As the most commonly used plasticizer, Di-(2-ethylhexyl)-phthalate (DEHP) exists everywhere in the environment due to the widespread use of polyvinyl chloride (PVC) in human life, and it is also a recognized environmental pollutant. Studies have proved the hepatotoxicity of DEHP, however the mechanism has not been adequately explored, especially the role of the reactive oxygen species (ROS) in it. In the present study, 21 day-old ICR mice were administered DEHP with dose of 0, 125, 250, and 375 mg/kg/day for 28 days by intragastrical gavage. After contamination, histopathology displayed that liver tissue were damaged mildly with the effect of DEHP; a significant increase of the serum liver function index (including aspartate transaminase (AST) and alanine transaminase (ALT)) were observed. Additionally, the level of lipid peroxidation markedly rise, especially ROS and malondialdehyde (MDA), but the activation of superoxide dismutase (SOD) was obviously decreased in mice liver. In addition, DEHP promoted the phosphorylation of JNK and p38MAPK proteins in mice liver, as well as increased the expression of p53 protein and decreased the level of DNA methylation in the p53 gene promoter region. These results indicated that the hepatotoxicity of mice caused by DEHP may be through activating the JNK/p38MAPK/p53 signaling pathway and further promoting the generation of ROS to induce lipid peroxidation in liver, and the role of DNA methylation may be inevitable.
1 September 2020 in Ecotoxicology and Environmental Safety
(1) Background: This study investigated the characteristics and influencing factors of exposure to fine particulate matter (PM2.5) and its chemical composition among elderly residents, with the aim of revealing potential differences in exposure. (2) Methods: A total of 258 elderly individuals were monitored for 72 h through individual, indoor, and outdoor PM2.5 measurements. Concentrations were determined, and non-targeted components were analyzed by gas chromatography-mass spectrometry (GC-MS). Through Spearman correlation analysis, generalized linear model, and linear regression to explore the influencing factors. (3) Results: The individual PM2.5 concentration was higher than both the indoor and outdoor concentrations. A total of 20,962 compounds were detected in personal PM2.5 samples, 6794 in indoor PM2.5 samples, among which 4285 compounds were shared between the two sample types. The components were mainly esters, aromatic compounds, and amines. PM2.5 concentration was correlated with age, housing area, humidifier use, and second-hand smoke exposure. Chemical composition is related to outdoor pollution, furniture material, and daily behavior. (4) Conclusions: The individual PM2.5 concentration is higher than the environmental concentration, and its chemical composition overlaps with the indoor and outdoor environment, which is jointly affected by demography, living conditions, and daily behavior.