Role of kinin receptors in skin pigmentation

Previous studies have shown that all kinin system is constitutively expressed in the normal and inflamed skin, with a potential role in both physiological and pathological processes. However, the understanding regarding the involvement of the kinin system in skin pigmentation and pigmentation disorders remains incomplete. In this context, the present study was designed to determine the role of kinins in the Monobenzone (MBZ)-induced vitiligo-like model. Our findings showed that MBZ induces higher local skin depigmentation in kinin receptors knockout mice (KOB1R, KOB2R and KOB1B2R) than in wild type (WT). Remarkably, lower levels of melanin content and reduced ROS generation were detected in KOB1R and KOB2R mice treated with MBZ. In addition, both KOB1R and KOB2R show increased dermal cell infiltrate in vitiligo-like skin, when compared to WT-MBZ. Additionally, lack of B1R was associated with greater skin accumulation of IL-4, IL-6, and IL-17 by MBZ, while KOB1B2R presented lower levels of TNF and IL-1. Of note, the absence of both kinin B1 and B2 receptors demonstrates a protective effect by preventing the increase in polymorphonuclear and mononuclear cell infiltrations, as well as inflammatory cytokine levels induced by MBZ. In addition, in vitro assays confirm that B1R and B2R agonists increase intracellular melanin synthesis, while bradykinin significantly enhanced extracellular melanin levels and proliferation of B16F10 cells. Our findings highlight that the lack of kinin receptors caused more severe depigmentation in the skin, as well as genetic deletion of both B1/B2 receptors seems to be linked with changes in levels of constitutive melanin levels, suggesting the involvement of kinin system in crucial skin pigmentation pathways.

Efficacy and tolerability of a depigmenting gel serum comprising tranexamic acid, niacinamide, 4-butylresorcinol, phytic acid, and a mixture of hydroxy acids that targets the biological processes regulating skin melanogenesis

BACKGROUND

The diverse causes of hyperpigmentation and complex nature of melanogenesis make it a challenge to manage. Current approaches either fail to deliver effective pigmentation control or have undesirable safety profiles that preclude their long-term use.

AIMS

To evaluate the capacity of a cosmetic gel serum comprising tranexamic acid, niacinamide, 4-butylresorcinol, phytic acid, and a mixture of hydroxy acids that was designed to target the biological processes regulating skin melanogenesis to attenuate melanin production in vitro and reduce hyperpigmentation clinically.

METHODS

Capacity to reduce melanin production in vitro was determined in melanocyte-containing reconstructed human epidermis (RHEm). Clinical efficacy and skin tolerability following twice daily application were assessed in 35 subjects with slight to moderate facial hyperpigmentation by instrumental (VISIA®-CR, Mexameter®) and clinical (mMASI, clinical score, IGA for hyperpigmentation) evaluation on D14, D28, D56, and D84. Maintenance of pigmentation control was followed up 1 month after cessation of treatment on D112.

RESULTS

In RHEm in vitro, melanin production was reduced by 50.0% from baseline (D0) on D14 (p < 0.001) and by 67.0% on D21 (p < 0.001). Clinical reductions from baseline in brown spots count (-9.0%; p < 0.05), brown spots area (-16.7%; p < 0.001), and the melanin index (-11.4%; p < 0.001) were observed within 14 days of use. Statistically significant improvements in all clinical parameters were achieved by D28. By the end of treatment on D84, the number and surface area of brown spots were reduced by 28.4% and 40.3% compared to D0, respectively (p < 0.001, both), the melanin index was reduced by 31.1% (p < 0.001), mMASI was reduced by 63.0% (p < 0.001), and skin luminosity was increased by 79.0% (p < 0.001). IGA was reduced from 2.3 on D0 to 1.3 on D84 (p < 0.001). Improvements to all these parameters were maintained until D112, 1 month after termination of treatment. The product also demonstrated very good skin tolerability.

CONCLUSION

A gel serum comprising tranexamic acid, niacinamide, 4-butylresorcinol, and hydroxy acids, designed to target the biological processes regulating skin melanogenesis, demonstrates rapid, robust, and sustained pigmentation control in this cohort.

Evaluation of efficacy and safety of vitiligo treatment with micro-needling combined with N-Acetylcysteine and micro-needling alone: A double-blinded randomized controlled clinical trial

INTRODUCTION

Vitiligo is a skin pigmentation disorder caused by the selective degradation of melanocytes. This study investigates the therapeutic effects of microneedling with and without N-acetylcysteine (NAC) in patients with persistent and limited vitiligo.

METHOD

This research employed a clinical trial design with double-blind randomization. Individuals affected by vitiligo and seeking treatment at Rasool Akram Medical Complex were divided into two separate treatment groups. In the intervention group, 24 affected areas underwent meso-microneedling using 5% NAC ampoules over six sessions, in addition to the application of 4.7% NAC cream once daily on the specified area. Conversely, the control group, consisting of 22 lesions, underwent microneedling using distilled water during six sessions. The severity of lesions and the extent of repigmentation were gauged using the Modified VETI Score. Assessment of treatment efficacy was determined through both physician evaluations and patient feedback.

RESULTS

Twenty patients with a mean age of 36.4 years were recruited. The mean percentage of lesions and their intensity were significantly improved 2 weeks after the third session and 1 month after the end of the treatment (p < 0.01). There was no statistically significant difference between the intervention and control groups. Gender, age, family history, duration of disease, duration of disease stability, and history of hypothyroidism had no statistically significant relationship with patients' treatment outcomes (p > 0.05).

CONCLUSION

Microneedling with or without the application of NAC appears to be an effective treatment option for persistent vitiligo lesions. However, despite the higher improvement rate with the application of NAC, the difference was not significant.

Skin lightening properties of zerumbone cream: A placebo-controlled study

OBJECTIVE

Despite the demonstrated anti-melanogenic and UV protective effects of Zerumbone (ZER) in vitro, there is a lack of clinical trials that have been done to assess these properties. The primary objective of this study was to assess the effectiveness of ZER in lightening the skin tone of human participants with a single-blind approach.

METHODS

Twenty-six participants were randomly assigned to two groups to investigate the application location (left or right volar forearm) for the placebo and ZER creams. Both creams were topically administered to the volar forearms twice daily over a duration of 4 weeks. Initial skin irritation was assessed before and 30 min after applying creams. The melanin and erythema levels were quantified with Mexameter MX 18.

RESULTS

Twenty participants were included in the analysis. The cream formulation had excellent physical properties and was well-received by the participants. The initial skin irritation study results indicated that neither of the creams elicited an allergic reaction. The administration of ZER cream resulted in a statistically significant reduction in melanin levels (p < 0.05) after 1 week compared to the initial baseline. Furthermore, after 2 weeks of application, ZER cream demonstrated significant differences in melanin levels compared to placebo (p < 0.05). No adverse effects were observed in the group using ZER cream.

CONCLUSION

ZER demonstrated significant potential as a skin-lightening agent.

