The effect of UV-filters on the viability of neuroblastoma (SH-SY5Y) cell line

Ultraviolet Filters: Dissecting Current Facts and Myths

Skin cancer is a global and increasingly prevalent issue, causing significant individual and economic damage. UV filters in sunscreens play a major role in mitigating the risks that solar ultraviolet ra-diation poses to the human organism. While empirically effective, multiple adverse effects of these compounds are discussed in the media and in scientific research. UV filters are blamed for the dis-ruption of endocrine processes and vitamin D synthesis, damaging effects on the environment, induction of acne and neurotoxic and carcinogenic effects. Some of these allegations are based on scientific facts while others are simply arbitrary. This is especially dangerous considering the risks of exposing unprotected skin to the sun. In summary, UV filters approved by the respective governing bodies are safe for human use and their proven skin cancer-preventing properties make them in-dispensable for sensible sun protection habits. Nonetheless, compounds like octocrylene and ben-zophenone-3 that are linked to the harming of marine ecosystems could be omitted from skin care regimens in favor of the myriad of non-toxic UV filters.

From cradle to grave: Deciphering sex-specific disruptions of the nervous and reproductive systems through interactions of 4-methylbenzylidene camphor and nanoplastics in adult zebrafish

4-methylbenzylidene camphor (4-MBC) and micro/nanoplastics (MNPs) are common in personal care and cosmetic products (PCCPs) and consumer goods; however, they have become pervasive environmental contaminants. MNPs serve as carriers of 4-MBC in both PCCPs and the environment. Our previous study demonstrated that 4-MBC induces estrogenic effects in zebrafish larvae. However, knowledge gaps remain regarding the sex- and tissue-specific accumulation and potential toxicities of chronic coexposure to 4-MBC and MNPs. Herein, adult zebrafish were exposed to environmentally realistic concentrations of 4-MBC (0, 0.4832, and 4832 μg/L), with or without polystyrene nanoplastics (PS-NPs; 50 nm, 1.0 mg/L) for 21 days. Sex-specific accumulation was observed, with higher concentrations in female brains, while males exhibited comparable accumulation in the liver, testes, and brain. Coexposure to PS-NPs intensified the 4-MBC burden in all tested tissues. Dual-omics analysis (transcriptomics and proteomics) revealed dysfunctions in neuronal differentiation, death, and reproduction. 4-MBC-co-PS-NP exposure disrupted the brain histopathology more severely than exposure to 4-MBC alone, inducing sex-specific neurotoxicity and reproductive disruptions. Female zebrafish exhibited autism spectrum disorder-like behavior and disruption of vitellogenesis and oocyte maturation, while male zebrafish showed Parkinson's-like behavior and spermatogenesis disruption. Our findings highlight that PS-NPs enhance tissue accumulation of 4-MBC, leading to sex-specific impairments in the nervous and reproductive systems of zebrafish.

Concentrations, compositional profiles, and health risks of benzophenones among the Taiwanese population based on analysis of 23 daily consumed foods

In this study, we analyzed the occurrence and distribution of 11 benzophenone-type ultraviolet filters (BPs) in 893 food samples spanning 7 food categories in Taiwan. We conducted a Monte Carlo simulation to determine the carcinogenic and noncarcinogenic risks of BPs. The results indicated that cornflakes had the highest mean level of BPs (103 ng/g), followed by bread (101 ng/g) and pastries (59 ng/g). BP was the most prevalent category, followed by 4-methylbenzophenone (4-MBP), 2-hydroxybenzophenone, and benzophenone-3. Estimation of the lifetime cancer risk (LTCR) of BP (average life expectancy of 80 years) placed them in the 50th and 97.5th percentiles [P50 (P97.5)] LTCR of 1.9 × 10-7 (5.7 × 10-6), indicating that BP in food poses a low renal hazard to the Taiwanese population. The noncarcinogenic risk of BPs was evaluated using a hazard quotient and combined margin of exposure (MOET), revealing a P50 (P97.5) hazard index of < 1 for BP, 4-MBP, and methyl-2-benzoylbenzoate. Although the P50 MOET values for all age groups were within the moderate range of concern, with a more conservative extreme (P2.5), the MOET values for the 0-3, 3-6, and 6-12 age groups fell below 100, indicating a high concern for renal degeneration and hyperplasia.

Sunscreen Safety and Efficacy for the Prevention of Cutaneous Neoplasm

Sunscreen is widely used for ultraviolet radiation protection. Studies validate sun protection factors (SPFs) to prevent ultraviolet (UV)-induced skin changes such as melanoma and squamous cell carcinoma (SCC). Few studies examine sunscreen's impact on endocrine and immune system dysregulation, the production of radical oxygen species, and whether the ingredients deteriorate under prolonged exposure. We present an investigation of sunscreen labels and how ingredients impact sun safety and human health. A review of the literature was conducted using Embase and PubMed to examine sunscreen safety, efficacy, and use to prevent UV-induced skin damage. Increasing sunscreen reapplication, wearing protective clothing, and limiting exposure can reduce the incidence of skin cancer. Inorganic sunscreens form barriers to block UV light, but without titanium dioxide (TiO2), they may not be advantageous due to their low UVA protection. Organic sunscreens absorb into the skin and provide a better feeling after application. Octocrylene and avobenzone are stable and provide UVA and UVB protection with minimal adverse effects. Oxybenzone is harmful to the neuroendocrine system and should be avoided. Titanium dioxide works for broad-spectrum UV protection and offers minimal adverse effects. Octocrylene and avobenzone are organic sunscreen ingredients that also provide a better feeling on the skin after application, which enables higher rates of use. Oxybenzone should be avoided.

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.

