Melanin pigmentary disorders: treatment update

Clinical effect of Pediococcus acidilactici PMC48 on hyperpigmented skin

BACKGROUND

The excessive production and accumulation of melanin in the epidermal skin layer can result in skin hyperpigmentation and darkening. Current technologies for regulating melanin are based on inhibiting melanin biosynthesis. They have low effectiveness and safety issues.

AIMS

This study aimed to evaluate the potential role of Pediococcus acidilactici PMC48 as a probiotic strain in medicines and cosmetics for skin treatment.

MATERIALS AND METHODS

Meanwhile, our research team has reported that P. acidilactici PMC48 strain isolated from sesame leaf kimchi can directly decompose the already synthesized melanin. It can also inhibit melanin biosynthesis. In the present study, we investigated the skin-whitening effect of this strain by arranging an 8-week clinical trial with 22 participants. PMC48 was applied to each participant's artificially UV-induced tanned skin in the clinical trial. Its whitening effect was investigated based on visual evaluation, skin brightness, and melanin index.

RESULTS

PMC48 showed a significant effect on the artificially induced pigmented skin. The color intensity of the tanned skin was decreased by 47.647%, and skin brightness was increased by 8.098% after the treatment period. PMC48 also significantly decreased the melanin index by 11.818%, indicating its tyrosinase inhibition capacity. Also, PMC48 improved skin moisture content level by 20.943%. Additionally, 16S rRNA-based amplicon sequencing analysis showed a distinct increase in Lactobacillaceae in the skin by up to 11.2% at the family level without affecting other skin microbiota. Furthermore, it showed no toxicity in in vitro or in vivo analyses.

DISCUSSION

These results indicate that P. acidilactici PMC48 is a promising probiotic strain that can be used to develop medicines and cosmetic products to solve skin-related problems.

CONCLUSIONS

These results demonstrate that P. acidilactici PMC48 can be a potential probiotic for the cosmetic industry against different skin disorders.

Cutaneous interaction with visible light: What do we know?

Visible light has been used therapeutically in dermatology for years for a variety of cosmetic and medical indications, including skin rejuvenation and the treatment of inflammatory and neoplastic conditions, among others. Until recently, visible light was thought to be relatively inert compared to its spectral neighbors, ultraviolet and infrared radiation. However, recent literature has described the ability of visible light to cause erythema in light skin and pigmentary changes in individuals with darker skin types. Concern surrounding its potentially damaging cutaneous effects has been raised in both the medical community and social media outlets. In this article, we provide an evidenced-based review describing what is currently known about visible light, focusing on its role in dermatologic diseases including disorders of hyperpigmentation such as melasma and postinflammatory hyperpigmentation.

Cryptochrome 1 activation inhibits melanogenesis and melanosome transport through negative regulation of cAMP/PKA/CREB signaling pathway

Cutaneous pigmentation was recently shown to be an event regulated by clock proteins. Cryptochrome (CRY) is a key protein composing the feedback loop of circadian clock, however, the function of CRY in melanocytes remains unclear. Here, we found that KL001, a synthetic small molecule modulator of CRY1, inhibited melanin synthesis, as well as reduced melanocyte dendrite elongation and melanosome transport. In addition, the dominant role of CRY1 in KL001-induced anti-melanogenesis was revealed by small interfering RNA transfection. Cellular tyrosinase activity and expression level of melanogenic proteins, including tyrosinase, TRP-1, TRP-2, and transport proteins like Rab27a, Cdc42 and Myosin Va induced by α-MSH were remarkably reversed after KL001 treatment. Mechanistically, CRY1 activation inhibited melanogenesis through CREB-dependent downregulation of MITF and CREB phosphorylation was mediated by classical cAMP/PKA pathway. In addition, the other CRY1 activator, KL044 also suppressed cAMP/PKA/CREB pathway and inhibited melanogenesis. Finally, anti-melanogenic efficacy of KL001 was confirmed by determination of melanin contents in UVB-tanning model of brown guinea pigs, which indicated that targeting CRY1 activity, via topical application of small molecule activator, can be utilized therapeutically to manage human pigmentary disorders.