2-Mercaptonicotinoyl glycine prevents UV-induced skin darkening and delayed tanning in healthy subjects: A randomized controlled clinical study

BACKGROUND

Chronic nonextreme sun exposure induces two mechanisms of skin pigmentation, causing immediate darkening and delayed tanning. A new molecule, 2-mercaptonicotinoyl glycine (2-MNG), has been shown in vitro to inhibit both immediate darkening and new melanin synthesis via covalent conjugation of the thiol group of 2-MNG to melanin precursors.

OBJECTIVE

To evaluate 2-MNG in preventing both mechanisms in vivo.

METHODS

In a randomized, intra-individual and controlled study, 33 subjects with melanin-rich skin were exposed to UV daylight on designated areas on the back and treated with a cosmetic formula containing 0.5% or 1% 2-MNG alone or 0.5% 2-MNG in association with lipohydroxy acid (LHA, 0.3%) plus Mexoryl-SX (MSX, 1.5%). The respective vehicles were used as controls and 4-n-butyl-resorcinol (4-n-BR, 2.5%) as a positive reference.

RESULTS

2-MNG alone significantly reduced immediate darkening and inhibited new melanin production when compared with vehicle, with higher performance at 1% than at 0.5%. 2-MNG at 0.5% in association with LHA and MSX showed significantly higher performance than 2-MNG 0.5% alone. 2-MNG at 0.5% and 1% showed significantly better performance than 4-n-BR.

CONCLUSIONS

2-MNG inhibited both UV-induced skin pigmentation mechanisms in vivo. The association of 2-MNG with LHA plus MSX showed the highest efficacy on melanin-rich skin with pigmentation induced by UV exposure.

A Mixture of Topical Forms of Polydeoxyribonucleotide, Vitamin C, and Niacinamide Attenuated Skin Pigmentation and Increased Skin Elasticity by Modulating Nuclear Factor Erythroid 2-like 2

It is well-known that increased oxidative stress caused by ultraviolet B (UV-B) radiation induces melanogenesis and activates metalloproteinases (MMPs), which degrade collagen and elastin fibers, leading to decreased skin elasticity. Various antioxidant agents, such as vitamin C and niacinamide, have been evaluated for use as treatments for photoaging or skin pigmentation. In this study, we evaluated the ability of a topical liquid formula of polydeoxyribonucleotide (PDRN), vitamin C, and niacinamide (PVN) delivered via a microneedling therapy system (MTS) to attenuate photoaging and pigmentation by increasing nuclear factor erythroid 2-like 2 (NRF2)/heme oxygenase-1 (HO-1) and decreasing MMP expression in a UV-B-radiated animal model. The effects of the PVN were compared with those of individual PDRN and hydroquinone (HQ) compounds. The expression of NRF2/HO-1 significantly increased in response to HQ, PDRN, and PVN in UV-B-radiated animal skin. The activity of nicotinamide adenine dinucleotide phosphate hydrogen oxidase decreased in response to HQ, PDRN, and PVN, and the superoxide dismutase activity increased. The expression of tumor protein p53 and microphthalmia-associated transcription factor and tyrosinase activity decreased in response to HQ, PDRN, and PVN, and this decrease was accompanied by decreased melanin content in the skin. The expression of nuclear factor kappa-light-chain enhancer of activated B cells and MMP2/3/9 decreased in response to HQ, PDRN, and PVN in UV-B-radiated skin. However, the expression of collagen type I α1 chain and the amount of collagen fibers that were evaluated by Masson’s trichrome staining increased in response to HQ, PDRN, and PVN. The contents of elastin fibers, fibrillin 1/2 and fibulin 5 increased in response to HQ, PDRN, and PVN. In conclusion, PVN delivered via MTS led to decreased melanogenesis and destruction of collagen and elastin fibers by MMPs, and, thus, PVN decreased skin pigmentation and increased skin elasticity.

In vivo melanin 3D quantification and z-epidermal distribution by multiphoton FLIM, phasor and Pseudo-FLIM analyses

Characterizing melanins in situ and determining their 3D z-epidermal distribution is paramount for understanding physiological/pathological processes of melanin neosynthesis, transfer, degradation or modulation with external UV exposure or cosmetic/pharmaceutical products. Multiphoton fluorescence intensity- and lifetime-based approaches have been shown to afford melanin detection, but how can one quantify melanin in vivo in 3D from multiphoton fluorescence lifetime (FLIM) data, especially since FLIM imaging requires long image acquisition times not compatible with 3D imaging in a clinical setup? We propose an approach combining (i) multiphoton FLIM, (ii) fast image acquisition times, and (iii) a melanin detection method called Pseudo-FLIM, based on slope analysis of autofluorescence intensity decays from temporally binned data. We compare Pseudo-FLIM to FLIM bi-exponential and phasor analyses of synthetic melanin, melanocytes/keratinocytes coculture and in vivo human skin. Using parameters of global 3D epidermal melanin density and z-epidermal distribution profile, we provide first insights into the in vivo knowledge of 3D melanin modulations with constitutive pigmentation versus ethnicity, with seasonality over 1 year and with topical application of retinoic acid or retinol on human skin. Applications of Pseudo-FLIM based melanin detection encompass physiological, pathological, or environmental factors-induced pigmentation modulations up to whitening, anti-photoaging, or photoprotection products evaluation.

Estimation of reflectance, transmittance, and absorbance of cosmetic foundation layer on skin using translucency of skin

We developed a method to estimate the reflectance, transmittance, and absorbance of a layer of cosmetic foundation (FD) applied to skin from the reflectance of bare skin and FD applied to skin under two measurement conditions using the translucency of skin. Conversely, using the relationship between the applied amount of FD and the reflectance of the FD layer, the applied amount could be estimated. These values could be measured stably regardless of the similarity of reflectance and color between bare skin and made-up skin. The measured values were taken from actual skin, which satisfies the condition of actual usage.

The Pathogenesis and Management of Acne-Induced Post-inflammatory Hyperpigmentation

Acne vulgaris is a common inflammatory disease. Among patients with darker skin phototypes (Fitzpatrick III-VI), the inflammatory processes of acne stimulate excess melanogenesis and abnormal melanin deposition, leading to pigmentary sequelae known as post-inflammatory hyperpigmentation and post-inflammatory erythema in all skin tones, although post-inflammatory hyperpigmentation is more common in darker skin and post-inflammatory erythema in lighter skin. These pigmentary alterations can be long lasting and are often more distressing to patients than the active acne lesions. This article discusses what is known about acne-related pigmentation, much of which is extrapolated from general study of nonspecific pigment deposition. Because dyspigmentation poses both a significant clinical concern to patients and a therapeutic challenge to clinicians, we formed a working group consisting of pigmentary experts with the aim of increasing awareness and education of acne-related pigmentary sequelae.