Mechanism of Microglial Cell Activation in the Benzophenone-3 Exposure Model

Benzophenone-3 (BP-3) is the most commonly used UV filter in cosmetics, which is absorbed through the skin and crosses the blood-brain barrier. This compound increases extracellular glutamate concentrations, lipid peroxidation, the number of microglia cells and induces process of apoptosis. The aim of this study was to determine the effect of BP-3 on the activation and polarization of microglial cells in the frontal cortex and hippocampus of adult male rats exposed to BP-3 prenatally and then for two weeks in adulthood. It has been found, that exposure to BP-3 reduced the expression of the marker of the M2 phenotype of glial cells in both examined brain structures. An increase in the CD86/CD206 microglial phenotype ratio, expression of transcription factor NFκB and activity of caspase-1 were observed only in the frontal cortex, whereas BP-3 increased the level of glucocorticoid receptors in the hippocampus. The in vitro study conducted in the primary culture of rat frontal cortical microglia cells showed that BP-3 increased the LPS-stimulated release of pro-inflammatory cytokines IL-1α, IL-1β, TNFα, but in cultures without LPS there was decreased IL-1α, IL-6 and TNFα production, while the IL-18 and IP-10 was elevated. The obtained results indicate that differences in the level of immunoactivation between the frontal cortex and the hippocampus may result from the action of this compound on glucocorticoid receptors. In turn, changes in cytokine production in microglial cells indicate that BP-3 aggravates the LPS-induced immunoactivation.

Contaminants of emerging concern in urine: a review of analytical methods for determining diisocyanates, benzotriazoles, benzothiazoles, 4-methylbenzylidene camphor, isothiazolinones, fragrances, and non-phthalate plasticizers

Human biomonitoring (HBM) frameworks assess human exposure to hazardous chemicals. In this review, we discuss and summarize sample preparation procedures and analytical methodology for six groups of chemicals of emerging concern (CECs), namely diisocyanates, benzotriazoles, benzothiazoles, 4-methylbenzylidene camphor, isothiazolinones, fragrances, and non-phthalate plasticizers, which are increasingly detected in urine, however, are not yet widely included in HBM schemes, despite posing a risk to human health. The sample preparation procedures depend largely on the chemical group; however, solid-phase extraction (SPE) is most often used due to the minimized sample handling, lower sample volume, and generally achieving lower limits of quantification (LOQs) compared to other extraction techniques. In terms of sample analysis, LC-based methods generally achieve lower limits of quantification (LOQs) compared to GC-based methods for the selected six groups of chemicals owing to their broader chemical coverage. In conclusion, since these chemicals are expected to be more frequently included in future HBM studies, it becomes evident that there is a pressing need for rigorous quality assurance programs to ensure better comparability of data. These programs should include the reporting of measurement uncertainty and facilitate inter-laboratory comparisons among the reporting laboratories. In addition, high-resolution mass spectrometry should be more commonly employed to enhance the specificity and selectivity of the applied analytical methodology since it is underrepresented in HBM. Furthermore, due to the scarcity of data on the levels of these CECs in urine, large population HBM studies are necessary to gain a deeper understanding of the associated risks.

Benzophenone-3: Comprehensive review of the toxicological and human evidence with meta-analysis of human biomonitoring studies

BACKGROUND

Benzophenone-3 (BP-3) and its major metabolite benzophenone-1 (BP-1) are widely used as UV filters in sunscreens and cosmetics to prevent sunburn and skin damage, or as stabilizers to prevent photodegradation in many commercial products. As a result, their presence is ubiquitous in the environment, wildlife and humans. Based on endocrine disruption concerns, international regulatory agencies are performing a closer evaluation.

OBJECTIVE AND METHODS

This work aimed to comprehensively review the available human relevant evidence for safety issues in MEDLINE/PubMed in order to create a structured database of studies, as well as to conduct an integrative analysis as part of the Human Biomonitoring for Europe (HBM4EU) Initiative.

RESULTS

A total of 1,635 titles and abstracts were screened and 254 references were evaluated and tabulated in detail, and classified in different categories: i) exposure sources and predictors; ii) human biomonitoring (HBM) exposure levels to perform a meta-analysis; iii) toxicokinetic data in both experimental animals and humans; iv) in vitro and in vivo rodent toxicity studies; and v) human data on effect biomarkers and health outcomes. Our integrative analysis showed that internal peak BP-3 concentrations achieved after a single whole-body application of a commercially available sunscreen (4% w/w) may overlap with concentrations eliciting endocrine disrupting effects in vitro, and with internal concentrations causing in vivo adverse female reproductive effects in rodents that were supported by still limited human data. The adverse effects in rodents included prolonged estrous cycle, altered uterine estrogen receptor gene expression, endometrium hyperplasia and altered proliferation and histology of the mammary gland, while human data indicated menstrual cycle hormonal alterations and increased risk of uterine fibroids and endometriosis. Among the modes of action reported (estrogenic, anti-androgenic, thyroid, etc.), BP-3 and especially BP-1 showed estrogenic activity at human-relevant concentrations, in agreement with the observed alterations in female reproductive endpoints. The meta-analysis of HBM studies identified a higher concern for North Americans, showing urinary BP-3 concentrations on average 10 and 20 times higher than European and Asian populations, respectively.

DISCUSSION AND CONCLUSIONS

Our work supports that these benzophenones present endocrine disrupting properties, endorsing recent European regulatory efforts to limit human exposure. The reproducible and comprehensive database generated may constitute a point of departure in future risk assessments to support regulatory initiatives. Meanwhile, individuals should not refrain from sunscreen use. Commercially available formulations using inorganic UV filters that are practically not absorbed into systemic circulation may be recommended to susceptible populations.