Bilateral periareolar hyperpigmentation after augmentation mammoplasty: a case report and literature review

Complications arising from breast augmentation procedures are broadly categorized as either surgery-related or prosthesis-related. Many reports have described complications associated with breast augmentation. However, to date, periareolar post-inflammatory hyperpigmentation (PIH) after breast augmentation has not been reported. Herein, we report a case of PIH after augmentation mammoplasty using a silicone implant through the periareolar approach. A 35-year-old woman, who underwent bilateral breast augmentation using a periareolar approach, presented with bilateral periareolar tissue changes, with dark brown, irregular macules appearing 6 weeks postoperatively. Based on clinical symptoms and histological examination, the lesion was diagnosed as PIH. Topical hydroquinone and retinoic acid were applied for 8 weeks after the pigmentation appeared. After 6 months of observation, the pigmentation faded. To summarize, we report a case of pigmentation around the bilateral nipples after periareolar breast augmentation along with a literature review.

A split-face comparison of fractional erbium: YAG laser plus Kligman's formula vs. Kligman's formula monotherapy for facial melasma

Melasma is a chronic hyperpigmentation disorder. Although several treatment methods are used for patients, it remains a challenging problem for physicians. Erbium-YAG laser is one of the laser treatment methods that proved its efficacy in melasma treatment. We aimed to compare the efficacy of combining the fractional Er: YAG laser and Kligman's formula with Kligman's formula alone in the treatment of melasma. Twenty female patients with bilateral melasma were randomly treated in a split-face controlled manner with a fractional Er: YAG laser followed by Kligman's formula on one side and Kligman's formula on the other side. All patients received three laser sessions with four-week intervals. The efficacy of treatments was determined through photographs, Visioface, and Melasma Area Severity Index (MASI) score, all performed at baseline and three months after the end of laser sessions. Fractional Er: YAG laser and Kligman's formula showed a significant decrease in MASI score than Kligman's formula alone (P = 0.005). There was a significant decrease in cheek Visioface score on Er: YAG laser and Kligman's formula vs Kligman's formula (P = 0.02). However, the Patient Global Assessment Scale of both sides was not statistically significant (P = 0.23). The combination of Fractional Er: YAG laser with Kligman's formula is an effective treatment method for melasma.

Melanin Bleaching and Melanogenesis Inhibition Effects of Pediococcus acidilactici PMC48 Isolated from Korean Perilla Leaf Kimchi

Overproduction and accumulation of melanin in the skin will darken the skin and cause skin disorders. So far, components that can inhibit tyrosinase, a melanin synthase of melanocytes, have been developed and used as ingredients of cosmetics or pharmaceutical products. However, most of existing substances can only inhibit the biosynthesis of melanin while melanin that is already synthesized and deposited is not directly decomposed. Thus, their effects in decreasing melanin concentration in the skin are weak. To overcome the limitation of existing therapeutic agents, we started to develop a substance that could directly biodegrade melanin. We screened traditional fermented food microorganisms for their abilities to direct biodegrade melanin. As a result, we found that a kimchi-derived Pediococcus acidilactici PMC48 had a direct melanin-degrading effect. This PMC48 strain is a new strain, different from P. acidilactici strains reported so far. It not only directly degrades melanin, but also has tyrosinase-inhibiting effect. It has a direct melanindecomposition effect. It exceeds existing melanin synthesis-inhibiting technology. It is expected to be of high value as a raw material for melanin degradation drugs and cosmetics.

Melochia corchorifolia extract inhibits melanogenesis in B16F10 mouse melanoma cells via activation of the ERK signaling

BACKGROUND

Numerous researches have focused on discovering available inhibitors of melanogenesis from natural medicinal plants with stable efficacy and safety to resolve cutaneous hyperpigmentary problems. Melochia corchorifolia Linn. (MC) has been used as folk medicine to treat various diseases. However, the effect of MC on melanogenesis remains unknown.

AIM

In this study, we investigated the effect of MC extract on melanogenesis and its underlying mechanisms in B16F10 mouse melanoma cells.

METHODS

B16F10 cells were treated with MC extract, and then, cell viability, melanin content, and tyrosinase activity were analyzed. The mRNA and protein expression of tyrosinase and microphthalmia-associated transcription factor (MITF) were evaluated using real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting, respectively. Phosphorylated or total protein levels in MC extract-induced signaling pathways were analyzed by Western blotting.