NNT mediates redox-dependent pigmentation via a UVB- and MITF-independent mechanism

Ultraviolet (UV) light and incompletely understood genetic and epigenetic variations determine skin color. Here we describe an UV- and microphthalmia-associated transcription factor (MITF)-independent mechanism of skin pigmentation. Targeting the mitochondrial redox-regulating enzyme nicotinamide nucleotide transhydrogenase (NNT) resulted in cellular redox changes that affect tyrosinase degradation. These changes regulate melanosome maturation and, consequently, eumelanin levels and pigmentation. Topical application of small-molecule inhibitors yielded skin darkening in human skin, and mice with decreased NNT function displayed increased pigmentation. Additionally, genetic modification of NNT in zebrafish alters melanocytic pigmentation. Analysis of four diverse human cohorts revealed significant associations of skin color, tanning, and sun protection use with various single-nucleotide polymorphisms within NNT. NNT levels were independent of UVB irradiation and redox modulation. Individuals with postinflammatory hyperpigmentation or lentigines displayed decreased skin NNT levels, suggesting an NNT-driven, redox-dependent pigmentation mechanism that can be targeted with NNT-modifying topical drugs for medical and cosmetic purposes.

Comparative Evaluation of Efficacy and Safety of Tacrolimus and Dinoprostone Following Dermabrasion in Stable Vitiligo

BACKGROUND

Dinoprostone (DNP), a prostaglandin E2 (PGE2) analogue, has been found to cause repigmenation in vitiliginous lesions. Combined medical and surgical therapy might be more useful for successful treatment of vitiligo.

OBJECTIVES

In this study, we aimed to evaluate the efficacy and safety of dermabrasion followed by dinoprostone gel and to compare it with tacrolimus ointment following the same procedure in the treatment of localized stable vitiligo.

METHODS

40 patients of stable vitiligo were enrolled which were divided in two groups of 20 patients each. In group 1, dermabrasion followed by tacrolimus 0.1% ointment was done and in group 2, dermabrasion followed by dinoprostone gel was done.

RESULTS

Group 1 patients showed slightly better response (P=0.039), whereas the side effect profile was better for group 2.

CONCLUSION

DNP and tacrolimus have immunomodulatory and melanocyte stimulating effect and are well tolerated when combined with dermabrasion. Their effect on skin pigmentation could be enhanced by dermabrasion. J Drugs Dermatol. 2021;20(5):519-522. doi:10.36849/JDD.5751.

Afamelanotide: An Orphan Drug with Potential for Broad Dermatologic Applications

Afamelanotide (SCENESSE&reg;) is a synthetic analogue of &alpha;-melanocyte-stimulating hormone that is FDA-approved to increase pain-free sunlight exposure in adult patients with erythropoietic protoporphyria. Its dual photoprotective and anti-inflammatory effects also make it a promising therapy for other photosensitive dermatologic diseases that are resistant to treatment. The PubMed/MEDLINE and ClinicalTrials.gov databases were searched for literature and ongoing trials describing the use of afamelanotide in treating cutaneous diseases. There is randomized controlled trial (RCT) evidence for the successful use of afamelanotide in several conditions beyond erythropoietic protoporphyria, including polymorphic light eruption and vitiligo. Smaller studies have also demonstrated its efficacy in treating acne vulgaris, Hailey-Hailey disease, and solar urticaria. No serious adverse effects with afamelanotide use have been reported, though diffuse hyperpigmentation is experienced by almost all patients. Larger scale studies are needed to confirm the efficacy of afamelanotide in treating dermatologic conditions beyond erythropoietic protoporphyria, and further research should focus on determining the safety, efficacy, and optimal dosing of afamelanotide for pediatric patients.J Drugs Dermatol. 2021;20(3):290-294. doi:10.36849/JDD.5526.

A natural compound harmine decreases melanin synthesis through regulation of the DYRK1A/NFATC3 pathway

BACKGROUND

Melanin plays important roles in determining human skin color and protecting human skin cells against harmful ultraviolet light. However, abnormal hyperpigmentation in some areas of the skin may become aesthetically unpleasing, resulting in the need for effective agents or methods to regulate undesirable hyperpigmentation.

OBJECTIVE

We investigated the effect of harmine, a natural harmala alkaloid belonging to the beta-carboline family, on melanin synthesis and further explored the signaling pathways involved in its mechanism of action.

METHODS

Human MNT-1 melanoma cells and human primary melanocytes were treated with harmine, chemical inhibitors, small interfering RNAs, or mammalian expression vectors. Cell viability, melanin content, and expression of various target molecules were assessed.

RESULTS

Harmine decreased melanin synthesis and tyrosinase expression in human MNT-1 melanoma cells. Inhibition of DYRK1A, a harmine target, decreased melanin synthesis and tyrosinase expression. Further studies revealed that nuclear translocation of NFATC3, a potential DYRK1A substrate, was induced via the harmine/DYRK1A pathway and that NFATC3 knockdown increased melanin synthesis and tyrosinase expression. Suppression of melanin synthesis and tyrosinase expression via the harmine/DYRK1A pathway was significantly attenuated by NFATC3 knockdown. Furthermore, harmine also decreased melanin synthesis and tyrosinase expression through regulation of NFATC3 in human primary melanocytes.

CONCLUSION

Our results indicate that harmine decreases melanin synthesis through regulation of the DYRK1A/NFATC3 pathway and suggest that the DYRK1A/NFATC3 pathway may be a potential target for the development of depigmenting agents.

The Therapeutic Use of Antioxidants for Melasma

Melasma is a chronic dermatologic condition with an incompletely understood pathogenesis and well-demonstrated impact on patient quality of life. Melasma is a common cause for seeking dermatologic care, and with no universally efficacious therapy or cure, com-bination treatment is the best approach for many cases. Numerous studies have demonstrated the role of oxidative stress in patients with melasma, prompting investigation into several antioxidants for melasma therapy. In this review, we discuss the well-defined role of oxidative stress in melasma and the therapeutic efficacy of various antioxidants for patients suffering from melasma. We focus our discussion on studies investigating the role of vitamin C, azelaic acid, cysteamine, glutathione, carotenoids, and numerous other antioxidants in disorders of hyperpigmentation. There is promising evidence for the use of these antioxidants, as topical, oral, and intra-venous preparations, both in isolation and in conjunction with other melasma therapies. J Drugs Dermatol. 2020;19(8):788-792. doi:10.36849/JDD.2020.5079.

Post-Inflammatory Hyperpigmentation: A Review of Treatment Strategies

Post-inflammatory hyperpigmentation (PIH) is a reactive process resulting from increased melanin or abnormal distribution of melanin secondary to inflammatory skin conditions, dermatologic therapies, and external stimuli. Because PIH is a common condition that has a substantial effect on the quality of life, an understanding of its treatment modalities is essential. Though there are many therapeutic strategies for hyperpigmentary conditions such as melasma that are described in the literature, fewer studies focus on PIH. This article aims to provide a comprehensive literature review of therapies specifically used to treat PIH, such as topical combinations, chemical peels, and lasers. J Drugs Dermatol. 2020;19(8): doi:10.36849/JDD.2020.4887.