Human health risk assessment of cinnamate UV absorbers: In vitro and in silico investigations

Organic UV absorbers (UVAs) are contaminants of emerging concern. Environmental persistence and potential toxicological enrichment studies of UVAs have attracted international concern. It is important to study the toxicity mechanism of UVAs. This study is the first to report the toxicological mechanism of two cinnamate UV absorbers (CUVAs), 2-ethyl 4-methoxycinnamate (OMC) and isoamyl 4-methoxycinnamate (IMC) based on cellular models and molecular models. Cellular models demonstrated that the CUVAs-induced apoptosis might be associated with cellular mitochondrial damage pathways. The results of molecular models showed that OMC and IMC could affect the binding between major proteins and enzymes in the mitochondrial damage pathway and contaminants, ultimately leading to apoptosis. The cellular-molecular models showed that IMC and OMC have dose-effect relationships on cytotoxicity. The composite model is more informative than a single model. This study further indicate that UVAs causes toxicology effects that have implications for the environment and human health.

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.

Environmentally relevant concentrations of benzophenones triggered DNA damage and apoptosis in male Chinese rare minnows (Gobiocypris rarus)

Benzophenone-type ultraviolet (UV) filters (BPs) are commonly used as sunscreen agents, fragrance enhancers and plastic additives, and are great threats to aquatic organisms due to their high detected concentrations in the aquatic environment. However, few studies on their toxicity and mechanism in fish have been clearly reported. In this study, Chinese rare minnows (Gobiocypris rarus) were exposed to benzophenone (BP), 2,4-dihydroxybenzophenone (BP-1), and 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid (BP-4) at 5, 50, 500 µg/L for 28 d to assess their toxicity. Transcriptomics screening showed that cell cycle, DNA replication and repair were significantly altered pathways (p < 0.05). The altered transcripts were similar to those identified by RNA-seq. DNA damage and 8-OHdG levels were significantly increased at 50 and 500 μg/L groups (p < 0.05). The DNA methylcytosine level was not significantly changed exposure to BP, BP-1 and BP-4. TUNEL assays indicated that hepatic apoptosis was significantly improved at 500 μg/L BP and BP-4 and 50 and 500 μg/L BP-1 (p < 0.05), with the significantly increasing the activity of caspase-3, -8 and -9 (p < 0.05). Molecular docking analysis revealed that BP, BP-1 and BP-4 could bind differently to caspase-3 through different binding interactions. Therefore, BP-1 induced more serious oxidative DNA damage and apoptosis by activating caspase-3 than BP and BP-4, which will provide theoretical basis and data support for ecological evaluation of aquatic organisms induced by BPs.

UV-filter octyl methoxycinnamate causes reproductive toxicity associated with germline apoptosis and vitellogenin decrease in Caenorhabditis elegans

Octyl methoxycinnamate (OMC) is a common UV filter found in personal care products such as sunscreen and cosmetics. However, OMC's presence in wastewater has raised concerns that it could potentially pollute aquatic ecosystems because of its limited biodegradability and its estrogenic disrupting properties. In this study, we investigated the environmental toxicity of OMC and its potential biomarkers using the nematode Caenorhabditis elegans. Our results showed that body length, eggs in utero, and total brood size decreased with increasing dose (experimental concentrations = 0, 1, 5, 10, 100, 500 μM for body length and eggs in utero, and 0, 5, 10 μM for total brood size) in C. elegans after L1 larval stage (the first larval stage for 0 - 12 hours post-hatching) larval stage exposure to OMC. The minimum effective concentrations were 1, 5, and 10 μM, respectively. Modeling results demonstrated that the threshold concentration of OMC inducing 10% inhibited eggs in utero was 0.33 μM (95.11 μg/L). Furthermore, germline apoptosis was induced in 10 μM OMC-treated worms (experimental concentrations = 0, 5, 10 μM). Decreased mRNA levels of vitellogenin-related genes (vit-2 and vit-6) and increased mRNA levels of apoptosis-related genes (egl-1 and ced-3) were observed in 10 μM OMC-treated C. elegans (experimental concentrations = 0, 10 μM), suggesting that reproductive toxicity was associated with decreased vitellogenin levels and germline apoptosis. In summary, our study shows that OMC is reproductively toxic and leads to reduced egg formation and decreased brood size in C. elegans by reducing vitellogenin levels and promoting germline apoptosis.

Impact of polypropylene microplastics and chemical pollutants on European sea bass (Dicentrarchus labrax) gut microbiota and health

Plastic pollution has become a global problem for marine ecosystems. Microplastics (MPs) are consumed by several marine organisms, including benthic and pelagic fish species that confuse them with food sources, thus contributing to bioaccumulation along the food chain. In addition to structural intestinal damage, ingestion of MPs represents a pathway for fish exposure to potentially hazardous chemicals, too. Most of them are endocrine disrupters, genotoxic or induce immune depression in fish. Accordingly, we assessed the combined toxicological effects of microplastics (MPs) and adsorbed pollutants by adding them to marine fish diet. European sea bass (Dicentrarchus labrax) juveniles were fed for 60 days with feeds containing polypropylene MPs, either virgin or contaminated with chemical pollutants (a blend of dichlorodiphenyldichloroethylene, chlorpyrifos, and benzophenone-3). The data demonstrated a synergic action of MPs and chemical pollutants to induce an inflammatory-like response in distal intestine of sea bass as shown by the up regulation of cytokine il-6 and tnf-α expression. Morphological analysis detected the presence of a focus of lymphocytes in anterior and posterior intestinal segments of fish fed with contaminants in the diet. With regard to microbiota, significant changes in bacterial species richness, beta diversity, and composition of gut microbiota were observed as a consequence of both pollutants and polluted MPs ingestion. These perturbations in gut microbial communities, including the reduction of beneficial lactic acid bacteria and the increase in potential pathogenic microorganism (Proteobacteria and Vibrionales), were undeniable signs of intestinal dysbiosis, which in turn confirmed the signs of inflammation caused by pollutants, especially when combined with MPs. The results obtained in this study provide, therefore, new insights into the potential risks of ingesting MPs as pollutant carriers in marine fish.

