Oral exposure to diisodecyl phthalate aggravates allergic dermatitis by oxidative stress and enhancement of thymic stromal lymphopoietin

Dog size and patterns of disease history across the canine age spectrum: Results from the Dog Aging Project

Age in dogs is associated with the risk of many diseases, and canine size is a major factor in that risk. However, the size patterns are complex. While small size dogs tend to live longer, some diseases are more prevalent among small dogs. In this study we seek to quantify how the pattern of disease history varies across the spectrum of dog size, dog age, and their interaction. Utilizing owner-reported data on disease history from a substantial number of companion dogs enrolled in the Dog Aging Project, we investigate how body size, as measured by weight, associates with the lifetime prevalence of a reported condition and its pattern across age for various disease categories. We found significant positive associations between dog size and the lifetime prevalence of skin, bone/orthopedic, gastrointestinal, ear/nose/throat, cancer/tumor, brain/neurologic, endocrine, and infectious diseases. Similarly, dog size was negatively associated with lifetime prevalence of ocular, cardiac, liver/pancreas, and respiratory disease categories. Kidney/urinary disease prevalence did not vary by size. We also found that the association between age and lifetime disease prevalence varied by dog size for many conditions including ocular, cardiac, orthopedic, ear/nose/throat, and cancer. Controlling for sex, purebred vs. mixed-breed status, and geographic region made little difference in all disease categories we studied. Our results align with the reduced lifespan in larger dogs for most of the disease categories and suggest potential avenues for further examination.

Melatonin reduces IL-33 and TSLP expression in human nasal epithelial cells by scavenging ROS directly

BACKGROUND

Chronic rhinosinusitis (CRS) is a chronic mucosal inflammation of the nasal cavity and sinuses. It is classified into CRS without nasal polyps and CRS with nasal polyps (CRSwNP). CRSwNP has high recurrence, especially CRSwNP with massive eosinophil infiltration which is mediated by type 2 inflammatory response. Melatonin is a hormone secreted by the pineal gland, it has powerful antioxidant and anti-inflammatory effects in addition to regulating biological rhythms. There are no studies on melatonin for the treatment of CRS, so we aimed to explore whether melatonin could be used for the treatment of CRS.

MATERIALS AND METHODS

In this study, we used melatonin to treat a cell model of CRS. Subsequently, MTT assay was performed to examine the cell viability of human nasal epithelial cells (HNEpCs), a reactive oxygen species (ROS) kit to detect ROS production, a malondialdehyde (MDA) kit to detect the MDA content in the cell culture supernatant, and an apoptosis kit and Western blot analysis to detect apoptosis. The expressions of Nrf2, HO-1, IL-33, TSLP, and IL-25 were detected by Western blot analysis.

RESULTS

Melatonin improved the viability of HNEpCs, reduced lipopolysaccharide-induced ROS, reduced the MDA content, and inhibited their apoptosis. More importantly, melatonin reduced the expression of IL-33 and TSLP, an important phenomenon for the treatment of CRSwNP.

CONCLUSION

Melatonin protects HNEpCs from damage in inflammation and reduces IL-33 and TSLP expression of HNEpCs.

Relationship between shellfish consumption and urinary phthalate metabolites: Korean National Environmental Health Survey (KoNEHS) cycle 3 (2015-2017)

Background

Phthalates are endocrine disrupting chemicals that are widely used in the production of items of daily life such as in polyvinylchloride plastics, insecticides, and medical devices. This study aimed to determine the association between phthalate exposure and shellfish consumption using data from the Korean National Environmental Health Survey (KoNEHS) cycle 3 (2015-2017), which is a nationally representative survey.

Methods

In this study, we analyzed the KoNEHS cycle 3 data of 3,333 (1,526 men and 1,807 women) adults aged more than 19 years. Data related to the variables of sociodemographic factors, health-related behaviors, dietary factors, seafood consumption frequency, and urinary phthalate metabolites concentrations were collected. The concentrations of urinary phthalate metabolites of all the participants were divided into quartiles to define high and low concentration groups based on the 75th percentile concentration. A χ² test was conducted to analyze the distribution of independent variables. To analyze the relationship between shellfish consumption and phthalate exposure, the odds ratios (ORs) were calculated using logistic regression analysis.

Results

Total adults with shellfish consumption frequency of over once a week showed the following adjusted ORs for high concentrations of the following metabolites compared with the group that consumed shellfish once a week or less: 1.43 (95% confidence interval [CI]: 1.01-2.06) for mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), 1.43 (95% CI: 1.01-2.03) for mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), 1.57 (95% CI: 1.10-2.24) for ∑di-2-ethylhexyl phthalate (∑DEHP), 2.01 (95% CI: 1.46-2.77) for mono-carboxyoctyl phthalate (MCOP), 1.56 (95% CI: 1.11-2.18) for mono-carboxy-isononly phthalate (MCNP), and 2.57 (95% CI: 1.85-3.56) for mono (3-carboxypropyl) phthalate (MCPP).

Conclusions

The concentrations of urinary phthalate metabolites (MEOHP, MECPP, ∑DEHP, MCOP, MCNP, and MCPP) were higher in adults with a higher frequency of shellfish consumption.