RESULTS

Treatment of B16F10 cells with MC extract inhibited melanin synthesis and intracellular tyrosinase activity in a dose-dependent manner with no cytotoxicity. Protein and mRNA expressions of tyrosinase and MITF were also significantly decreased by MC extract treatment. In addition, phosphorylated level of extracellular signal-regulated kinase (ERK) was obviously increased by MC extract, but AKT pathway was not activated. Inhibited ERK phosphorylation by pretreatment with a selective ERK inhibitor PD98059 significantly reversed the decreased melanin content induced by treatment with MC extract in B16F10 cells.

CONCLUSION

MC extract inhibits melanogenesis in B16F10 mouse melanoma cells through suppression of MITF-tyrosinase signaling pathway by ERK activation.

Vanillic acid in Panax ginseng root extract inhibits melanogenesis in B16F10 cells via inhibition of the NO/PKG signaling pathway

Panax ginseng C. A. Meyer has been widely used in skin care. Our previous study showed that the phenolic acids in ginseng root extract (GRE) impart inhibitory effects on melanogenesis. In this study, we found that as the most abundant component of phenolic acids in GRE, vanillic acid decreased tyrosinase activity and melanin levels with or without α-MSH stimulation and suppressed the expression of microphthalmia-associated transcription factor (MITF) and melanogenic enzymes in B16F10 cells. Furthermore, vanillic acid downregulated NOS activity, nitric oxide (NO) content, cGMP level, guanylate cyclase (GC) and protein kinase G (PKG) activity, and the phosphorylation of cAMP-response element-binding protein (CREB), whereas arbutin had no effect on the NO/PKG pathway. These findings indicate that vanillic acid in GRE suppressed melanogenesis by inhibiting the NO/PKG signaling pathways. This study provides a potential mechanism underlying the inhibitory effect of ginseng on melanogenesis.

Evaluation of Anti-Tyrosinase and Antioxidant Properties of Four Fern Species for Potential Cosmetic Applications

Ferns are poorly explored species from a pharmaceutical perspective compared to other terrestrial plants. In this work, the antioxidant and tyrosinase inhibitory activities of hydrophilic and lipophilic extracts, together with total polyphenol content, were evaluated in order to explore the potential cosmetic applications of four Spanish ferns collected in the Prades Mountains (Polypodium vulgare L., Asplenium adiantum-nigrum L., Asplenium trichomanes L., and Ceterach officinarum Willd). The antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, oxygen radical absorbance capacity (ORAC) and xanthine/xanthine oxidase (X/XO) assays. The potential to avoid skin hyperpigmentation was tested by inhibiting the tyrosinase enzyme, as this causes melanin synthesis in the epidermis. All ferns were confirmed as antioxidant and anti-tyrosinase agents, but interestingly hydrophilic extracts (obtained with methanol) were more potent and effective compared to lipophilic extracts (obtained with hexane). Polypodium vulgare, Asplenium adiantum-nigrum, and Ceterach officinarum methanolic extracts performed the best as antioxidants. Polypodium vulgare methanolic extract also showed the highest activity as a tyrosinase inhibitor.

Effects on skin of Stichopus japonicus viscera extracts detected with saponin including Holothurin A: Down-regulation of melanin synthesis and up-regulation of neocollagenesis mediated by ERK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Stichopus japonicus (sea cucumber), edible traditional food in Asia, and its extracts are renowned for their wound healing, pain relieving, and cosmetic effects in traditional medicine. Holothurins, toxins isolated from sea cucumber, are thought to be active components for their beneficial effects. However, researchers have yet to outline specific mechanisms thereof.

AIM OF THE STUDY

The present study was designed to evaluate the anti-melanogenic and anti-wrinkle properties of S. japonicus viscera extracts (VF) on the skin via in vitro and ex vivo experiments and to assess the anti-aging effects of S. japonicus viscera extracts in relation to known wound healing and cosmetic processes.

MATERIALS AND METHODS

The viscera of live S. japonicus specimens were freeze dried and ground into a powder. Aqueous extracts were subsequently prepared from the concentrated powder using a water extraction method. To investigate the inhibitory effects of VF on melanogenesis, mushroom tyrosinase activity assay and melanin assay were performed on Melan-A cells. To further delineate the anti-melanogenic properties of VF, western blot analysis for tyrosinase, TRP-1, TRP-2, MITF, and ERK was conducted. Changes in collagen synthesis in human dermal fibroblast (HDF) were evaluated via CCK-8 assay and immunocytochemistry to determine the anti-wrinkle effects of VF. Finally, anti-aging properties were examined in a human skin equivalent ex vivo model.

