Photoprotection

Cosmetic Products with Potential Photoprotective Effects Based on Natural Compounds Extracted from Waste of the Winemaking Industry

Grape marc is a by-product resulting from the winemaking industry that still contains beneficial compounds that can be valorized. Thus, we report here the possibility of using polyphenolic extracts of grape marc origin to obtain sun protection creams. The extractions were performed in ethanol and acetone solutions using pomace from different grape varieties (Merlot, Bläufrankisch, Fetească Neagră, Isabella) as a raw material. The obtained extracts were analyzed in order to determine the total phenolic content, the antioxidant activity, and the sun protection factor (SPF) via Mansur spectrophotometric assay. The best results were achieved using 70% ethanol in water as a solvent. The extracts with the highest potential photoprotective effects are from the Merlot variety (SPFspectrophotometric = 7.83 ± 0.76). The sunscreens were prepared using the 70% ethanolic extract of the Merlot variety evaporated to dryness, redissolved in either distilled water or ethanol. The SPF estimated in vitro via the COLIPA method showed values of 14.07 ± 1.50 and 11.46 ± 1.32 for the aqueous and ethanolic extracts, respectively, when working with a cream to polyphenolic extract a ratio of 1/1 (w/w). At the same time, the use of aqueous polyphenolic extracts ensures the better stability of creams compared with the ethanolic ones.

Formulation of Ensulizole with Beta-Cyclodextrins for Improved Sunscreen Activity and Biocompatibility

In today's context, prolonged exposure to sunlight is widely recognized as a threat to human health, leading to a range of adverse consequences, including skin cancers, premature skin aging, and erythema. To mitigate these risks, preventive actions mainly focus on advocating the application of sunscreen lotions and minimizing direct exposure to sunlight. This research study specifically centered on ensulizole (ENS), a prominent ingredient in sunscreens. The objective was to create inclusion complexes (ICs) with Beta-cyclodextrin (B-CD) and its hydroxypropyl derivatives (H-CD). Using phase solubility measurements, we determined that both B-CD and H-CD form 1:1 stoichiometric ICs with ENS. Proton nuclear magnetic resonance spectral (1H NMR) analysis confirmed that the phenyl portion of ENS is encapsulated within the B-CD cavity. Significant changes in surface morphology were observed during the formation of these ICs compared to ENS and CDs alone. Quantum mechanical calculations were employed to further support the formation of ICs by providing energy data. Particularly, the photostability of the ENS:B-CD ICs remained intact for up to four hours of UV exposure, with no significant alterations in the structure of ENS. Furthermore, comprehensive biocompatibility assessments yielded encouraging results, suggesting the potential application of these inclusion complexes in cosmetics as a UVB sunscreen. In summary, our research underscores the successful creation of inclusion complexes characterized by enhanced photostability and safe biocompatibility.

Liposomes in the cosmetics: present and outlook

Liposomes are small spherical vesicles composed of phospholipid bilayers capable of encapsulating a variety of ingredients, including water- and oil-soluble compound, which are one of the most commonly used piggybacking and delivery techniques for many active ingredients and different compounds in biology, medicine and cosmetics. With the increasing number of active cosmetic ingredients, the concomitant challenge is to effectively protect, transport, and utilize these substances in a judicious manner. Many cosmetic ingredients are ineffective both topically and systemically when applied to the skin, thus changing the method of delivery and interaction with the skin of the active ingredients is a crucial step toward improving their effectiveness. Liposomes can improve the delivery of active ingredients to the skin, enhance their stability, and ultimately, improve the efficacy of cosmetics and and pharmaceuticals. In this review, we summarized the basic properties of liposomes and their recent advances of functionalities in cosmetics and and pharmaceuticals. Also, the current state of the art in the field is discussed and the prospects for future research areas are highlighted. We hope that this review will provide ideas and inspiration on the application and development of cosmetics and pharmaceuticals.

Different therapeutic approaches in melasma: advances and limitations

Melasma is a chronic hyperpigmentation skin disorder that is more common in the female gender. Although melasma is a multifactorial skin disorder, however, sun-exposure and genetic predisposition are considered as the main etiologic factors in melasma occurrence. Although numerous topical and systemic therapeutic agents and also non-pharmacologic procedural treatments have been considered in melasma management, however, the commonly available therapeutic options have several limitations including the lack of sufficient clinical effectiveness, risk of relapse, and high rate of unwanted adverse drug reactions. Recruitment of nanotechnology for topical drug delivery in melasma management can lead to enhanced skin penetration, targeted drug delivery to the site of action, longer deposition at the targeted area, and limit systemic absorption and therefore systemic availability and adverse drug reactions. In the current review, first of all, the etiology, pathophysiology, and severity classification of melasma have been considered. Then, various pharmacologic and procedural therapeutic options in melasma treatment have been discussed. Afterward, the usage of various types of nanoparticles for the purpose of topical drug delivery for melasma management was considered. In the end, numerous clinical studies and controlled clinical trials on the assessment of the effectiveness of these novel topical formulations in melasma management are summarized.

Anthraquinones from Rhamnus alaternus L.: A Phytocosmetic Ingredient with Photoprotective and Antimelanogenesis Properties

The purpose of the present work was to develop a phytocosmetic sunscreen emulsion with antioxidant activity and an anti-melanogenic effect, containing an anthraquinone-enriched extract of Rhamnus alaternus (A.E.). Our findings demonstrated that A.E. decreased the levels of reactive oxygen species, DNA damage, and malondialdehyde induced by UVA in human keratinocytes and melanocytes. Furthermore, the calculated SPF value in vitro of the cream containing A.E. was 14.26±0.152. Later, it was shown that A.E. extract had an inhibitory effect on the amount of melanin. This extract could also reduce B16F10 intracellular tyrosinase activity. Besides, docking studies were carried out to provide a logical justification for the anti-tyrosinase potential. The findings showed that, A.E. may provide protection against UVA-induced oxidative stress and could be thought of as a viable treatment for hyperpigmentation disorders.

Recent developments in tuning the efficacy of different types of sunscreens

Due to recent global warming threats, the changes in the atmosphere have caused significant ultraviolet (UV) radiation exposure, primarily emitted by the sun, which creates more awareness of photoprotection. Sunscreen development has been a convenient and crucial approach to photoprotection against ultraviolet radiation. Due to high demand, upgrading the quality of sunscreen products and certifying methods are necessary to guarantee the safety of commercial sunscreen products for use. Sunscreen products should have a satisfactory amount of sun protection factor (SPF), ultraviolet A protection factor, as well as the photostability of the sunscreens for them to be considered effective and safe for use. A rigorous study on the effectiveness of the sunscreen components and their safety standards is essential for the productive use and further improvement of the available sunscreen materials. This article summarizes the effects and issues, protective measures of sunscreen usage, and its components, mainly ultraviolet filters.

