Journal of Environmental Science and Health Part C-Toxicology and Carcinogenesis最新文献

This systematic review aimed to evaluate existing evidence on the associations between trace elements exposure and age-related eye diseases. PubMed and Google scholar databases were searched for epidemiological and postmortem studies on the relationship between exposure to trace elements and Age-related eye diseases such as age-related macular degeneration (AMD), cataract, glaucoma and diabetic retinopathy (DR), in population groups aged 40 years and above. Available evidence suggests that cadmium (Cd) exposure may be positively associated with the risks of AMD and cataract. There is also evidence that exposure to lead (Pb) may be positively associated with higher risk of cataract and glaucoma. There is limited number of relevant studies and lack of prospective studies for most of the investigated associations. Evidence for other trace elements is weak and inconsistent, and the number of available studies is small. Likewise, there are very few relevant studies on the role of trace elements in DR. Chemical elements that affect the distribution and absorption of other trace elements have never been investigated. The suggestive but limited evidence motivates large and quality prospective studies to fully characterize the impact of exposure to trace (toxic and essential) elements on age-related eye diseases.

Nanoparticles (NPs) are now being used in many industrial activities, such as mining, paint and glass industries. The frequent industrial use of NPs contributes to environmental pollution and may cause cellular and oxidative damage in native organisms. In this study, the toxic effects of titanium dioxide nanoparticles (TiO₂ NPs) were investigated using Galleria mellonella larvae as a model insect species. Alterations in cell damage indicators, such as alanine transferase, aspartate transferase, lactate dehydrogenase, non-enzymatic antioxidants and biochemical parameters, were determined in the hemolymph of G. mellonella larvae exposed to TiO₂ NPs at different concentrations (5, 50, 250 and 1250 μg/mL) in their diets. TiO₂ NPs caused concentration-dependent cellular damage in the hemolymph of G. mellonella larvae and increased the levels of the non-enzymatic antioxidants uric acid and bilirubin. In addition, total protein in hemolymph significantly decreased at the highest concentration (1250 μg/mL) of TiO₂ NPs. Level of the urea increased at the highest concentration (1250 μg/mL) of TiO₂ NPs, whereas the amount of glucose was not affected. These findings demonstrated that TiO₂ NPs caused concentration-dependent toxic effects on G. mellonella larvae.

This study investigated the effects of Sudan IV dye (S4D) on antioxidant biomarkers using palm oil adulterated with S4D. Thirty male albino rats were grouped into five (n = 6); Normal control, palm oil (PO), PO + S4D (100 mg/kg), PO + S4D (250 mg/kg), and S4D (250 mg/kg) for 21 days. Oxidative stress biomarkers were assessed in the serum, liver, and kidneys. Exposure to S4D (alone and in adulterated PO) occasioned significant depletions in the activities of SOD, CAT, and GPx, as well as GSH levels in the assessed compartments. Contrastingly, the levels of NO and MDA were significantly (p < 0.05) increased in the serum, liver, and kidney of rats exposed to PO + S4D (both doses) and S4D (250 mg/kg) when compared to control rats. Further, the expressions of the genes coding for CAT, GPx-1, GSR, and Nrf-2 were significantly (p < 0.05) down-regulated, relative to β-actin, in groups exposed to S4D compared to the control. Interestingly, these parameters were not significantly different (p > 0.05) in the unadulterated PO-exposed rats compared to the control. These results show that S4D depleted the antioxidant capacities, while potentiating the generation of reactive species and oxidative damage. This study provides useful information on the oxidative mechanisms associated with consumption of S4D-containing consumer products.

Hepatic metabolism catalyzed by the cytochrome P450 (CYP) superfamily affects liver toxicity associated with exposures to natural compounds and xenobiotic agents. Previously we generated a battery of HepG2-derived stable cell lines that individually express 14 CYPs (1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, 3A4, 3A5, and 3A7). In this study, we comprehensively characterized each cell line for its CYP expression and enzyme activity. Specifically, we measured the mRNA expression, protein expression, and metabolite formation. Using CYP3A4, 2D6, and 2C9-overexpressing cells as representatives, we examined the stability of these cells in long-term cultures for up to 10 passages. The results showed that CYPs can be stably overexpressed for up to 10 cell culture passages without losing their activities. The robustness of responses to stimuli among the cells at different passages was also investigated in CYP3A4-overexpressing cells and the response to amiodarone and dronedarone showed no difference between the cells at the passage 2 and 10. Moreover, the mRNA expression level of most CYPs was higher in CYP-overexpressing HepG2 cells than that in HepaRG cells and primary human hepatocytes. This study confirmed the stability of CYP-overexpressing HepG2 cell lines and provided useful information for a broader use of these cells in pharmacologic and toxicologic research.

Environmental pollution by heavy metal ions, organic pollutants, oils, pesticides or dyes is a ubiquitous problem adversely affecting human health and environmental ecology. Development and application novel adsorbents in full-scale treatment systems with effectiveness properties could effective ways to facilitate the extraction and adsorption of environment pollutants from wastewater. Graphene materials have drawn much attention due to their extraordinary electron mobilities, high surface areas, good thermal conductivities, and excellent mechanical properties. Three-dimensional graphene materials can provide the inherent advantages of 2D graphene sheets and exhibit micro/nanoporous structures, increased specific surface areas, high electron conductivities, fast mass transport kinetics, and strong mechanical strength. Potential applications for 3D graphene materials include environmental remediation, chemical and biological sensing, catalysis, and super capacitors. Recent advances in the applications of 3D functionalized graphene materials (3D FGMs) doped with heteroatoms for the extraction and adsorption of environmental pollutants in wastewater are summarized in this review.

