Melanogenic Difference Consideration in Ethnic Skin Type: A Balance Approach Between Skin Brightening Applications and Beneficial Sun Exposure

Clinical Applications of Sunscreens and Formulation Advancements

Sunscreens cover the big market ratio in terms of cosmetic applications, but the therapeutic necessity of sunscreen still needs to be uncovered in the clinical context. Clinically, sunscreens are being employed more often nowadays as a result of the rising consequences of skin malignancies and the photodamaging effects of UV radiation. Sunscreens are essential to prevent aging by shielding the skin from the harmful effects of ultraviolet (UV) radiation. Over the recent decades, there has been a significant evolution in the usage of sunscreens as photo protectants. The demand for sunscreen formulations will inevitably rise as more people become aware of the protection that sunscreens provide against tanning, photoaging, non-melanoma skin cancers, premalignant skin lesions, and skin melanomas. The novel contemporary formulation techniques are also beneficial in enhancing the product's aesthetic look and quality. Recently, regulatory agencies have also started paying attention to the regulation of the clinical application, efficacy, and safety parameters related to sunscreen. This review underlines the pathophysiological response of UV exposure with the therapeutic applications of sunscreen in various dermatological conditions and the recent formulation advancements in the development of sunscreen.

Vitamin D and wound healing: Assessing skin barrier function and implications for chloasma treatment

Chloasma, which is distinguished by irregularities in the pigmentation of skin, poses substantial challenge in the field of dermatology. The regulatory influence of vitamin D on the functions of skin cells implies that it may have the capacity to effectively treat chloasma and promote wound healing. To assess the efficacy of vitamin D in chloasma treatment and its impact on the function of skin barrier during the process of wound healing. The research spanned from April 2022 to September 2023, in Shanghai, China, examined 480 individuals who had been diagnosed with chloasma. A double-blind, placebo-controlled clinical trial was utilized to evaluate effectiveness of topical vitamin D3 in treatment of chloasma. Concurrently, randomized control trial investigated the effects of ingested vitamin D3 supplements on the process of wound healing. Transepidermal water loss (TEWL), chloasma severity score changes, wound size reduction and skin hydration levels were critical performance indicators. Statistically, the severity scores of chloasma decreased significantly in the vitamin D treatment group at 3 and 6 months compared with the placebo (p < 0.05). The Vitamin D group exhibited superior wound healing outcomes, including more substantial reduction in lesion size and enhanced skin barrier function, as evidenced by increased skin hydration and decreased TEWL (p < 0.05). Vitamin D substantially mitigated the severity of chloasma and has beneficial effect on wound healing and integrity of the skin barrier. Based on the results obtained, vitamin D exhibited promise as a therapeutic intervention in the field of dermatology, specifically in treatment of chloasma and promotion of wound recovery.

12-Week, Single-Center Study of a Targeted Pigment-Correcting Dark Spot Treatment for Post-Inflammatory Hyperpigmentation and Solar Lentigines

Purpose

Post-inflammatory hyperpigmentation (PIH) and solar lentigines are dark spots of skin from excessive melanin production due to injury or UV exposure. This 12-week single-center study assessed the efficacy and tolerability of a novel targeted pigment-correcting spot treatment gel suspension cream (Dark Spot Treatment) for improving mild-to-moderate PIH or solar lentigines.

Patients and Methods

Female participants (N = 41) aged 25-65 with mild-to-moderate facial dark spots applied Dark Spot Treatment daily for 12 weeks. Investigators assessed overall hyperpigmentation, skin tone evenness, and dark spot intensity, contrast, and size at Weeks 2, 4, 8, and 12. Participant self-assessments occurred at Weeks 1, 2, 4, 8, and 12. Tolerability was assessed by clinical grading and participant reporting.

Results

Dark Spot Treatment improved overall hyperpigmentation, skin tone evenness, and dark spot intensity and contrast at Weeks 2 through 12, and dark spot size at Weeks 4 through 12 (all p < 0.001 compared to baseline). Participant self-assessments showed high overall satisfaction. Dark Spot Treatment was well tolerated.