Are Phthalate Exposure Related to Oxidative Stress in Children and Adolescents with Asthma? A Cumulative Risk Assessment Approach

Childhood asthma has become one of the most common chronic diseases in children and adolescents. However, few case–control studies investigating the relationship between phthalate exposure and asthma in children and adolescents have been conducted, especially in Asia. Therefore, we assessed the potential associations between phthalate exposure and asthma among children and adolescents in Taiwan. Because various demographic and environmental variables may influence the incidence and prognosis of asthma, we performed a case–control study with propensity score matching. Out of 615 Childhood Environment and Allergic Diseases Study participants, we conditionally matched 41 children with clinically diagnosed asthma with 111 controls. We then analyzed 11 phthalate metabolites by using liquid chromatography with tandem mass spectrometry. Compared with the control group, the median urinary phthalate levels for most phthalate metabolites in the case group were slightly increased, including monomethyl phthalate, mono-n-butyl phthalate, monobenzyl phthalate, monoethylhexyl phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethyl-5-carboxypentyl) phthalate, and mono-(2-carboxymethylhexyl) phthalate. Hence, our results suggest that phthalate exposure may be associated with the development of asthma. In addition, prenatal environmental factors, such as active or passive smoking during pregnancy, may increase the risk of asthma.

The Complicated Role of Nuclear Factor Erythroid-Derived 2-Like 2 in Allergy and Asthma

Nuclear factor erythroid-derived 2-like 2 (Nrf2) is a stress-activated transcription factor that is highly responsive to oxidative stress and electrophilic stimuli. Upon activation, Nrf2 upregulates a battery of cytoprotective genes meant to prevent cell death or damage. In many models of inflammation, Nrf2 protects against the immune response and decreases injury, including in the context of asthma and allergy. However, in some models of asthma and allergy, Nrf2 either does not play a role or can even exacerbate inflammation. In general, the reasons behind these discrepancies are not clear and the mechanisms by which Nrf2 modulates immune response are largely uncharacterized. The aim of this review is to highlight current literature assessing the role of Nrf2 in allergy and asthma to understand Nrf2 as a potential therapeutic target. SIGNIFICANCE STATEMENT: Nuclear factor erythroid-derived 2-like 2 (Nrf2) is an important immune mediator that modulates numerous immune cell types in various inflammatory diseases, including allergy and asthma. There is considerable interest in Nrf2 as a drug target in inflammation, which is complicated by the complex nature of Nrf2 in the immune system. This review focuses on the role of Nrf2 in asthma and allergy, including in regulating immune cell function and in detoxifying xenobiotics that exacerbate these diseases.

The aggravation of allergic airway inflammation with dibutyl phthalate involved in Nrf2-mediated activation of the mast cells

Dibutyl phthalate (DBP)-an organic pollutant-is ubiquitous in the environment. DBP as an immune adjuvant is related to the development of multiple allergic diseases. However, the current research involving DBP-induced pulmonary toxicity remains poorly understood. Therefore, this research aimed to explore the adverse effect and potential mechanism of DBP exposure on the lungs in rats. In our study, ovalbumin was used to build a rat model of allergic airway inflammation to study any harmful effect of DBP exposure on lung tissues. Rats were treated by intragastric administration of DBP (500 mg kg^-1 or 750 mg kg^-1) and/or subcutaneous injection of SFN (4 mg kg^-1). The results of histopathological analysis, cell count, and myeloperoxidase showed that DBP promoted the inflammatory damage of lungs. In the lung tissues, the detection of terminal deoxynucleotidyl transferase dUNT nick end labeling and oxidative stress indices showed that DBP significantly increased the level of apoptosis and oxidative stress. Western blot analysis indicated that DBP raised the expression level of thymic stromal lymphopoietin and reduced the nuclear expression level of nuclear factor-erythroid-2-related factor 2 (Nrf2), which was further verified by quantitative real-time PCR. Meanwhile, DBP treatment markedly up-regulated the inflammatory cytokines such as IL-4 and IL-13, and rat mast cell protease-2, a marker secreted by mast cells (MCs). Conversely, sulforaphane, a Nrf2 inducer, ameliorated the pulmonary damage induced by DBP in the above. Altogether, our data provides a new insight into the impacts of the activation of MCs on the DBP-induced pulmonary toxicity as well as the safety evaluation of DBP.

Melatonin prevents allergic airway inflammation in epicutaneously sensitized mice

PURPOSE

The pathological process of atopic dermatitis (AD) progressing into other types of allergic diseases such as asthma and allergic rhinitis during the first several years of life is often referred to as the atopic march. Although the phenomenon of atopic march has been recognized for decades, how asthma stems from AD is still not fully understood, confounding a universal strategy to effectively protect people from the atopic march.

METHODS

We established experimental atopic march mice by first inducing allergic dermatitis with 0.5% fluorescein isothiocyante (FITC) applied to the skin, followed by an ovalbumin (OVA) airway challenge. In addition, by examining serum immunoglobulin (Ig) concentrations, airway cytokines, the levels of oxidative stress markers, histopathological changes in lung tissue and airway hyperresponsiveness (AHR), we were able to validate the successful establishment of the model. Furthermore, by detecting the attenuating effects of melatonin (MT) and the levels of oxidative stress in the atopic march mice, we explored the potential molecular mechanisms involved in the development of atopic march.

RESULTS

By successfully establishing an experimental atopic march mouse model, we were able to demonstrate that overproduction of oxidative stress in the lung significantly up-regulated the activation of nuclear factor-κB (NF-κB) signaling pathways causing thymic stromal lymphopoietin (TSLP) release, which further promotes the development of atopic march.

CONCLUSIONS

To mitigate the development of the atopic march, antioxidants such as MT may be imperative to inhibit NF-κB activation in the lung, especially after the onset of AD.

Curcumin decreases dibutyl phthalate-induced renal dysfunction in Kunming mice via inhibiting oxidative stress and apoptosis

Curcumin (Cur) has been used extensively in dietary supplement with antioxidant and anti-apoptotic properties. Although dibutyl phthalate (DBP) has adverse effects on the kidney, any association between DBP exposure and the role of Cur is unclear. We tested the hypothesis that exposure to DBP has adverse consequences on renal dysfunction in mice and the potential protective role of Cur in decreasing DBP-induced renal dysfunction via inhibiting oxidative stress and apoptosis. Kidney function, oxidative stress biomarkers, and apoptosis factors as well as Bcl-2 and Bax were investigated. The results showed a marked increase of renal dysfunction, oxidative stress and apoptosis level after DBP exposure compared to the control. While administration of Cur to DBP-treated mice may reduce these adverse biochemical changes compared with DBP-alone group. Overall, these results suggest that oxidative stress and apoptosis are involved in DBP-induced renal disorder, whereas Cur plays a protective role in inhibiting these two pathways.