Objective: This study aims to explore the mechanism of miR-30d-5p in regulating the development of lung squamous cell carcinoma (LUSC) via targeting DBF4.

Methods: Bioinformatics methods were employed to analyze the differentially expressed genes in LUSC tissue microarray. qRT-PCR was employed to detect the expression of miR-30d-5p and DBF4 mRNA in normal human bronchial epithelial cells and LUSC cells. CCK-8 was used to detect LUSC cell activity. Wound healing assay was employed to detect the migratory ability of LUSC cells. Transwell was employed to detect invasive ability. Dual-luciferase reporter assay was used to detect the targeting relationship between miR-30d-5p and DBF4. Western blot was used to detect the protein expression of marker molecules associated with epithelial-mesenchymal transition (EMT).

Results: In this study, the expression of miR-30d-5p in LUSC cell lines was found to be obviously low compared with that in normal human bronchial epithelial cell line, which was opposite to the expression of DBF4. Dual-luciferase reporter assay verified that miR-30d-5p could target DBF4 and the overexpression of miR-30d-5p downregulated the expression of DBF4. Overexpression of DBF4 promoted the proliferation, migration, invasion, and EMT of LUSC, whereas over-expression of miR-30d-5p could weaken the promotion of DBF4 on cancer cells.

Conclusion: miR-30d-5p downregulates the expression of DBF4 to regulate the development of LUSC.

Chronic kidney disease of unknown etiology (CKDu) is a major health issue in agricultural areas in Sri Lanka. Despite many attempts to identifying causative factors of CKDu, the real cause/s remain/s elusive to date. Understanding the progression of potential etiologies may provide valuable insight into this quest. Literature relevant to CKDu addresses several etiologies, including quality of drinking water in the affected areas including hardness, fluoride, ionicity, agrochemical and heavy metal contaminations, consumption of contaminated food, and the genetic makeup of vulnerable populations. Progression of the etiologies revealed persistent interest in heavy metals of multiple origins: waterborne, foodborne, or soilborne. Secondary factors, such as water hardness, fluoride, and ionicity appear to act synergistically, aggravating the role of heavy metals on the onset, and the progression of CKDu. Demographical factors, such as male sex, over 50 years of age, agriculture-related occupation, and the consumption of contaminated water and food are intricately related with the disease progression while other minor risk factors such as smoking, alcohol consumption, etc. exasperate the disease condition. Since, none of these etiologies are examined adequately, conducting laboratory exposure studies under in-vivo and in-vitro settings to understand their role in CKDu is crucial.

Nigeria receives copious annual precipitation to nourish its forests and agriculture, it has an extensive river drainage system, and it possesses valuable mineral deposits that stimulate both commercial and artisan mining activities. The combination of these features complicates Nigeria's efforts to produce adequate amounts of healthy foods to support its population. Toxic heavy metals like lead, cadmium, and mercury, and toxic metalloids such as arsenic, are also present in its mineral deposits and they migrate gradually into the soil and water of Nigeria by natural means. However, mining activities can liberate higher levels of toxic metals, which adversely affect Nigerian ecosystems and its food chains. Thus, environmental pollution due to anthropogenic activities is a major public health concern in Nigeria. This review covers the importance of native Nigerian and African wild and cultivated plants along with livestock and wild animals as sentinel species to evaluate heavy metals as environmental stressors and the use of sentinel species for food safety monitoring and for predicting potential risks to human health.

Arsenic contamination in the groundwater of Southern Assam, India is well-documented. A specific type of smokeless tobacco (sadagura, SG) is highly prevalent among the local population. Thus, the present study is aimed to evaluate the toxicological implications of arsenic and smokeless tobacco co-exposure on the reproductive health of female mice. The estrous cycle of experimental animals was monitored for 30 days. Histopathological studies and comet assay of ovarian and uterine tissues were performed after 30 days of exposure to SG and arsenic (sodium arsenite, SA). Oxidative stress was estimated biochemically by taking tissue glutathione, lipid peroxidation (LPO), and superoxide dismutase activity as endpoints. Our findings indicated a prolonged diestrus phase in the SG + L + SA group (p < 0.001). Histopathological study revealed abnormal tissue architecture in treated groups. Comet assay study showed that SG + SA exposure significantly induced DNA damage in test animals. The elevated LPO level in the SG + SA group indicated oxidative stress generation in the reproductive tissues. The present study suggests that female reproductive organs are vulnerable to SA and SG and oxidative stress generation may be the possible mechanism behind DNA damage, impaired follicular growth, atresia, and altered estrous cycle in the mice test system.

Pyrrolizidine alkaloids (PAs) are hepatotoxic, genotoxic, and carcinogenic phytochemicals. Upon metabolic activation, PAs produce dehydropyrrolizidine alkaloids (dehydro-PAs) as reactive primary pyrrolic metabolites. Dehydro-PAs are unstable, facilely hydrolyzed to (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP). Both dehydro-PAs and DHP are capable of binding to cellular DNA and proteins to form DHP-DNA and DHP-protein adducts leading to tumorigenicity and cytotoxicity. We recently determined that the reaction of dehydro-PAs with glutathione and cysteine generated 7-glutathione-DHP (7-GS-DHP) and 7-cysteine-DHP, respectively which can also bind to DNA to produce DHP-DNA adducts. In this study, we determined the effects of glutathione and cysteine on the induction of hepatocytotoxicity and the formation of DHP-DNA adducts in primary hepatocytes cultured with riddelliine and monocrotaline. We found that both glutathione and cysteine can drastically reduce hepatotoxicity while the levels of DHP-DNA adduct formation are slightly affected.