Environmental Toxicology最新文献

Liriodendrin, a bioactive lignan diglucoside derived from several medicinal plants, has been demonstrated to exhibit pharmacological activities, such as antioxidative and anti-inflammatory activities. Up to now, no evidence has shown that acute respiratory distress syndrome (ARDS) is improved by liriodendrin. This study was conducted to investigate the protective effects of liriodendrin against oxidative stress and ferroptosis, key mechanisms underlying the pathogenesis of ARDS, in a mouse model of lipopolysaccharide (LPS)-induced ARDS. To investigate the potential of liriodendrin to mitigate oxidative stress and inhibit ferroptosis, adult BALB/c male mice with LPS-induced ARDS were treated with varying concentrations of liriodendrin. Mice received liriodendrin or dexamethasone before LPS administration. The effects of liriodendrin were evaluated by measuring changes in pulmonary histopathology, levels of lipid peroxidation, activities of antioxidative enzymes (superoxide dismutase, catalase, glutathione peroxidase), and expression of ferroptosis-related proteins (heme oxygenase-1, cystine/glutamate antiporter SLC7A11, glutathione peroxidase-4). In addition, we measured the phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf-2), a critical regulator of cellular defense mechanisms against oxidative damage. The results indicated that liriodendrin substantially suppressed histopathological damage, reduced lipid peroxidation, and restored antioxidative enzyme activity in a dose-dependent manner. Furthermore, this compound markedly upregulated the expression of ferroptosis-related proteins and promoted the phosphorylation of Nrf-2. Our findings suggest that liriodendrin protects against LPS-induced ARDS by regulating oxidative stress and ferroptosis. The ability of liriodendrin to modulate both antioxidative responses and ferroptosis markers through Nrf-2 phosphorylation highlights its potential as a therapeutic agent in the treatment of ARDS.

Methoxyfenozide is a diacylhydrazine-class insect growth regulator functioning as an ecdysone receptor agonist and inducing premature and lethal molt in susceptible larvae. This investigation was conducted to evaluate the impact of methoxyfenozide-based commercial insecticide BYPASS on multiple end points in tissues of juvenile Oncorhynchus mykiss following 7, 14, and 21 days of exposure to sublethal concentrations of 0.042, 0.21, and 0.42 mg/L. There was not any significant change in CF and/or HSI. The treatment resulted in diminished AChE activity in brain and muscle together with a significant decline in Na⁺, K⁺-ATPase in gill and kidney tissues. The increase in the activities of antioxidant enzymes was followed by elevated levels of TBARS and PC throughout the experiment in all tissues, proving the status of oxidative stress. It is supported by the observed increase in 8-OHdG level following 21 days of exposure. Caspase-3 activity rose in a tissue-specific manner indicating the initiation of apoptosis via the mitochondrial pathway. Multi-biomarker responses showed concentration-dependent effects in calculated indexes as well as higher biomarker scores for antioxidant enzymes. Overall, the neurotoxic potential and pro-oxidant activity of BYPASS, along with its potency to cause DNA damage, apoptosis, and to disrupt osmoregulation, were revealed. The outcomes manifest the first experimental sublethal effects caused by methoxyfenozide in tissues of O. mykiss , increasing our understanding of the risk insecticides represent and the need for strict regulatory scrutiny to mitigate the risk for non-target organisms.

Health problems caused by air pollutants, such as fine particulate matter, are becoming more prevalent worldwide, and there is an urgent need to develop prevention and treatment strategies to combat this increase. A main mechanism by which air pollutants cause health problems is by entering the respiratory system and increasing oxidative stress. Oleanolic acid (OA) is a natural pentacyclic triterpenoid compound found in various plants that exhibits many physiological effects, including antioxidant, anticancer, and anti-inflammatory effects. However, the effect of OA on lung injury caused by air pollutants has not been reported. We therefore analyzed the effect of OA using a mouse model of particulate matter (PM)-induced lung injury. Oral administration of OA (5–80 mg/kg) to male ICR mice suppressed PM-induced increases in inflammatory cell counts, protein levels, and dsDNA levels in bronchoalveolar lavage fluid; however, the effects were not significant. We therefore analyzed the efficacy of intravenous administration using OA encapsulated in polyethylene glycol-modified liposomes (OA-Lipo). Intravenous administration of OA-Lipo (20–100 μg/kg) was more effective against PM-induced lung injury at lower doses than oral administration. OA-Lipo also significantly suppressed increased expression of inflammatory cytokines and chemokines and ROS production in PM-exposed mice. Furthermore, intravenous administration of OA-Lipo increased the expression of various antioxidant factors in the lungs of mice. Based on these results, we believe that OA-Lipo exerts an antioxidant effect by increasing the expression of various antioxidant factors, thereby preventing the development of lung injury caused by air pollutants.