Impact of Iron-Oxide Containing Formulations Against Visible Light-Induced Skin Pigmentation in Skin of Color Individuals

Visible light (400-700nm), which contributes to 45% of solar radiation, contributes to skin darkening and worsening of dyschromias, particularly in individuals with Fitzpatrick skin phototypes III and higher. Currently, sunscreens provide limited protection against that spectrum. Due to their capabilities in absorbing, scattering, and reflecting visible light, topical products containing pigments and/or metal oxides can provide additional photoprotection. In this study, the efficacy of two formulations containing iron oxide was evaluated in preventing visible light-induced pigmentation compared with a non-tinted mineral SPF 50+ sunscreen. Expert grading and colorimetry demonstrated that the iron-oxide containing formulations significantly protected against visible light-induced pigmentation compared to untreated skin or mineral SPF 50+ sunscreen in Fitzpatrick IV individuals. These results highlight that iron-oxide containing formulas in a foundation format have dual functions and can provide additional benefits in patients' daily routine by masking existing pigmentation and preventing the development of pigmentation triggered by sunlight exposure, extending protection beyond UV spectrum. J Drugs Dermatol. 2020;19(7): doi:10.36849/JDD.2020.5032 THIS ARTICLE HAD BEEN MADE AVAILABLE FREE OF CHARGE. PLEASE SCROLL DOWN TO ACCESS THE FULL TEXT OF THIS ARTICLE WITHOUT LOGGING IN. NO PURCHASE NECESSARY. PLEASE CONTACT THE PUBLISHER WITH ANY QUESTIONS.

The Effectiveness of Galactomyces Ferment Filtrate, Dexpanthenol, and Centella Asiatica Combination Serum in the Treatment of Post-Acne Hyperpigmentation in Subjects with Skin of Color

Post-acne hyperpigmentation (PAH) occurs secondary to acne vulgaris and may cause significant adverse effects. Although may occur in any skin types, PAH has been found to be more common and severe in people with colored skin. This study aimed to assess the effectiveness of combination serum containing galactomyces ferment filtrate (GFF), dexpanthenol, and Centella asiatica for treating PAH. This randomized controlled clinical trial involved Fitzpatrick skin type (FST) IV and V patients with PAH. Subjects were equally divided into treatment group, who received three drops of combination serum twice daily for 8 weeks, and placebo group. The melanin index (MI) and Lightness (L*) score were assessed every 2 weeks. Out of 51 subjects, the L* score of the treatment group in subjects with FST V was significantly higher on the 4th and 6th week compared to the placebo group (P ˂ 0.05). The MI of subjects with FST IV was significantly lower compared to the placebo group after 8 weeks (P ˂ 0.05). The treatment group showed consistent increasing and decreasing trend in L* score and MI, respectively (r ˃ 0.9, P ˂ 0.05). Combination serum containing GFF, dexpanthenol, and C. asiatica may be effective in treating PAH in subjects with colored skin by accelerating lessening of PAH.

Seven traditional Chinese herbal extracts fermented by Lactobacillus rhamnosus provide anti-pigmentation effects by regulating the CREB/MITF/tyrosinase pathway

Skin pigmentation is resulted from several processes, such as melanin synthesis transportation and abnormal melanin accumulation in keratinocytes. Various studies have suggested that seven traditional Chinese herbal extracts from Atractylodes macrocephala, Paeonia lactiflora, Bletilla striata, Poria cocos, Dictamnus dasycarpus, Ampelopsis japonica and Tribulus terrestris (which we collectively named ChiBai), show several protective effects toward skin-related diseases. Lactobacillus rhamnosus, a lactic acid bacterium, has been reported to treat skin inflammation and atopic dermatitis. In this study, the broth produced by the cofermentation of ChiBai with Lactobacillus rhamnosus was studied for its effects on skin pigmentation through in vitro and in vitro experiments. In the in vitro experiments, we found that the fermented broth of ChiBai (FB-ChiBai) suppressed alpha-melanocyte stimulating hormone (α-MSH)-induced melanogenesis in B16F0 murine melanoma cells without any cytotoxicity at a concentration of 0.5%. FB-ChiBai significantly attenuated melanin production, tyrosinase activities and melanogenesis-related signaling pathways. Treatment with FB-ChiBai also reduced the nuclear translocation and promoter binding activities of MITF. In the in vivo experiments, FB-ChiBai was topically applied to the dorsal skin of C57BL/6J nude mice and concurrently irradiated with UVB, three times a week for 8 weeks. The results indicated that FB-ChiBai alleviated UVB-induced hyperpigmentation by reducing epidermal hyperplasia and inhibiting the CREB/MITF/tyrosinase pathway. In conclusion, our data indicated that the anti-melanogenic effects of FB-ChiBai are mediated by the inhibition of CREB/MITF/tyrosinase signaling pathway. The findings suggest that FB-ChiBai can protect against UV-B irradiation and that it might be used as an agent in cosmetic products to protect against UVB-induced hyperpigmentation.

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.

Parallel discourses: leveraging the Black Lives Matter movement to fight colorism and skin bleaching practices

OBJECTIVES

The 'Black Lives Matter' (BLM) movement in 2020 exemplifies efforts to counter prejudices and the colourist narrative. Harmful use of topical skin lightening agents continues worldwide despite interdiction or restricted use under domestic, European and international regulations.

STUDY DESIGN

Commentary.

METHODS

Narrative review.

RESULTS

In this Short Communication, we consider the significance of societal perspectives of skin colour, glocalized whiteness, efforts to attain self-esteem and social mobility through skin lightening practices, and the role of cosmetic products in fuelling this phenomenon.

CONCLUSIONS

Addressing the inadvertent (or indeed conscious) vehicles of systematic racism and sustaining of skin colour prejudices and stereotypes of fair skin beauty by cosmetic companies is warranted. Targeted health messaging is an imperative.

Efficacy and Safety of Tacrolimus 0.1% for the Treatment of Facial Vitiligo: A Multicenter Randomized, Double-Blinded, Vehicle-Controlled Study

BACKGROUND

Topical calcineurin inhibitors are used off label in the treatment of vitiligo, and there is a lack of placebo-controlled, blinded studies to support their use.

OBJECTIVE

This study aimed to compare the efficacy of tacrolimus 0.1% ointment with that of the vehicle for repigmentation in adult patients with facial vitiligo.

DESIGN

This study was a 24-week multicenter randomized parallel double-blind study with a 24-week post-treatment follow-up extension.

POPULATION

Participants included were adult patients with recent facial vitiligo target lesions (<2 years) without changes in pigmentation or size over the previous 3 months.

INTERVENTION

Patients received either tacrolimus 0.1% ointment or vehicle twice daily.

MAIN OUTCOMES AND MEASURES

The primary outcome was a therapeutic success, defined as a change ≥75% in the repigmentation of the target lesion between baseline and week 24, measured by ImageJ software. Secondary outcome measures were a variation of the physicians' global assessment scores and patients' satisfaction scores, safety data, and the rate of relapse at week 48.

RESULTS

A total of 42 patients were included. Therapeutic success was achieved in 65% of tacrolimus-treated patients versus 0% of vehicle-treated patients at week 24 (P < 0.0001). Only 40% of relapse was observed at 48 weeks.

CONCLUSIONS AND RELEVANCE

Twice-daily tacrolimus 0.1% ointment showed superior efficacy to that of the vehicle through the 24 weeks of intervention and 24 weeks of follow-up in adult patients with facial vitiligo.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov (identifier: NCT02466997).

