Uncovering the neuroprotective effect of vitamin B12 in pneumococcal meningitis: insights into its pleiotropic mode of action at the transcriptional level.

Background: The interplay between bacterial virulence factors and the host innate immune response in pneumococcal meningitis (PM) can result in uncontrolled neuroinflammation, which is known to induce apoptotic death of progenitor cells and post-mitotic neurons in the hippocampal dentate gyrus, resulting in cognitive impairment. Vitamin B12 attenuates hippocampal damage and reduces the expression of some key inflammatory genes in PM, by acting as an epidrug that promotes DNA methylation, with increased production of S-adenosyl-methionine, the universal donor of methyl. Material and methods: Eleven-day-old rats were infected with S. pneumoniae via intracisternal injection and then administered either vitamin B12 or a placebo. After 24 hours of infection, the animals were euthanized, and apoptosis in the hippocampal dentate gyrus, microglia activation, and the inflammatory infiltrate were quantified in one brain hemisphere. The other hemisphere was used for RNA-Seq and RT-qPCR analysis. Results: In this study, adjuvant therapy with B12 was found to modulate the hippocampal transcriptional signature induced by PM in infant rats, mitigating the effects of the disease in canonical pathways related to the recognition of pathogens by immune cells, signaling via NF-kB, production of pro-inflammatory cytokines, migration of peripheral leukocytes into the central nervous system, and production of reactive species. Phenotypic analysis revealed that B12 effectively inhibited microglia activation in the hippocampus and reduced the inflammatory infiltrate in the central nervous system of the infected animals. These pleiotropic transcriptional effects of B12 that lead to neuroprotection are partly regulated by alterations in histone methylation markings. No adverse effects of B12 were predicted or observed, reinforcing the well-established safety profile of this epidrug. Conclusion: B12 effectively mitigates the impact of PM on pivotal neuroinflammatory pathways. This leads to reduced microglia activation and inflammatory infiltrate within the central nervous system, resulting in the attenuation of hippocampal damage. The anti-inflammatory and neuroprotective effects of B12 involve the modulation of histone markings in hippocampal neural cells.

EPA/DHA and linseed oil have different effects on liver and adipose tissue in rats fed with a high-fat diet.

The incidence of cardiovascular diseases and metabolic disorders has increased worldwide. Clinical and experimental research has shown that the consumption of ω-3 FAs can be beneficial to metabolism in several ways, as they can act on metabolic pathways. Our objective was to evaluate the effect of treatment with linseed oil, a vegetable oil rich in alpha-linolenic acid, and EPA and DHA in different proportions (3:1 EPA:DHA, and 1:3 EPA:DHA), on the metabolic disorders induced by a high-fat diet (20 % lipids) in rats for 2 weeks, after 18 weeks of consumption of a high-fat diet. In 18 weeks, the high-fat diet increased blood glucose, systolic blood pressure, triglyceride concentration in the liver and adipose tissue, and impaired insulin sensibility without interfering in the weight of the animals. All treatments were effective in reducing the deposition of hepatic type III collagen, the proportion of ω-6/ω-3 in the liver and WAT (white adipose tissue), the proportion of area/number of adipocytes, and the gene expression of the ACC, FAS, and CPT1 enzymes. In addition, treatment with EPA and DHA reduced blood glucose, serum TNF-α concentration, amount of liver fat, degree of microsteatosis and type I collagen deposition in the liver, deposition of type I and III collagen in TA, gene expression of the transcription factor SREBP-1c, and increased hepatic binucleation. EPA in major proportion was more effective in reducing the area of adipocytes, hepatic triglyceride concentration, PPAR-α expression, and WAT fat weight. DHA in a major proportion reduced the concentration of MCP1 in WAT. LO treatment did not have any isolated effects. We concluded that EPA and DHA were more effective in treating metabolic damage than treatment with LO, leading to a more favorable metabolic profile.

Dietary supplementation with omega-3 fatty acid attenuates 5-fluorouracil induced mucositis in mice.