Conclusion

The novel pigment-correcting Dark Spot Treatment significantly improved the appearance of PIH and solar lentigines, had high participant satisfaction, and was well tolerated.

A Cross-Sectional Assessment of Quantitative Epidermal Melanin and Erythema Indices among North Indians

Background

Remarkable diversity of skin tones among Indians ranging from pale pinkish to dark brown appears to be an ideal choice for the assessment of skin pigment variation.

Aim

The present study was designed to assess the variation observed in melanin and erythema indices among north Indians.

Material and Methods

Skin reflectance data (n = 574) was collected from six diverse populations of north India using DermaSpectrometer (DSM II ColorMeter) followed by statistical analysis to investigate the impact of geographical location and gender on constitutive skin pigmentation.

Results

The melanin index (MI) varied between 17.93 and 56.92 (Mean (M) = 35.80 ± 6.26) whereas the erythema index (EI) varied between 4.92 and 18.82 (M = 10.48 ± 2.68). MI and EI of females were found to be significantly lower than males (P < 0.001). Geographical location exhibited a significant association with MI and EI (P < 0.001). Furthermore, we have noted a positive correlation between MI and EI (P < 0.001).

Conclusion

The study has refined our understanding of skin pigmentation variation among north Indians in terms of significant association with geographical location {MI: F _(5,568) = 31.07, P < 0.001; EI: F _(5,568) = 73.37, P < 0.001} and gender {MI: t ₍₃₈₆₎ = -4.06, P < 0.001; EI: t ₍₃₈₆₎ = -11.96, P < 0.001} and rendered opportunities for further studies.

Melanin levels in relation to vitamin D among first-generation immigrants from different ethnic groups and origins: A comparative national Canadian cross-sectional study

Introduction

Immigrants to Western countries tend to have darker skin than native-born populations. We examined the relationship between skin melanin and serum vitamin D (vitD) [S-25(OH)D] levels and explored whether melanin levels explained S-25(OH)D variations between immigrants and native-born Canadians. This study offers novel findings as no such study has been conducted.

Methods

We used a national cross-sectional population-based design with data from the Canadian Health Measures Survey (CHMS). Skin melanin levels among first-generation immigrants based on their ethnicity and origin/country of birth were compared with white and native-born populations. We assessed the association between S-25(OH)D and melanin after adjusting for independent variables related to S-25(OH)D, melanin level, and immigration status.

Results

Of 11,579 participants, 21.9% were immigrants aged 3-79 years (mean age 39.23 years). Compared with non-immigrants, immigrants had lower S-25(OH)D levels (mean: 51.23 vs. 62.72; 95% CI: 8.37, 14.62; P < 0.001) but higher melanin levels (mean [SE]: 17.08 [0.25] vs. 16.29 [0.29]; 95% CI: -1.29, -0.281; P = 0.004). Melanin did not differ by length of stay in Canada but was weakly positively correlated (r = 0.088, P < 0.001) with S-25(OH)D. Sex (male), age (≥18 years), summer/fall seasons, sunlight exposure, sunscreen non-use, smoking, and alcohol consumption were associated with higher melanin levels, whereas indoor tanning use was not.

Conclusion

Skin melanin levels were associated with sociodemographic and behavioral characteristics. Immigrants had higher melanin levels, but melanin did not differ by length of stay in Canada. The weak positive correlation between melanin and S-25(OH)D suggested confounding factors may impact the relationship between melanin levels, S-25(OH)D, and immigration status.

Pharmaceutical based cosmetic serums

The growth and demand for cosmeceuticals (cosmetic products that have medicinal or drug-like benefits) have been enhanced for the last few decades. Lately, the newly invented dosage form, i.e., the pharmaceutical-based cosmetic serum has been developed and widely employed in various non-invasive cosmetic procedures. Many pharmaceutical-based cosmetic serums contain natural active components that claim to have a medical or drug-like effect on the skin, hair, and nails, including anti-aging, anti-wrinkle, anti-acne, hydrating, moisturizing, repairing, brightening and lightening skin, anti-hair fall, anti-fungal, and nail growth effect, etc. In comparison with other pharmaceutical-related cosmetic products (creams, gels, foams, and lotions, etc.), pharmaceutical-based cosmetic serums produce more rapid and incredible effects on the skin. This chapter provides detailed knowledge about the different marketed pharmaceutical-based cosmetic serums and their several types such as facial serums, hair serums, nail serums, under the eye serum, lip serum, hand, and foot serum, respectively. Moreover, some valuable procedures have also been discussed which provide prolong effects with desired results in the minimum duration of time after the few sessions of the serum treatment.