New Protocol for Long-Term Results With a Multi-Pulse Nd:YAG Laser for Melasma Treatment: A Descriptive Cohort Study

BACKGROUND

Melasma is a photoaging condition with a typical clinical and histological pattern under a genetic and epigenetic context. Over the years, many treatments modalities have been proposed including topical agents, oral medication, procedures, and combination treatments aiming at different aspects of the pathogenesis including photodamage, inflammation, vascularity, and pigmentation. Recently, lasers have become an alternative for the treatment of melasma using thermal energy to target, in a selective way, the chromophore found in the skin such as melanin.

OBJECTIVE

This study aimed to show how we have implemented a multifactorial approach that not only treats the symptoms but addresses the primary underlying cause of melasma.

MATERIALS AND METHODS

Twenty female patients with dermal and mixed melasma were admitted to Medical Art between December 2017 and April 2018 and received a four-step Fotona laser protocol. Clinical evaluation of a clearance percentage of melasma was performed 1 month after the last session by a blinded dermatologist grading the images taken during the study. Follow-up evaluation was performed at 6 and 12 months following the completion of the laser treatment, which was 6 sessions. Patients were also asked following the end of the treatment about their satisfaction, which was evaluated with a 5-point scale.

RESULTS

This descriptive cohort study included patients with melasma who underwent the four-step laser protocol treatment at 2-week intervals. The clearance percentage score showed 70% with excellent reduction, 25% with good reduction in appearance of melasma, none of the patients with a fair reduction, and 5% with a poor reduction. The mean score of patient satisfaction was 4,65 &plusmn; 0,93 (93%).

CONCLUSION

Results of this study indicate that the four-step Fotona laser protocol is a safe and effective treatment option for melasma. J Drugs Dermatol. 2021;20(2):150-154. doi:10.36849/JDD.1221.

Efficacy and Tolerability of a Novel Topical Treatment for Neck: A Randomized, Double-blind, Regimen-Controlled Study

The neck plays a telling role as an age indicator. Due to its anatomy and function, neck skin ages differently than facial skin and special considerations need to be taken when providing treatment. A randomized, double-blind, regimen-controlled study was conducted to assess the efficacy and tolerability of a novel topical cosmetic cream (NCC) specifically tailored to address the signs of skin aging of the neck and d&eacute;colletage. Twice daily application of NCC significantly improved skin sagging/laxity of the neck as well as the appearance of fine and coarse lines/wrinkles, crepiness, tactile roughness, overall skin texture, hyperpigmentation, skin tone evenness, and radiance. NCC also significantly improved the appearance of fine and coarse lines/wrinkles, tactile roughness, hyperpigmentation, skin tone evenness, and radiance of the d&eacute;colletage. Investigator assessments were corroborated by objective cutometer measurements that demonstrated improved skin firmness and elasticity. In vitro analysis in human 3D skin models show that stimulation of neocollagenesis and neoelastogenesis as well as support of cellular proteostasis through proteasome and autophagy activation are potential mechanisms of action for the observed clinical outcomes. J Drugs Dermatol. 2021;20(2):184-191. doi:10.36849/JDD.5819 THIS ARTICLE HAD BEEN MADE AVAILABLE FREE OF CHARGE. PLEASE SCROLL DOWN TO ACCESS THE FULL TEXT OF THIS ARTICLE WITHOUT LOGGING IN. NO PURCHASE NECESSARY. PLEASE CONTACT THE PUBLISHER WITH ANY QUESTIONS.

A colorimetric comparison of sunless with natural skin tan

The main ingredient of sunless tanning products is dihydroxyacetone (DHA). DHA reacts with the protein and amino acid composition in the surface layers of the skin, producing melanoidins, which changes the skin colour, imitating natural skin tan caused by melanin. The purpose of this study was to characterise DHA-induced skin colour changes and to test whether we can predict the outcome of DHA application on skin tone changes. To assess the DHA-induced skin colour shift quantitatively, colorimetric and spectral measurements of the inner forearm were obtained before, four hours and 24 hours after application of a 7.5% concentration DHA gel in the experimental group (n = 100). In a control group (n = 60), the same measurements were obtained on both the inner forearm (infrequently sun-exposed) and the outer forearm (frequently sun-exposed); the difference between these two areas was defined as the naturally occurring tan. Skin colour shifts caused by DHA tanning and by natural tanning were compared in terms of lightness (L*), redness (a*) and yellowness (b*) in the standard CIELAB colour space. Naturalness of the DHA-induced skin tan was evaluated by comparing the trajectory of the chromaticity distribution in (L*, b*) space with that of naturally occurring tan. Twenty-four hours after DHA application, approximately 20% of the skin colour samples became excessively yellow, with chromaticities outside the natural range in (L*, b*) space. A principal component analysis was used to characterise the tanning pathway. Skin colour shifts induced by DHA were predicted by a multiple regression on the chromaticities and the skin properties. The model explained up to 49% of variance in colorimetric components with a median error of less than 2 ΔE. We conclude that the control of both the magnitude and the direction of the colour shift is a critical factor to achieve a natural appearance.

Hispanic/Latinos and Skincare: Disparities in Product Development, Marketing, and Toxicity

&ldquo;Hispanic&rdquo; and &ldquo;Latino&rdquo; (also known as Mestizo) describe a diverse racial and ethnic group, with a range of cultures, languages, and biological ancestry. It includes individuals of Mexican, Central-to-South American, and Spanish-Caribbean (eg, Cuban, Puerto Rican, and Dominican) descent.1 Individuals of Hispanic/Latino race and ethnicity represent a heterogenous group of people with different skin tones and Fitzpatrick phototypes. Hispanic/Latinos are the fastest growing population in the United States (US) - projected to increase from 55 million in 2014 to 119 million in 2060, an increase of 115%.2 By 2060, more than one-quarter (29%) of the US is projected to be Hispanic/Latino.2.

Carvedilol, an Adrenergic Blocker, Suppresses Melanin Synthesis by Inhibiting the cAMP/CREB Signaling Pathway in Human Melanocytes and Ex Vivo Human Skin Culture

Catecholamines function via G protein-coupled receptors, triggering an increase in intracellular levels of 3′,5′-cyclic adenosine monophosphate (cAMP) in various cells. Catecholamine biosynthesis and the β-adrenergic receptor exist in melanocytes; thus, catecholamines may play critical roles in skin pigmentation. However, their action and mechanisms mediating melanogenesis in human skin have not yet been investigated. Therefore, we examined the potential anti-melanogenetic effect of carvedilol, a nonselective β-blocker with weak α1-blocking activities. Carvedilol reduced melanin content and cellular tyrosinase activity without compromising cellular viability in normal human melanocytes as well as in mel-Ab immortalized mouse melanocytes. Carvedilol downregulated microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2. Carvedilol treatment led to the downregulation of phosphor-cAMP response element-binding protein (CREB). Moreover, the increase in cAMP levels upon treatment with forskolin reversed the anti-melanogenic action of carvedilol. In addition, carvedilol remarkably reduced the melanin index in ultraviolet-irradiated human skin cultures. Taken together, our results indicate that carvedilol effectively suppresses melanogenesis in human melanocytes and ex vivo human skin by inhibiting cAMP/protein kinase A/CREB signaling. The anti-melanogenic effects of carvedilol have potential significance for skin whitening agents.