The interplay between mast cells, pineal gland, and circadian rhythm: Links between histamine, melatonin, and inflammatory mediators

Our daily rhythmicity is controlled by a circadian clock with a specific set of genes located in the suprachiasmatic nucleus in the hypothalamus. Mast cells (MCs) are major effector cells that play a protective role against pathogens and inflammation. MC distribution and activation are associated with the circadian rhythm via two major pathways, IgE/FcεRI- and IL-33/ST2-mediated signaling. Furthermore, there is a robust oscillation between clock genes and MC-specific genes. Melatonin is a hormone derived from the amino acid tryptophan and is produced primarily in the pineal gland near the center of the brain, and histamine is a biologically active amine synthesized from the decarboxylation of the amino acid histidine by the L-histidine decarboxylase enzyme. Melatonin and histamine are previously reported to modulate circadian rhythms by pathways incorporating various modulators in which the nuclear factor-binding near the κ light-chain gene in B cells, NF-κB, is the common key factor. NF-κB interacts with the core clock genes and disrupts the production of pro-inflammatory cytokine mediators such as IL-6, IL-13, and TNF-α. Currently, there has been no study evaluating the interdependence between melatonin and histamine with respect to circadian oscillations in MCs. Accumulating evidence suggests that restoring circadian rhythms in MCs by targeting melatonin and histamine via NF-κB may be promising therapeutic strategy for MC-mediated inflammatory diseases. This review summarizes recent findings for circadian-mediated MC functional roles and activation paradigms, as well as the therapeutic potentials of targeting circadian-mediated melatonin and histamine signaling in MC-dependent inflammatory diseases.

Occurrence, removal, and environmental risk of phthalates in wastewaters, landfill leachates, and groundwater in Poland

Phthalates or phthalic acid esters (PAEs) are chemical compounds whose use is exceptionally widespread in everyday materials but, at the same time, have been proven to have harmful effects on living organisms. Effluents from municipal wastewater treatment plants (WWTP) and leachates from municipal solid waste (MSW) landfills are important sources of phthalates with respect to naturally occurring waters. The main aim of this research was determination, mass loads, removal rates and ecological risk assessment of eight phthalates in municipal wastewaters, landfill leachates and groundwater from Polish WWTPs and MSW landfills. Solid-phase microextraction and gas chromatography with mass spectrometry were used for the extraction and determination of analytes. Summed up concentrations of eight phthalates ranged from below LOD to 596 μg/L in influent wastewater with the highest concentration found for bis-2-ethylhexyl phthalate (DEHP) (143 μg/L). The average degree of phthalate removal varies depending on the capacity of a given treatment plant with larger treatment plants coping better than smaller ones. The highest treatment efficiency for all tested treatment plants, over 90%, was reported for dimethyl phthalate (DMP) and diethyl phthalate (DEP). Overall concentrations of phthalates in leachates ranged from below LOD to 303 μg/L while the highest maximum concentration was registered for DEHP (249 μg/L). Overall concentrations of phthalic acid esters in groundwater from upstream monitoring wells ranged from below LOD to 1.8 μg/L and from LOD to 27.9 μg/L in samples from wells downstream of MSW landfills. The obtained data shows that diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), DEHP, and diisononyl phthalate (DINP) pose a high risk for all trophic levels being considered in effluent wastewaters. In the case of groundwater high environmental risk was recorded for DBP and DEHP for all tested trophic levels. Phthalates, in concentrations that pose a high environmental risk, are present in Polish municipal after-treatment wastewater as well as in groundwater under municipal solid waste landfills.

Dibutyl phthalate induces allergic airway inflammation in rats via inhibition of the Nrf2/TSLP/JAK1 pathway

Dibutyl phthalate (DBP), an important plastic contaminant in the environment, is known to cause organ toxicity. Although current research has shown that DBP-induced organ toxicity is associated with oxidative stress, the toxic effect of DBP on the lungs have not been fully elucidated. Therefore, we investigated the potential mechanism by which DBP induces pulmonary toxicity using a model of DBP-induced allergic airway inflammation in rats. The results showed that chronic exposure to DBP induced histopathological damage, inflammation, oxidative stress, apoptosis, and increased the protein levels of thymic stromal lymphopoietin (TSLP) and its downstream protein Janus kinase 1 (JAK1) and signal transducer and activator of transcription 6 (STAT6). Moreover, DBP exposure inhibited nuclear factor-erythroid-2-related factor 2 (Nrf2) and levels of its target genes NAD(P)H quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1). Additionally, using in vitro experiments, we found that DBP induced oxidative stress, reduced cell viability, and inhibited the Nrf2/HO-1/NQO1 pathway in mouse alveolar type II epithelial cell line. Overall, these data demonstrate that DBP induces allergic airway inflammation in rats via inhibition of the Nrf2/TSLP/JAK1 pathway.