Evaluating the Sun Protection Factor of Cosmetic Formulations Containing Afzelin

Exposure to UV radiation damages the skin and increases the risk of skin cancer. Sunscreen is used to protect the skin from the harmful effects of UV radiation. However, the chemical UV filters used in sunscreen can show toxicity and cause allergic reactions. A safe sunscreen that includes a lower content of chemical UV filters and exerts an excellent effect on UV protection needs to be developed. The objective of this study was to investigate whether the addition of afzelin to sunscreen could improve the sun protection factor (SPF). A synergistic effect between afzelin and organic sunscreen agents including padimate O and oxybenzone was confirmed. Interestingly, 100% in vitro SPF-boosting was observed when afzelin (0.05%) was applied with a standard SPF formulation containing organic sunscreens while afzelin alone had no contribution to the SPF. In vivo SPF analysis of the standard SPF formulation showed an SPF value of 13.3 that increased to 20.1 when supplemented with afzelin (0.05%). Additionally, afzelin showed no skin irritation in a human trial. These results suggest that afzelin is useful as a natural additive in sunscreen formulations and provides an SPF-boosting effect. Afzelin supplementation to the formulation showed the potential to reduce the use of synthetic photoprotectors, which could minimize the risk of synthetic agent toxicity.

Endocrine disruptors also function as nervous disruptors and can be renamed endocrine and nervous disruptors (ENDs)

Endocrine disruption (ED) and endocrine disruptors (EDs) emerged as scientific concepts in 1995, after numerous chemical pollutants were found to be responsible for reproductive dysfunction. The World Health Organization established in the United Nations Environment Programme a list of materials, plasticizers, pesticides, and various pollutants synthesized from petrochemistry that impact not only reproduction, but also hormonal functions, directly or indirectly. Cells communicate via either chemical or electrical signals transmitted within the endocrine or nervous systems. To investigate whether hormone disruptors may also interfere directly or indirectly with the development or functioning of the nervous system through either a neuroendocrine or a more general mechanism, we examined the scientific literature to ascertain the effects of EDs on the nervous system, specifically in the categories of neurotoxicity, cognition, and behaviour. To date, we demonstrated that all of the 177 EDs identified internationally by WHO are known to have an impact on the nervous system. Furthermore, the precise mechanisms underlying this neurodisruption have also been established. It was previously believed that EDs primarily function via the thyroid. However, this study presents substantial evidence that approximately 80 % of EDs operate via other mechanisms. It thus outlines a novel concept: EDs are also neurodisruptors (NDs) and can be collectively termed endocrine and nervous disruptors (ENDs). Most of ENDs are derived from petroleum residues, and their various mechanisms of action are similar to those of "spam" in electronic communications technologies. Therefore, ENDs can be considered as an instance of spam in a biological context.

Risks of organic UV filters: a review of environmental and human health concern studies

Organic UV filters are compounds that absorb UV irradiation by their highly conjugated structure. With the developing consciousness over the last century of the skin damage UV radiation can cause, the demand for organic UV filters has risen, for use not only in sunscreens, but also in other personal care products. The massive production and usage of these organic UV filters has resulted in extensive release into the aquatic environment, and thereby making an important group of emerging contaminants. Considering the widespread occurrence of organic UV filters in not only ambient water, but also sediment, soil and even indoor dust, their threats towards the health of living organisms have been a subject of active investigation. In this review article, we present an overall review of existing knowledge on the risks of organic UV filters from the aspects of both environmental and human health impacts. As for the environment, some organic UV filters are proven to bioaccumulate in various kinds of aquatic organisms, and further to have adverse effects on different kinds of animal models. Toxicological studies including in vivo and in vitro studies are important and effective means to ascertain the effects and mechanisms of organic UV filters on both the ecosystem and humans. Subsequent concerns arise that these compounds will affect human health in the long term. This review concludes by suggesting future lines of research based on the remaining knowledge gaps.

UV-Protection Performance of Calophyllum inophyllum Seed Extracts: A Natural Ultraviolet Screening Agent

Demand for sunscreen products has been rising in recent years due to increasing cases of skin damage caused byultraviolet radiation (UVR). Recent studies have proved that some materials in commercial sunscreen products are harmful to the marine ecosystem. Therefore, the development of a photoprotective and environmentally friendly screening agent has been a leading direction for the cosmetic industry. Calophyllum inophyllum is a seaside plant found in the Pacific Rim, regarded as a potential source of biodiesel feedstock given the high oil content of its seeds. Due to the harsh environment of its natural habitat, C. inophyllum has developed UV-absorbing secondary metabolites, which are natural sources for screening agents. In this study, samples of seed extracts of C. inophyllum were subjected to in vitro UV, Fourier-transform infrared (FTIR) spectroscopy, and cytotoxicity analysis; all the samples extracted by solvents of various polarities showed different chemical compositions by FTIR spectroscopy and levels of cytotoxicity. The n-hexane seed extract showed the highest UVA and UVB absorption efficiencies. In the in vitro cytotoxicity test on human skin fibroblast cells, seed oil of C. inophyllum demonstrated low cytotoxicity. Results have shown that seed extracts of C. inophyllum can be an ideal material for a natural high-efficiency screening agent.