Skin pigmentation and vitamin D-folate interactions in vascular function: an update

PURPOSE OF REVIEW

Vitamin D and folate promote vascular endothelial health and may therefore help mitigate the development of cardiovascular disease (CVD). Ultraviolet radiation (UVR) exposure stimulates cutaneous vitamin D synthesis but degrades the bioactive metabolite of folate, 5-methyltetrahydrofolate (5-MTHF). Skin melanin absorbs UVR, thereby modulating the impact of UVR exposure on vitamin D and 5-MTHF metabolism. This review presents recent findings regarding the inter-relations among UVR, skin pigmentation, folate and vitamin D, and endothelial function.

RECENT FINDINGS

Evidence for roles of folic acid or vitamin D supplementation on CVD endpoints is inconsistent, although preclinical and clinical studies have demonstrated the efficacy of both micronutrients for improving endothelial function. Vitamin D deficiency is most prevalent in darkly pigmented individuals living in relatively low-UVR environments. Conversely, there is a negative relation between accumulated UVR exposure and serum folate concentration in lightly pigmented adults. The interactions among UVR and bioavailable folate and vitamin D differentially impact endothelial function in differently pigmented skin.

SUMMARY

UVR exposure disparately impacts folate and vitamin D metabolism in differently pigmented skin depending upon regional UVR intensity and seasonality. These findings present new clinical research questions regarding the interactions among UVR, skin pigmentation, folate and vitamin D bioavailability, and endothelial health.

An Open-Label Study Assessing the Efficacy and Tolerability of a Skincare Regimen in Subjects of Different Ethnicities with Moderate-to-Severe Hyperpigmentation

Background

Hyperpigmentation is a common cosmetic concern that significantly impacts self‐esteem. A skincare regimen has been developed to improve the appearance, tone, texture, and luminosity of subjects with facial hyperpigmentation (Even Up^® Hyperpigmentation Regimen; Colorescience, Inc., Carlsbad, CA).

Aims

The objective of this open‐label trial was to assess the efficacy and tolerability of this regimen for treating facial hyperpigmentation.

Patients/Methods

Subjects with moderate‐to‐severe facial hyperpigmentation (N = 33) were randomized to those not using prescription, advanced or physician‐dispensed skin care products (Group A, n = 23) and those currently using prescription, advanced or physician‐dispensed skincare products for facial hyperpigmentation (Group B, n = 10). Both groups were provided three skincare products comprising the hyperpigmentation regimen and instructions for use. Subjects were evaluated at baseline and Weeks 2, 4, 8 and 12.

Results

The overall median (range) baseline MASI score at baseline was 9.0 (2, 31), decreasing by 0.0 (−7, 0) points at Week 2 (p = 0.002), 0.6 (−8, 0) points at Week 4 (p < 0.0001), 1.5 (−16, 0) points by Week 8 (p < 0.0001) and 2.4 (−20, 0) points at Week 12 (p < 0.0001). At Week 12, the overall median improvement in MASI score was 26% and higher for Group B (32% vs. 22%). By Week 2, subjects reported lighter, less noticeable brown spots (76%), brighter, more luminous skin (88%), more even skin tone (67%), and healthier look and feel (85%). Improvements continued throughout the study. No adverse events were observed or reported.

Conclusions

This regimen addresses facial hyperpigmentation and protects skin against the damaging effects of ultraviolet and high energy visible light (HEV). It is safe to use on all skin types and tones.