Prenatal and childhood exposure to phthalic acid esters and vaccination antibodies in children: A 15-year follow-up birth cohort study

Phthalic acid esters (PAE) are widely used during chemical synthesis and do not form covalent linkages with products. It has been reported that exposure to PAE affects the immune response. However, their effect on antibody concentrations in children is still under investigation. We aimed to examine the association between early-life phthalate exposure and antibody concentrations in children in a longitudinal birth cohort established in 2000-2001. We recruited 398 neonates in central Taiwan and followed them up every 2-3 years, with various antibody-related studies at 11- and 14-year follow-ups. Seven urinary phthalate metabolites were quantified in mothers during pregnancy and children aged 11 years. Four antibody concentrations were analyzed in children aged 11 and 14 years. The percent change in antibody concentrations from ages 11 to 14 years was calculated and its association with phthalate exposure was evaluated via multivariate regression analysis. Eighty-one followed-up children were with sufficient data. After adjusting for prenatal exposure and other confounders, double concentrations of the urinary sum of di-2-ethylhexyl phthalate (ΣDEHPm) and mono-n-butyl phthalate (MnBP) were associated with a 18.06% (95% CI = 3.34%, 32.78%) and 22.53% decrease (95% CI = 3.39%, 41.66%) in antibody concentration against hepatitis B, respectively. Phthalate exposure was found to be related to decreased antibody concentrations against hepatitis B (DEHP, DBnP) in the early teens. This exposure is suggested to be considered for clinical re-booster vaccines among junior high school students. Further verification with additional cohorts and studies on the underlying mechanisms of phthalate exposure are warranted.

Combined exposure to formaldehyde and PM2.5: Hematopoietic toxicity and molecular mechanism in mice

PM2.5 and formaldehyde (FA) are major outdoor and indoor air pollutants in China, respectively, and both are known to be harmful to human health and to be carcinogenic. Of all the known chronic health effects, leukaemia is one of the most serious health risks associated with these two pollutants. To explore the influence and underlying mechanisms of exposure to formaldehyde and PM2.5 on hematopoietic toxicity, we systematically studied the toxicity induced in hematopoietic organs: bone marrow (BM); spleen; and myeloid progenitor cells (MPCs). Male Balb/c mice were exposed to: PM2.5 (20, 160 μg/kg·d) at a dose of 40 μL per mouse or formaldehyde (0.5, 3.0 mg/m3) for 8 h per day for 2 weeks or co-exposed to formaldehyde and PM2.5 (20 μg/kg·d PM2.5 + 0.5 mg/m3 FA, 20 μg/kg·d PM2.5 + 3 mg/m3 FA, 160 μg/kg·d PM2.5 + 0.5 mg/m3 FA, 160 μg/kg·d PM2.5 + 3 mg/m3 FA) for 2 weeks. Similar toxic effects were found in the formaldehyde-only and PM2.5-only groups, including significant decrease of blood cells and MPCs, along with decreased expression of hematopoietic growth factors. In addition, individual exposure of formaldehyde or PM2.5 increased oxidative stress, DNA damage and immune system disorder by destroying the balance of Th1/Th2, and Treg/Th17. DNA repair was markedly inhibited by deregulating the mammalian target of rapamycin (mTOR) pathway. Combined exposure to PM2.5 and formaldehyde led to more severe effects. Administration of Vitamin E (VE) was shown to attenuate these effects. In conclusion, our findings suggested that PM2.5 and formaldehyde may induce hematopoietic toxicity by reducing the expression of hematopoietic growth factors, increasing oxidative stress and DNA damage, activating the 'immune imbalance' pathway and suppressing the DNA-repair related mTOR pathway. The hematopoietic toxicity induced by combined exposure of PM2.5 and formaldehyde might provide further insights into the increased incidence of hematological diseases, including human myeloid leukaemia.

Dibutyl phthalate aggravated asthma-like symptoms through oxidative stress and increasing calcitonin gene-related peptide release

Dibutyl phthalate (DBP) is one of the most ubiquitous phthalate esters found in everyday products, and is receiving increased attention as an immunologic adjuvant. However, information regarding DBP-aggravated allergic asthma is still limited. This study used a mouse model sensitized with ovalbumin (OVA) to determine any adverse effects of DBP on allergic asthma. Our results reveal that allergic asthmatic mice exposed to DBP for an extended period had a significant increase in inflammatory cell infiltration; a significant increase in levels of serum immunoglobulin and T helper 2 cell (Th2) and T helper 17 cell (Th17) cytokines in lung tissue; and significant changes in lung histology and AHR, all of which are typical asthmatic symptoms. The levels of oxidative stress and levels of the neuropeptide, calcitonin gene related peptide (CGRP), were also elevated after DBP exposure. Interestingly, blocking oxidative stress by administering melatonin (MT) not only reduced oxidative stress and CGRP levels, but also ameliorated the asthmatic symptoms. Collectively, these results show that DBP exacerbates asthma-like pathologies by increasing the expression of CGRP mediated by oxidative stress.

Biochemical and behavior effects induced by diheptyl phthalate (DHpP) and Diisodecyl phthalate (DIDP) exposed to zebrafish

Both Diheptyl-phthalate (DHpP) and Diisodecyl-phthalate (DIDP) were used extensively as plasticizers. Recently, their occurrence in the environmental matrices and human body fluids have been reported. Unfortunately, these phthalate congeners are without basic toxicity profiles. Hence, we studied the toxic effects of both DHpP and DIDP in the median lethal concentration (LC₅₀ 96-h) on zebrafish (Danio rerio). We assessed swimming behavior strength and tissues biomarker responses including total antioxidants capacity (TAOC), transaminases, and acetylcholinesterase (AChE) enzyme. Fish exposed to phthalate congeners (Treatment-I and-II) for 15-days showed alterations on fish swimming behavior and circadian rhythm. At the end of the exposure period, both liver and heart tissue transaminases activities were found to be accelerated in DHpP and DIDP treated fish, when compared to control group. TAOC and AChE activities were found to be decreased in brain, gills, intestine, and muscle tissues of phthalate congeners treated fish than the control group. Alterations observed in the studied biomarkers were concentration-based response. Among treatment groups DHpP showed higher effects. Comparative studies on swimming behavior and biochemical activities were reasonable to know the swimming responses are mediated due to external stress or internal stress. More studies on molecular and biomarkers assessments are warranted on toxicity of emerging contaminants.

