An investigation into bisphenol A leaching from materials used intraorally

Commercially available mouthguards: Unearthing trace elements for the first time

The use of mouthguards is advocated by the American Dental Association for orofacial injury prevention and teeth protection. However, the chemical environment in the mouth may cause harmful substances within the mouthguard's polymer material to leach out and be absorbed by the user. Considering this, the present study for the first time analyzed commercially available mouthguards and disclosed the presence of trace elements. Specifically, an analytical method was developed based on closed-vessel microwave-assisted digestion and plasma-based atomic spectrometry for determining toxic trace elements in mouthguard samples. Initially, 75 elements were assessed and, thereafter, quantified cadmium (Cd), copper (Cu) and lead (Pb) in each sample by inductively coupled plasma mass spectrometry (ICP-MS). Method validation was carried out by analyzing a certified reference material of Low-Density Polyethylene, and by addition and recovery experiments. Results for copper were further validated by ICP optical emission spectrometry (ICP-OES). While most samples exhibited elemental levels beneath the method's limit of quantification, Cd, Cu and Pb were detected in four samples. Remarkably, one sample had Cu levels exceeding safe limits by 109 times, highlighting potential toxicity risks. This initial research underscores the need for stricter contamination control in mouthguard materials to minimize potentially health hazards.

Comprehensive investigation of hepatotoxicity of the mixture containing phthalates and bisphenol A

Connections between the mixture containing bis(2- ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and bisphenol A (BPA) and liver injury were explored through in silico investigation and 2 in vivo models. Comparative Toxicogenomics Database (CTD), ShinyGO, ToppCluster and Cytoscape were used for bioinformatic analysis. In vivo subacute study was performed on rats - five groups (n = 6): (1) Control: corn oil, (2) DEHP: 50 mg/kg b.w./day, (3) DBP: 50 mg/kg b.w./day, (4) BPA: 25 mg/kg b.w./day, (5) MIX: DEHP + DBP + BPA. Zebrafish embryos were exposed to the investigated substances in different doses, singularly and combined (binary and ternary mixtures). Liver injury was linked to 75 DEHP, DBP, and BPA genes, mostly connected to inflammation/oxidative stress. In rats, significant alterations in redox status/bioelements and pathohistology were most notable or exclusively present in MIX (probable additive effects). BPA decreased liver area (LA) index in dose-dependent manner. DEHP (< 2 µg/mL) and DBP (≤ 5 µg/mL) reduced LA values, while their higher doses increased LA index. The effect of DBP in binary mixtures led to a lethal outcome at the two highest concentrations, while the hepatotoxicity of DEHP/DBP/BPA mixture was dictated by BPA (confirmed by the benchmark dose analysis).

Pierre Robin Sequence and 3D Printed Personalized Composite Appliances in Interdisciplinary Approach

This paper introduces a complex novel concept and methodology for the creation of personalized biomedical appliances 3D-printed from certified biocompatible photopolymer resin Dental LT Clear (V2). The explained workflow includes intraoral and CT scanning, patient virtualization, digital appliance design, additive manufacturing, and clinical application with evaluation of the appliance intended for patients with cranio-facial syndromes. The presented concept defines virtual 3D fusion of intraoral optical scan and segmented CT as sufficient and accurate data defining the 3D surface of the face, intraoral and airway morphology necessary for the 3D design of complex personalized intraoral and extraoral parts of the orthopedic appliance. A central aspect of the concept is a feasible utilization of composite resin for biomedical prototyping of the sequence of marginally different appliances necessary to keep the pace with the patient rapid growth. Affordability, noninvasiveness, and practicality of the appliance update process shall be highlighted. The methodology is demonstrated on a particular case of two-year-old infant with Pierre Robin sequence. Materialization by additive manufacturing of this photopolymer provides a highly durable and resistant-to-fracture two-part appliance similar to a Tübingen palatal plate, for example. The paper concludes with the viability of the described method and material upon interdisciplinary clinical evaluation of experts from departments of orthodontics and cleft anomalies, pediatric pneumology and phthisiology, and pediatric otorhinolaryngology.

Concentrations of bisphenol a (BPA) in fresh pork loin meat under standard stock-farming conditions and after oral exposure - A preliminary study

Bisphenol A (BPA) is a substance commonly used in the production of plastics. It may be leached from plastics, penetrate to food and has multidirectional negative effects on living organisms. The aim of this study was to evaluate BPA levels in fresh pork meat collected immediately after the death of animals kept in standard stock-farming conditions, as well as from animals receiving various oral doses of BPA (0.05 mg/kg body weight (b.w.)/day and 0.5 mg/kg b. w./day). In animals kept in standard conditions, the average concentration of BPA in loin meat amounted to 37.03 ± 6.18 ng/g dry weight (d.w.). In animals receiving lower and higher doses of BPA, this value achieved 47.44 ± 4.39 ng/g d. w. and 214.30 ± 66.73 ng/g d. w, respectively. The results show that pork meat may be a source of BPA in human food and the presence of BPA in the meat may result from the exposure of animals over their lifetime. This observation shows that the elimination of BPA from the production of items used for animal husbandry and animal feed may reduce meat contaminated with this substance and, therefore, increase consumer safety.