Ursolic acid inhibits pigmentation by increasing melanosomal autophagy in B16F1 cells

Melanosomes are specialized membrane-bound organelles that are involved in melanin synthesis. Unlike melanosome biogenesis, the melanosome degradation pathway is poorly understood. Among the cellular processes, autophagy controls degradation of intracellular components by cooperating with lysosomes. In this study, we showed that ursolic acid inhibits skin pigmentation by promoting melanosomal autophagy, or melanophagy, in melanocytes. We found that B16F1 cells treated with ursolic acid suppressed alpha-melanocyte stimulating hormone (α-MSH) stimulated increase in melanin content and activated autophagy. In addition, we found that treatment with ursolic acid promotes melanosomal degradation, and bafilomycin A1 inhibition of autophagosome-lysosome fusion blocked the removal of melanosomes in α-MSH-stimulated B16F1 cells. Furthermore, depletion of the autophagy-related gene 5 (ATG5) resulted in significant suppression of ursolic acid-mediated anti-pigmentation activity and autophagy in α-MSH-treated B16F1 cells. Taken together, our results suggest that ursolic acid inhibits skin pigmentation by increasing melanosomal degradation in melanocytes.

Successful Management of a Black Male With Psoriasis and Dyspigmentation Treated With Halobetasol Propionate 0.01%/Tazarotene 0.045% Lotion: Case Report

Skin of color patients with psoriasis face unique challenges related to disease characteristics and treatment. Dyspigmentation, including postinflammatory hypo- and hyperpigmentation, more frequently and severely affects patients with skin of color and remains a challenge in psoriasis management. We present the case of a 58-year-old Black male with moderate psoriasis who was treated for 8 weeks with a fixed combination halobetasol propionate 0.01%/tazarotene 0.045% (HP/TAZ) lotion during a phase 3 study (NCT02462070). HP/TAZ was efficacious in this patient, whose Investigator&rsquo;s Global Assessment score decreased from 3 (moderate) at baseline to 1 (almost clear) within 4 weeks, with maintenance of & "almost clear"; through week 12 (4 weeks posttreatment). Affected body surface area decreased by 50% and quality of life greatly improved from baseline to week 8. The patient experienced dyspigmentation of the affected skin during the trial; hypopigmentation was primarily experienced from weeks 2-8, with the greatest degree at week 4. By week 12, the affected skin area had returned to normal, with only small regions of hyperpigmentation, primarily around the periphery of the lesion. These results indicate that HP/TAZ may be a treatment option for patients with skin of color, who are disproportionally affected by postinflammatory dyspigmentation. J Drugs Dermatol. 2020;19(10):1000-1004. doi:10.36849/JDD.2020.5347.

Melasolv induces melanosome autophagy to inhibit pigmentation in B16F1 cells

The melanosome is a specialized membrane-bound organelle that is involved in melanin synthesis, storage, and transportation. In contrast to melanosome biogenesis, the processes underlying melanosome degradation remain largely unknown. Autophagy is a process that promotes degradation of intracellular components' cooperative process between autophagosomes and lysosomes, and its role for process of melanosome degradation remains unclear. Here, we assessed the regulation of autophagy and its contributions to depigmentation associated with Melasolv (3,4,5-trimethoxycinnamate thymol ester). B16F1 cells-treated with Melasolv suppressed the α-MSH-stimulated increase of melanin content and resulted in the activation of autophagy. However, introduction of bafilomycin A1 strongly suppressed melanosome degradation in Melasolv-treated cells. Furthermore, inhibition of autophagy by ATG5 resulted in significant suppression of Melasolv-mediated depigmentation in α-MSH-treated cells. Taken together, our results suggest that treatment with Melasolv inhibits skin pigmentation by promoting melanosome degradation via autophagy activation.

Randomized, Double-Blinded, Split-Face Study Comparing the Efficacy and Tolerability of Two Topical Products for Melasma

BACKGROUND

Melasma is a common disorder of hyperpigmentation that disproportionately affects individuals with skin of color. There is a paucity of studies evaluating non-hydroquinone (HQ) topical therapies for the treatment of melasma in darker skin types.

OBJECTIVE

To compare the safety, efficacy, and tolerability of a HQ-free, retinol-free cosmetic topical brightener (CTB) and HQ 4% in the treatment of moderate symmetric facial melasma in patients with Fitzpatrick skin types (FST) III&ndash;VI. Methods &amp; Materials: This was a randomized, double-blinded, split-face clinical trial. Eighteen adult patients with facial melasma were treated with CTB and HQ 4%, each to a different side of the face, twice daily for 12 weeks. Clinical assessments included half-face Melasma Area Severity Index (MASI), Overall Hyperpigmentation scale, and Melasma Severity Rating Scale (MSRS). Patients completed a Melasma Quality of Life (MelasQoL) questionnaire and clinical photographs were taken at each visit.

RESULTS

CTB and HQ 4% demonstrated statistically significant improvements in half-face MASI, Overall Hyperpigmentation, MSRS and MelasQol compared to baseline. HQ 4% showed statistically significant improvements in MSRS at week 12 compared to CTB, but was non-superior for all other clinical endpoints.

CONCLUSION

HQ-free, retinol-free CTB and HQ 4% both are effective and well-tolerated in the treatment of moderate facial melasma in FST III&ndash;VI. J Drugs Dermatol. 2020;19(9):822-827. doi:10.36849/JDD.2020.5353.

Algae Metabolites in Cosmeceutical: An Overview of Current Applications and Challenges

Cosmetics are widely used by people around the world to protect the skin from external stimuli. Consumer preference towards natural cosmetic products has increased as the synthetic cosmetic products caused adverse side effects and resulted in low absorption rate due to the chemicals' larger molecular size. The cosmetic industry uses the term "cosmeceutical", referring to a cosmetic product that is claimed to have medicinal or drug-like benefits. Marine algae have gained tremendous attention in cosmeceuticals. They are one of the richest marine resources considered safe and possessed negligible cytotoxicity effects on humans. Marine algae are rich in bioactive substances that have shown to exhibit strong benefits to the skin, particularly in overcoming rashes, pigmentation, aging, and cancer. The current review provides a detailed survey of the literature on cosmeceutical potentials and applications of algae as skin whitening, anti-aging, anticancer, antioxidant, anti-inflammation, and antimicrobial agents. The biological functions of algae and the underlying mechanisms of all these activities are included in this review. In addition, the challenges of using algae in cosmeceutical applications, such as the effectiveness of different extraction methods and processing, quality assurance, and regulations concerning extracts of algae in this sector were also discussed.

