Toxicological effects of air settled particles from the Vitoria Metropolitan Area mediated by oxidative stress, pro-inflammatory mediators and NFΚB pathway.

Atmospheric pollution is a major environmental and public health risk due to its effect on global air quality and climate. Increase in pollutants concentrations, especially particulate matter (PM), are associated with increased respiratory diseases. The pathophysiology of respiratory diseases involves molecular and cellular mechanisms as inflammatory biomarkers and reactive oxygen species production. Thus, the present study aimed to investigate the in vitro cytotoxic and pro-inflammatory effects of particulate matter (PM) of six monitoring stations (1-6) from the Vitoria Metropolitan Area (VMA), Espirito Santo, Brazil in 2018. The PM was chemically characterized by inductively coupled plasma mass spectrometry. In vitro cytotoxic effects of PM (3.12-200.0 µg/mL) were analyzed in human lung epithelial cells (A549) and macrophage cells (RAW 264.7) by MTT assay (3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide). To investigate the pro-inflammatory effects of PM in RAW 264.7 cells, the levels of proinflammatory mediators such as nitric oxide (NO), superoxide anion (O2•-), tumor necrosis factor (TNF-α), interleukin 6 (IL-6), and the activation of nuclear factor kappa B (NF- κB) were measured. The comet assay evaluated genotoxicity. Cell cycle, oxidative stress (DCF and DHE), and apoptosis were analyzed by flow cytometry. Chemical analysis of PM revealed aluminum (Al) and Iron (Fe) as the major chemical elements in all studied monitoring stations. In addition, worrying concentrations of mercury (Hg) were detected in the PM. The in vitro results showed that PM presents a dose-dependent cytotoxic effect in macrophage and pulmonary epithelial cell lines. The PM increased the production of NO, O2•-, and pro-inflammatory cytokines TNF-α and IL-6. PM also promoted alterations in the cell cycle, increased apoptosis frequency, and DNA damage. Moreover, PM increased the expression NF-κB. In addition, a positive correlation between Al and Fe and ROS production was observed. Based on the results obtained during the study period, it was concluded that the sedimented particles from the VMA might have deleterious effects on human health, which was evidenced by the increase in oxidative stress, an increase in pro-inflammatory mediators, and genotoxic effects partially mediated by the NF-κB pathway. These results add aspects to elucidate the molecular mechanisms involved in the effects of sedimented particles in vivo and in vitro.

Oxidative Stress and Dementia in Alzheimer's Patients: Effects of Synbiotic Supplementation.

BACKGROUND: Alzheimer's disease (AD) is the most common cause of dementia in elderly patients. Recently, several studies have shown that inflammation and oxidative stress precede the cardinal neuropathological manifestations of AD. In view of the proven antioxidant effects of probiotics, we proposed that continuous dietary supplementation with milk fermented with kefir grains might improve cognitive and metabolic and/or cellular disorders in the AD patients. METHODS: This study was designed as an uncontrolled clinical investigation to test the effects of probiotic-fermented milk supplementation (2 mL/kg/daily) for 90 days in AD patients exhibiting cognitive deficit. Cognitive assessment, cytokine expression, systemic oxidative stress levels, and blood cell damage biomarkers were evaluated before (T0) and after (T90) kefir synbiotic supplementation. RESULTS: When the patients were challenged to solve 8 classical tests, the majority exhibit a marked improvement in memory, visual-spatial/abstraction abilities, and executive/language functions. At the end of the treatment, the cytometric analysis showed an absolute/relative decrease in several cytokine markers of inflammation and oxidative stress markers (·O2 -, H2O2, and ONOO-, ~30%) accompanied by an increase in NO bioavailability (100%). In agreement with the above findings by using the same technique, we observed in a similar magnitude an improvement of serum protein oxidation, mitochondrial dysfunction, DNA damage/repair, and apoptosis. CONCLUSION: In conclusion, we demonstrated that kefir improves cognitive deficits, which seems to be linked with three important factors of the AD-systemic inflammation, oxidative stress, and blood cell damage-and may be a promising adjuvant therapy against the AD progression.