Photoprotection in ethnic skin

Beyond Traditional Sunscreens: A Review of Liposomal-Based Systems for Photoprotection

Sunscreen products are essential for shielding the skin from ultraviolet (UV) radiation, a leading cause of skin cancer. While existing products serve this purpose, there is a growing need to enhance their efficacy while minimizing potential systemic absorption of UV filters and associated toxicological risks. Liposomal-based formulations have emerged as a promising approach to address these challenges and develop advanced photoprotective products. These vesicular systems offer versatility in carrying both hydrophilic and lipophilic UV filters, enabling the creation of broad-spectrum sunscreens. Moreover, their composition based on phospholipids, resembling that of the stratum corneum, facilitates adherence to the skin's surface layers, thereby improving photoprotective efficacy. The research discussed in this review underscores the significant advantages of liposomes in photoprotection, including their ability to limit the systemic absorption of UV filters, enhance formulation stability, and augment photoprotective effects. However, despite these benefits, there remains a notable gap between the potential of liposomal systems and their utilization in sunscreen development. Consequently, this review emphasizes the importance of leveraging liposomes and related vesicular systems as innovative tools for crafting novel and more efficient photoprotective formulations.

BRAF V600E Mutations and Beyond: A Molecular Perspective of Melanoma from a Tertiary Cancer Referral Center of India

Vaibhavi VengurlekarObjectives  Malignant melanoma demonstrates frequently occurring mutations of genes in the serine/threonine kinase pathway, namely BRAF, NRAS, and neurofibromin 1. There is rare documentation of a detailed analysis of these mutations in cases of melanoma among Indian patients. We present molecular features in cases of malignant melanoma, diagnosed at a tertiary cancer referral center in India, over a period of 8 years (2011-2018). Materials and Methods  This study was performed on formalin fixed paraffin embedded tissues of 88 histologically confirmed cases of malignant melanoma. BRAF gene alterations were studied by both Sanger sequencing and real-time polymerase chain reaction techniques ( n  = 74). Molecular testing for BRAF and NRAS gene alterations was accomplished in 74/88 cases (80%). Molecular test results were correlated with clinicopathological features using IBM SPSS Statistical software 25.0. Results  The age ranged from 13 to 79 years (median = 57), with a M:F ratio of 1.4:1. BRAF mutations were observed in 12/74 (16.21%) patients, including V600E ( n  = 7), A594T ( n  = 1), T599 = ( n  = 2), V600K ( n  = 1), and Q612P ( n  = 1), while NRAS mutations were observed in 6/38 (15.7%) patients. Among various subtypes, nodular melanoma was the most frequent subtype (33%) among cutaneous malignant melanomas. Among non-cutaneous melanomas, mucosal melanomas were observed in 37.5% of cases. Conclusion  This constitutes one of the few reports on comprehensive analysis of molecular alterations underlying melanomas in Indian patients. A larger sample size, with more extensive molecular markers, would yield additional information on the disease manifestation.

Assessment of anthropogenic pollution by UV filters using macrophytes as bioindicators

Marine environment pollution has increased in recent decades as a result of anthropogenic activities. Macrophytes can assimilate the compounds dissolved in the water and respond to changes in surround conditions, for that, they can be used as bioindicators of pollution in aquatic environments. Currently organic ultraviolet (UV) filters have shown ever-increasing in pollution levels in marine ecosystems. The anthropogenic pollution produced by eight organic ultraviolet (UV) filters in coastal macrophytes was studied. A microwave-assisted extraction (MAE), followed by ultrahigh-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) was applied to 76 macrophyte (seaweeds and seagrass) samples from three different beaches on the Gran Canaria Island (Spain), collected for 6 months. All studied UV filters were found with different detection frequencies from 16% to 100% in macrophyte samples. Octocrylene (OC) was detected in all the analysed samples throughout the sampling period. The highest concentration, 19,369 ng·g^-1 dry weight (dw), was for this compound in the seagrass Cymodocea nodosa. The bioconcentration ratio was determined for several seaweed groups (red, brown, green). Different bioconcentration grades were obtained. Those above 1000 indicated significant accumulation, which increases the possibility of chronic effects on seaweed and at upper tropic levels.

Risk factors of recurrence and distant metastasis in primary cutaneous melanoma in Taiwan

Risk factors of recurrence and distant metastasis of acral lentiginous melanoma (ALM) are of great interest for the high percentage of ALM in cutaneous melanoma in Asian populations. This single-center retrospective cohort including 177 patients with localized melanoma diagnosed from 2004 to 2020 aims to identify adverse predictors in cutaneous melanoma in Taiwan, with a focus on ALM. The relationship between clinicopathological features and outcomes, including incidences of recurrence and distant metastasis in 5 years from diagnosis, was analyzed. This study included 124 patients (70.1%) with ALM and 53 (29.9%) with non-ALM melanoma. Regarding clinicopathological characteristics, ALM patients were diagnosed at an older age and received sentinel lymph node biopsies (SLNBs) more often, while adjacent melanocytic nevi were more prevalent in non-ALM patients. With respect to prognostic implications of clinicopathological features, in ALM, implementation of SLNB was associated with a lower 5-year distant metastasis rate. Thickness of melanoma lesions over 4 mm, ulceration, and neurotropism, were related to both higher 5-year recurrence and distant metastasis rates. With regard to non-ALM patients, diagnoses made at or over 65 years old was linked to a higher 5-year recurrence rate, whereas ulceration was associated with both higher 5-year recurrence and distant metastasis rates. In conclusion, several clinicopathological characteristics have been identified to be associated with poor prognosis of cutaneous melanoma, especially ALM.