RESULTS

In Melan-A cells, VF treatment reduced melanin contents in a concentration-dependent manner. The anti-melanogenic effects of VF appeared to be due to enzymatic inhibition of tyrosinase. In CCK-8 assay, VF also significantly increased the viability of HDFs in a concentration-dependent manner. Immunoblot analysis revealed phosphorylation of ERK in HDFs treated with VF. In a human skin equivalent ex vivo model (Neoderm®-ED), VF treatment at a concentration of 50 μg/ml enhanced collagen type IV and Ki-67 expression and downregulated MMP-9 expression.

CONCLUSION

This study demonstrated that aqueous extracts from S. japonicus viscera are effective whitening and anti-aging agents that stimulate ERK signaling to inhibit melanin synthesis and promote collagen synthesis.

Antiwrinkle and antimelanogenesis activity of the ethanol extracts of Lespedeza cuneata G. Don for development of the cosmeceutical ingredients

To develop the ingredient with the cosmeceutical function, the antiwrinkle and antimelanogenesis effects of the ethanol extract of Lespedeza cuneata G. Don were investigated. DPPH radical scavenging activity was significantly increased with the extract of L. cuneata G. Don. Cell viability on CCD986Sk human fibroblast was also increased by the ethanol extract of L. cuneata G. Don. The inhibitory function of the extract of L. cuneata G. Don on collagenase, elastase, and tyrosinase was evaluated. Protein expression level of Claudin-1, Occludin, and ZO-1 was up-regulated in HaCaT human keratinocyte by the extract of L. cuneata G. Don. In addition, the extract of L. cuneata G. Don inhibited melanin synthesis in B16F10 murine melanoma cells by decreasing MITF, TRP1, and TRP2 protein levels and increasing the phosphorylated Erk and Akt. Thus, these findings would be useful for developing the new cosmeceutical formulations based on the extract of L. cuneata G. Don.

Fractional erbium-doped yttrium aluminum garnet laser-assisted drug delivery of hydroquinone in the treatment of melasma

Background

Melasma is a difficult-to-treat hyperpigmentary disorder. Ablative fractional laser (AFL)-assisted delivery of topically applied drugs to varied targets in the skin has been an area of ongoing study and research.

Objective

The objective of this study was to evaluate the efficacy and safety of fractional erbium-doped yttrium aluminum garnet (Er:YAG) laser as an assisted drug delivery for enhancing topical hydroquinone (HQ) permeation into the skin of melasma patients.

Patients and methods

Thirty female patients with bilateral melasma were randomly treated in a split-face controlled manner with a fractional Er:YAG laser followed by 4% HQ cream on one side and 4% HQ cream alone on the other side. All patients received six laser sessions with a 2-week interval. The efficacy of treatments was determined through photographs, dermoscopic photomicrographs and Melasma Area Severity Index (MASI) score, all performed at baseline and at 12 weeks of starting therapy. The patient’s level of satisfaction was also recorded.

Results

Er:YAG laser + HQ showed significantly better results (p<0.005) with regard to decrease in the degree of pigmentation as assessed on the 4-point scale than HQ alone. There was a significant decrease in MASI scores on Er:YAG laser + HQ side vs HQ side. Minor reversible side effects were observed on both sides.

Conclusion

AFL-assisted delivery of HQ is a safe and effective method for the treatment of melasma.

Levetiracetam-Induced Skin Hyperpigmentation: An Extremely Rare Undesirable Side Effect

Levetiracetam is one of the newer second-generation antiepileptic drugs with multiple mechanisms of action. Cutaneous side effects due to levetiracetam are rarely reported in the literature. In this article, we describe a patient with skin hyperpigmentation due to the treatment with levetiracetam with complete resolution after discontinuation of the medication. In addition, we review the topic and hypothesize the mechanism behind this rare complication. To the best of our knowledge, this is the first report of skin hyperpigmentation as a side effect of levetiracetam in the literature. The prescribing physicians should inform the patients about all potential side effect of levetiracetam including skin hyperpigmentation. Similar to many undiagnosed conditions, increased awareness of their existence is the key to diagnosis. Early recognition and timely cessation of therapy are important to reverse this effect. Further studies should be conducted to explore the pathophysiology of this rare side effect.

