Active sunscreen ingredients in Australia

Environmental fate of organic UV filters: Global occurrence, transformation, and mitigation via advanced oxidation processes

Organic UV filters are used in personal care products, plastics, paints, and textiles to protect against UV radiation. Despite regulatory limits, these compounds still enter the environment through direct wash-off during swimming, evaporation, leaching from products, and incomplete removal in wastewater treatment plants. They have been detected in various environmental matrices worldwide. Once in the environment, organic UV filters can undergo phototransformation and biotransformation, forming transformation products that, together with parent substances, pose health risks to humans and wildlife and harm marine ecosystems, especially coral reefs. The increasing concern over water scarcity and the environmental impact of pollutants underscores the importance of eliminating these contaminants from aquatic environments. This review primarily focuses on organic UV filters approved for use in sunscreens, many of which are also utilized in other materials, with a few exceptions including UV stabilizer UV-328. It includes an in-depth analysis of 155 peer-reviewed articles published from 2015 to 2024, assessing the concentrations of these filters in various environmental matrices, including water and solid matrices, air and biota. Moreover, this review explores the environmental transformation of these chemicals and assesses the effectiveness of advanced oxidation processes (AOPs) in removing these pollutants. The findings highlight the pervasive presence of organic UV filters in the environment and the promising potential of AOPs to mitigate the associated environmental challenges.

Allergen Composition, Marketing Claims, and Affordability of Pediatric Sunscreens

BACKGROUND

Childhood sun exposure is associated with development of future skin cancers. Sunscreens are an important tool to prevent harmful ultraviolet rays.

OBJECTIVES

The aims of the study are to evaluate sunscreens targeted to children and to analyze cost, marketing claims, ingredients, and allergens to help consumers select products.

METHODS

The top 50 pediatric sunscreens across retailers were analyzed for their cost, marketing claims, ingredients, vehicles, and containers. Ingredients were compared with the American Contact Dermatology Society 2020 Core Allergen List.

RESULTS

The mean price was $6.20 per ounce (range, $0.25-$39.98). The mean sun protection factor was 48.5 (range, 30-100; SD, 48.5). There was a mean of 17.5 ingredients and a mean of 1.1 allergens in products. On average, products marketed as "sensitive skin" were not only significantly more expensive ($8.90 vs $3.50 per ounce, P = 0.01) but also were significantly more likely to not contain any allergens (36.0%, n = 18 vs 12%, n = 6; P = 0.05). Products with mineral-only UV blockers were significantly less likely to have any allergen when compared with products that had chemical UV blockers (5.6%, n = 1 vs 94.4%, n = 17; P = 0.02).

CONCLUSIONS

The current market of pediatric sunscreens varies significantly in price, marketing claims, and active ingredients. Products marked as suitable for sensitive skin had significantly fewer allergens, but a majority of these products still had at least one allergen. Many sunscreens contain contact allergens, which is an important selection consideration.

Correlates of non-persistent endocrine disrupting chemical mixtures among reproductive-aged Black women in Detroit, Michigan

Some studies indicate that Black women have higher exposure to multiple non-persistent endocrine disrupting chemicals (EDCs) than white women, but little is known about correlates of exposure to EDC mixtures. Using baseline data from a prospective cohort study of reproductive-aged Black women (N = 751), we characterized profiles of EDC mixtures and identified correlates of exposure. At baseline, we quantified biomarkers of 16 phthalates, 7 phenols, 4 parabens, and triclocarban in urine and collected covariate data through self-administered questionnaires and interviews. We used principal component (PC) analysis and k-means clustering to describe EDC mixture profiles. Associations between correlates and PCs were estimated as the mean difference (β) in PC scores, while associations between correlates and cluster membership were estimated as the odds ratio (OR) of cluster membership. Personal care product use was consistently associated with profiles of higher biomarker concentrations of non-persistent EDCs. Use of nail polish, menstrual and vaginal products (e.g., vaginal powder, vaginal deodorant), and sunscreen was associated with a mixture of phthalate and some phenol biomarkers using both methods. Current vaginal ring use, a form of hormonal contraception placed inside the vagina, was strongly associated with higher concentrations of high molecular weight phthalate biomarkers (k-means clustering: OR = 2.42, 95% CI = 1.28, 4.59; PCA: β = -0.32, 95% CI = -0.71, 0.07). Several dietary, reproductive, and demographic correlates were also associated with mixtures of EDC biomarkers. These findings suggest that personal care product use, diet, and contraceptive use may be sources of exposure to multiple non-persistent EDCs among reproductive-aged Black women. Targeted interventions to reduce exposure to multiple EDCs among Black women are warranted.