Phthalate exposure and allergic diseases: Review of epidemiological and experimental evidence

Phthalates are among the most ubiquitous environmental contaminants and endocrine-disrupting chemicals. Exposure to phthalates and related health effects have been extensively studied over the past four decades. An association between phthalate exposure and allergic diseases has been suggested, although the literature is far from conclusive. This article reviews and evaluates epidemiological (n = 43), animal (n = 49), and cell culture studies (n = 42), published until the end of 2019, on phthalates and allergic diseases, such as asthma, rhinoconjunctivitis, and eczema. In contrast to earlier reviews, emphasis is placed on experimental studies that use concentrations with relevance for human exposure. Epidemiological studies provide support for associations between phthalate exposures and airway, nasal, ocular, and dermal allergic disease outcomes, although the reported significant associations tend to be weak and demonstrate inconsistencies for any given phthalate. Rodent studies support that phthalates may act as adjuvants at levels likely to be relevant for environmental exposures, inducing respiratory and inflammatory effects in the presence of an allergen. Cell culture studies demonstrate that phthalates may alter the functionality of innate and adaptive immune cells. However, due to limitations of the applied exposure methods and models in experimental studies, including the diversity of phthalates, exposure routes, and allergic diseases considered, the support provided to the epidemiological findings is fragmented. Nevertheless, the current evidence points in the direction of concern. Further research is warranted to identify the most critical windows of exposure, the importance of exposure pathways, interactions with social factors, and the effects of co-exposure to phthalates and other environmental contaminants.

Longitudinal effect of phthalates exposure on allergic diseases in children

BACKGROUND

Environmental chemicals, such as phthalates, phenols, and parabens, may affect children's immune development and contribute to the risk of atopic diseases and asthma.

OBJECTIVE

To evaluate the associations between prenatal and childhood phthalate exposure and atopic diseases in children at the age of 9 years.

METHODS

This analysis is restricted to 145 mother-child pairs from the prospective Polish Mother and Child Cohort Study. Phthalate metabolite levels were assessed in the urine samples collected from mothers during the third trimester of pregnancy and from children at age of 2 and 9 years. For the appropriate recognition of children's health status, a questionnaire was administered to the mothers and completed with information from the medical record of each child. The clinical examination was performed by a pediatrician/allergist in the presence of the mother or a relative.

RESULTS

A higher urine concentration of mono-2-ethyl-5-oxohexyl phthalate increased the risk of food allergy in children at the age of 9 years (odds ratio [OR], 1.75; 95% CI, 1.19-2.57; P = .004) and decreased the risk of atopic dermatitis (OR, 0.49; 95% CI, 0.27-0.87; P = .02). For mono-2-ethyl-5-hydroxyhexyl phthalate, an increased risk of atopic dermatitis was observed (OR, 1.90; 95% CI, 1.18-3.05; P = .008). A higher urine concentration of mono-benzyl phthalate increased the risk of asthma in children (OR, 1.67; 95% CI, 1.08-2.58; P = .02), but the risk of asthma decreased when the concentration of mono-2-ethylhexyl phthalate was higher (OR, 0.64; 95% CI, 10.43-0.97; P = .04).

CONCLUSION

Our study has not provided clear evidence of the negative effect of phthalate exposure during pregnancy and within the 9 years after birth on allergic diseases in children.

The synergistic or adjuvant effect of DINP combined with OVA as a possible mechanism to promote an immune response

Diisononyl phthalate (DINP) is commonly used as a plasticizer in industrial and consumer product applications. Several studies have suggested a possible link between exposure to DINP and the development of allergic asthma, and the synergistic effect of DINP combined with Ovalbumin (OVA) is a possible way to promote an immune response. These findings are still speculative, since there is insufficient evidence to assess the ability of DINP to influence "allergic asthma pathology". This study was designed to determine any effects of OVA/DINP exposure on airway reactivity, particularly when combined with allergen exposure. Experiments to determine these effects were conducted after 15 days of combined exposure and a subsequent challenge with aerosolized ovalbumin for one week. Airway hyper-responsiveness (lung function), lung tissue pathology, cytokines and oxidative stress biomarkers were investigated. We showed that oral exposure to OVA/DINP could induce airway hyper-responsiveness (AHR), and aggravate airway wall remodeling, and that this deterioration was concomitant with increased immunoglobulin-E and Th2 cytokines secretion. The data also demonstrated that DINP could promote oxidative damage in the lung. In summary, this study showed that DINP has an adjuvant effect on allergic asthma affecting lung function, lung histopathology, immune molecules and causes oxidative damage.

Casearia decandra leaves present anti-inflammatory efficacy in a skin inflammation model in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Casearia decandra (guaçatonga) is popularly used as an anti-inflammatory. We investigated the antioxidant and anti-inflammatory effect of C.decandra leaves (CdE) ethanolic extract and of the rutin standard (present in the CdE).

MATERIALS AND METHODS

Male adult Swiss mice were used (25-30 g; 5-6 animals by a group). CdE phytochemical analysis was performed by HPLC method. The antioxidant potential of CdE and rutin was assessed by different methods. Topical anti-inflammatory effect of CdE (0.001-1mg/ear) and rutin (0.003-0.03mg/ear) was evaluated by ear edema formation and inflammatory cells infiltration (MPO activity and histology) on a skin inflammation model induced by topical application of croton oil (1mg/ear).