Challenging Cosmetic Innovation: The Skin Microbiota and Probiotics Protect the Skin from UV-Induced Damage

Many studies performed in the last decade have focused on the cutaneous microbiota. It has been shown that this microbiota plays a key role in skin homeostasis. Considered as “a second barrier” to the environment, it is very important to know how it reacts to exogenous aggressions. The cosmetics industry has a started to use this microbiota as a source of natural ingredients, particularly ones that confer photoprotection against ultraviolet (UV) rays. Interestingly, it has been demonstrated that bacterial molecules can block UV rays or reverse their harmful effects. Oral probiotics containing living microorganisms have also shown promising results in restoring skin homeostasis and reversing the negative effects of UV rays. Microbial-based active sunscreen compounds have huge potential for use as next-generation photoprotection products.

Bemotrizinol-Loaded Carnauba Wax-Based Nanostructured Lipid Carriers for Sunscreen: Optimization, Characterization, and In vitro Evaluation

Nanostructured lipid carriers (NLC) are aqueous dispersions of nanoparticles formed by solid and liquid lipids. In this study, NLC containing an organic UV filter, bemotrizinol, were developed for sunscreen formulation using carnauba wax and caprylic/capric triglycerides through ultrasonication technique. A Box-Behnken design was used to evaluate the influence of three variables on the particle size with the purpose of choosing the best system for further characterization. The particle size decreased as the surfactant concentration increased, reaching an average size of 122.4 ± 0.3 nm at 30 days of storage. Scanning electron microscopy showed intact and spherical particles. Thermal analysis and Fourier-transform infrared spectroscopy suggest that bemotrizinol was incorporated into the NLC. The X-ray diffraction showed a reduction in the crystallinity of the NLC. In vitro analysis indicated an improvement in the photoprotective activity of bemotrizinol when incorporated into NLC. These findings suggest a promising, stable, and biocompatible system.

Sunlight exposure, sun-protective behaviour, and anti-citrullinated protein antibody positivity: A general population-based study in Quebec, Canada

OBJECTIVES

To examine associations between sunlight exposure and anti-citrullinated protein antibodies (ACPA) using general population data in Quebec, Canada.

METHODS

A random sample of 7600 individuals (including 786 positive ACPA subjects and 201 self-reported rheumatoid arthritis, RA cases) from the CARTaGENE cohort was studied cross-sectionally. All subjects were nested in four census metropolitan areas, and mixed-effects logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CIs) for ACPA positivity related to sunlight exposure, adjusting for sun-block use, industrial fine particulate matter (PM_2.5 ) exposures, smoking, age, sex, French Canadian ancestry, and family income. We also performed sensitivity analyses excluding subjects with RA, defining ACPA positivity by higher titers, and stratifying by age and sex.

RESULTS

The adjusted ORs and 95% CIs did not suggest conclusive associations between ACPA and sunlight exposure or sun-block use, but robust positive relationships were observed between industrial PM_2.5 emissions and ACPA (OR 1.19 per µg/m³ , 95% CI 1.03 - 1.36 in primary analyses).

CONCLUSIONS

We did not see clear links between ACPA and sunlight exposure or sun-block use, but we did note positive associations with industrial PM_2.5 . Future studies of sunlight and RA (or ACPA) should take air pollution exposures into account.

Disposable Potentiometric Sensory System for Skin Antioxidant Activity Evaluation

The skin is a natural barrier between the external and internal environment. Its protective functions and the relationship of its state with the state of health of the organism as a whole are very important. It is known that oxidant stress (OS) is a common indicator of health status. This paper describes a new sensory system for monitoring OS of the skin using antioxidant activity (AOA) as its criteria. The contact hybrid potentiometric method (CHPM) and new electrochemical measuring scheme were used. A new sensory system, including disposable modified screen-printed carbon and silver electrodes covered by membrane impregnated by mediator, was developed. Its informative ability was demonstrated in the evaluation of the impact of fasting, consumption of food and food enriched by vitamins (antioxidants) on skin AOA. This device consisting of a sensory system and potentiometric analyzer can be used in on-site and in situ formats.