In silico design of bio-marker detection fluorescent probes

Fluorescent probes capable of sensing the biological medium are of utmost importance in medical diagnostics. However, the optical spectrum of such probes needs to be tuned with care for compatibility with living tissues. More specifically, fluorescent bioprobes must be adjusted so as to avoid light interference with pigments (e.g. hemoglobin), tissue photodamage, scattering of the emitted light, and autofluorescence. This leads to two important conditions on the optical spectrum of the probes. On the one hand, the emission wavelength must be in an optical window of 650 to 950 nm. On the other hand, the Stokes shift must be large, ideally greater than 150 nm. In this paper, we showcase the in-silico design of potential fluorescent biomarkers fulfilling these two conditions by means of heteroatomic substitution and conjugation on a 1,2,4-triazole core initially far away from biological standards.

Super-Antioxidant Vitamin A Derivatives with Improved Stability and Efficacy Using Skin-Permeable Chitosan Nanocapsules

Retinyl palmitate (RP) is a retinol ester with strong antioxidant and anti-inflammatory properties as an antiwrinkle agent. However, it has poor aqueous solubility and easily degrades into inactive forms for topical applications. Therefore, we developed chitosan-coated nanocapsules (ChiNCs) to encapsulate RP using a simple nanoprecipitation method for protection against physiological conditions and to enable deep skin penetration. The as-prepared RP-loaded nanocapsules (RP@ChiNCs) loaded with approximately 5 wt.% RP exhibited a hydrodynamic diameter of 86 nm and surface charge of 24 mV. They had adequate stability to maintain their physicochemical properties after lyophilization in a biological buffer. Notably, ChiNCs provided RP with remarkable protection against degradation for 4 weeks at 37 °C. Thus, RP@ChiNCs exhibited good antioxidant activity in situ for sufficiently long periods without considerable changes in their efficacy. Furthermore, ChiNCs enhanced the skin penetration of lipophilic RP based on the inherent nature of chitosan. RP@ChiNCs exhibited good in vitro antioxidant and anti-inflammatory effects without causing any cytotoxicity in dermal fibroblasts. Accordingly, they promoted cell proliferation in a wound-scratch test and enhanced collagen synthesis. These results suggest that RP@ChiNCs are promising candidates for cosmetic and biomedical applications.

Accuracy and adequacy of photoprotection in pediatric systemic lupus erythematosus patients, and the effect of education on photoprotection: a prospective study

BACKGROUND

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that is associated with multiple organ involvement and leads to significant morbidity and mortality. One of the important environmental factors that influences the exacerbation of preexisting SLE is ultraviolet (UV) radiation, so photoprotection is essential. The aims of this study were to evaluate the accuracy and adequacy of photoprotection in pediatric SLE patients, and to investigate the effect of education on photoprotection.

METHODS

SLE patients aged ≤ 18 years who attended pediatric outpatient clinics were prospectively enrolled. The accuracy and adequacy of photoprotection were assessed by the questionnaire, and compared between baseline and the ≥ 3-month follow-up timepoint. Comprehensive written and verbal photoprotection education was provided to all patients and parents/caregivers after the first assessment.

RESULTS

One hundred patients were included (mean age 13.6 ± 2.5, 92% female). At the first assessment, 79% of patients used sunscreen with a sunburn protection factor ≥ 30 (77%) and protection grade of ultraviolet A +  +  + (63%). Fifty-two percent of patients applied sunscreen every day. A minority of patients applied an adequate amount of sunscreen (32%), used water-resistant sunscreen (34%), used lip balm with sunscreen (23%) and reapplied sunscreen when sweating (13%). The most commonly missed areas when applying sunscreen were the ears and dorsum of the feet. The least often practiced sun protection behavior was wearing sunglasses. The most often reported activities during the peak UV index, were playing with friends and walking to the cafeterias. At the second assessment, the majority of photoprotection practices were improved in all aspects except using water-resistant sunscreen, reapplying sunscreen when sweating, applying sunscreen on the ears and dorsum of feet, and wearing sunglasses. The main reason for not using sunscreen switched from thinking it was unnecessary at the first assessment to disliking its texture at the second assessment.

CONCLUSIONS

Education on photoprotection was effective in improving photoprotection practices. The photoprotection practices that need to be specifically emphasized are applying an adequate amount of sunscreen and using lip balm with sunscreen. The photoprotection which were least practiced at both the first and seconds assessments were reapplying sunscreen when sweating, applying sunscreen on the ears and dorsum of the feet, and wearing sunglasses.

Photoaging's portrait: The road map towards its photoprotection

OBJECTIVE

To summarize key research published by the author's group, dealing with skin photoaging and its photoprotection.

MATERIALS AND METHODS

Two methodologies (standard photographs and selfies imaging) resulting from referential skin ageing atlases were applied on 2487 subjects of different ancestries, ages and gender. These aimed at first to best assess and grade the variable severities of some facial signs (texture/wrinkles, pigmentary spots, sagging and vascular disorders) that occur progressively during the photoaging process. Second, such methodologies were used to record the benefits brought by a photoprotective regimen (671 women and men).

RESULTS

In all studied ancestries, each facial sign show an increase severity along decades, at its own pace, some showing a linear like progression, whereas some plateau at early ages. These changes differed according to skin innate colour (phototype) and with individual behaviours vis-à-vis sun exposures, more so among European women than North-East Asian women. An effect of gender (less severe alterations) was observed on Chinese men, as compared to Chinese women. Pigmentary disorders were found hallmarks of photo-aged North-East Asian women. Globally, photoaging impact the apparent age of the different subjects. The counteracting effects of strong topical Photoprotective regimens were evidenced along a 6-month seasonality in Chinese and French women or 1-year period in Brazilian women with phototypes II to VI. Photoprotection led to a more even skin complexion among Indian subjects with pigment irregularities.

CONCLUSION

Two factors clearly hamper a better assessment of the efficiency of photoprotection of the sun-induced cutaneous ageing: short durations (months) of the studies with regard to the global fate of photoaging by decades and the number of studied subjects, limited to hundreds for practical reasons. The methodology based on the automatic analysis of facial signs through selfies images could theoretically bypass both factors, allowing thousands of subjects to be studied along years.

New developments in sunscreens

Topical sunscreen application is one of the most important photoprotection tool to prevent sun damaging effects in human skin at the short and long term. Although its efficacy and cosmeticity have significantly improved in recent years, a better understanding of the biological and clinical effects of longer wavelength radiation, such as long ultraviolet A (UVA I) and blue light, has driven scientists and companies to search for effective and safe filters and substances to protect against these newly identified forms of radiation. New technologies have sought to imbue sunscreen with novel properties, such as the reduction of calorific radiation. Cutaneous penetration by sunscreens can also be reduced using hydrogels or nanocrystals that envelop the filters, or by binding filters to nanocarriers such as alginate microparticles, cyclodextrins, and methacrylate polymers. Finally, researchers have looked to nature as a source of healthier products, such as plant products (e.g., mycosporines, scytonemin, and various flavonoids) and even fungal and bacterial melanin, which could potentially be used as substitutes or enhancers of current filters.