RESULTS

Rutin (27.81 ± 1.11 mg/g) was identified in CdE by HPLC analysis. The required amounts of CdE, rutin and ascorbic acid to reduce the initial concentration of radical DPPH by 50% (IC₅₀) were 7.77 (6.31-9.57) μg/mL, 3.62 (3.26-4.01) μg/mL and 3.74 (3.37-4.14) μg/mL with a radical DPPH reduction of 91 ± 1.2%, 91 ± 0.5%, and 96 ± 0.44% (at 30 μg/mL), respectively. Moreover, CdE and rutin presented H₂O₂ scavenging activity with H₂O₂ levels reduction of 41 ± 7% and 46 ± 6%, respectively and SOD-like activity of 60 ± 4% and 51 ± 14%, respectively. On the other hand, just rutin presented nitric oxide scavenging activity of 54 ± 6%. CdE and rutin topically applied inhibited the ear edema with a maximum inhibition of 70 ± 5% (1 mg/ear) and 78 ± 10% (0.03 mg/ear), respectively. Treatments reduced the MPO activity (42 ± 4% to CdE; 1mg/ear and 30 ± 8% to rutin; 0.03 mg/ear). Histologically, the topical treatments also reduced the dermis thickness and the inflammatory cells infiltration.

CONCLUSION

We demonstrated the antioxidant and anti-inflammatory effect of C.decandra leaves and rutin. Its antioxidant potential may contribute to inflammatory process attenuation, supporting the C.decandra leaves used as a promising alternative in the therapy of the inflammatory diseases.

Update of the risk assessment of di-butylphthalate (DBP), butyl-benzyl-phthalate (BBP), bis(2-ethylhexyl)phthalate (DEHP), di-isononylphthalate (DINP) and di-isodecylphthalate (DIDP) for use in food contact materials

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP Panel) was asked by the European Commission to update its 2005 risk assessments of di‐butylphthalate (DBP), butyl‐benzyl‐phthalate (BBP), bis(2‐ethylhexyl)phthalate (DEHP), di‐isononylphthalate (DINP) and di‐isodecylphthalate (DIDP), which are authorised for use in plastic food contact material (FCM). Dietary exposure estimates (mean and high (P95)) were obtained by combining literature occurrence data with consumption data from the EFSA Comprehensive Database. The highest exposure was found for DINP, ranging from 0.2 to 4.3 and from 0.4 to 7.0 μg/kg body weight (bw) per day for mean and high consumers, respectively. There was not enough information to draw conclusions on how much migration from plastic FCM contributes to dietary exposure to phthalates. The review of the toxicological data focused mainly on reproductive effects. The CEP Panel derived the same critical effects and individual tolerable daily intakes (TDIs) (mg/kg bw per day) as in 2005 for all the phthalates, i.e. reproductive effects for DBP (0.01), BBP (0.5), DEHP (0.05), and liver effects for DINP and DIDP (0.15 each). Based on a plausible common mechanism (i.e. reduction in fetal testosterone) underlying the reproductive effects of DEHP, DBP and BBP, the Panel considered it appropriate to establish a group‐TDI for these phthalates, taking DEHP as index compound as a basis for introducing relative potency factors. The Panel noted that DINP also affected fetal testosterone levels at doses around threefold higher than liver effects and therefore considered it conservative to include it within the group‐TDI which was established to be 50 μg/kg bw per day, expressed as DEHP equivalents. The aggregated dietary exposure for DBP, BBP, DEHP and DINP was estimated to be 0.9–7.2 and 1.6–11.7 μg/kg bw per day for mean and high consumers, respectively, thus contributing up to 23% of the group‐TDI in the worst‐case scenario. For DIDP, not included in the group‐TDI, dietary exposure was estimated to be always below 0.1 μg/kg bw per day and therefore far below the TDI of 150 μg/kg bw per day. This assessment covers European consumers of any age, including the most sensitive groups. Based on the limited scope of the mandate and the uncertainties identified, the Panel considered that the current assessment of the five phthalates, individually and collectively, should be on a temporary basis.

This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2019.EN-1747/full

Dibutyl phthalate-mediated oxidative stress induces splenic injury in mice and the attenuating effects of vitamin E and curcumin

Dibutyl phthalate (DBP) is a ubiquitous environmental contaminant that at certain levels can be harmful to human health. Although DBP has been widely linked to immunotoxicity, any association between DBP exposure and splenic injury remains unknown. The purpose of this study was to investigate whether DBP exposure can induce splenic injury and the antagonistic effects of two antioxidants, vitamin E (VitE) and curcumin (Cur), on DBP-induced splenic injury. The levels of ROS, GSH, T-AOC, IL-1β, TNF-α, cytochrome C, caspase-8, caspase-9 and caspase-3 in the spleen homogenate of mice were measured. Any histopathological changes in the spleen were observed using H&E and toluidine blue staining. And the morphology of mitochondria was observed using Janus Green B staining. The results indicate that exposure to 50 mg/kg DBP could cause histopathological changes of the spleen and result in inflammation and apoptosis associated with oxidative stress, which may lead to splenic injury in mice. Moreover, both VitE and Cur could antagonize the oxidative stress induced by DBP to reduce splenic injury. These findings help to expand our understanding of DBP-mediated immunotoxicity, and to show that VitE and Cur can alleviate DBP-induced splenic injury and the possible DBP-associated decline in immune function.

Platinum and palladium nanoparticle-containing mixture, PAPLAL, does not induce palladium allergy

Palladium (Pd) is a common metal found in jewellery and dental appliances, but it has been shown to be likely to cause metal allergy. We previously reported that platinum (nPt) and palladium (nPd) nanoparticle-containing mixture (PAPLAL) has both superoxide dismutase and catalase activities and that the topical application of PAPLAL improved skin atrophy induced by chronic oxidative damage in an ageing mouse model. However, the safety of PAPLAL for preventing Pd allergy remains unclear. In the present study, we investigated whether or not PAPLAL induces Pd allergy. We found that PAPLAL treatment caused no skin inflammation, while nPd administration caused only slight skin inflammation compared to the palladium chloride-induced severe reaction in an experimental metal allergy model. A gene expression analysis revealed that PAPLAL treatment significantly suppressed the expression of Inf-γ, Il-1β and Tnfα genes. Even in human clinical trials using patches containing metal nanoparticles, nPd and PAPLAL failed to induce significant skin inflammation. These results suggest that mixing with nPt in PAPLAL suppresses the inflammation response of nPd. PAPLAL can be expected to be applied to various skin treatments as a safe topical substance.