Effects of anti-wrinkle and skin-whitening fermented black ginseng on human subjects and underlying mechanism of action

The aim of this study was to determine the effects of anti-wrinkle and skin-whitening of fermented black ginseng (FBG) in human subjects and to examine underlying biochemical mechanisms of action. A clinical study was performed to evaluate efficacy and safety using a 1% FBG cream formulation. Twenty-three subjects were recruited and instructed to apply control or FBG creams each on half of their face twice daily for 8 weeks. After 8 weeks FBG cream significantly reduced appearance of eye wrinkles compared to prior to exposure and control cream. Skin color was significantly brightened using FBG cream in comparison with control cream. To determine the mechanism of actions involved in anti-wrinkle and skin-whitening effects various concentrations of FBG were applied to human fibroblast CCD-986sk and mouse melanoma B16F1 cells. Collagen synthesis in CCD-986sk cells was improved significantly at 1, 3, 10, or 30 µg/ml of FBG. At 30 µg/ml, FBG significantly inhibited (73%) collagenase, and matrix metalloproteinase-1 (MMP-1) compared to control. Tyrosinase activity and DOPA (3,4-dihydroxy-L-phenylalanine) oxidation were significantly decreased at all tested concentrations. Melanin production in B16F1 cells was concentration-dependently reduced 15% to 60% by all concentrations of FBG. These results suggested that a 1% FBG cream exerted anti-wrinkle and skin-whitening effects.

Tacrolimus (FK506) ointment combined with Nb-UVB could activate both hair follicle (HF) and dermal melanocyte precursors in vitiligo: the first histopathological and clinical study

Topical Tacrolimus, especially when combined with Nb-UVB, has been proven clinically to be effective in the treatment of vitiligo. However, no histological study has evaluated the repigmentation mechanism of tacrolimus ointment in combination therapy with Nb-UVB. In this study, the histological findings in patients receiving Nb-UVB were compared with those receiving topical tacrolimus combined with Nb-UVB. Twenty patients were recruited and received Nb-UVB treatment. The first ten patients were selected for the combination therapy and instructed to apply tacrolimus 0.1% ointment twice daily on the specified lesion of interest. The remaining ten patients did not receive any other topical treatments. Skin biopsy was performed at baseline from the depigmented area and 2-3 months post-treatment from the repigmented area. Biopsy specimens were stained with haematoxylin-eosin-safran (HES), Fontana Masson, HMB45, Melan A, MITF, SOX10 and Nestin. Clinically, in the combination therapy group, interfollicular repigmentation in addition to the perifollicular and marginal pattern was observed. Histologically, in the combination therapy group, besides the migration of melanocytes from the bulge of the hair follicle seen in the monotherapy group, for the first time, we observed dermal melanocyte precursors located in mid- and superficial dermis.

Administration of Apple Polyphenol Supplements for Skin Conditions in Healthy Women: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

This clinical study was performed to evaluate the effects of continuous apple polyphenol (AP) administration on facial skin conditions and pigmentation induced by ultraviolet (UV) irradiation in healthy women participants. Participants (n = 65, age 20–39 years) were randomized to receive tablets containing AP (300 or 600 mg/day) or placebo in a double-blinded, placebo-controlled clinical trial. Continuous administration of AP for 12 weeks significantly prevented UV irradiation induced skin pigmentation (erythema value, melanin value, L value), although a dose-dependent relationship was not clearly observed. In contrast, no significant differences were detected between the groups with regard to water content and trans-epidermal water loss. Our study demonstrated that APs and their major active compounds, procyanidins, have several health benefits. Here, we report that continuous administration of AP for 12 weeks alleviated UV irradiation induced skin pigmentation, when compared with placebo, in healthy women.

Lecithin-Based Dermal Drug Delivery for Anti-Pigmentation Maize Ceramide

Ceramides have several well-known biological properties, including anti-pigmentation and anti-melanogenesis, which make them applicable for use in skincare products in cosmetics. However, the efficacy of ceramides is still limited. Dermal or transdermal drug delivery systems can enhance the anti-pigmentation properties of ceramides, although there is currently no systemic evaluation method for the efficacy of these systems. Here we prepared several types of lecithin-based emulsion of maize-derived glucosylceramide, determining PC70-ceramide (phosphatidylcholine-base) to be the safest and most effective anti-pigmentation agent using zebrafish larvae. We also demonstrated the efficacy of PC70 as a drug delivery system by showing that PC70-Nile Red (red fluorescence) promoted Nile Red accumulation in the larval bodies. In addition, PC70-ceramide suppressed melanin in mouse B16 melanoma cells compared to ceramide alone. In conclusion, we developed a lecithin-based dermal delivery method for ceramide using zebrafish larvae with implications for human clinical use.

Photoprotection and Skin Pigmentation: Melanin-Related Molecules and Some Other New Agents Obtained from Natural Sources

Direct sun exposure is one of the most aggressive factors for human skin. Sun radiation contains a range of the electromagnetic spectrum including UV light. In addition to the stratospheric ozone layer filtering the most harmful UVC, human skin contains a photoprotective pigment called melanin to protect from UVB, UVA, and blue visible light. This pigment is a redox UV-absorbing agent and functions as a shield to prevent direct UV action on the DNA of epidermal cells. In addition, melanin indirectly scavenges reactive oxygenated species (ROS) formed during the UV-inducing oxidative stress on the skin. The amounts of melanin in the skin depend on the phototype. In most phenotypes, endogenous melanin is not enough for full protection, especially in the summertime. Thus, photoprotective molecules should be added to commercial sunscreens. These molecules should show UV-absorbing capacity to complement the intrinsic photoprotection of the cutaneous natural pigment. This review deals with (a) the use of exogenous melanin or melanin-related compounds to mimic endogenous melanin and (b) the use of a number of natural compounds from plants and marine organisms that can act as UV filters and ROS scavengers. These agents have antioxidant properties, but this feature usually is associated to skin-lightening action. In contrast, good photoprotectors would be able to enhance natural cutaneous pigmentation. This review examines flavonoids, one of the main groups of these agents, as well as new promising compounds with other chemical structures recently obtained from marine organisms.

Potential adverse effect of tyrosinase inhibitors on teleosts:A review

Coloration plays a crucial role in the social communication and survival of organisms. Multidisciplinary studies have been conducted to elucidate the correlation between coloration and melanin biosynthesis (referred as melanogenesis). The multi-copper enzyme tyrosinase catalyzes the first two steps of melanogenesis for coloration in teleosts. Due to the increasing demand of tyrosinase inhibitors for the production of skin whitening cosmetics, hypopigmentation pharmaceuticals, and anti-browning agents, a large number of natural and synthetic inhibitors have been developed over the past few decades. Although a number of previous studies have focused on human use and toxicity, such as the increased cytotoxic effects of ROS-generating compounds, their ecotoxicological impacts on aquatic organisms are still poorly understood. Hence, the focus of the present review is to describe the role of coloration in teleosts as well as potential ecotoxicological effects elicited by exposure to tyrosinase inhibitors. Furthermore, this review introduces our recently registered adverse outcome pathway (AOP) related to tyrosinase inhibition and population decline in teleosts.

An Herbal H2 Blocker in Melasma Treatment

BACKGROUND

Melasma is a skin pigmentation disorder that remains resistant to available therapies. The exact cause of melasma is unknown. Histamine is an inflammatory factor. Its involvement in pigmentation is obscure. The aim of this study is to introduce an herbal antihistamine H2 receptor which is effective in these disorders.

METHODS

This is a review study by searching the electronic databases and also Persian Medicine books, from 2000 to 2018 by the keywords such as H2 antagonist, H2 blocker and melasma.