Influence of BPA exposure, measured in saliva, on childhood weight

INTRODUCTION

Endocrine disruptors such as bisphenol A (BPA), BPA glycidyl methacrylate, and other BPA acrylate-based derivatives have been related to type 2 diabetes, the metabolic syndrome, and obesity, among other metabolic disorders. The objective of this study is to examine the influence of BPA exposure by saliva analysis and daily physical activity on the risk of overweight/obesity in schoolchildren from southern Spain.

METHODS

The study included 300 children (53.5% girls) aged 7-10 years. Participants completed a questionnaire with four sections: participant data, including demographic information and life and family habits; semi-quantitative food frequency questionnaire; anthropometric variables; and physical activity variables. All participants underwent dental examination, when the presence of sealants/composites in each tooth and other dental alterations was recorded, and samples of whole saliva were collected for UHPLC-MS/MS analyses.

RESULTS

Risk of overweight/obesity was significantly influenced by body fat composition (OR = 10.77), not walking to and from school (OR = 1.38), lesser energy expenditure in sedentary activities (OR = 12.71), greater energy expenditure in sports (OR =1.62), and exposure to BPA from dental sealants/composites (OR = 1.38; p = 0.058).

DISCUSSION

Further research is warranted on this issue in children, who may be especially vulnerable to the negative health effects of endocrine disruption.

Integrating in silico with in vivo approach to investigate phthalate and bisphenol A mixture-linked asthma development: Positive probiotic intervention

The aim of this study was to explore the mechanisms of bis(2- ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and bisphenol A (BPA) mixture-induced asthma development and test probiotic as a potential positive intervention. Comparative Toxicogenomics Database (CTD) and ToppGene Suite were used as the main tools for in silico analysis. In vivo 28-day experiment was conducted on rats - seven groups (n = 6): (1) Control: corn oil, (2) P: probiotic (8.78 * 10⁸ CFU/kg/day); (3) DEHP: 50 mg/kg b.w./day, (4) DBP: 50 mg/kg b.w./day, (5) BPA: 25 mg/kg b.w./day; (6) MIX: DEHP + DBP + BPA; (7) MIX + P. Lungs, thymus and kidneys were extracted and prepared for redox status and essential metals analysis. By conducting additional in vitro experiment, probiotic phthalate and BPA binding ability was explored. There were 24 DEHP, DBP and BPA asthma-related genes, indicating the three most probable mechanisms - apoptosis, inflammation and oxidative stress. In vivo experiment confirmed that significant changes in redox status/essential metal parameters were either prominent, or only present in the MIX group, indicating possible additive effects. In vitro experiment confirmed the ability of the multy-strain probiotic to bind DEHP/DBP/BPA mixture, while probiotic administration ameliorated mixture-induced changes in rat tissue.

Rutin prevents cardiac oxidative stress and inflammation induced by bisphenol A and dibutyl phthalate exposure via NRF-2/NF-κB pathway

AIM

Environmental pollutants such as plastic-component substances (phthalates and bisphenol A) that coexist in natural ecosystems have been linked to an increase in the occurrence of human health hazards, particularly cardiovascular health. This study was designed to investigate single and combined cardio-toxic effects of dibutyl phthalate and bisphenol-A and the possible interventional role of rutin.

MATERIALS AND METHODS

Forty-two rats were randomized into 7 groups of 6 animals each and were treated as follows for 28 days: Control (0.1% DMSO), Bisphenol-A (BPA, 25 mg/kg, p.o), Dibutyl phthalate (DBP, 25 mg/kg, p.o), BPA + Rutin (25 mg/kg, Rt 50 mg/kg), DBP + Rt (25 mg/kg, Rt 50 mg/kg), BPA + DBP, BPA + DBP + Rt. Cardiac lipid peroxidation, antioxidants and inflammatory markers activities were measured.

KEY FINDINGS

The result showed that BPA reduced the superoxide dismutase (SOD) activity, DBP and DBP+ BPA reduced the catalase (CAT) activity, DBP reduced glutathione (GSH) and nuclear factor erythroid 2-related factor 2 (Nrf2) while malondialdehyde (MDA) increased in DBP + BPA group. Also, DBP increased tissue C-reactive protein (CRP); DBP, DBP + BPA increased tissue nuclear factor kappa B (NF-κB); DBP + BPA increased plasma CRP; BPA increased plasma NF-κB. However, rutin efficiently reduced MDA level, CRP and NF-κB; increasing SOD, GSH and Nrf2 levels in DBP and BPA exposed rats.