A chalcone derivative suppresses the induction of TSLP in mice and human keratinocytes and attenuates OVA-induced antibody production in mice

Thymic stromal lymphopoietin (TSLP) is a key epithelial-derived factor that aggravates allergic diseases. Therefore, TSLP inhibitors are candidate compounds for the treatment of allergic diseases. Previously, we reported that KCMH-1, a mouse keratinocyte cell line, constitutively produces TSLP. In this study, we tried to identify inhibitors of TSLP by screening 2169 compounds in KCMH-1 cells and found one such chalcone derivative (code no. 16D10). 16D10 inhibited TSLP expression and TSLP promoter activation in HaCaT cells, a human keratinocyte cell line. Although nuclear factor kappa-B (NF-κB) is a key transcription factor for the induction of TSLP, 16D10 did not inhibit the activation pathway of NF-κB, such as degradation of inhibitor of κB (IκB) and p65 nuclear translocation. 16D10 activated the Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor (erythroid-derived 2)-like 2 (Nrf2) system, although this system was not involved in the inhibitory effect of 16D10. 16D10 also inhibited TSLP production in a lipopolysaccharide (LPS)- or ovalbumin (OVA)-induced air-pouch-type inflammation model. Further, repeated 16D10 administration diminished serum immunoglobulin G1 (IgG1) and IgE concentration in an OVA-induced air-pouch-type sensitization model. Taken together, these results indicate that 16D10 is an inhibitor of TSLP production and has an anti-allergic effect. This inhibitory effect is independent of the activation of NF-κB and the Keap1-Nrf2 system. Therefore, 16D10 could be a new type of candidate drug for allergic diseases.

Prenatal high molecular weight phthalates and bisphenol A, and childhood respiratory and allergic outcomes

BACKGROUND

The prevalence of asthma and allergy is increasing in US children. In utero exposure to chemicals used in personal care products and plastics may contribute to increase in these diseases.

METHODS

We quantified urinary concentrations of eight phthalate metabolites and bisphenol A in mothers twice during pregnancy in 1999-2000 in Salinas, California. We assessed probable asthma, aeroallergies, eczema, and spirometry in their children at age 7, and measured T helper 1 and T helper 2 cells in blood at ages 2, 5, and 7 (N = 392). We employed Bayesian model averaging to select confounders from additional biomarkers measured in this population and controlled for them in logistic and linear regressions.

RESULTS

Monocarboxyisooctyl phthalate was associated with increased odds for probable asthma (odds ratio: 1.54, 95% CI: 1.12, 2.12), and with lower forced expiratory volume in one second (β: -0.09 L, 95% CI: -0.15, -0.03) and forced expiratory flow from 25% to 75% of forced vital capacity (β: -7.06 L/s, 95% CI: -11.04, -2.90). Several other associations were attenuated in final models that controlled for additional biomarkers.

CONCLUSION

Monocarboxyisooctyl phthalate was associated with lower respiratory health after controlling for related chemical exposure, which suggests that confounding by multiple chemical exposures should be considered in future research.

Exposure to formaldehyde and diisononyl phthalate exacerbate neuroinflammation through NF-κB activation in a mouse asthma model

Diisononyl phthalate (DINP) and formaldehyde both are associated with asthma and allergies. However, it is unclear about the adverse effect of DINP and formaldehyde exposure on the brain for asthma patients. Here, we determined the effect of DINP and/or formaldehyde exposure on neuroinflammation in brain by a murine asthma model and investigated the underlying mechanisms. Mice were exposed to formaldehyde and/or DINP and sensitization with ovalbumin. The results show that exposure to formaldehyde and/or DINP not only exacerbated allergic asthma-like symptoms, but also promoted neuroinflammation in brain. The incrassation of the airway wall and exacerbation of neuroinflammation were more obviously when mice were subjected to a combined exposure to DINP and formaldehyde. Exposure to DINP and/or formaldehyde enhances oxidative stress and the activation of NF-κB in the prefrontal cortex of mouse asthma model. Exposure to DINP and/or formaldehyde also induced an increase in IL-1β, IL-17, and NGF. Blocking oxidative stress by administering melatonin or inhibiting NF-κB activation by treatment with Dehydroxymethylepoxyquinomicin effectively prevented increasing the levels IL-1β, IL-17 and nerve growth factor. The data indicated that DINP and/or formaldehyde exposure promoted neuroinflammation in the brain through enhanced oxidative stress and activation of NF-κB in a mouse asthma model.

para-Aminothiophenol Radical Reaction-Functionalized Gold Nanoprobe for One-to-All Detection of Five Reactive Oxygen Species In Vivo

Five major reactive oxygen species (ROS) are generated in diseases including H₂O₂, ^•OH, O₂^•-, ROO^•, and ¹O₂. Simultaneous detection of the five ROS with a single probe is crucial for a comprehensive understanding of the development and progression of many diseases, such as cancer and inflammatory diseases. However, currently reported detection systems are limited by targeting one ROS with one probe. This one-to-one detection mode may fail to sufficiently unveil the diseased state. In this study, we achieved simultaneous detection of all the five ROS with one probe (i.e., one-to-all detection), by designing a novel para-aminothiophenol (PATP) and hemin-decorated gold (Au/PATP/Hemin) nanoprobe. The design is principled by our discovery that PATP can react with ^•OH, O₂^•-, ROO^•, and ¹O₂ by a radical oxidative coupling mechanism to form 4,4'-dimercaptoazobenzene (DMAB). The DMAB then elicited strong characteristic surface-enhanced Raman scattering (SERS) peaks at 1142, 1386, and 1432 cm^-1; which in turn enables direct detection of ^•OH, O₂^•-, ROO^•, and ¹O₂ and indirect detection of H₂O₂ by hemin-catalyzed fenton reaction to convert H₂O₂ into ^•OH. In two representative ROS-elevated mice models of tumors and allergic dermatitis, the Au/PATP/Hemin nanoprobe demonstrated its robust performance of monitoring tumor development and inflammation progression in a highly sensitive and quantitative manner.