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.

Holistic Photoprotection, Broad Spectrum (UVA-UVB), and Biological Effective Protection Factors (BEPFs) from Baccharis antioquensis Hydrolysates Polyphenols

Overexposure to solar radiation has become an increasingly worrying problem due to the damage to the skin caused by ultraviolet radiation (UVR). In previous studies, the potential of an extract enriched with glycosylated flavonoids from the endemic Colombian high-mountain plant Baccharis antioquensis as a photoprotector and antioxidant was demonstrated. Therefore, in this work we sought to develop a dermocosmetic formulation with broad-spectrum photoprotection from the hydrolysates and purified polyphenols obtained from this species. Hence, the extraction of its polyphenols with different solvents was evaluated, followed by hydrolysis and purification, in addition to the characterization of its main compounds by HPLC-DAD and HPLC-MS, and evaluation of its photoprotective capacity through the measurement of the Sun Protection Factor (SPF), UVA Protection Factor (UVAPF), other Biological Effective Protection Factors (BEPFs), and its safety through the cytotoxicity. In the dry methanolic extract (DME) and purified methanolic extract (PME), flavonoids such as quercetin and kaempferol were found, which demonstrated antiradical capacity, as well as UVA-UVB photoprotection and prevention of harmful biological effects, such as elastosis, photoaging, immunosuppression, DNA damage, among others, which demonstrates the potential of the ingredients in this type of extract to be applied in photoprotection dermocosmetics.

Depigmenting topical therapy based on a synergistic combination of compounds targeting the key pathways involved in melasma pathophysiology

Melasma has a complex pathophysiology with different cell types and signalling pathways involved. Paracrine factors secreted by keratinocytes, fibroblasts and endothelial cells act on melanocytes and stimulate melanogenesis. These paracrine factors are involved in the oxidative stress, inflammatory, vascular and hormonal pathways, among others. Damage of the dermoepidermal barrier also occurs and facilitates melanin deposition in the dermis, also known as dermal or mixed melasma. We used artificial intelligence tools to define the best combination of compounds for skin pigmentation inhibition. Mathematical models suggested the combination of retinol, diosmin and ferulic acid to be the most effective one. In vitro cellular tyrosinase activity assay proved that this combination had a synergistic depigmenting effect. Further assays proved that the combination could inhibit key pathways involved in melasma by downregulating ET-1 and COX-2 gene expression and IBMX-induced dendricity in human melanocytes, and upregulated the gene expression of IL-1b, TIMP3 and several endogenous antioxidant enzymes. The combination also reduced melanin levels in a phototype VI 3D epidermis model. These results indicate that the combination of retinol, diosmin and ferulic acid is an effective synergistic complex for the treatment of melasma by regulating the key molecular pathways involved in skin hyperpigmentation pathophysiology.

Photoprotective and antigenotoxic properties of Cutibacterium acnes ecotypes native to terrestrial subsurface habitats

Actinobacteria are known to produce a variety of secondary metabolites with skin-protective properties. This study aimed to investigate the photoprotective and antigenotoxic properties against UVB of extracts obtained from Cutibacterium acnes strains. Bacterial growth was measured spectrophotometrically and the constant maximum growth rate (μ) value to each strain, were calculated. In vitro photoprotection efficacy was evaluated using in vitro indices such as sun protection factor (SPFespectrophotometric) and critical wavelength (λc). UVB-antigenotoxicity was also evaluated using the SOS Chromotest. Correlation analysis was used to examine the relationship between SPFespectrophotometric and extract concentration and the %GI estimates. Among the studied strains, one showed low (6.0 ≤ SPFespectrophotometric ≤ 14.9) and eight showed media (15.0 ≤ SPFespectrophotometric ≤ 29.9) UVB photoprotection efficacy. All of them resulted in broad-spectrum (UVA-UVB) photoprotection (λc > 370 nm). In total, two C. acnes ecotypes with different growth rates were evidenced, but the protective metabolites in the extracts were produced without the influence of growth rate. Photoprotective efficacy depended on the extract concentration and was correlated with antigenotoxicity. We demonstrated that C. acnes extracts can be used as sunscreen ingredients that reduce UVB-induced genotoxicity.

The Comparison of Sun Protection Factor 30 Persistence Between Inorganic and Organic Sunscreen in Swimmers: Double-blind Randomized Clinical Trial

BACKGROUND

Long-term sun exposure is one of the risks faced by outdoor swimmers and can cause sunburn. Using sunscreen is one way to prevent sunburn; however, physical activity can trigger sweat, friction, and water washing that can interfere with sunscreen efficacy and decrease its sun protection factor (SPF). Sunscreens are classified into inorganic and organic based on their filter. Organic sunscreen has a better bond to the skin than inorganic sunscreen, which forms a barrier above the skin layer that makes removing it easier. Organic sunscreen lasts longer than inorganic sunscreen when used in physical activities, but it has a limited spectrum, is more photolabile, and is more allergenic.

OBJECTIVE

This study aims to evaluate the persistency of SPF 30 between inorganic and organic sunscreens on the back area after 1.5 hours of swimming.

METHODS

This study is a randomized, split-body, double-blind clinical trial to evaluate the persistency of SPF 30 of the inorganic versus organic sunscreens in swimmers. Randomization was done to allocate the participants into treatment groups. Each participant received inorganic and organic sunscreen treatments applied to the back area. The research participants were swimmers from the Cikini swimming pool and Bina Taruna swimming pool, both in Jakarta, Indonesia.

RESULTS

A total of 22 swimmers were enrolled in this study. The analysis showed no significant difference between the SPF of the two sunscreens before swimming (P=.22). After swimming, the SPF levels of both sunscreens decreased: the inorganic sunscreen decreased from a median of 27 (range 23-47) to 12.3 (range 8-19), and the organic sunscreen decreased from a median of 30 (range 24-47) to 9.9 (range 6-19), which was statistically significant (P<.001). When comparing the SPF of inorganic and organic sunscreens after swimming, there was a statistically significant difference in the decrease in SPF levels between the two groups (P=.02), which indicated a better SPF persistence for inorganic sunscreens when compared to organic sunscreens.

CONCLUSIONS

There was a decrease in the SPF levels of inorganic and organic sunscreens after 1.5 hours of swimming, with better persistence in inorganic sunscreens compared to organic sunscreens.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04618536; https://clinicaltrials.gov/ct2/show/NCT04618536.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/42504.