SIGNIFICANCE

These results revealed that bisphenol and dibutyl phthalate exposure caused oxidative stress and inflammation in the heart through Nrf2/NF-κB signaling pathway while oral administration of rutin prevents these effects via upregulation of Nrf2 and suppression of NF-κB signaling pathway.

Probiotic reduced the impact of phthalates and bisphenol A mixture on type 2 diabetes mellitus development: Merging bioinformatics with in vivo analysis

Linkage between bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and bisphenol A (BPA) co-exposure and type 2 diabetes mellitus (T2DM), as well as ability of multi-strained probiotic to reduce DEHP, DBP and BPA mixture-induced oxidative damage in rat pancreas were investigated. The Comparative Toxicogenomics Database, Cytoscape software and ToppGene Suite were used for data-mining. Animals were sorted into seven groups (n = 6): (1) Control group: corn oil, (2) P: probiotic: Saccharomyces boulardii + Lactobacillus rhamnosus + Lactobacillus plantarum LP 6595 + Lactobacillus plantarum HEAL9; (3) DEHP: 50 mg/kg b.w./day, (4) DBP: 50 mg/kg b.w./day, (5) BPA: 25 mg/kg b.w./day, and (6) MIX: 50 mg/kg b.w./day DEHP + 50 mg/kg b.w/day DBP + 25 mg/kg b.w./day BPA; (7) MIX + P. Rats were sacrificed after 28 days of oral exposure. In silico investigation highlighted 44 DEHP, DBP and BPA mutual genes linked to the T2DM, while apoptosis and oxidative stress were highlighted as the main mechanisms of DEHP, DBP and BPA mixture-linked T2DM. In vivo experiment confirmed the presence of significant changes in redox status parameters (TOS, SOD and SH groups) only in the MIX group, indicating possible additive effects, while probiotic ameliorated mixture-induced redox status changes in rat pancreatic tissue.

Multi-strain probiotic ameliorated toxic effects of phthalates and bisphenol A mixture in Wistar rats

Phthalates and bisphenol A, to which people are mainly exposed through food, interfere with the body's endocrine system, along with various other toxic effects. Literature data suggest that probiotic cultures might be able to decrease the adverse effects of toxic substances by various mechanisms. The aim of this study was to investigate if treatment with multi-strained probiotic could reduce the toxicity of phthalates and bisphenol A mixture in Wistar rats. Animals were divided into four experimental groups (n = 6): (1) Control (corn oil); (2) P (probiotic (8.78 * 10⁸ CFU/kg/day): Saccharomyces boulardii + Lactobacillus rhamnosus + Lactobacillus planarum LP 6595+ Lactobacillus planarum HEAL9); (3) MIX (50 mg/kg b.w./day DEHP + 50 mg/kg b.w/day DBP + 25 mg/kg b.w./day BPA); (4) MIX + P. Animals were euthanized after 28 days of daily oral gavage treatment; blood and organs were collected for further analysis. Probiotic reduced systemic inflammation and had protective effects on liver, kidneys, spleen, lipid status and serum glucose level. It almost completely annulled the changes in biochemical, hematological and hormonal parameters and mitigated changes in relative liver size, food consumption and organ histology. These results suggest considering multi-strained probiotics as a dietary therapeutic strategy against toxicity of the investigated mixture.

Suppressive effects of neonatal bisphenol A on the neuroendocrine system

The aim of this study was to assess the effects of neonatal bisphenol A (BPA) administration on neuroendocrine features (the thyroid–brain axis). BPA (20 or 40 µg/kg) was orally administered to juvenile male albino rats ( Rattus norvegicus) from postnatal days (PNDs) 15 to 30. Both doses resulted in lower serum thyroxine (T4), triiodothyronine (T3), and growth hormone levels and higher thyrotropin level than the control levels at PND 30. In the neonatal cerebellum and cerebrum, vacuolation, pyknosis, edema, degenerative changes, and reductions in the size and number of the cells were observed in both treated groups. Alternatively, elevations in oxidative markers (lipid peroxidation, nitric oxide, and hydrogen peroxide [H2O2]) at both dose levels were recorded at PND 30, along with decreased activities of antioxidant markers (ascorbic acid, total thiol [t-SH], glutathione, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and catalase) with respect to control levels. Thus, the BPA-induced hypothyroid state may disturb the neonatal thyroid–brain axis via production of free radicals, and this could damage the plasma membrane and cellular components, delaying cerebrum and cerebellum development.