Benzophenone-2 Concentration and Its Effect on Oxidative Stress and Apoptosis Markers in Rat Brain

UV filter benzophenone-2: Effects on zebrafish (Danio rerio) cytochrome P450

Benzophenone-2 (2,2', 4,4'- Tetrahydroxybenzophenone; BP-2) is widely used as a sunscreen in Personal and Care Products (PCPs) for protection against ultraviolet (UV) radiation. The effects of BP-2 on random-sex adult zebrafish (Danio rerio) cytochrome P450 (CYP450) were studied. The main goal was to investigate the detoxification mechanisms underlying the adverse consequences of exposure to xenobiotic chemicals such as BP-2. Total protein content, CYP450 content, and erythromycin N-demethylase (ERND) activity were evaluated as indicators of protein CYP3A expression. Five sets of pooled random-sex adult zebrafish were exposed to 0.0, 0.1, 5.0, and 10.0 mg/L of BP-2 to evaluate their acute and chronic toxicity (4 and 15 days, respectively). ERND activity was significantly increased in the chronic toxicity group compared to that in the control group, whereas CYP450 remained unchanged. The results suggest a sufficiently fast catalytic process that does not alter the total CYP450 content. It implies a mediation of CYP450 3A induction by BP-2 and the pregnane X receptor ligand-binding domain (PXR LBD) interaction. Ligand-protein interactions were confirmed via in silico docking with AutoDock Vina. Further computational studies indicate BP-2 potential binding affinity for the Estrogen receptor alpha ligand binding domain (ERα LBD). These results suggest that CYPs effects may result in significant toxicity in the zebrafish. Our study highlights the importance of studying biomarkers in aquatic organisms to assess xenobiotic exposure and the potential toxicity of UV filters to humans.

A review of sources, pathways, and toxic effects of human exposure to benzophenone ultraviolet light filters

Benzophenone ultraviolet light filters (BPs) are high-production-volume chemicals extensively used in personal care products, leading to widespread human exposure. Given their estrogenic properties, the potential health risks associated with exposure to BPs have become a public health concern. This review aims to summarize sources and pathways of exposure to BPs and associated health risks. Dermal exposure, primarily through the use of sunscreens, constitutes a major pathway for BP exposure. At a recommended application rate, dermal exposure of BP-3 via the application of sunscreens may reach or exceed the suggested reference dose. Other exposure pathways to BPs, such as drinking water, seafood, and packaged foods, contribute minimal to the overall dose. Inhalation is a minor pathway of exposure; however, its contribution cannot be ignored. Human exposure to BPs is an order of magnitude higher in North America than in Asia and Europe. Studies conducted on laboratory animals and cells have consistently demonstrated the toxic effects of BP exposure. BPs are estrogenic and elicit reproductive and developmental toxicities. Furthermore, neurotoxicity, hepatotoxicity, nephrotoxicity, and carcinogenicity have been reported from chronic BP exposure. In addition to animal and cell studies, epidemiological investigations have identified associations between BPs and couples' fecundity and other reproductive disorders, as well as adverse birth outcomes. Further studies are urgently needed to understand the risks posed by BPs on human health.

Benzophenone-2 exerts reproductive toxicity in male rats

Benzophenone derivatives such as benzophenone-2 (BP-2) belong to the group of endocrine disrupting compounds (EDCs). Increased exposure to EDCs is considered to be an important factor behind the decline of human fertility. The main aim of the present study was to determine the effect of BP-2 on testicular function specified by sperm analysis, the level of sex hormones and their receptors. Since BP-2 has been shown to activate the immune system, another aim of the research was to verify the hypothesis that the immune system may be contributing to the testis toxicity of this compound and for this purpose changes in macrophage and lymphocyte populations in the testes were determined. BP-2 at a dose of 100 mg/kg was administered dermally, twice daily at a dose of 100 mg/kg for 4-weeks. It was shown that BP-2 reduced the number and motility of sperm and increased the number of sperm showing morphological changes. By determining the concentration of sex hormones, a significant decrease in testosterone levels and an increase in the blood levels of 17β-estradiol were demonstrated. Similar to the results obtained from the blood samples, testosterone levels in the testes were lowered, which could affect sperm parameters. The effect of BP-2 on lowering testosterone levels and the number of sperm cells may be due to immunoactivation in the testes, because it has been detected that this compound significantly decreased the number of the immunosuppressive resident testicular macrophages (TMs) (CD68-CD163+), but increased pro-inflammatory TMs with monocyte-like properties (CD68+CD163-).

Benzophenones alter autophagy and ER stress gene expression in pancreatic beta cells in vitro

Benzophenones (BPs) are endocrine disruptors frequently used in sunscreens and food packaging as UV blockers. Our goal was to assess the effect of benzophenone 2 (BP2) and 3 (BP3) on gene expression related to autophagy process and ER stress response in pancreatic beta cells. To that end, the mouse pancreatic beta cell line MIN6B1 was treated with 10 µM BP2 or BP3 in the presence or absence of the autophagy-inhibitor chloroquine (CQ, 10 µM) or the autophagy-inducer rapamycin (RAPA, 50 nM) during 24 h. BP3 inhibited the expression of the autophagic gene Ulk1, and additional effects were uncovered when autophagy was modified by CQ and RAPA. BP3 counteracted CQ-induced Lamp2 expression but did not compensate CQ-induced Sqstm1/p62 gene transcription, neither BP2. Nevertheless, the BPs did not alter the autophagic flux. In relation to ER stress, BP3 inhibited unspliced and spliced Xbp1 mRNA levels in the presence or absence of CQ, totally counteracted CQ-induced Chop gene expression, and partially reverted CQ-induced Grp78/Bip mRNA levels, while BP2 also partially inhibited Grp78/Bip mRNA induction by CQ. In conclusion, BPs, principally BP3, affect cellular adaptive responses related to autophagy, lysosomal biogenesis, and ER stress in pancreatic beta cells, indicating that BP exposure could lead to beta cell dysfunction.