RESULTS

According to the researched studies, histamine can induce melanogenesis and melasma after a series of stages in the body. Also, Histamine, through receptors 2, triggers melasma. Therefore, it can be said that antihistamine H2 receptor can be effective in melasma. Considering chemical antihistamine, H2 receptors have side effects, such as digestive problems, H2 antagonists can be used in the treatment of diseases such as dyspepsia but they have multiple complications. On the other hand, there is an herbal H2 antagonist that can be useful for melasma due to having some special properties.

CONCLUSION

Herbal H2 blockers should be noted in melasma treatment along with the topical drugs.

Discovery of a Highly Selective MC1R Agonists Pentapeptide to Be Used as a Skin Pigmentation Enhancer and with Potential Anti-Aging Properties

One of the first lines of cutaneous defense against photoaging is (a) the synthesis of melanin and (b) the initiation of an oxidative stress response to protect skin against the harmful effects of solar radiation. Safe and selective means to stimulate epidermal pigmentation associated with oxidative stress defense are; however, scarce. Activation of the melanocortin-1 receptor (MC1R) on epidermal melanocytes represents a key step in cutaneous pigmentation initiation and, additionally, it regulates cellular defense mechanisms like oxidative stress and DNA-repair. Thus, making the activation of MC1R an attractive strategy for modulating skin pigmentation and oxidative stress. In this context, we designed and synthesized pentapeptides that act as MC1R agonists. These peptides bound, with high potency, to MC1R and activated cAMP synthesis in CHO cells expressing human MC1R. Using one lead pentapeptide, we could show that this activation of MC1R was specific as testing the activation of other G-protein coupled receptors, including the MC-receptor family, was negative. In vitro efficacy on mouse melanoma cells showed similar potency as for the synthetic MC1R agonist alpha-melanocyte stimulating hormone (NDP-alpha-MSH). Moreover, we could reproduce this activity in human skin tissue culture. The lead pentapeptide was able to induce ex-vivo protein expression of key melanogenesis markers melanocyte inducing transcription factor (MITF), tyrosinase (TYR), and tyrosinase-related protein 1 (TYRP-1). Concerning oxidative stress response, we found that the pentapeptide enhanced the activation of Nrf2 after UVA-irradiation. Our results make this pentapeptide an ideal candidate as a skin pigmentation enhancer that mimics alpha-MSH and may also have anti-photoaging effects on the skin.

Oral Polypodium Leucotomos Extract and Its Impact on Visible Light-Induced Pigmentation in Human Subjects

BACKGROUND: Visible light (VL) has multiple effects on the skin that currently available sunscreens do not protect against. Polypodium leucotomos extract (PLE) has properties that may offer protection against VL. OBJECTIVES: To determine the effectiveness of PLE in preventing VL-induced effects. METHODS: Twenty-two subjects with Fitzpatrick skin phototype IV-VI were enrolled. On day 0, subjects were irradiated with VL. Clinical Investigator’s Global Assessment (IGA) scoring and spectroscopic evaluations were performed immediately, 24 hours, and 7 days after irradiation. Subjects then received a 28-day supply of PLE (480 mg daily). Irradiation and evaluation were repeated. Three 4-mm punch biopsies were obtained for immunohistochemistry analysis: one from normal unirradiated skin and the other two twenty-four hours after irradiation, pre- and post-PLE, from sites irradiated with highest dose of VL. RESULTS: All subjects had immediate pigment darkening, persistent pigment darkening, and delayed tanning both pre- and post-PLE. For the highest VL dose (480 J/cm²) spectroscopic assessments demonstrated a statistically significant decrease in persistent pigment darkening and delayed tanning post-PLE. In addition, there was a significant decrease in cyclooxygenase-2, and a trend towards decreases in the markers for cellular damage post-PLE. While there was a trend towards lower IGA scores post-PLE, statistical significance was not reached possibly due to lack of sensitivity of the visual IGA scoring system in detecting small changes. CONCLUSIONS: Spectroscopic data and immunohistochemistry indicate an effect of PLE on visible light induced effects. As such, PLE may be used as an adjuvant to traditional means of photoprotection to protect against the effects of VL. Clinical trial registration number: NCT02904798. J Drugs Dermatol. 2019;18(12):1198-1203.

An Advanced, Physician-Strength Retinol Peel Improves Signs of Aging and Acne Across a Range of Skin Types Including Melasma and Skin of Color

Background: Facial chemical peels are highly sought after by patients with photodamage, acne, and melasma. An advanced, physician-strength superficial peel, containing 3% retinol with other firming and volumizing ingredients was developed to exfoliate, improve the appearance of fine lines and wrinkles, and plump and firm skin, while promoting a bright, even complexion. Objective: A clinical study was conducted to evaluate the tolerability, safety, and efficacy of the 3% retinol peel with a supportive homecare regimen across a range of peel candidates, females aged 18-65 years, with photodamage, acne, hyperpigmentation or melasma, and skin of color, over a series of 2-4 peels. Method: The 3% retinol peel formulation was administered under physician direction in 6-week intervals. Subjects with photodamaged skin, acne, hyperpigmentation/melasma, or skin of color (Fitzpatrick skin types IV-VI) received 2-4 peels along with a supportive homecare regimen. Dermatologist grading, self-assessment, and digital photography documented tolerability and efficacy parameters. Results: 24 subjects participated in the study with a total of 78 peels administered (Photodamage group, n=14 [with an Acne subgroup, n=5]; Melasma group, n=5; Skin of Color, n=5). The 3% retinol peel along with the homecare regimen was well tolerated under physician direction in all skin types and conditions assessed. Obvious peeling was noticeable in many subjects 3 days post-peel and resolved by day 7. In the photodamaged group, dermatologist clinical grading of fine lines, wrinkles, pore size, laxity, mottled pigmentation, lack of clarity/radiance, and overall photodamage was significantly improved (P<0.05). Benefits were observed in all groups and supported by self-assessment. Digital photography demonstrated tolerability in the days immediately post-peel, along with benefits to photodamage. Conclusion: The 3% retinol superficial peel was well tolerated and an efficacious cosmetic treatment under physician supervision in subjects of all skin types to firm skin, improve fine lines and wrinkles, and promote a bright, even complexion. J Drugs Dermatol. 2019;18(9):918-923.

Therapeutic Insights in Melasma and Hyperpigmentation Management

Melasma and postinflammatory hyperpigmentation (PIH) are the most common forms of dyschromia in patients with skin of color. Both are associated with a high psychological burden of disease. To exacerbate this burden, the need for treatment is chronic, and the results are often suboptimal in the eyes of the patient. Successful treatment is therefore contingent upon a correct diagnosis, patient education, and a carefully considered therapeutic approach. The latter is often multimodal in its design, incorporating sun protection, topical and systemic medications, and in some cases, procedural intervention. Although topical hydroquinone is a mainstay of treatment for melasma and PIH, there are alternatives that have emerged as of late that have shown varying degrees of promise, both in terms of safety and efficacy. In this article, we review the epidemiological, clinical, and histologic features of melasma and postinflammatory hyperpigmentation, and discuss important considerations for both established and emerging treatments for these vexingly common and difficult to treat conditions.