Inhibition of collagenase and melanogenesis by ethanol extracts of Orostachys japonicus A. Berger: possible involvement of Erk and Akt signaling pathways in melanoma cells

Orostachys japonicus is an herb that contains several functional components and has traditionally been used to treat various diseases in Asia. In this study, bioactive components from different parts of the O. japonicus plant were investigated, and the contents of the functional components in ethanol extracts of O. japonicus cultivated in Korea and China were compared. The antioxidant effects of O. japonicus ethanol extracts were investigated using Raw 264.7 cells. It was found that 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity was significantly decreased in the cells treated with the extracts. Moreover, the novel inhibitory functions of O. japonicus extracts on collagenase, elastase, and tyrosinase were established. We also found that O. japonicus extracts strongly inhibited melanin synthesis in B16F10 melanoma cells by decreasing MITF protein levels and activating the Erk and Akt signaling pathways. Thus, these findings would be useful for developing new cosmetic and pharmaceutical formulations based on O. japonicus extracts.

Pharmacologic Treatment of Vitiligo in Children and Adolescents: A Systematic Review

BACKGROUND

The true pathogenic mechanism of vitiligo is still unknown. About half of the patients with this disease have onset before the age of 20 years, making it a serious dermatologic disorder in childhood.

OBJECTIVES

The objective of this study was to review the literature in a systematic way and identify the main pharmacologic treatments and outcomes in children and adolescents with vitiligo.

METHODS

Four databases-the National Library of Medicine (MEDLINE-PubMed), Web of Science, Scopus, and Latin American and Caribbean Health Sciences (LILACS)-were used for the search up to January 2015. All electronic search titles, selected abstracts and full-text articles were independently reviewed by a minimum of two reviewers.

RESULTS

There were 15 articles from 13 different countries: 3 were retrospective and 12 were prospective; the number of participants in the studies varied between 9 and 400, ages ranged from 0 to 18 years, and the duration of disease ranged from 1 to 17 years. The most commonly used drugs were tacrolimus alone (or combined with clobetasol), pimecrolimus, corticosteroids, and calcipotriol. Treatment duration ranged from 10 days to 6 months with a topical route of administration.

CONCLUSIONS

The main outcome measurements were morphometric analysis performed using a computer program, hematologic or biochemical change, and photography (predominant). It is unclear which was the most effective treatment for vitiligo, however, it was found that these therapies are all promising in the treatment of the disease. With proper care, disease control and repigmentation, even if partial, can be achieved.

Impact of pigmentary disorders on quality of life in Japan: Interest of the BeautyQoL instrument

Skin pigmentary disorders and uneven skin tone represent common cosmetic concerns in Japan where fairer skin is culturally desirable. As the demographics of Asian countries continue to evolve, there is a need to understand the impact of cosmetic skin concerns on quality of life (QoL). 199 Japanese women self-claiming facial skin pigmentation disorders were asked to complete the BeautyQoL questionnaire, and the results were compared with those of a control group of 200 women. Of the five dimensions of the BeautyQoL questionnaire, the dimension "mood" appeared to be significantly lower in the group presenting facial dark spots, as compared with the control group (p < 0.05). In the group presenting facial dark spots, the five dimensions and the global score showed that subjects concerned had lower scores than subjects less concerned, even if statistical significance was not reached. This study confirms that common pigmentary disorders such as facial black spots may negatively impact QoL. Further comparative studies with a controlled randomized design would be necessary to confirm these findings.

cAMP-dependent activation of protein kinase A as a therapeutic target of skin hyperpigmentation by diphenylmethylene hydrazinecarbothioamide

BACKGROUND AND PURPOSE

cAMP as a second messenger stimulates expression of microphthalmia-associated transcription factor (MITF) or the tyrosinase gene in UVB-induced skin pigmentation. Diphenylmethylene hydrazinecarbothioamide (QNT 3-80) inhibits α-melanocyte-stimulating hormone (α-MSH)-induced melanin production in B16 murine melanoma cells but its molecular basis remains to be defined. Here, we investigated the mechanism underlying the amelioration of skin hyperpigmentation by QNT 3-80.

EXPERIMENTAL APPROACH

We used melanocyte cultures with raised levels of cAMP and UVB-irradiated dorsal skin of guinea pigs for pigmentation assays. Immunoprecipitation, kemptide phosphorylation, fluorescence analysis and docking simulation were applied to elucidate a molecular mechanism of QNT 3-80.