Exposure to a combination of formaldehyde and DINP aggravated asthma-like pathology through oxidative stress and NF-κB activation

Several epidemiological and experimental studies indicate a positive association between exposure to formaldehyde or phthalates and allergic asthma. However, nothing is yet known about the effects of exposure to formaldehyde and phthalates together, nor the role of each on allergic asthma. Here, we investigated the effects of a combined exposure to formaldehyde and diisononyl phthalate (DINP) on asthma-like pathology in mice, and determined the underlying mechanisms implicated in NF-κB and ROS. Mice were exposed to formaldehyde and/or DINP and sensitization with OVA. The results showed that exposure to 1.0 mg/m³ formaldehyde or 20 mg/kg·d DINP slightly aggravated the airway wall remodeling, promoted the production of IgE and IgG1, and induced the occurrence of airway hyperresponsiveness (AHR). However, these pathological responses and AHR were greatly exacerbated by the combined exposure to formaldehyde and DINP. Administering melatonin to block oxidative stress, alleviated the pathological responses and AHR induced by formaldehyde and DINP, and inhibited the activation of the NF-κB and the secretion of TSLP. Blocking NF-κB with Dehydroxymethylepoxyquinimicin, inhibited the elevation of TSLP expression and Th2/Th17 cytokine secretion, and effectively alleviated the allergic asthma-like symptoms. The results suggested that exposure to both formaldehyde and DINP aggravated hypersensitivity asthma symptoms by promoting oxidative stress and activating NF-κB. These findings expand our understanding of how formaldehyde and DINP exposure affect the development of allergic asthma.

Associations of urinary phthalate metabolites and lipid peroxidation with sperm mitochondrial DNA copy number and deletions

BACKGROUND

Phthalates, a chemical class of plasticizers, are ubiquitous environmental contaminants that have been associated with oxidative stress. Mitochondria DNA copy number (mtDNAcn) and DNA deletions (mtDNAdel) are emerging biomarkers for cellular oxidative stress and environment exposures.

OBJECTIVES

To examine associations of urinary phthalate metabolite and isoprostane concentrations on sperm mtDNAcn and mtDNAdel in male partners undergoing assisted reproductive technologies (ART).

METHODS

Ninety-nine sperm samples were collected from male partners undergoing ART at Baystate Medical Center in Springfield, MA as part of the Sperm Environmental Epigenetics and Development Study (SEEDS). Seventeen urinary phthalate metabolite concentrations were analyzed by the Centers for Disease Control using tandem mass spectrometry. Urinary 15-F2t-isoprostane concentrations, a biomarker of lipid peroxidation, were measured using a competitive enzyme-linked immunosorbent assay. A triplex qPCR method was used to determine the relative quantification of mtDNAcn and mtDNAdel.

RESULTS

Sperm mtDNAcn and mtDNAdel were positively correlated (Spearman rho = 0.31; p = .002). Adjusting for age, BMI, current smoking, race, and measurement batch, urinary monocarboxy-isononyl phthalate (MCNP) concentrations were positively associated with mtDNAcn (β = 1.63, 95% CI: 0.14, 3.11). Other urinary phthalate metabolite and isoprostane concentrations were not associated with sperm mtDNAcn or mtDNAdel.

CONCLUSIONS

Among this cohort of male ART participants, those with higher MCNP had higher mtDNAcn; other phthalate metabolites and isoprostane were not associated with mtDNAcn and mtDNAdel. Given our relatively small sample size, our results should be interpreted with caution. Future research is needed to replicate the findings in larger studies and among sperm samples obtained from the general population.

Exposure to diisodecyl phthalate exacerbated Th2 and Th17-mediated asthma through aggravating oxidative stress and the activation of p38 MAPK

Diisodecyl phthalate (DIDP) is considered to be one of the less toxic phthalates. However epidemiological studies suggest that DIDP is associated with the occurrence of asthma. The effect of DIDP exposure on allergic asthma and the underlying mechanism have not been fully elucidated. Here, mice were exposed to DIDP and sensitization with OVA. The results demonstrated that DIDP exposure aggravated allergic asthma. Exposure to 15 mg/kg/day DIDP markedly exacerbated airway remodeling and promoted airway hyperresponsiveness (AhR). The study suggests that exposure to DIDP not only promotes a predominant Th2 response, but also induces Th17-type immunity. The induced allergic asthma was accompanied by elevation of IgE, an increase in TSLP expression and exacerbation of oxidative stress. Inhibition of oxidative stress by Vitamin E effectively alleviated the airway remodeling and AhR induced by DIDP and OVA sensitization. Treatment with Vitamin E inhibited the Th2 response and the production of TSLP. Blocking the activation of p38 MAPK by SB203580 prevented elevation of IL-1β and IL-17A induced by DIDP and OVA sensitization and effectively alleviated Th17 type asthmatic lesions. These results suggest that exposure to DIDP exacerbates the Th2 and Th17 response through aggravating oxidative stress and activation of the p38 MAPK pathway.