Impact on facial skin aging signs of a 1-year standardized photoprotection over a classical skin care routine in skin phototypes II-VI individuals: A prospective randomized trial

Gain of Protection Afforded by the Methoxypropylamino Cyclohexenylidene Ethoxyethylcyanoacetate (MCE) UVA1 Filter on Pigmentary and Aging Signs: An Outdoor 4-Week Randomized, Intra-Individual Comparative Study in 52 Brazilian Women

BACKGROUND

Conventional sunscreens shield the skin from ultraviolet (UV) rays up to 370 nm leaving wavelengths between 370 and 400 nm unfiltered despite their potentially harmful biological and clinical effects.

OBJECTIVE

The beneficial effects of methoxypropylamino cyclohexenylidene ethoxyethylcyanoacetate (MCE) UVA1 filter were explored at 1% in a SPF50 sunscreen under outdoors summer conditions against pigmentation and aging signs compared against a reference SPF50 without the MCE filter.

MATERIALS AND METHODS

A prospective randomized comparative intra-individual study was conducted in 52 Brazilian women (phototype I-III). A hemiface application was performed for the SPF50 sunscreen with 1% MCE and SPF50 reference without MCE before 1-h outdoor sunlight exposure, twice daily for 4 weeks. Study endpoint included expert panel grading of pigmentation (3), vascular (1) signs as well as facial skin ageing and assessment of facial skin radiance and skin homogeneity by a naïve panel.

RESULTS

Significant differences were reported for all facial signs comparing areas protected with SPF50/MCE and SPF50, respectively: upper lip wrinkles, crow's feet wrinkles, upper lip texture, upper lip pigmentation, vascular abnormalities (all p < 0.0001), texture of the mouth contour (p = 0.001), ptosis of lower face (p = 0.003), lateral facial pigmentation (p = 0.005), and whole face pigmentation (p = 0.01). The evaluations performed by naïve panel showed a significant superiority of the SPF50/MCE product for skin homogeneity (p = 0.043).

CONCLUSION

Overall, this study demonstrates a significant gain of protection with the SPF50 containing 1% MCE in reducing hyperpigmentation, redness and aging signs compared to the same SPF50 sunscreen without MCE, thus supporting the need for an enlarged UVA1 photoprotection.

A Bayesian network meta-analysis of 14 molecules inhibiting UV daylight-induced pigmentation

INTRODUCTION

Hyperpigmentation disorders are very frequent, affect the quality of life and may become a psychological burden for afflicted patients. Many anti-pigmenting or depigmenting agents are available with various efficacy and almost no comparative data. 2-mercaptonicotinoyl glycine (2-MNG) was recently proposed as a viable candidate showing safe and effective results on hyperpigmentation control in vitro and in vivo.

OBJECTIVES

A Bayesian network meta-analysis (BNMA) was conducted to map and rank the anti-pigmenting and depigmenting efficacy of 2-MNG 0.5% on UV daylight (UVDL)-induced pigmentation together with 13 other reference molecules. A comparison in the kinetics of 2-MNG 0.5% was also performed.

METHODOLOGY

Fourteen studies were conducted, for each, on 15-30 women of skin phototype III in Shanghai, China and Paris, France. The products were applied on mini zone, in randomized and blinded protocol, on the back, 5 days a week during 6 weeks, at a dose of 4 mg/cm2. During the second week, volunteers were exposed under to varying minimum erythemal dose of UVDL during 4 consecutive days-adapted to obtain a similar induction of skin pigmentation regardless of the population. Assessments were performed instrumentally using Chromameter®. Ascorbic acid 7% was used as a positive control for all experiments. A Bayesian network meta-analysis was then established to map and follow the kinetics of 2-MNG 0.5% performance with 13 reference molecules (glutathione 2%, kojic acid 1%, hydroquinone 4%, ascorbyl glucoside 2%, niacinamide 4%, etc.).

RESULTS

2-MNG 0.5% dominated the ranking at all time points with a significant high probability of strong efficacy against UVDL-induced pigmentation. Ascorbic acid 7% ranks second after 4 days of irradiations (D12) whereas hydroquinone 4% ranks second 1 month after irradiations (D40). In the kinetics, 2-MNG at 0.5% was effective as from the end of irradiations (D12) to the study endpoint (D40). This suggested an immediate and persistent efficacy across all timepoints evaluated.

CONCLUSION

The BNMA revealed a rapid and lasting efficacy of 2-MNG 0.5% on the anti-pigmenting and depigmenting phases of the clinical protocol. 2-MNG 0.5% ranked first, with immediate and lasting effect compared to 13 other references. This study is the first allowing comparison between reference anti-pigmenting and depigmenting agents and will help clinicians for proposing the most effective approach for their patients.

Awareness of sun exposure risks and photoprotection for preventing pigmentary disorders in Asian populations: Survey results from three Asian countries and expert panel recommendations

BACKGROUND

In this article, we review and discuss the photoprotection behavior of Asians based on the literature, along with a subanalysis of an original online survey, and make recommendations to optimize photoprotection for Asian populations to prevent photoaging and pigmentary disorders.

METHODS

An international panel of eight dermatologists from Asia (China, Korea, Japan, Singapore, Indonesia, and Vietnam) met to discuss sunscreen photoprotection for Asian patients. Additionally, a subanalysis of an online survey by 3000 respondents from three Asian countries (China, Indonesia, and Japan) investigated general public awareness and attitudes to sun exposure.

RESULTS

A pre-meeting survey of the eight experts from Asia showed key concerns of Asian patients consulting dermatologists are pigmentary disorders, especially actinic/senile lentigo, post-inflammatory hyperpigmentation, melasma, vitiligo, and Hori's nevus. The survey subanalysis of participants from China, Indonesia, and Japan with predominantly Fitzpatrick skin types (FST) II to IV revealed that they are particularly concerned about sun exposure causing photoaging and pigmentary disorders. Most of the respondents indicated they have limited knowledge on sunlight radiation and appropriate sunscreen protection factors. Only 22%, 13%, and 3% for China, Indonesia, and Japan, respectively, systematically use multiple protective measures (using sunscreen, avoiding midday sun, staying in the shade, wearing a hat, protective clothing, and sunglasses) when exposed to the sun.

CONCLUSIONS

Further education is needed for Asian populations on the importance of comprehensive daily photoprotection, including broad-spectrum sunscreen, with high UVA and visible light protection, to reduce and prevent photoaging and pigmentary disorders.

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.