Determining the trace-level photoinitiators in juices and milk from various types of packages in Taiwan by a micro-QuEChERS-based UPLC-MS/MS

The distribution of 16 photoinitiators (PIs)-benzophenone (BP) and its five derivatives, 4-methylbenzophenone (4-MBP), methyl-2-benzoylbenzoate (M2BB), 2-ethylhexyl-4-dimethylaminobenzoate (EHDAB), and the other 7 PIs-in packaged juice and milk was assessed using an UPLC-MS/MS with micro-QuEChERS. The validated method demonstrated robust linearity (≥0.9908), LOQs (juice: 0.006-7.26 ng/mL; milk: 0.004-7.14 ng/mL), intra- and inter-day accuracy (93.1%-110.1% for juice and 66.8%-114.6% for milk with relative standard deviations (RSDs) of ≤16.8%), and matrix effect with RSDs of ≤14.8%. BP exceeded the LOQ in 100% of 136 packaged juice (14.22 ± 7.60 ng/mL) and 51 milk (8.45 ± 3.25 ng/mL) samples, and the quantitation rates for M2BB and EHDAB in packaged juice were 100%. Notably, the 4-MBP in both juice and milk was significantly related to the packaging material. The method has been successfully applied to evaluate the occurrence and distribution of PIs in packaged juice and milk.

Effect of Benzophenone-3 to Acetylcholinesterase and Antioxidant System in Zebrafish (Danio rerio) Embryos

Benzophenone-3 (BP-3) is one of the most used UV filters. The present study aimed to evaluate the toxic effects of BP-3 during embryo stages of zebrafish four hours post-fertilization (4hpf). Embryos were exposed to 0, 1, and 10 µg L^-1 of BP-3 for 72 h. We investigated biochemical and molecular biomarkers of neurotoxicity (AChE) and the antioxidant system (gene expression of catalase, CAT, superoxide dismutase, SOD, glutathione peroxidase, GPX, the concentration of total glutathione, GSH, and lipid hydroperoxides, LPO). Results indicated that the acute exposure to BP-3 in zebrafish embryos did not show significant differences in survival, hatching rate, or antioxidant system biomarkers. In contrast, there were significant differences associated with AChE gene expression and activity.

Characteristics of exposure to multiple environmental chemicals among pregnant women in Wuhan, China

BACKGROUND

Previous studies on environmental pollutant exposure during pregnancy have mostly focused on individual chemical substances or single urine measurements. Thus, our understanding of the potential cumulative or interactive effects of exposure is limited.

OBJECTIVE

We aimed to ascertain the characteristics and predictors of exposure to environmental chemicals over three trimesters among pregnant women.

METHODS

We measured the concentrations of 34 chemicals in spot urine samples provided by 745 participants in their early, middle, and late pregnancy. We calculated Spearman correlation coefficients (SCC) between exposure levels of multiple chemicals in each trimester. K-means clustering and principal components analysis (PCA) were applied to classify the populations and reduce data dimensionality. We used generalized linear models (GLM) to confirm predictors of each cluster and principal component.

RESULTS

SCC showed that the correlations of chemical concentrations from the same classes were higher than those among concentrations of different classes. Cluster analysis categorized participants into three clusters, and each cluster represented different chemical concentrations. We restricted the principal components to six, which explained more than 50% of the data variations. Several physiological, socio-demographic factors, and behavior patterns were related to different clusters and principal components.

CONCLUSION

Distinct exposure patterns and dominant exposure components of multiple environmental chemicals among pregnant women might help research the potential health effects of exposure to chemical mixtures and develop relevant public health interventions.

Protective Effect of Vitamin D3 Against Pb-Induced Neurotoxicity by Regulating the Nrf2 and NF-κB Pathways

Lead (Pb) is a known toxic heavy metal which accumulates in different tissues and causes oxidative stress (OS) and inflammation. The brain tissue is considered as one of the most vulnerable organs to the Pb-induced toxicity. The aim of this study was to investigate the therapeutic effects of vitamin D3 (VD) supplementation against the damages caused by chronic Pb toxicity in the cerebral cortex. Forty Wistar rats were divided into four equal groups and were treated as follows: control group received no treatment, VD group received 1000 IU/kg of VD by intramuscular injection every other day, Pb group received 1000 mg/L of Pb in drinking water, and Pb + VD group received VD and Pb simultaneously. The experiment lasted for 4 weeks and the analyses were conducted 24 h after the last administrations. The obtained results demonstrated that Pb significantly increased cortical lipid peroxidation and reactive oxygen species (ROS) levels. At the same time, there was a significant reduction in glutathione (GSH) content, catalase (CAT), and superoxide dismutase (SOD) activities, as well as a significant increase in the tissue level of inflammatory cytokines. Furthermore, Pb increased the messenger RNA (mRNA) expression level of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB). Anyhow, VD administration during the period of Pb exposure suppressed the OS and inflammation by increasing the antioxidant molecules and decreasing the inflammatory cytokines and consequently repaired Pb-induced cortical tissue damages. Remarkably, these responses were concomitant with the alterations in Nrf2 and NF-κB gene expressions. In conclusion, the present study discloses the potential protective effects for VD against Pb-induced neurotoxicity via anti-inflammatory and antioxidative mechanisms.