Evaluating Hemolytic and Photo Hemolytic Potential of Organophosphorus by In Vitro Method as an Alternative Tool Using Human Erythrocytes

AIMS

The present study aims to determine the phototoxic and haemolytic activity of organophosphorus. The use of alternative in vitro assays with human erythrocytes is suggested to predict the polluting effect of these products on health.

METHODOLOGY

Human erythrocytes from Toluca Blood Bank were used. Sodium dodecyl sulfate was employed as a positive control. Additionally, the haemolysis percentage of three organophosphate (Acetate, Chlorpyrifos, Malathion, Methamidophos, Methyl Parathion) induced photo haemolysis formulated with surfactants on a concentration of 2 x 109 erythrocytes were evaluated. Finally, the products were classified as irritant or phototoxic.

RESULTS

Results showed that the HC50 red blood cells were similar for each organophosphate (Malathion and Methamidophos) indicating very irritant action with ratio classification (L/D) of 0.041 and 0.053, respectively. On the other hand, Chlorpyrifos was classified as an irritant with L/D= 0.14. On the other hand, the HC50 obtained photo hemolysis assays irradiated red blood cells was similar for each organophosphate (Acetate, Chlorpyrifos, Malathion, Methamidophos, Methyl Parathion) indicating no phototoxic action.

CONCLUSION

As a conclusion, it can be said that the parameters of haemolysis and denaturation of proteins are good indicators to classify organophosphorus formulated with surfactants as irritating or phototoxic.

Unplanned absorption of sunscreen ingredients: Impact of formulation and evaluation methods

Permeation of sunscreens agents reduces its effectiveness and safety, leading to systemic circulation and causing unknown adverse effects. In order to maintain the sunscreen efficacy and safety, the filters must stay on the skin surface, with minimum penetration through dermis. Even facing the possibility of filters permeation, the use of sunscreen is important to avoid skin damage as erythema, free-radicals formation, skin ageing and skin cancer, caused by ultraviolet radiation. Aiming potential side effects caused by topical absorption of sunscreens, studies are carried to improve formulation characteristics and stability, reduce skin permeation and evaluate sun protections factor (SPF). Current assays to detect the permeation of sunscreens involve in vivo or in vitro studies, to simulate physiological conditions of use. The aim of this review is to revisit sunscreen skin permeation data over the last decade and the factors that can enhance skin permeation or improve the sunscreen efficacy.

Ex vivo penetration analysis and anti-inflammatory efficacy of the association of ferulic acid and UV filters

BACKGROUND

Unprotected chronic exposure to ultraviolet (UV) radiation generates many harmful effects to human skin and sunscreens are essential to health, however, traditional products do not provide enough protection against cutaneous oxidative stress, a process amplified by UV radiation. Therefore, the development of multifunctional photoprotective formulations seems to be a more efficacious approach, since these enable the absorption/reflection of UV radiation and maintain the cutaneous homeostasis.

OBJECTIVES

In the present study, ferulic acid (FA), a well-known antioxidant, has been combined with two UV filters, bemotrizinol and ethylhexyl triazone, and the safety and efficacy of this formulation has been assessed combining ex vivo and in vivo methods.

METHODS

Skin permeation assays were performed by applying the formulation in the volar forearm of participants, after which consecutive samples of the stratum corneum were collected by tape stripping, and the quantification of FA, bemotrizinol and ethylhexyl triazone was performed by high-performance liquid chromatography (HPLC). Also, the FA anti-inflammatory action in combination with the UV filters was probed through a method employing Laser Doppler flowmetry to measure the vasodilatory response to methyl nicotinate topical application.

RESULTS

Skin permeation assay was able to characterize the penetration depth of each substance. It should also be noted that a specific HPLC analytical method was developed in this study to enable the rapid simultaneous quantification of the three substances. Results from Laser Doppler flowmetry showed that the FA was able to mitigate the vasodilatory response.

CONCLUSIONS

FA proved to be a valuable resource in a multifunction sunscreen, not only providing an increase in the SPF of sunscreens, previously published, but also decreasing the extent of inflammation.

Photopatch testing in a tropical country, Thailand: 20 years' experience

BACKGROUND

Photoallergic contact dermatitis is one of the important parts of photodermatoses. The investigation of choice is photopatch testing. However, reports with photopatch test results from Asian countries are scarce. The objective of this study was to determine the prevalence of positive photopatch test reactions and to ascertain the common photoallergens among Thai patients during 1998-2018.

METHODS

We retrospectively reviewed the records of 339 patients who were clinically suspected of having photoallergic contact dermatitis and had undergone photopatch testing.

RESULTS

A total of 44 photoallergic contact reactions in 38 patients (11.2%) were found. The positive photoallergic reactions were mainly found with organic ultraviolet filters and fragrances.