Persistent organic pollutants (POPs) and personal care products (PCPs) in the surface sediments of a large tropical bay (Todos os Santos Bay, Brazil)

The occurrence and spatial distribution of persistent organic pollutants (POPs) and personal care products (PCPs) were investigated in surface sediments of Todos os Santos Bay. Samples were Soxhlet-extracted and analyzed by gas chromatography coupled with tandem mass spectrometry. Quantification limits (QL) ranged from 0.0025 ng g^-1 for POPs to 0.25 ng g^-1 for PCPs. Of the POPs studied, only PCBs and DDTs were detectable, with concentrations ranging from <QL to 4.66 ng g^-1, with increased concentrations near urban and industrial areas. PCPs ranged from <QL to 27.5 ng g^-1 and presented a homogeneous spatial distribution, probably related to the continuous inputs of these compounds from diffuse sources. Mean contaminant inventories ranged from 0.33 ± 0.23 ng cm^-2 for DDTs to 8.3 ± 8.4 ng cm^-2 for fragrances. To the best of our knowledge, this is the first study on the occurrence of UV filters in sediments from Brazilian coastal environments.

Environmental relevant concentrations of benzophenone-3 induced developmental neurotoxicity in zebrafish

Benzophenone-3 (BP3 or oxybenzone) is an organic UV filter that has been widely used in personal care products. Its frequent detection in the environment and humans as well as its structural similarity to estradiol have prompted most research focus on its endocrine effect. However, these effects are usually associated with concentrations 10-100 fold higher than its environmental relevant concentrations. Few studies explore its adverse effects at environmental relevant concentrations. In the present study, we evaluated the developmental neurotoxic (DNT) effects of low concentration BP3 exposure during a sensitive developmental window in zebrafish. Our findings revealed that BP3 exposure at 10 μg/L (0.04 μM) during 6-24 h post fertilization (hpf) led to various DNT effects such as increased spontaneous movement at 21 and 24 hpf, decreased touch response at 27 hpf, heightened hyperactivity in locomotor response at 5 day post fertilization (dpf), decreased shoaling behavior at 11 dpf and decreased mirror attacks at 12 dpf. These effects were accompanied with decreased axonal growth at 27 hpf, decreased cell proliferation and increased cell apoptosis in the head region of larval zebrafish immediately after BP3 exposure at 24 hpf, and increased expression of retinoid X receptor gene rxrgb at 5 dpf. Interestingly, rxrgb knockdown through morpholino injection largely restored most of BP3-induced DNT effects, axonal growth delay, cell proliferation and cell apoptosis, suggesting that BP3-induced DNT effects are likely mediated through the Rxrgb receptor. In considering with recent findings on the endocrine effects of BP3, we conclude that BP3 at environmental relevant concentrations has limited estrogenic effect, but is neurotoxic to developing embryos in zebrafish.

Effect of Combined Prenatal and Adult Benzophenone-3 Dermal Exposure on Factors Regulating Neurodegenerative Processes, Blood Hormone Levels, and Hematological Parameters in Female Rats

Benzophenone-3 (BP-3), the most widely used UV chemical filter, is absorbed well through the skin and gastrointestinal tract and can affect some body functions, including the survival of nerve cells. Previously, we showed that BP-3 evoked a neurotoxic effect in male rats, but since the effects of this compound are known to depend on gender, the aim of the present study was to show the concentration and potential neurotoxic action of this compound in the female rat brain. BP-3 was administered dermally to female rats during pregnancy, and then in the 7th and 8th weeks of age to their female offspring. The effect of BP-3 exposure on short-term and spatial memory, its concentrations in blood, the liver, the frontal cortex, and the hippocampus, and the effect on selected markers of brain damage were determined. Also, the impact of BP-3 on sex and thyroid hormone levels in blood and hematological parameters was examined. It has been found that this compound was present in blood and brain structures in females at a lower concentration than in males. BP-3 in both examined brain structures increased extracellular glutamate concentration and enhanced lipid peroxidation, but did not induce the apoptotic process. The tested compound also evoked hyperthyroidism and decreased the blood progesterone level and the number of erythrocytes. The presented data indicated that, after the same exposure to BP-3, this compound was at a lower concentration in the female brain than in that of the males. Although BP-3 did not induce apoptosis in the hippocampus and frontal cortex, the increased extracellular glutamate concentration and lipid peroxidation, as well as impaired spatial memory, suggested that this compound also had adverse effects in the female brain yet was weaker than in males. In contrast to the weaker effects of the BP-3 on females than the brain of males, this compound affected the endocrine system and evoked a disturbance in hematological parameters more strongly than in male rats.

Microbial biotransformation of some novel hydantoin derivatives: Perspectives for bioremediation of potential sunscreen agents

Having identified novel hydantoin derivatives (compounds 1-5) demonstrating promising photoprotective capacity against UV radiation, and understainding the problem of the biotic and abiotic degradation of UV filters, the aim of the study was to evaluate their metabolic fate with the environmental fungus Cunninghamella echinulata. In parallel, compound 1 in vitro microsomal metabolic pattern was evaluated. Finally, in silico toxicity of test compounds and their biotransformation products was estimated, and parent compounds photostability was assessed. The study demonstrated the capacity for C. echinulata to metabolize 1-5, which were biotransformed to a greater extent than the standard UV filter. O-dealkylation of the side chains attached to the phenyl or hydantoin rings, and hydroxylation of the phenyl ring occurred during microbial transformation. O-dealkylation product was a unique metabolite observed in microsomal biotransformation of 1, being its intrinsic clearance in the medium category range. In silico study demonstrated that compounds 1-5 have low toxicity risk. Among the resulting metabolites, four can increase the risk of reproductive effects as shown by OSIRIS prediction. Noteworthy, all indicated metabolites belong to minor metabolites, except for compound 3 major metabolite. Moreover, the results of the photostability study showed that 1-5 were considered to be photostable. To sum up, the obtained in vitro biotransformation, photostability, and in silico toxicity results encourage further studies on hydantoin derivatives as potential UV photoprotective agents. The presented biotransformation profile of compounds 1-5 by C. echinulata suggests that these compounds may follow a similar biodegradation fate when released into the environment.