GWAS Identifies Multiple Genetic Loci for Skin Color in Korean Women

Human skin color is largely determined by genetic factors. Recent GWASs have reported several genetic variants associated with skin color, mostly in European and African populations. In this study, we performed GWAS in 17,019 Korean women to identify genetic variants associated with facial skin color, quantitatively measured as CIELAB color index. We identified variants in three, one, and six genomic loci associated with facial skin color index L∗, a∗, and b∗ values, respectively, and replicated the associations (combined analysis P-value < 5.0 × 10^-8). The significant loci included variants in known genes (OCA2 rs74653330, BNC2 rs16935073, rs72620727 near KITLG, and SLC6A17 rs6689641) and to our knowledge previously unreported genes (SCARB1 rs10846744, SYN2 rs12629034, and LINC00486 rs6543678). This is GWAS to elucidate genetic variants of facial skin color in a Korean female population. Further functional characterizations of the investigated genes are warranted to elucidate their contribution to skin pigmentation-related traits.

Influence of Ethnicities and Skin Color Variations in Different Populations: A Review

BACKGROUND

In the world scientific tradition, skin color is the primary physical characteristic used to divide humans into groups. Human skin has a wide range of tones and colors, which can be seen in a wide range of demographic populations. Many factors influence the color of people's skin, but the pigment melanin is by far the most important. Melanin is produced by cells called melanocytes in the skin and is the primary determinant of skin color in people with darker skin. Indeed, >150 genes have now been identified as having a direct or indirect effect on skin color. Vitamin D has recently been discovered to regulate cellular proliferation and differentiation in a variety of tissues, including the skin. The mechanisms through which the active vitamin D metabolite 1,25 dihydroxyvitamin D3 (or calcitriol) affects keratinocyte development are numerous and overlap with the mechanisms by which calcium influences keratinocyte differentiation. Ultraviolet (UV) is the most major modifiable risk factor for skin cancer and many other environmental-influenced skin disorders when it is abundant in the environment. Although the UV component of sunlight is known to cause skin damage, few researches have looked at the impact of non-UV solar radiation on skin physiology in terms of inflammation, and there is less information on the role of visible light in pigmentation.

SUMMARY

The quantity and quality of melanin are regulating by the expression of genes. The enzyme tyrosinase is primarily responsible for the genetic mechanism that controls human skin color. Genetics determines constitutive skin color, which is reinforced by facultative melanogenesis and tanning reactions. High quantities of melanin and melanogenic substances are typically accepted in darker skin to protect against UV radiation-induced molecular damage. Previous research has proposed that skin color variation is caused by a dynamic genetic mechanism, contributing to our understanding of how population demographic history and natural selection shape human genetic and phenotypic diversity. However, the most significant ethnic skin color difference is determined by melanin content. This current review aimed to assess the influence of skin color variations in skin structure and functions as well as difference in dermatological disease patterns. Also, this article reviewed several cases of skin color adaptation in different populations. Key Messages: Skin color impacts the composition and activity. Therefore, the contrast of dermatological ailments between distinct race-related categories is remarkable. Skin color adaptation is a challenging procedure. Refinement of skin color is an age-old craving of humans with ever-evolving drifts.

Pooled Sequencing Analysis of Geese (Anser cygnoides) Reveals Genomic Variations Associated With Feather Color

During the domestication of the goose a change in its feather color took place, however, the molecular mechanisms responsible for this change are not completely understood. Here, we performed whole-genome resequencing on three pooled samples of geese (feral and domestic geese), with two distinct feather colors, to identify genes that might regulate feather color. We identified around 8 million SNPs within each of the three pools and validated allele frequencies for a subset of these SNPs using PCR and Sanger sequencing. Several genomic regions with signatures of differential selection were found when we compared the gray and white feather color populations using the F_ST and Hp approaches. When we combined previous functional studies with our genomic analyses we identified 26 genes (KITLG, MITF, TYRO3, KIT, AP3B1, SMARCA2, ROR2, CSNK1G3, CCDC112, VAMP7, SLC16A2, LOC106047519, RLIM, KIAA2022, ST8SIA4, LOC106044163, TRPM6, TICAM2, LOC106038556, LOC106038575, LOC106038574, LOC106038594, LOC106038573, LOC106038604, LOC106047489, and LOC106047492) that potentially regulate feather color in geese. These results substantially expand the catalog of potential feather color regulators in geese and provide a basis for further studies on domestication and avian feather coloration.