Antibiotics are frequently detected in aquatic environments, yet their effects on aquatic biota remain poorly understood. This study evaluated the toxic effects of long-term (28 days) exposure of Rhamdia quelen to environmentally relevant concentrations of ciprofloxacin (1, 10, and 100 μg L⁻¹), focusing on the gills and posterior kidney. After the exposure period, the fish were anesthetized and euthanized. Gills were collected for biochemical and histopathological biomarker analysis. The posterior kidney was sampled for biochemical, genotoxic, and histopathological biomarkers, as well as for the evaluation of apoptosis, cell necrosis, and the incidence of melanomacrophage centers (MMC). Results showed oxidative stress in the gills of both male and female fish. Exposure to 10 and 100 μg L⁻¹ CIP induced epithelial alterations in the gills in a concentration-dependent manner in both sexes. In the kidney, CIP exposure caused DNA damage and necrosis in females. At 10 μg L⁻¹, CIP disrupted the normal histoarchitecture of the renal parenchyma, and at 100 μg L⁻¹, necrosis was observed in both sexes. Exposure to 10 and 100 μg L⁻¹ also led to an increase in MMC. These findings indicate that contamination of aquatic habitats with antibiotics such as CIP is an environmental concern. In addition to affecting target organisms, such contaminants may have sublethal effects on fish that could extend to higher ecological levels.

This study examines the teratogenic effects of a sublethal dose (0.1 ppm) of a combination insecticide containing 50% chlorpyrifos (CP) and 5% cypermethrin (CM) on chick embryo limb development, revealing severe skeletal abnormalities and disruptions in key molecular pathways. Early-stage defects, including reduced somite numbers and abnormal somite patterning, were observed by day 2, with prominent limb deformities, such as limb shortening and twisted digits, emerging by days 10 and 21. X-ray analysis confirmed skeletal anomalies, while Alcian blue-Alizarin red staining revealed malformed cartilage and bone structures. Gene and protein expression analyses showed significant downregulation of Sonic hedgehog (SHH), Fibroblast Growth Factors (FGF10, FGF8), and WNT7A, leading to impaired digit formation and limb elongation. HOX genes (HOXA11, HOXD11) were initially upregulated but later downregulated, disrupting limb segment identity. Additionally, downregulation of Tbx4 and Pitx1 contributed to hindlimb malformations. Dysregulation of CASPASE3 impaired apoptosis, resulting in defective digit separation. Molecular docking studies indicated strong binding affinities of CP and CM to SHH, FGF10, WNT7A, and HOX proteins, suggesting interference with these signaling pathways. Notably, the disruption of the SHH-FGF-WNT axis, essential for limb patterning, was a key driver of these defects. Biochemical assays further revealed reduced hydroxyproline content, indicating impaired collagen synthesis. These findings highlight severe disruptions in SHH, FGF, WNT, HOX, Tbx4, and Pitx1 pathways, emphasizing the need for stricter pesticide regulations to prevent congenital limb malformations.

Mushroom cultivation and traditional mushroom procurement are widespread worldwide. Therefore, it is important to determine the extent of the risk of heavy metal exposure by consuming wild edible mushrooms. The aim of this study was to determine the levels of four elemental impurities (Cd, Pb, As, and Hg) in edible mushroom species (Macrolepiota mastoidea, Bovista aestivalis, Tricholoma fracticum, Helvella sp., and Rhizopogon roseolus) collected from Çanakkale and Van regions of Türkiye and to investigate potential health risks. For elemental impurity analysis, 0.3 g dry samples of mushrooms collected in Çanakkale and Van provinces between 2022 and 2023 were weighed and analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Target hazard quotient (THQ) was calculated for non-carcinogenic risk assessment in children and adults, followed by hazard index (HI) for each mushroom. Carcinogenic risk (CR) was determined. Probabilistic total THQ and total CR in children and adults were calculated using the Monte Carlo simulation method. Cd levels in five mushroom species ranged between 11.19–4838.71 μg/kg, Pb levels between 495.43 and 2836.81 μg/kg, As levels between 3267.52 and 25823.07 μg/kg, and Hg levels between 0.00 and 1594.50 μg/kg. The non-carcinogenic risk potential of As level was observed in all mushroom samples. THQ value was found to be greater than 1. These values also affected the HI value in all mushrooms; the latter was also greater than 1. Since As was detected in all mushrooms in the study and the CR value of this risk element was at a level that may pose a potential carcinogenic hazard, a potential health risk in adults and children can be noted. Furthermore, the Monte Carlo simulation showed that the health risks due to elemental impurity accumulation in mushrooms may increase significantly in children and adults, causing serious health problems. Children are more severely affected by elemental impurity concentrations than adults, especially considering their body weight, which makes it necessary to take protective measures.