality dimensions (NEO-FFI), and quality of life (Short Form-36 Health Survey). Systemic lupus erythematosus patient's clinical and laboratorial evaluation was performed by indicators of activity (Systemic Lupus Erythematosus Disease Activity Index) of accumulated damage (Systemic Lupus International Collaborating Clinics/ACR Damage Index), length of disease, and therapy. Results An association between alexithymia and psychopathological symptoms, and personality and quality of life dimensions was found. By means of multiple regression analysis, openness and depression were the 2 predictors for alexithymia in SLE patients. We found a high prevalence rate of alexithymia in SLE patients; however, when controlling for depression symptoms (Hospital Anxiety and Depression Scale–Depression, <7), we found a lower percentage of alexithymic traits than that of the total sample of SLE. Conclusion Alexithymia was associated with psychological distress and with quality of life impairment. Understanding the role of psychological factors in SLE patients may contribute to a more comprehensive perspective of the disease, its impact on patient's daily routine, and how patients adapt emotionally to a chronic disease.
The use of probiotic lactobacilli has been proposed as a strategy to mitigate damage associated with exposure to toxic metals. Their protective effect against cationic metal ions, such as those of ...mercury or lead, is believed to stem from their chelating and accumulating potential. However, their retention of anionic toxic metalloids, such as inorganic arsenic, is generally low. Through the construction of mutants in phosphate transporter genes (
) in
and
strains, coupled with arsenate As(V) uptake and toxicity assays, we determined that the incorporation of As(V), which structurally resembles phosphate, is likely facilitated by phosphate transporters. Surprisingly, inactivation in
of PhoP, the transcriptional regulator of the two-component system PhoPR, a signal transducer involved in phosphate sensing, led to an increased resistance to arsenite As(III). In comparison to the wild type, the
strain exhibited no differences in the ability to retain As(III), and there were no observed changes in the oxidation of As(III) to the less toxic As(V). These results reinforce the idea that specific transport, and not unspecific cell retention, plays a role in As(V) biosorption by lactobacilli, while they reveal an unexpected phenotype for the lack of the pleiotropic regulator PhoP.
Human milk oligosaccharides (HMOs) are a mixture of structurally diverse carbohydrates that contribute to shape a healthy gut microbiota composition. The great diversity of the HMOs structures does ...not allow the attribution of specific prebiotic characteristics to single milk oligosaccharides. We analyze here the utilization of four disaccharides, lacto-N-biose (LNB), galacto-N-biose (GNB), fucosyl-α1,3-GlcNAc (3FN) and fucosyl-α1,6-GlcNAc (6FN), that form part of HMOs and glycoprotein structures, by the infant fecal microbiota. LNB significantly increased the total levels of bifidobacteria and the species Bifidobacterium breve and Bifidobacterium bifidum. The Lactobacillus genus levels were increased by 3FN fermentation and B. breve by GNB and 3FN. There was a significant reduction of Blautia coccoides group with LNB and 3FN. In addition, 6FN significantly reduced the levels of Enterobacteriaceae family members. Significantly higher concentrations of lactate, formate and acetate were produced in cultures containing either LNB or GNB in comparison with control cultures. Additionally, after fermentation of the oligosaccharides by the fecal microbiota, several Bifidobacterium strains were isolated and identified. The results presented here indicated that each, LNB, GNB and 3FN disaccharide, might have a specific beneficial effect in the infant gut microbiota and they are potential prebiotics for application in infant foods.
Preterm microbial colonization is affected by gestational age, antibiotic treatment, type of birth, but also by type of feeding. Breast milk has been acknowledged as the gold standard for human ...nutrition. In preterm infants breast milk has been associated with improved growth and cognitive development and a reduced risk of necrotizing enterocolitis and late onset sepsis. In the absence of their mother's own milk (MOM), pasteurized donor human milk (DHM) could be the best available alternative due to its similarity to the former. However, little is known about the effect of DHM upon preterm microbiota and potential biological implications. Our objective was to determine the impact of DHM upon preterm gut microbiota admitted in a referral neonatal intensive care unit (NICU). A prospective observational cohort study in NICU of 69 neonates <32 weeks of gestation and with a birth weight ≤1,500 g was conducted. Neonates were classified in three groups according to feeding practices consisting in their MOM, DHM, or formula. Fecal samples were collected when full enteral feeding (defined as ≥150 cc/kg/day) was achieved. Gut microbiota composition was analyzed by 16S rRNA gene sequencing. Despite the higher variability, no differences in microbial diversity and richness were found, although feeding type significantly influenced the preterm microbiota composition and predictive functional profiles. Preterm infants fed MOM showed a significant greater presence of Bifidobacteriaceae and lower of Staphylococcaceae, Clostridiaceae, and Pasteurellaceae compared to preterm fed DHM. Formula fed microbial profile was different to those observed in preterm fed MOM. Remarkably, preterm infants fed DHM showed closer microbial profiles to preterm fed their MOM. Inferred metagenomic analyses showed higher presence of
genus in mother's milk group was related to enrichment in the Glycan biosynthesis and metabolism pathway that was not identified in the DHM or in the formula fed groups. In conclusion, DHM favors an intestinal microbiome more similar to MOM than formula despite the differences between MOM and DHM. This may have potential beneficial long-term effects on intestinal functionality, immune system, and metabolic activities.
•BPS caused endocrine disruption in the prostate of male and female gerbils.•BPS caused more pronounced prostate morphological changes than BPA.•BPS promoted up-regulation of the androgen and ...estrogen receptors in the prostate.
This study evaluated the effects of BPS (40 μg/kg/day, during 28 consecutive days) on the male ventral prostate and female prostate of adult gerbils. For comparative purposes, gerbils were also exposed to BPA under the same experimental conditions. The prostates were submitted to biometric, morphometric, histopathological, immunohistochemical and ultrastructural analyses. The results demonstrated that exposure to both types of bisphenol caused no changes in testosterone or estradiol serum levels. Morphologically, the effects of BPS and BPA on female prostates were similar and included changes in prostatic tissue compartments, glandular hyperplasia, AR and ERα up-regulation and increased cell proliferation. In males, BPS and BPA promoted differential effects, since the prostate presented morphological changes and proliferative disorders that were more pronounced in the BPS group. Therefore, this study demonstrates that BPS caused endocrine disruption in the prostate of male and female gerbils.
Polyphosphate (poly-P) biosynthesis in bacteria has been linked to many physiological processes and has been characterized as an interesting functional molecule involved in intestinal homeostasis. We ...determined the capacity for poly-P production of 18 probiotic strains mainly belonging to Bifidobacterium and former Lactobacillus genera, showing that poly-P synthesis varied widely between strains and is dependent on the availability of phosphate and the growth phase. Bifidobacteria were especially capable of poly-P synthesis and poly-P kinase (ppk) genes were identified in their genomes together with a repertoire of genes involved in phosphate transport and metabolism. In Bifidobacterium longum KABP042, the strain we found with highest poly-P production, variations in ppk expression were linked to growth conditions and presence of phosphate in the medium. Moreover, the strain produced poly-P in presence of breast milk and lacto-N-tetraose increased the amount of poly-P synthesized. Compared to KABP042 supernatants low in poly-P, exposure of Caco-2 cells to KABP042 supernatants rich in poly-P resulted in decreased epithelial permeability and increased barrier resistance, induction of epithelial protecting factors such as HSP27 and enhanced expression of tight junction protein genes. These results highlight the role of bifidobacteria-derived poly-P as a strain-dependent functional factor acting on epithelial integrity.
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