KEY RESULTS

QNT 3-80 inhibited melanin production in melanocyte cultures with elevated levels of cAMP, including those from human foreskin. This compound also ameliorated hyperpigmentation in vivo in UVB-irradiated dorsal skin of guinea pigs. As a mechanism, QNT 3-80 directly antagonized cAMP binding to the regulatory subunit of PKA, nullified the dissociation and activation of inactive PKA holoenzyme in melanocytes and fitted into the cAMP-binding site on the crystal structure of human PKA under the most energetically favourable simulation. QNT 3-80 consequently inhibited cAMP- or UVB-induced phosphorylation (activation) of cAMP-responsive element-binding protein in vitro and in vivo, thus down-regulating expression of genes for MITF or tyrosinase in the melanogenic process.

CONCLUSIONS AND IMPLICATIONS

Our data suggested that QNT 3-80 could contribute significantly to the treatment of skin disorders with hyperpigmented patches with the cAMP-binding site of PKA as its molecular target.

Evidence-based treatment for melasma: expert opinion and a review

Introduction

Melasma is one of the most common pigmentary disorders seen by dermatologists and often occurs among women with darker complexion (Fitzpatrick skin type IV–VI). Even though melasma is a widely recognized cause of significant cosmetic disfigurement worldwide and in India, there is a lack of systematic and clinically usable treatment algorithms and guidelines for melasma management. The present article outlines the epidemiology of melasma, reviews the various treatment options along with their mode of action, underscores the diagnostic dilemmas and quantification of illness, and weighs the evidence of currently available therapies.

Methods

A panel of eminent dermatologists was created and their expert opinion was sought to address lacunae in information to arrive at a working algorithm for optimizing outcome in Indian patients. A thorough literature search from recognized medical databases preceded the panel discussions. The discussions and consensus from the panel discussions were drafted and refined as evidence-based treatment for melasma. The deployment of this algorithm is expected to act as a basis for guiding and refining therapy in the future.

Results

It is recommended that photoprotection and modified Kligman’s formula can be used as a first-line therapy for up to 12 weeks. In most patients, maintenance therapy will be necessary with non-hydroquinone (HQ) products or fixed triple combination intermittently, twice a week or less often. Concomitant camouflage should be offered to the patient at any stage during therapy. Monthly follow-ups are recommended to assess the compliance, tolerance, and efficacy of therapy.

Conclusion

The key therapy recommended is fluorinated steroid containing 2–4% HQ-based triple combination for first line, with additional selective peels if required in second line. Lasers are a last resort.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-014-0064-z) contains supplementary material, which is available to authorized users.

Inhibition of melanogenesis by the antidiabetic metformin

Several reports have demonstrated the inhibitory effect of metformin, a widely used drug in the treatment of type 2 diabetes, on the proliferation of many cancers including melanoma. Recently, it has been shown that metformin is able to modulate the cAMP level in the liver. As cAMP has a crucial role in melanin synthesis and skin pigmentation, we investigated the effect of metformin on melanogenesis both in vitro and in vivo. We showed that metformin led to reduced melanin content in melanoma cells and in normal human melanocytes by decreasing cAMP accumulation and cAMP-responsive element-binding protein phosphorylation. This inhibitory effect is correlated with decreased expression of master genes of melanogenesis, microphthalmia-associated transcription factor, tyrosinase, dopachrome tautomerase, and tyrosinase-related protein 1. Furthermore, we demonstrated that the antimelanogenic effect of metformin is independent of the AMPK pathway. Interestingly, topical application of metformin induced tail whitening in mice. Finally, we confirmed the antimelanogenic effect of metformin on reconstituted human epidermis and on human skin biopsies. These data emphasize the depigmenting effect of metformin and suggest a clinical strategy for using metformin in the topical treatment of hyperpigmentation disorders.

The use of botanically derived agents for hyperpigmentation: a systematic review

BACKGROUND

Hyperpigmentation disorders are common among those seeking care from dermatologists and primary care physicians. The cosmeceutical and natural product industries are rapidly growing and many botanical agents are purported to improve hyperpigmentation disorders.

OBJECTIVE

We sought to review clinical evidence for the use of botanical agents in the treatment of hyperpigmentation.