Characteristic of Ultrastructure of Mice B16 Melanoma Cells under the Influence of Different Lighting Regimes

Circadian rhythms of physiological processes, constantly being in a state of dynamic equilibrium and plastically associated with changes in environmental conditions, are the basis of homeostasis of an organism of human and other mammals. Violation of circadian rhythms due to significant disturbances in parameters of main environmental effectors (desynchronosis) leads to the development of pathological conditions and a more severe course of preexisting pathologies. We conducted the study of the ultrastructure of cells of mice transplantable malignant melanoma B16 under the condition of normal (fixed) lighting regime and under the influence of constant lighting. Results of the study show that melanoma B16 under fixed light regime represents a characteristic picture of this tumor-predominantly intact tissue with safe junctions of large, functionally active cells with highly irregular nuclei, developed organelles and a relatively low content of melanin. The picture of the B16 melanoma tissue structure and the ultrastructure of its cells under the action of constant lighting stand in marked contrast to the group with fixed light: under these conditions the tumor exhibits accelerated growth, a significant number of cells in the state of apoptosis and necrosis, ultrastructural signs of degradation of the structure and functions, and signs of embryonization of cells with the background of adaptation to oxygen deficiency.

Nanoparticles for Topical Application in the Treatment of Skin Dysfunctions-An Overview of Dermo-Cosmetic and Dermatological Products

Nanomaterials (NM) arouse interest in various fields of science and industry due to their composition-tunable properties and the ease of modification. They appear currently as components of many consumer products such as sunscreen, dressings, sports clothes, surface-cleaning agents, computer devices, paints, as well as pharmaceutical and cosmetics formulations. The use of NPs in products for topical applications improves the permeation/penetration of the bioactive compounds into deeper layers of the skin, providing a depot effect with sustained drug release and specific cellular and subcellular targeting. Nanocarriers provide advances in dermatology and systemic treatments. Examples are a non-invasive method of vaccination, advanced diagnostic techniques, and transdermal drug delivery. The mechanism of action of NPs, efficiency of skin penetration, and potential threat to human health are still open and not fully explained. This review gives a brief outline of the latest nanotechnology achievements in products used in topical applications to prevent and treat skin diseases. We highlighted aspects such as the penetration of NPs through the skin (influence of physical-chemical properties of NPs, the experimental models for skin penetration, methods applied to improve the penetration of NPs through the skin, and methods applied to investigate the skin penetration by NPs). The review summarizes various therapies using NPs to diagnose and treat skin diseases (melanoma, acne, alopecia, vitiligo, psoriasis) and anti-aging and UV-protectant nano-cosmetics.

Understanding Melasma-How Can Pharmacology and Cosmetology Procedures and Prevention Help to Achieve Optimal Treatment Results? A Narrative Review

Melasma is a chronic skin condition that involves the overproduction of melanin in areas exposed to ultraviolet radiation. Melasma treatment is long-term and complicated with recurrence and resistance to treatment. The pathogenesis of melasma is highly complex with multiple pathologies occurring outside of the skin pigment cells. It includes photoaging, excessive melanogenesis, an increased number of mast cells, increased vascularization, and basement membrane damage. In addition, skin lesions related to melasma and their surrounding skin have nearly 300 genes differentially expressed from healthy skin. Traditionally, melasma was treated with topical agents, including hydroquinone, tretinoin, glucocorticosteroids and various formulations; however, the current approach includes the topical application of a variety of substances, chemical peels, laser and light treatments, mesotherapy, microneedling and/or the use of systemic therapy. The treatment plan for patients with melasma begins with the elimination of risk factors, strict protection against ultraviolet radiation, and the topical use of lightening agents. Hyperpigmentation treatment alone can be ineffective unless combined with regenerative methods and photoprotection. In this review, we show that in-depth knowledge associated with proper communication and the establishment of a relationship with the patient help to achieve good adherence and compliance in this long-term, time-consuming and difficult procedure.

Benzophenone-3 and antinuclear antibodies in U.S. adolescents and adults ages 12-39 years

Background

Between 1988 and 2012, prevalence of antinuclear antibodies (ANA) increased in the U.S., especially in adolescents and non-Hispanic Whites. Female predominance of ANA suggests a role for hormonal factors, including xenobiotic exposures that may disrupt endocrine signaling. Benzophenone-3 (BP-3) is one such chemical with increasing exposure through sunscreen use. We investigated whether urinary BP-3 levels were related to ANA in adolescents and young adults.

Methods

In a sample of 1,785 individuals ages 12-39 years in the National Health and Nutrition Examination Survey (NHANES; 2003-4, 2011-12), we examined cross-sectional associations of ANA (N=192; 3+ or 4+ at the 1:80 dilution, measured by HEp-2 immunofluorescence) with urinary BP-3, and other phenols bisphenol-A, triclosan, and parabens. Adjusted prevalence odds ratios (POR) were calculated in season-stratified models [winter (November-April) and summer (May-October)], given differences in sunscreen use and BP-3 concentrations.

Results

BP-3 concentrations (detected in >98.5% of individuals) did not differ by ANA positivity in the summer (geometric mean, GM 30.6 ng/ml ANA-positive vs. 35.3 ANA-negative; GM ratio 1.15), but in winter were higher among ANA-positives (50.2 vs. 20.1 ANA-negative; GM ratio 2.50). ANA was associated with log₁₀BP-3 in winter (POR 1.57; 95%CI 1.07-2.30 per unit increase) but not summer (0.94; 0.61, 1.44; interaction p=0.09). Triclosan, parabens, and bisphenol-A levels were unrelated to ANA overall or by season (ORs 0.64 to 1.33).

Conclusions

The association of urinary BP-3 with ANA in the winter may reflect different exposure patterns or unmeasured confounders. Findings warrant replication in prospective studies and including past and year-round exposures.

Flower Extracts from Ornamental Plants as Sources of Sunscreen Ingredients: Determination by In Vitro Methods of Photoprotective Efficacy, Antigenotoxicity and Safety

Plants are sources of sunscreen ingredients that prevent cellular mutations involved in skin cancer and aging. This study investigated the sunscreen properties of the extracts from some ornamental plants growing in Colombia. The UV filter capability of the flower extracts obtained from Rosa centifolia L., Posoqueria latifolia (Rudge) Schult, and Ipomoea horsfalliae Hook. was examined. Photoprotection efficacies were evaluated using in vitro indices such as sun protection factor and critical wavelength. UVB antigenotoxicity estimates measured with the SOS Chromotest were also obtained. Extract cytotoxicity and genotoxicity were studied in human fibroblasts using the trypan blue exclusion and Comet assays, respectively. Major compounds of the promising flower extracts were identified by UHPLC–ESI+–Orbitrap–MS. The studied extracts showed high photoprotection efficacy and antigenotoxicity against UVB radiation, but only the P. latifolia extract showed broad-spectrum photoprotection at non-cytotoxic concentrations. The P. latifolia extract appeared to be safer for human fibroblast cells and the R. centifolia extract was shown to be moderately cytotoxic and genotoxic at the highest assayed concentrations. The I. horsfalliae extract was unequivocally cytotoxic and genotoxic. The major constituents of the promising extracts were as follows: chlorogenic acid, ecdysterone 20E, rhamnetin-rutinoside, cis-resveratrol-diglucoside, trans-resveratrol-diglucoside in P. latifolia; quercetin, quercetin-glucoside, quercetin-3-rhamnoside, kaempferol, kaempferol-3-glucoside, and kaempferol-rhamnoside in R. centifolia. The potential of the ornamental plants as sources of sunscreen ingredients was discussed.