BACKGROUND: Studies showed the positive effects of omega-3 fatty acid (n-3 FA) for the treatment of inflammatory bowel disease as it alleviated the symptoms and promoted better mucosal integrity. The objective of this study was to determine whether a diet with the addition of n-3 FA helps control the inflammation observed in 5-fluorouracil (5-FU) induced mucositis. METHODS: BALB/c mice were randomly divided into four groups as follows: 1: control (CTL), fed a standard chow diet; 2: CTL + n-3 FA - n-3 FA, fed a diet with n-3; 3: mucositis (MUC), fed a standard chow diet and subjected to mucositis; and 4: MUC+ n-3 FA, fed a diet with n-3 FA and subjected to mucositis. On the 8th day, the animals of the MUC and MUC + n-3 FA groups received an intraperitoneal injection of 300 mg/kg 5-FU for mucositis induction. After 24 h or 72 h, all mice were euthanized and evaluated for intestinal permeability, bacterial translocation, intestinal histology and apoptosis. RESULTS: Mice that received the diet with n-3 FA and a 5-FU injection showed less weight loss compared to the animals of the MUC group (p < 0.005). Decreased intestinal permeability and bacterial translocation were also observed in animals fed n-3 FA, and these mice underwent mucositis compared to the MUC group (p < 0.005). These data were associated with mucosal integrity and a reduced number of apoptotic cells in the ileum mucosa compared to the mice that received the control diet and 5-FU injection. CONCLUSION: Together, these results show that omega-3 fatty acid decreases the mucosal damage caused by 5-FU-induced mucositis.

Experimental benznidazole treatment of Trypanosoma cruzi II strains isolated from children of the Jequitinhonha Valley, Minas Gerais, Brazil, with Chagas disease

Trypanosoma cruzi strains from distinct geographic areas show differences in drug resistance and association between parasites genetic and treatment response has been observed. Considering that benznidazole (BZ) can reduce the parasite burden and tissues damage, even in not cured animals and individuals, the goal is to assess the drug response to BZ of T. cruzi II strains isolated from children of the Jequitinhonha Valley, state of Minas Gerais, Brazil, before treatment. Mice infected and treated with BZ in both phases of infection were compared with the untreated and evaluated by fresh blood examination, haemoculture, polymerase chain reaction, conventional (ELISA) and non-conventional (FC-ALTA) serologies. In mice treated in the acute phase, a significant decrease in parasitaemia was observed for all strains. Positive parasitological and/or serological tests in animals treated during the acute and chronic (95.1-100%) phases showed that most of the strains were BZ resistant. However, beneficial effect was demonstrated because significant reduction (p < 0.05%) and/or suppression of parasitaemia was observed in mice infected with all strains (acute phase), associated to reduction/elimination of inflammation and fibrosis for two/eight strains. BZ offered some benefit, even in not cured animals, what suggest that BZ use may be recommended at least for recent chronic infection of the studied region.

Assessment of acute toxicity of the ethanolic extract of Lychnophora pinaster (Brazilian arnica)

Species of the Lychnophora genus are plants native to Brazil, popularly known as "Brazilian arnica" and used in folk medicine as alcoholic and hydro-alcoholic preparations for the treatment of bruises, inflammation, pain, rheumatism and insect bites. The present study aimed to evaluate the safety of the use of Lychnophora pinaster Mart., Asteraceae. Acute toxicity of the crude ethanolic extract was evaluated by administration of the extract by oral route to male and female Swiss mice. A single extract dose of 125, 250 or 500 mg/kg was administered and the effects on spontaneous locomotor activity, exploratory behavior, muscle strength, body weight, food and water consumption, relative organ weight, histology, as well as hematological and biochemical parameters were evaluated. The three doses administered to the animals did not cause muscle tone alterations, but doses of 250 and 500 mg/kg induced a significant inhibition of the spontaneous locomotor activity and exploratory behavior of the animals in open-field test. There was no alteration to hematological parameters and consumption of water and food, body weight variation and organs relative weight. Changes were observed in AST and ALT during assessment of biochemical parameters. The histopathological evaluation showed that the extract provoked cellular alterations, such as vacuolar degeneration and inflammation in kidneys and liver at all doses. Liver morphometric analyses of male and female mice showed that the extract did not have dose-dependent effects. Although females showed a significant increase in inflammatory cells, the effect was not dose-dependent.