Discovery of Novel UV-Filters with Favorable Safety Profiles in the 5-Arylideneimidazolidine-2,4-dione Derivatives Group

Effective protection from the harmful effects of UV radiation may be achieved by using sunscreens containing organic or inorganic UV filters. The number of currently available UV filters is limited and some of the allowed molecules possess limitations such as systemic absorption, endocrine disruption properties, contact and photocontact allergy induction, and low photostability. In the search for new organic UV filters we designed and synthesized a series consisting of 5-benzylidene and 5-(3-phenylprop-2-en-1-ylidene)imidazolidine-2,4-dione (hydantoin) derivatives. The photoprotective activity of the tested compounds was confirmed in methanol solutions and macrogol formulations. The most promising compounds possessed similar UV protection parameter values as selected commercially available UV filters. The compound diethyl 2,2'-((Z)-4-((E)-3-(4-methoxyphenyl)allylidene)-2,5-dioxoimidazolidine-1,3-diyl)diacetate (4g) was characterized as an especially efficient UVA photoprotective agent with a UVA PF of 6.83 ± 0.05 and favorable photostability. Diethyl 2,2'-((Z)-4-(4-methoxybenzylidene)-2,5-dioxo- imidazolidine-1,3-diyl)diacetate (3b) was the most promising UVB-filter, with a SPFin vitro of 3.07 ± 0.04 and very good solubility and photostability. The main photodegradation products were geometric isomers of the parent compounds. These compounds were also shown to be non-cytotoxic at concentrations up to 50 µM when tested on three types of human skin cells and possess no estrogenic activity, according to the results of a MCF-7 breast cancer model.

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

Benzophenones, frequently used as UV chemical filters, are absorbed through the skin and can exert systemic adverse effects. So far, most of the data are related to their action on sex hormone receptors whereas potential neurotoxic effect is expected mainly on the basis of in vitro studies. The aim of the present study was to determine concentrations of BP-2, oxidative stress and apoptosis markers in the rat brain after topical administration of this compound. Male Wistar rats were treated dermally with BP-2 (100 mg/kg, 4 weeks), and next, blood and tissue BP-2 concentrations and oxidative stress and apoptotic markers in the frontal cortex and hippocampus were determined. After dermal BP-2 administration, blood level of this compound was about 300 ng/ml while in the liver and adipose tissue 1354 and 823 ng/g wt tissue, respectively. In the studied brain structures, the levels of the test compound were from 5 to 19 ng/g tissue. In the hippocampus, where BP-2 level was about 3.5-fold lower than in the frontal cortex, no significant changes in either oxidative stress and apoptosis markers were observed. There was also no change in apoptosis markers in the frontal cortex but unexpectedly the oxidative stress markers were reduced. The research showed that BP-2 passes through the blood-brain barrier but its concentration in the brain structures are much lower than in the blood. This compound did not exacerbate oxidative stress and apoptosis markers in the hippocampus and frontal cortex, and even lowered oxidative stress in the frontal cortex.

Can oxybenzone cause Hirschsprung's disease?

Oxybenzone is a ultraviolet (UV) absorber used in 70% of sunscreen products, is a recognized endocrine disrupting chemical (EDC) and is small enough to pass through skin and placenta barriers. Numerous studies have identified this chemical in the urine/blood of pregnant women as well as in fetal and umbilical cord blood. A recent study demonstrated that women with medium to high levels of oxybenzone in their urine was associated with giving birth to neonates with Hirschsprung's Disease (HSCR). Testing in human cell lines confirmed that low levels of oxybenzone has the potential to disrupt cell migration and function in a manner similar to what is associated with HSCR. Analysis of human exposure levels to oxybenzone from sunscreen use, under normal conditions, demonstrates that enough chemical can cross into the mother's blood making it available to the fetus at high enough levels that can indeed inhibit migration of neural crest cells during critical embryonic development.

Prenatal exposure to benzophenone-3 (BP-3) induces apoptosis, disrupts estrogen receptor expression and alters the epigenetic status of mouse neurons

Current evidence indicates that benzophenone-3 (BP-3) can pass through the placental and blood-brain barriers and thus can likely affect infant neurodevelopment. Despite widespread exposure, data showing the effects of BP-3 on the developing nervous system are scarce. This study revealed for the first time that prenatal exposure to BP-3 led to apoptosis and neurotoxicity, altered the levels of estrogen receptors (ERs) and changed the epigenetic status of mouse neurons. In the present study, subcutaneous injections of pregnant mice with BP-3 at 50 mg/kg, which is an environmentally relevant dose, evoked activation of caspase-3 and lactate dehydrogenase (LDH) release as well as substantial loss of mitochondrial membrane potential in neocortical cells of their embryonic offspring. Apoptosis-focused microarray analysis of neocortical cells revealed up-regulation of 22 genes involved in apoptotic cell death. This effect was supported by increased BAX and CASP3 mRNA and protein levels, as evidenced by qPCR, ELISAs and western blots. BP-3-induced apoptosis and neurotoxicity were accompanied by decreases in the mRNA and protein expression levels of ESR1 and ESR2 (also known as ERα and ERβ), with a simultaneous increase in GPER1 (also known as GPR30) expression. In addition to the demonstration that treatment of pregnant mice with BP-3 induced apoptosis, caused neurotoxicity and altered ERs expression levels in neocortical cells of their embryonic offspring, we showed that prenatal administration of BP-3 inhibited global DNA methylation as well as reduced DNMTs activity. BP-3 also caused specific hypomethylation of the genes Gper1 and Bax, an effect that was accompanied by increased mRNA and protein expression levels. In addition, BP-3 caused hypermethylation of the genes Esr1, Esr2 and Bcl2, which could explain the reduced mRNA and protein levels of the estrogen receptors. This study demonstrated for the first time that prenatal exposure to BP-3 caused severe neuronal apoptosis that was accompanied by impaired ESR1/ESR2 expression, enhanced GPER1 expression, global DNA hypomethylation and altered methylation statuses of apoptosis-related and ERs genes. We suggest that the effects of BP-3 in embryonic neurons may be the fetal basis of the adult onset of nervous system disease.