Antagonistic Skin Toxicity of Co-Exposure to Physical Sunscreen Ingredients Zinc Oxide and Titanium Dioxide Nanoparticles

Being the main components of physical sunscreens, zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO₂ NPs) are often used together in different brands of sunscreen products with different proportions. With the broad use of cosmetics containing these nanoparticles (NPs), concerns regarding their joint skin toxicity are becoming more and more prominent. In this study, the co-exposure of these two NPs in human-derived keratinocytes (HaCaT) and the in vitro reconstructed human epidermis (RHE) model EpiSkin was performed to verify their joint skin effect. The results showed that ZnO NPs significantly inhibited cell proliferation and caused deoxyribonucleic acid (DNA) damage in a dose-dependent manner to HaCaT cells, which could be rescued with co-exposure to TiO₂ NPs. Further mechanism studies revealed that TiO₂ NPs restricted the cellular uptake of both aggregated ZnO NPs and non-aggregated ZnO NPs and meanwhile decreased the dissociation of Zn²⁺ from ZnO NPs. The reduced intracellular Zn²⁺ ultimately made TiO₂ NPs perform an antagonistic effect on the cytotoxicity caused by ZnO NPs. Furthermore, these joint skin effects induced by NP mixtures were validated on the epidermal model EpiSkin. Taken together, the results of the current research contribute new insights for understanding the dermal toxicity produced by co-exposure of different NPs and provide a valuable reference for the development of formulas for the secure application of ZnO NPs and TiO₂ NPs in sunscreen products.

Nanoliposome Use to Improve the Stability of Phenylethyl Resorcinol and Serve as a Skin Penetration Enhancer for Skin Whitening

Phenylethyl resorcinol (PR) is a potent tyrosinase inhibitor and a cosmeceutical skin lightening agent. However, the application of PR is limited by photoinstability and poor solubility. In this study, we formulated and optimized phenylethyl resorcinol loaded nanoliposomes (PR-NLPs) to improve the stability and effective delivery of PR. PR-NLPs were prepared by the ethanol injection method and optimized by a single factor experimental and Box–Behnken design. In addition, Diethylamino Hydroxybenzoyl Hexyl Benzoate (DHHB) as the UBA absorber was added to PR-NLPs, which significantly improved the photostability of PR. The mean size, polydispersity index (PDI), and zeta potential of the optimized PR-NLPs were 130.1 ± 3.54 nm, 0.225 ± 0.02, and −43.9 ± 3.44 mV, respectively. The drug encapsulation efficiency (EE) and loading efficiency (LC) of PR-NLPs were 96.81 ± 3.46% and 8.82 ± 0.6%, respectively. These PR-NLPs showed good physicochemical stability for 3 months at 4 °C and 25 °C in the dark. They showed typical sustained and prolonged drug-release behavior in vitro. The in vitro cytotoxicity assay and cellular uptake demonstrated that the PR-NLPs had excellent biocompatibility and cell transport ability. It significantly inhibited tyrosinase activity and reduced melanin production in B16F10 cells at concentrations of 20 or 30 μg/mL. Moreover, the PR-NLPs enhanced the PR into the skin. These results indicate that PR-NLPs can be used as a nanocarrier to improve the transdermal delivery of PR.

Photoprotection and skin irritation effect of hydrogels containing hydroalcoholic extract of red propolis: A natural pathway against skin cancer

The use of natural products in sunscreen formulations as a prophylactic measure against skin cancer is receiving special attention attributed to the photoprotective and antioxidant properties of their chemical components. In this work, we describe the development of topical hydrogel formulations containing hydroalcoholic extract of red propolis (HERP), and the evaluation of the dermal sensitizing effect of the developed products. Sunscreen formulations composed of HERP in different concentrations (1.5, 2.5 or 3.5% w/w) alone or in combination with a chemical (octyl methoxycinnamate) and/or physical (titanium dioxide) filters were developed using poloxamer 407 as gel basis. The preliminary and accelerated stability tests, texture analysis and spreadability tests were performed. All formulations revealed to be stable in preliminary stability assessment. The formulations containing HERP 1.5 and 2.5% alone or associated with the filters showed intense modifications during accelerated stability test, which were confirmed by rheological analyses. The incorporation of HERP and filters in the poloxamer hydrogel decreased the toughness of product (p < 0.05) and the formulation containing HERP alone presented the lowest adhesivity (p < 0.001). The incorporation of HERP in the hydrogel decreased the poloxamer transition temperature, showing different rheological behavior with the increase of HERP concentration. The developed formulations were stable, exhibited non-Newtonian and pseudoplastic behavior, showing in vivo skin compatibility and no skin irritancy.

Elucidating the photoprotective properties of natural UV screening agents: ZEKE-PFI spectroscopy of methyl sinapate

As a prominent derivative of a natural sunscreen, methyl sinapate is an ideal candidate to provide fundamental insight into strategies on how to come to a rational design of artificial sunscreen filters with improved photoprotective properties. Here, static and time-resolved Zero Kinetic Energy-Pulsed Field Ionization (ZEKE-PFI) photoelectron spectroscopy has been used to study the spectroscopy and decay pathways of its electronically excited states. We find that different conformers are subject to distinct structural changes upon electronic excitation, and trace the structural changes that occur upon excitation back to the character of the LUMO. Ionization efficiency spectra in combination with pump-probe ZEKE-PFI spectra are consistent with the conclusion that the long-lived electronically excited state observed in the decay of the lowest excited singlet state is the lowest excited triplet state. Concurrently with providing information on the electronically excited states, the studies allow for a detailed characterization of the spectroscopic properties of the ground state of the radical ion, which is important in the context of the use of cinnamates in nature as antioxidants. Our studies determine the adiabatic ionization energies of the syn/cis, anti/cis and anti/trans conformers as 60 291.1 ± 0.5, 60 366.9 ± 0.5 and 60 503.9 ± 1.0 cm^-1, respectively, and provide accurate vibrational fequencies of low-frequency modes of the molecular ion in its electronic ground state. Finally, the studies emphasize the important role of vibrational and electronic autoionization processes that start to dominate the ionization dynamics in non-rigid molecules of the present size.