A Specific Melon Concentrate Exhibits Photoprotective Effects from Antioxidant Activity in Healthy Adults

Skin is the largest body organ and the first barrier to exogenous threats. This organ is constantly exposed to external factors such as ultraviolet radiation, which induces many adverse effects including sunburn, depigmentation, photo aging, photo immune suppression, and even skin cancer. Antioxidants seem to be good candidates in order to reduce ultraviolet-mediated damages and to prevent the health consequences of ultraviolet exposure. The present investigation aims to further characterize the potential skin photoprotective effects of a food supplementation and a topical administration of a melon concentrate alone or in combination. A clinical study assessing the Minimal Erythema Dose (MED) was first set up to evaluate photoprotection. Afterward, an independent in vitro study was performed on human skin explants from a donor to evaluate the effect of the melon concentrate at different levels including on the sunburn cells formation and on the endogenous antioxidant enzymes and its influence on melanin. Clinical study results demonstrate that melon concentrate application and/or supplementation increased MED. It also increased the endogenous antioxidant enzymes and reduced sunburn cells and melanin level on irradiated skin explants. Therefore, it is suggested that melon concentrate administration (oral and/or topical) could be a useful strategy for photoprotection due to its antioxidant properties.

'My child did not like using sun protection': practices and perceptions of child sun protection among rural black African mothers

BACKGROUND

Photodamage is partially mitigated by darker skin pigmentation, but immune suppression, photoaging and cataracts occur among individuals with all skin types.

METHODS

To assess practices and acceptability to Black African mothers of sun protection equipment for their children living in a rural area, participants were recruited at the time of their child's 18-month vaccinations. Mothers completed a baseline questionnaire on usual sun behaviours and sun protection practices. They were then provided with sun protection equipment and advice. A follow-up questionnaire was administered two weeks later.

RESULTS

Mothers reported that during the week prior to the baseline questionnaire, children spent on average less than 1 hour of time outdoors (most often spent in the shade). Most mothers (97%) liked the sun protection equipment. However, many (78 of 86) reported that their child did not like any of the sun protection equipment and two-thirds stated that the sun protection equipment was not easy to use.

CONCLUSIONS

Among Black Africans in rural northern South Africa, we found a mismatch between parental preferences and child acceptance for using sun protection when outdoors. A better understanding of the health risks of incidental excess sun exposure and potential benefits of sun protection is required among Black Africans.

A clinicopathological analysis of 153 acral melanomas and the relevance of mechanical stress

The pathogenesis of melanomas emerging in plantar surfaces remains unclear; however, mechanical stress has been reported to increase the formation of melanomas. In this study, we conducted a multicenter retrospective analysis of 153 acral melanomas diagnosed between 2000 and 2015 in Taiwan. The male-to-female ratio of the patients in question was 1:1.28, and the mean age at diagnosis was 68 years. We examined whether melanomas which developed in different areas of the patients' soles differed in their associations with various clinicopathological characteristics and survival. Testing by goodness of fit indicated that stress-bearing areas were significantly more conducive to the generation of melanomas than non-stress-bearing areas (P < 0.0001). More specifically, compared to the arch, the rear of the foot and front of the foot were significantly more conducive to the generation of melanomas (P < 0.0001 and P < 0.0001, respectively). The distribution pattern was not associated with differences in age, gender, right/left foot involvement, ulceration, mitosis, lymph node metastasis, tumor thickness, or stage. The overall, distant metastasis-free, and recurrence-free survival rates did not differ significantly between the stress-bearing and non-stress-bearing areas. Furthermore, while acral melanomas tended to develop on stress-bearing areas, the distribution pattern was not associated with the prognostic index or survival.

Clinicopathological features and prognosis of patients with de novo versus nevus-associated melanoma in Taiwan

Studies surveying melanomas associated with melanocytic nevi in Asia are rare. In this study, we examined whether nevus-associated melanomas differ from de novo melanomas in terms of their associations with clinical factors, histologic characteristics, and patient survival in Taiwan. Using data on cancer cases obtained from the Department of Pathology archives and the Cancer Registry of National Taiwan University Hospital, we conducted a retrospective analysis of 103 consecutive melanoma patients who were diagnosed between 2010 and 2015 and received follow-up through November 2016. Approximately 17.5% of the melanomas in question were associated with a nevus. In patients under 65 years of age, non-acral lentiginous melanomas were significantly associated with a higher percentage of nevus-associated melanomas. The superficial spreading subtype, younger patient age, thinner tumor, intermittent solar exposure, and early stage were significant predictors of a melanoma being histologically associated with a nevus. The appearance of a nevus associated with a melanoma predicted better recurrence-free survival compared with de novo melanomas. Although acral lentiginous melanomas (70.9%) constituted the most common histologic subtype, only 9.6% of the acral lentiginous melanomas were associated with a nevus. Furthermore, there was no statistically significant difference between the nevus-associated and de novo acral lentiginous melanomas with regard to clinicopathological factors and survival. In conclusion, nevus-associated melanomas were uncommon among acral lentiginous melanomas. Relatedly, because over half of all melanomas in Asians are acral lentiginous melanomas, Asians are less likely than Caucasians to have nevus-associated melanomas.