Effects of UV filter 4-methylbenzylidene camphor during early development of Solea senegalensis Kaup, 1858

The inclusion of organic UV filters in personal care products (PCPs) has increased in recent years. 4-Methylbenzylidene camphor (4MBC) is one of the most used UV filters, and thus it is commonly found in aquatic ecosystems, with proved negative effects on aquatic organisms. Effects on early life stages of marine vertebrates are largely unknown. Therefore, the main goal of this work was to evaluate 4MBC effects on Senegalese sole (Solea Senegalensis Kaup, 1858) larvae at different levels of biological organization. S. senegalensis were exposed to increasing concentrations of 4MBC from egg stage until 96 h. Mortality, growth, malformations, behaviour and biochemical responses, including enzymatic biomarkers were studied. The exposure to 4MBC until 96 h post-fertilization (hpf) induced mortality and malformations in a dose-response manner. Besides, reduced growth with increasing concentrations was observed. The exposure to 4MBC also caused alterations on behaviour, including overall lower swimming time during light and dark periods. Biomarker alterations caused by 4MBC included imbalance of neurotransmission related endpoints (increased acetylcholinesterase activity) and decreased activity of enzymes related to anaerobic metabolism (lower cellular lactate dehydrogenase activity) at the lower concentrations tested. Furthermore, our results suggest that 4MBC do not induce oxidative stress in S. senegalensis larvae, since catalase and lipid peroxidation levels were not significantly altered by 4MBC. S. senegalensis revealed to be a good model species for vertebrate animal testing in the marine environment. Sub-lethal concentrations of 4MBC induced toxic effects at all organizational levels. Swimming behaviour was a sensitive endpoint and showed that exposure to 4MBC causes impairment on response to light stimulus which is possibly linked with the observed imbalances on cholinesterase activity in larvae. Conservation concerns along distribution range of S. senegalensis should consider that increasing levels of UV filters in marine environment might have impact on the ecology of the species.

Photoprotection of ultraviolet-B filters: Updated review of endocrine disrupting properties

The Ultraviolet (UV) radiation is emitted by the sun and is part of the electromagnetic spectrum. There are three types of UV rays (UV-A, UV-B and UV-C), however only UV-A and UV-B have biologic effects in humans, with UV-B radiation being primarily responsible for these effects. Among the measures of photoprotection advised by the health authorities, the topical application of sunscreens (containing UV-B filters) is the preferred worldwide. Currently, octylmethoxycinnamate (OMC) is the most commonly used UV-B filter in sunscreens. Their application has proven to be effective in preventing burns, but its efficiency against melanoma continues under intense controversy. Studies have shown that OMC behaves like an endocrine disruptor, altering the normal functioning of organisms. However, few studies have evaluated their multiple hormonal activities. Some studies suggest that the OMC exerts an estrogenic, anti-androgenic, anti-progestenic and anti-thyroid activity. But, through what mechanisms? In humans, few studies were performed, and some questions remain unclear. Thus, the purpose of this review is to present the multiple hormonal activities established for the OMC, making a critical analysis and relationship between the effects in cells, animals and humans.

Multigenerational effects of 4-methylbenzylidene camphor (4-MBC) on the survival, development and reproduction of the marine copepod Tigriopus japonicus

One of the most widely used organic UV filters, 4-methylbenzylidene camphor (4-MBC), is present at high concentrations in offshore waters. The marine copepod Tigriopus japonicus was exposed to different concentrations of 4-MBC (i.e., 0, 0.5, 1, 5 and 10μgL^-1) for 4 consecutive generations (F0-F3) to evaluate the impact of 4-MBC on marine ecosystems. The results showed that in the F0 generation, 4-MBC caused significant lethal toxicity in T. japonicas at concentrations of 5 and 10μgL^-1 and the nauplii were more sensitive to 4-MBC toxicity than the adults. However in the F1-F3 generations, 4-MBC exposure did not affect the survival rate. The hatching rate and the developmental duration from the nauplii to the copepodite (N-C) and from the nauplii to adult (N-A) decreased significantly in the F1-F2 generations and in the F2-F3 generations, respectively, even at the lowest exposure concentration (0.5μgL^-1). In the subsequent two generations (i.e., the F4-F5 generations) of recovery exposure in clean seawater, the growth rates of the original 4-MBC exposure groups were still faster than the control in both the N-C and N-A stages, suggesting possible transgenerational genetic and/or epigenetic changes upon chronic 4-MBC exposure. The expression of the ecdysone receptor gene was up-regulated by 4-MBC, which was consistent with the decrease of the N-C/N-A duration. In addition, 4-MBC may induce oxidative stress and trigger apoptosis in T. japonicas, resulting in developmental, reproductive and even lethal toxicity. A preliminary risk assessment suggested that under environmentally realistic concentrations, 4-MBC had significant potential to pose a threat to marine crustaceans and marine ecosystems.