Xeroderma Pigmentosum: General Aspects and Management

Xeroderma Pigmentosum (XP) is a rare genetic syndrome with a defective DNA nucleotide excision repair. It is characterized by (i) an extreme sensitivity to ultraviolet (UV)-induced damages in the skin and eyes; (ii) high risk to develop multiple skin tumours; and (iii) neurologic alterations in the most severe form. To date, the management of XP patients consists of (i) early diagnosis; (ii) a long-life protection from ultraviolet radiation, including avoidance of unnecessary UV exposure, wearing UV blocking clothing, and use of topical sunscreens; and (iii) surgical resections of skin cancers. No curative treatment is available at present. Thus, in the last decade, in order to prevent or delay the progression of the clinical signs of XP, numerous strategies have been proposed and tested, in some cases, with adverse effects. The present review provides an overview of the molecular mechanisms featuring the development of XP and highlights both advantages and disadvantages of the clinical approaches developed throughout the years. The intention of the authors is to sensitize scientists to the crucial aspects of the pathology that could be differently targeted. In this context, the exploration of the process underlining the conception of liposomal nanocarriers is reported to focus the attention on the potentialities of liposomal technology to optimize the administration of chemoprotective agents in XP patients.

Quality by design enabled the development of stable and effective oil-in-water emulsions at compounding pharmacy: the case of a sunscreen formulation

It is widely accepted that the use of topical sunscreens has medical importance with potential to prevent skin damage by protecting from solar ultraviolet radiation (UVR) effects. Pharmaceutical emulsions require an optimal qualitative and quantitative combination of emollients, emulsifiers and others compounds such as softening agents and, for sunscreens, a combination of chemical and physical UV filters. Herein, we applied the quality by design (QbD) concept to achieve stable and effective compounded sunscreen emulsions. By using the statistical tool of design of experiments, it was possible to identify the influence of emulsifier type (with low and high Hydrophile-Lipophile Balance) and concentrations of emollient and softening agent on the achievement of formulations with suitable organoleptic and physicochemical features. Compounded emulsions with pleasant macroscopic aspects were obtained. Three formulations with physicochemical properties in targeted ranges were selected, namely pH ∼6.0, conductivity > 0.0 µS/cm², spreadability factor ∼1-1.5 g/mm², viscosity ∼12000 mPa.s and sunscreen protection factor ∼30. Freeze-thaw cycle and accelerated stability study under different storage conditions allowed selecting a stable emulsion that ensured photoprotection in biological assays. The QbD approach was essential to select the best, low-cost compounded sunscreen emulsion, with targeted physicochemical parameters.

Plants growing in Colombia as sources of active ingredients for sunscreens

INTRODUCTION

Plants can be sources of photoprotective/antigenotoxic compounds that prevent cellular mutations involved in skin cancer and aging by regulating UV-induced mutability.

PURPOSE

The study was aimed at investigating the sunscreen properties of plants growing in Colombia.

MATERIALS AND METHODS

Ultraviolet (UV) radiation-absorption capability of different plant extracts was examined. In vitro photoprotection efficacies were evaluated using in vitro indices such as sun protection factor (SPF_in vitro) and critical wavelength (λc). Pearson correlation analysis was used to examine the relationship between SPF_in vitro and complementary UVB- antigenotoxicity estimates (%GI) based on the SOS Chromotest database. The cytotoxicity in human fibroblasts was studied using the trypan blue exclusion assay. Major compounds of promising plant extracts were determined by gas chromatography coupled to mass spectrometry (GC/MS).

RESULTS

We showed that plant extracts have sunscreen properties against UVB, whereas broad-spectrum radiation protection efficacy was poor. SPF_in vitro and %GI were correlated (R = 0.71, p < .0001) for the plant extracts under study. Three extracts obtained from Achyrocline satureioides, Chromolaena pellia, and Lippia origanoides species resulted to possess high protection efficacy and relatively low cytotoxicity in human fibroblasts. These plant extracts contained major compounds such as α-pinene, trans-β-caryophyllene, γ-muurolene, γ-cadinene and caryophyllene oxide in A. Satureioides extract, trans-β-caryophyllene, caryophyllene oxide, squalene and α-amyrin in C. pellia extract, and p-cymene, carvacrol, trans-β-caryophyllene and pinocembrin in L. origanoides extract.

CONCLUSIONS

Plants growing in Colombia contain compounds that can be useful for potential sunscreens. SPF_in vitro and %GI estimates were correlated, but %GI estimates were more sensitive to detecting activity at lower plant extract concentrations. Our results supported the need to use DNA damage detection assays as a complement to photoprotection efficacy measurement.

An evaluation of the course of facial sunscreen coverage and sustainability over an 8-hour workday among outdoor workers

BACKGROUND

Reapplication of sunscreen every 2 hours is recommended, especially after swimming, sweating, or working outdoors. However, the sustainability of sunscreen during the workday among outdoor workers is still unclear.

OBJECTIVE

To evaluate the course of facial sunscreen coverage and sustainability over an 8-hour workday among outdoor workers.

MATERIALS AND METHODS

This open-label trial included 20 healthy subjects who spend at least 80% of their workday outdoors. All volunteers applied 2 mg/cm2 of provided broad-spectrum sunscreen mixed with the invisible blue fluorescent agent to all parts of their face in the morning. A VISIA-CR camera was used to capture facial fluorescence intensity every 2 hours, and digital image analysis software was used to quantify fluorescence intensity at six areas of the face at each time point for 8 hours.

RESULTS

Sunscreen coverage declined most rapidly during the first 2 hours with a mean reduction of 18.31%. By the end of the 8-hour study workday, the mean decrease in sunscreen coverage was 31.63% (range: 17.39%-45.29%).

CONCLUSION

Reapplication of sunscreen is essential among outdoor workers. After 4 hours, the amount of sunscreen remaining on the face may not be sufficient for protecting the skin from harmful ultraviolet radiation.

(+)-Usnic Acid as a Promising Candidate for a Safe and Stable Topical Photoprotective Agent

The study aimed to examine whether usnic acid—a lichen compound with UV-absorbing properties—can be considered as a prospective photoprotective agent in cosmetic products. Moreover, a comparison of two usnic acid enantiomers was performed to preselect the more effective compound. To meet this aim, an in vitro model was created, comprising the determination of skin-penetrating properties via skin-PAMPA assay, safety assessment to normal human skin cells (keratinocytes, melanocytes, fibroblasts), and examination of photostability and photoprotective properties. Both enantiomers revealed comparable good skin-penetrating properties. Left-handed usnic acid was slightly more toxic to keratinocytes (IC₅₀ 80.82 and 40.12 µg/mL, after 48 and 72 h, respectively) than its right-handed counterpart. The latter enantiomer, in a cosmetic formulation, was characterized by good photoprotective properties and photostability, comparable to the UV filter octocrylene. Perhaps most interestingly, (+)-usnic acid combined with octocrylene in one formulation revealed enhanced photoprotection and photostability. Thus, the strategy can be considered for the potential use of (+)-usnic acid as a UV filter in cosmetic products. Moreover, the proposed model may be useful for the evaluation of candidates for UV filters.