CONCLUSIONS

Organic ultraviolet filter chemicals especially benzophenone-3 and fragrances were found to have a high prevalence of photoallergic contact reactions. Monitoring of the photoallergens employed in photopatch tests should be conducted periodically to provide the best patient care.

Biocompatible UV-absorbing polymer nanoparticles prepared by electron irradiation for application in sunscreen

The electron-irradiated polymer nanoparticles exhibit no significant signs of cytotoxicity and phototoxicity while providing excellent UV-shielding performance.

A newly identified photolyase from Arthrospira platensis possesses a unique methenyltetrahydrofolate chromophore-binding pattern

Cyclobutane pyrimidine dimers (CPD), as a common DNA damage caused by UV radiation, often lead to skin cancer. Here, we identified a photolyase from the alga Arthrospira platensis (designated as Ap-phr), which has been regarded as a safe organism for humans for centuries, that can efficiently repair CPD lesions in ssDNA and dsDNA in vitro. The 1.6 Å resolution crystal structure of Ap-phr revealed that it possesses a unique methenyltetrahydrofolate chromophore-binding pattern with high energy transfer efficiency. Our study of Ap-phr highlights its potential use in cosmetic, industrial and aesthetic medicine applications.

Toxicokinetics of urinary 2-ethylhexyl salicylate and its metabolite 2-ethyl-hydroxyhexyl salicylate in humans after simulating real-life dermal sunscreen exposure

Chemical UV filters are common components in sunscreens and cosmetic products. The question of adverse health risks is not completely resolved, partly owing to lacking human data from dermal exposure, which are essential for sound risk assessment. Therefore, we investigated the urinary toxicokinetics of 2-ethylhexyl salicylate (EHS) after a 1-day dermal real-life sunscreen application scenario. Twenty human volunteers were dermally exposed to a commercial sunscreen for 9 h under real-life conditions (2 mg/cm² body surface area; double re-application; corresponding to 3.8 g EHS). Urine samples were analyzed for EHS and one of its specific metabolites 2-ethyl-5-hydroxyhexyl salicylate (5OH-EHS) using a two-dimensional liquid chromatographic electrospray-ionization tandem mass spectrometric procedure. EHS and 5OH-EHS were excreted after sunscreen application and reached up to 525 µg/g and 213 µg/g creatinine, respectively. The toxicokinetic models showed concentration peaks between 7 and 8 h after first application. First-phase terminal half-lives were 8-9 h. For 5OH-EHS, a second-phase terminal half-life could be determined (87 h). EHS and 5OH-EHS showed a faster elimination with 70-80% of the overall excretion occurring within 24 h after application compared to more lipophilic UV filters. Cumulative excreted amounts over 24 h reached up to 334 µg EHS and 124 µg of 5OH-EHS. Simulated real-life sunscreen use for 1 day leads to the bioavailability of the UV filter EHS in humans. The kinetic profiles with a prolonged systemic availability indicate a skin depot and make accumulation during consecutive multi-day exposure likely.

Cyanidin-3-o-glucoside inhibits UVA-induced human dermal fibroblast injury by upregulating autophagy

BACKGROUND/PURPOSE

Ultraviolet (UV) A (315-400 nm) is the UV light that most frequently reaches the Earth's surface and can penetrate the epidermis through to the dermis, causing various issues, including skin aging and skin cancer. The results of our previous studies have shown that the flavonoid monomer cyanidin-3-o-glucoside (C3G) can effectively inhibit primary human dermal fibroblast (HDF) oxidative damage and apoptosis caused by UVA radiation. Many flavonoids can regulate the level of autophagy. However, whether C3G inhibits UVA-induced oxidative damage to primary HDFs by regulating autophagy levels remains unclear.

METHODS AND RESULTS

In this study, we used different doses (0-12 J/cm² ) of UVA to irradiate cells and showed that the expression levels of autophagy-related gene 5 (Atg5) and microtubule-associated protein 1 light chain 3 (LC3)-II in primary HDFs first increased and then decreased. The expression of Atg5 and LC3-II was significantly decreased under 12 J/cm² (light-damage model). C3G increased the levels of Atg5 and LC3-II. Primary HDFs were pretreated with C3G, followed by treatment with the autophagy inhibitor 3-methyladenine (3-MA) after 12 J/cm² UVA irradiation. The inhibitory effects of C3G on morphological changes, oxidative damage, and apoptosis in primary HDFs induced by UVA were significantly decreased.

CONCLUSION

C3G can inhibit UVA-induced damage to primary HDFs by inducing autophagy. These results provide a theoretical basis for the application of natural compounds to resist light damage to the skin in the future.