Benzophenone-3 Impairs Autophagy, Alters Epigenetic Status, and Disrupts Retinoid X Receptor Signaling in Apoptotic Neuronal Cells

Benzophenone-3 (BP-3) is the most widely used compound among UV filters for the prevention of photodegradation. Population studies have demonstrated that it penetrates through the skin and crosses the blood-brain barrier. However, little is known about the impact of BP-3 on the nervous system and its possible adverse effects on the developing brain. We demonstrated that the neurotoxic effects of BP-3 were accompanied by the induction of apoptosis, as evidenced by apoptosis-related caspase-3 activation and apoptotic body formation as well as the inhibition of autophagy, as determined by the downregulation of autophagy-related genes, decreased autophagosome formation, and reduced LC3B-to-LC3A ratio. In this study, we showed for the first time that the BP-3-induced apoptosis of neuronal cells is mediated via the stimulation of RXRα signaling and the attenuation of RXRβ/RXRγ signaling, as demonstrated using selective antagonist and specific siRNAs as well as by measuring the mRNA and protein expression levels of the receptors. This study also demonstrated that environmentally relevant concentrations of BP-3 were able to inhibit autophagy and disrupt the epigenetic status of neuronal cells, as evidenced by the inhibition of global DNA methylation as well as the reduction of histone deacetylases and histone acetyl transferases activity, which may increase the risks of neurodevelopmental abnormalities and/or neural degenerations.

Photolysis and cellular toxicities of the organic ultraviolet filter chemical octyl methoxycinnamate and its photoproducts

Organic ultraviolet filter chemicals (UVFCs) are the active ingredients used in many sunscreens to protect the skin from UV light; these chemicals have been detected in numerous aquatic environments leading to concerns about how they might affect aquatic organisms and humans. One commonly used organic UVFC is octyl methoxycinnamate (OMC), better known by its commercial name, octinoxate. Upon exposure to UV light, OMC degrades rapidly, forming numerous photoproducts, some of which have been previously identified. In this study, we isolated and completely characterized the major products of OMC photolysis, including the two major stable OMC cyclodimers. One of these cyclodimers is a δ-truxinate, resulting from a head-to-head dimerization of two OMC molecules, and the other cyclodimer is an α-truxillate, resulting from a head-to-tail dimerization of two OMC molecules. Additionally, the cellular toxicities of the individual photoproducts were determined; it was found that the parent UVFC, OMC, 4-methoxybenzaldehyde, and two cyclodimers are significantly toxic to cells. The photoproduct 2-ethylhexanol is not cytotoxic, demonstrating that different components of OMC photolysate contribute differently to its cellular toxicity. This study thus provides an enhanced understanding of OMC photolysis and gives toxicity data that can be used to better evaluate OMC as a sunscreen agent.

Neurotoxic effect of active ingredients in sunscreen products, a contemporary review

Sunscreen application is the main strategy used to prevent the maladies inflicted by ultraviolet (UV) radiation. Despite the continuously increasing frequency of sunscreen use worldwide, the prevalence of certain sun exposure-related pathologies, mainly malignant melanoma, is also on the rise. In the past century, a variety of protective agents against UV exposure have been developed. Physical filters scatter and reflect UV rays and chemical filters absorb those rays. Alongside the evidence for increasing levels of these agents in the environment, which leads to indirect exposure of wildlife and humans, recent studies suggest a toxicological nature for some of these agents. Reviews on the role of these agents in developmental and endocrine impairments (both pathology and related mechanisms) are based on both animal and human studies, yet information regarding the potential neurotoxicity of these agents is scant. In this review, data regarding the neurotoxicity of several organic filters: octyl methoxycinnamate, benzophenone-3 and −4, 4-methylbenzylidene camphor, 3-benzylidene camphor and octocrylene, and two allowed inorganic filters: zinc oxide and titanium dioxide, is presented and discussed. Taken together, this review advocates revisiting the current safety and regulation of specific sunscreens and investing in alternative UV protection technologies.

Apoptosis Induced by the UV Filter Benzophenone-3 in Mouse Neuronal Cells Is Mediated via Attenuation of Erα/Pparγ and Stimulation of Erβ/Gpr30 Signaling

Although benzophenone-3 (BP-3) has frequently been reported to play a role in endocrine disruption, there is insufficient data regarding the impact of BP-3 on the nervous system, including its possible adverse effects on the developing brain. Our study demonstrated that BP-3 caused neurotoxicity and activated apoptosis via an intrinsic pathway involving the loss of mitochondrial membrane potential and the activation of caspases-9 and -3 and kinases p38/MAPK and Gsk3β. These biochemical alterations were accompanied by ROS production, increased apoptotic body formation and impaired cell survival, and by an upregulation of the genes involved in apoptosis. The BP-3-induced effects were tissue-specific and age-dependent with the most pronounced effects observed in neocortical cells at 7 days in vitro. BP-3 changed the messenger RNA (mRNA) expression levels of Erα, Erβ, Gpr30, and Pparγ in a time-dependent manner. At 3 h of exposure, BP-3 downregulated estrogen receptor mRNAs but upregulated Pparγ mRNA. After prolonged exposures, BP-3 downregulated the receptor mRNAs except for Erβ mRNA that was upregulated. The BP-3-induced patterns of mRNA expression measured at 6 and 24 h of exposure reflected alterations in the protein levels of the receptors and paralleled their immunofluorescent labeling. Erα and Pparγ agonists diminished, but Erβ and Gpr30 agonists stimulated the BP-3-induced apoptotic and neurotoxic effects. Receptor antagonists caused the opposite effects, except for ICI 182,780. This is in line with a substantial reduction in the effects of BP-3 in cells with siRNA-silenced Erβ/Gpr30 and the maintenance of BP-3 effects in Erα- and Pparγ siRNA-transfected cells. We showed for the first time that BP-3-affected mRNA and protein expression levels of Erα, Erβ, Gpr30, and Pparγ, paralleled BP-3-induced apoptosis and neurotoxicity. Therefore, we suggest that BP-3-evoked apoptosis of neuronal cells is mediated via attenuation of Erα/Pparγ and stimulation of Erβ/Gpr30 signaling.