Prodigiosin Production and Photoprotective/Antigenotoxic Properties in Serratia marcescens Indigenous Strains from Eastern Cordillera of Colombia

Serratia marcescens is a bacterial species that produces an antibacterial pigment (Prodigiosin) showing a wide adaptive response to environmental stresses. The study aimed to investigate Prodigiosin production in S. marcescens wild-type strains, as well as its relation to photoprotection and antigenotoxicity against UVB. Prodigiosin yield was spectrophotometrically assayed in extracts of bacterial strains grown in different culture media. In vitro photoprotection efficacy was evaluated using the in vitro indices sun protection factor (SPF_in vitro ) and critical wavelength (λc). The percentage of UVB antigenotoxicity estimates (%GI) in the SOS Chromotest was also evaluated. Correlation analysis was used to examine the relationship between Prodigiosin yield, SPF_in vitro , %GI estimates and environmental traits (altitude, temperature, rainfall and solar irradiance). Prodigiosin yield in S. marcescens strains varied depending on culture media used for its growth, and it was correlated with environmental variables such as temperature and solar irradiance. SPF_in vitro estimates were well correlated with Prodigiosin concentration and %GI values in the bacterial strains being studied. UVB photoprotective efficacy of the extracts obtained from S. marcescens strains depends on the strain's Prodigiosin yield and its antigenotoxic potential. The extracts with Prodigiosin yield higher than ˜17 μg mL^-1 could be used as sources of sunscreen ingredients.

Elucidating the Photoluminescence Quenching in Ensulizole: an Artificial Water Soluble Sunscreen

Employing natural or artificial sunscreens is essential to protect the skin from ultraviolet radiations that cause premature aging and develop melanoma and other forms of skin cancer. The 2-Phenylbenzimidazole-5-sulfonic acid, commonly known as ensulizole is a water-soluble artificial sunscreen that absorb UV-B (280 nm - 315 nm) radiations and protects the skin against the harmful effects of these radiations. We have measured steady-state photoluminescence (SSPL) spectra and photoluminescence (PL) kinetics of this compound in various conditions. Steady-state absorption indicates a strong absorption feature at 303 nm and a weak one at 316 nm that have been identified as π → π* and n → π* transitions, respectively. The spectra of PL induced by these absorptions indicate that the PL of ensulizole is less Stokes-shifted in polar solvents and more Stokes-shifted in non-polar solvents. The average PL lifetime of ensulizole is longer in non-polar solvents than in polar solvents and it exhibits the shortest PL lifetime in aqueous medium that maximize its transition efficiency in water. This suggests in non-polar solvents intersystem crossing is the dominant mode of relaxation of the excited ππ* state. Furthermore, an increase of pH of ensulizole solution decreases the PL intensity and the lifetime. Stern-Volmer equation is employed to evaluate bimolecular quenching rate constant k_q. The evaluation result suggests the diffusional dynamic mode of PL quenching is operative.

Exploring Mycosporine-Like Amino Acids (MAAs) as Safe and Natural Protective Agents against UV-Induced Skin Damage

Prolonged exposure to harmful ultraviolet radiation (UVR) can induce many chronic or acute skin disorders in humans. To protect themselves, many people have started to apply cosmetic products containing UV-screening chemicals alone or together with physical sunblocks, mainly based on titanium–dioxide (TiO₂) or zinc-oxide (ZnO₂). However, it has now been shown that the use of chemical and physical sunblocks is not safe for long-term application, so searches for the novel, natural UV-screening compounds derived from plants or bacteria are gaining attention. Certain photosynthetic organisms such as algae and cyanobacteria have evolved to cope with exposure to UVR by producing mycosporine-like amino acids (MAAs). These are promising substitutes for chemical sunscreens containing commercially available sunblock filters. The use of biopolymers such as chitosan for joining MAAs together or with MAA-Np (nanoparticles) conjugates will provide stability to MAAs similar to the mixing of chemical and physical sunscreens. This review critically describes UV-induced skin damage, problems associated with the use of chemical and physical sunscreens, cyanobacteria as a source of MAAs, the abundance of MAAs and their biotechnological applications. We also narrate the effectiveness and application of MAAs and MAA conjugates on skin cell lines.

The Role of Photoprotection in Optimizing the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with an estimated prevalence of 10-15% in children and 2-10% in adults. Clinically, there is notable phenotypic variability driven by a complex interaction between genetics, immune function, and the environment. Impairment of the skin barrier plays a significant role in the pathogenesis of AD. The apparent beneficial effect of sunlight in patients with atopic eczema is questioned due to its capacity to disrupt the skin barrier and generate free radicals that can damage proteins, lipids, and DNA. The sum of the external factors that an individual is exposed to throughout their lifetime is termed the exposome. Environmental factors such as sun exposure, temperature, and humidity contribute to both AD flares and regional prevalence variation. Literature on photoprotection in atopic dermatitis is very scarce. The use of adequate sunscreens in atopic dermatitis can ensure the level of photoprotection required to prevent skin photoaging and skin cancer and to mitigate skin barrier dysfunction, decrease inflammation, and neutralize facial redness. Herein we discuss and review the role of UV radiation and the exposome in the etiology of AD, as well as the role of adequate photoprotection.

Visible light. Part II: Photoprotection against visible and ultraviolet light

Cutaneous photobiology studies have focused primarily on the ultraviolet portion of the solar spectrum. Visible light (VL), which comprises 50% of the electromagnetic radiation that reaches the Earth's surface and, as discussed in Part I of this CME, has cutaneous biologic effects, such as pigment darkening and erythema. Photoprotection against VL includes avoiding the sun, seeking shade, and using photoprotective clothing. The organic and inorganic ultraviolet filters used in sunscreens do not protect against VL, only tinted sunscreens do. In the United States, these filters are regulated by the Food and Drug Administration as an over-the-counter drug and are subject to more stringent regulations than in Europe, Asia, and Australia. There are no established guidelines regarding VL photoprotection. Alternative measures to confer VL photoprotection are being explored. These novel methods include topical, oral, and subcutaneous agents. Further development should focus on better protection in the ultraviolet A1 (340-400 nm) and VL ranges while enhancing the cosmesis of the final products.

Simple, green, ultrasound-assisted preparation of novel core-shell microcapsules from octyl methoxycinnamate and oligomeric proanthocyanidins for UV-stable sunscreen

Without sunscreens, UV rays in sunlight cause skin damage, ranging from dark spots and premature aging to skin cancer. Present sunscreens, however, are readily photodegraded, producing highly reactive radicals that can damage cells. To address this problem, we have now used ultrasound to prepare core-shell microcapsules, which offer improved protection against UV light and improved UV stability. The composite microcapsules have oligomeric proanthocyanidins (OPCs), which are amphiphilic plant-derived secondary metabolites, as the shell and octyl methoxycinnamate (OMC), which is a UVB absorber, as the core. The polyphenolic flavonoid structure of OPCs improves the UV stability of OMC and thus avoids the skin damage caused by OMC photodegradation products. In the microcapsules, π-π stacking interactions between OPCs and OMC molecules enhance the ability of OMC to absorb UV radiation and extend the absorption range from the UVB region (280-320 nm) to include the UVA and UVC regions (200-400 nm). The composite microcapsules were shown to be stable on storage and to be non-irritant to human skin. The ultrasound-assisted preparation of OMC/OPCs composite microcapsules is simple, efficient and green and provides a feasible strategy for the development of novel, more effective, sunscreens.

Transdermal uptake of benzophenone-3 from clothing: comparison of human participant results to model predictions

BACKGROUND

Models of transdermal uptake of chemicals from clothing have been developed, but not compared with recent human subject experiments. In a well-characterized experiment, participants wore t-shirts pre-dosed with benzophenone-3 (BP-3) and BP-3 and a metabolite were monitored in urine voids.

OBJECTIVE

Compare a dynamic model of transdermal uptake from clothing to results of the human subject experiment.

METHODS

The model simulating dynamic transdermal uptake from clothing was coupled with direct measurements of the gas phase concentration of benzophenone-3 (BP-3) near the surface of clothing to simulate the conditions of the human subject experiment.

RESULTS

The base-case model results were consistent with the those reported for human subjects. The results were moderately sensitive to parameters such as the diffusivity in the stratum corneum (SC), the SC thickness, and SC-air partition coefficient. The model predictions were most sensitive to the clothing fit. Tighter clothing worn during exposure period significantly increased excretion rates but tighter fit "clean" clothing during post-exposure period acts as a sink that reduces transdermal absorption by transferring BP-3 from skin surface lipids to clothing. The shape of the excretion curve was most sensitive to the diffusivity in the SC and clothing fit.

SIGNIFICANCE

This research provides further support for clothing as an important mediator of dermal exposure to environmental chemicals.

Ultraviolet filters in sunscreens and cosmetic products-A market survey

BACKGROUND

As several reports have raised a variety of environmental, health, and safety issues related to ultraviolet (UV) filters, it is crucial to understand the trends in the exposure of the population to UV filters.

OBJECTIVE

To determine the frequency of UV filter usage in sunscreens and other cosmetic products in Thai market.

METHODS

We surveyed the UV filter labelling on sunscreens and cosmetic products sold in the Thai market. In all, 312 sunscreens and 1350 other cosmetic products were investigated.

RESULTS

Titanium dioxide was the most frequently used UV filter in both sunscreens (66.7%) and other cosmetic products (68.4%). Ethylhexyl methoxycinnamate was the most common organic UVB filter, whereas butyl methoxydibenzoylmethane was the most common organic UVA filter. In sunscreens aimed at children, bis-ethylhexyloxyphenol methoxyphenyl triazine was the most commonly used UV filter. The most frequent co-occurrence of UV filters was titanium dioxide and ethylhexyl methoxycinnamate.

CONCLUSIONS

Titanium dioxide was the most commonly used UV filter, which differs from the findings of previous surveys. Knowing the availability and frequency of each UV filter provides valuable information about consumer exposure levels, facilitates refinements of the allergen series in patch testing, and enhances the monitoring of adverse effects of UV filters.

Photoprotection With Mineral-Based Sunscreens

BACKGROUND

Although chemical sunscreens have traditionally been at the forefront of sun protection, safety concerns and increasing awareness of the environmental impact of personal-care products have led to greater interest in the use of mineral blockers as photoprotective agents.

OBJECTIVE

To examine the safety and efficacy of mineral-based sunscreens to allow patients to make informed choices about ultraviolet (UV) protection.

MATERIALS AND METHODS

A review of the literature was performed using the PubMed database.

RESULTS

This article provides an overview of physical blockers and focuses on the efficacy of mineral sunscreens in offering broad-spectrum UV protection and safety concerns, including the controversy surrounding the use of nanoparticles. Practical tips for application are also reviewed.

CONCLUSION

Mineral sunscreens are an attractive, efficacious option for consumers who prefer alternative choices in sun protection.

Insights and controversies on sunscreen safety

Although sunlight provides several benefits, ultraviolet (UV) radiation plays an important role in the development of various skin damages such as erythema, photoaging, and photocarcinogenesis. Despite cells having endogenous defense systems, damaged DNA may not be efficiently repaired at chronic exposure. In this sense, it is necessary to use artificial defense strategies such as sunscreen formulations. UV filters should scatter, reflect, or absorb solar UV radiation in order to prevent direct or indirect DNA lesions. However, the safety of UV filters is a matter of concern due to several controversies reported in literature, such as endocrine alterations, allergies, increased oxidative stress, phototoxic events, among others. Despite these controversies, the way in which sunscreens are tested is essential to ensure safety. Sunscreen regulation includes mandatory test for phototoxicity, but photogenotoxicity testing is not recommended as a part of the standard photosafety testing program. Although available photobiological tests are still the first approach to assess photosafety, they are limited. Some existing tests do not always provide reliable results, mainly due to limitations regarding the nature of the assessed phototoxic effect, cell UV sensitivity, and the irradiation protocols. These aspects bring queries regarding the safety of sunscreen wide use and suggest the demand for the development of robust and efficient in vitro screening tests to overcome the existing limitations. In this way, Saccharomyces cerevisiae has stood out as a promising model to fill the gaps in photobiology and to complete the mandatory tests enabling a more extensive and robust photosafety assessment.

Exposure to ZnO/TiO2 Nanoparticles Affects Health Outcomes in Cosmetics Salesclerks

Concerns about the effects of nanoparticles (NPs) on human health are being raised by researchers because the risks of nanocosmetics like sunscreen are unknown. We explored the association between urinary oxidative stress markers and exposure of cosmetics salesclerks to 20 cosmetics that might contain titanium dioxide (TiO₂)/zinc oxide (ZnO) NPs. We then recruited 40 cosmetics salesclerks and 24 clothing salesclerks and categorized them based on their exposure to ZnO and TiO₂ NPs. Nineteen and 15 samples met the EU definition for TiO₂ and ZnO nanomaterials, respectively. Participants with a higher co-exposure index of ZnO and TiO₂ NPs had a significantly higher base level of urinary 8-hydroxy-2′-deoxyguanosin (8-OHdG) concentrations than the lower co-exposure group (5.82 vs. 2.85 ng/mL, p < 0.001). After potential confounding factors had been adjusted for, the TiO₂ and ZnO NP co-exposure index was significantly positively associated with the urinary 8-OHdG base concentration (β = 0.308, 95% CI = 0.106 to 0.510) and the creatinine-adjusted concentration (β = 0.486, 95% CI = 0.017 to 0.954). Current evidence suggests that the likelihood of harm from using sunscreens containing nanoparticles might result in higher urinary 8-OHdG. However, our limited number and types of sample cosmetics might underestimate the risk.