METHODS

We searched MEDLINE and Embase databases and a total of 26 articles met inclusion criteria. Study methodology was analyzed and the reproducibility of the studies was graded.

RESULTS

Several botanical agents appear promising as treatment options but few studies were methodologically rigorous. Several plant extract and phytochemicals effectively lighten signs of epidermal melasma and hyperpigmentation induced by ultraviolet radiation exposure. Results were mixed for treatment of solar lentigines or dermal hyperpigmentation.

LIMITATIONS

There were few rigorously designed studies; future research will be critical to further ascertain the discussed results.

CONCLUSIONS

The subtype of hyperpigmentation is important for treatment prognosis, with dermal hyperpigmentation less responsive to treatment. Botanical extracts may play an integrative role in the treatment of hyperpigmentation and further studies that integrate them with standard therapies are needed. Side effects, including worsened hyperpigmentation, need to be discussed when considering these therapies.

A study on fractional erbium glass laser therapy versus chemical peeling for the treatment of melasma in female patients

Introduction:

Melasma is a commonly acquired hypermelanosis and a common dermatologic skin disease that occurs on sun-exposed areas of face.

Aims:

To assess the efficacy and safety of non-ablative 1,550 nm Erbium glass fractional laser therapy and compare results with those obtained with chemical peeling.

Materials and Methods:

We selected 30 patients of melasma aged between 20 years and 50 years for the study. The patients were divided into two groups of 15 patients each. Group I patients were subjected to four sessions of 1,550 nm Erbium glass non-ablative fractional laser at 3 weeks interval. In group II patients, four sessions of chemical peeling with 70% glycolic acid was performed.

Results:

After 12 weeks of treatment, percentage reduction in Melasma Area and Severity Index (MASI) score was seen in 62.9% in the laser group and 58.7% in the peels group.

Conclusion:

It was observed that 1,550 nm fractional laser is as effective as 70% glycolic acid peel in reducing MASI score in patients with melasma.

Lasers

Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients.

cAMP-binding site of PKA as a molecular target of bisabolangelone against melanocyte-specific hyperpigmented disorder

Microphthalmia-associated transcription factor (MITF) is inducible in response to cAMP and has a pivotal role in the melanocyte-specific expression of tyrosinase for skin pigmentation. Here we suggest that the cAMP-binding site of protein kinase A (PKA) is a target in the inhibition of the melanogenic process in melanocytes, as evidenced from the molecular mechanism of small molecules such as bisabolangelone (BISA) and Rp-adenosine 3',5'-cyclic monophosphorothioate (Rp-cAMPS). BISA is a sesquiterpene constituent of Angelica koreana, a plant of the Umbelliferae family, whose roots are used as an alternative medicine. BISA competitively inhibited cAMP binding to the regulatory subunit of PKA and fitted into the cAMP-binding site on the crystal structure of PKA under the most energetically favorable simulation. In α-melanocyte-stimulating hormone (α-MSH)-activated melanocytes, BISA and Rp-cAMPS nullified cAMP-dependent PKA activation, dissociating catalytic subunits from an inactive holoenzyme complex. They resultantly inhibited cellular phosphorylation of the cAMP-responsive element-binding protein (CREB) or another transcription factor SOX9, thus downregulating the expression of MITF or the tyrosinase gene with decreased melanin production. Taken together, this study defined the antimelanogenic mechanism of BISA or Rp-cAMPS with a notable implication of the cAMP-binding site of PKA as a putative target ameliorating melanocyte-specific hyperpigmented disorder.

Plants from Brazilian Cerrado with potent tyrosinase inhibitory activity

The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation. Using in vitro tyrosinase inhibitory activity assay, extracts from 13 plant species from Brazilian Cerrado were evaluated. The results showed that Pouteria torta and Eugenia dysenterica extracts presented potent in vitro tyrosinase inhibition compared to positive control kojic acid. Ethanol extract of Eugenia dysenterica leaves showed significant (p<0.05) tyrosinase inhibitory activity exhibiting the IC₅₀ value of 11.88 µg/mL, compared to kojic acid (IC₅₀ value of 13.14 µg/mL). Pouteria torta aqueous extract leaves also showed significant inhibitory activity with IC₅₀ value of 30.01 µg/mL. These results indicate that Pouteria torta and Eugenia dysenterica extracts and their isolated constituents are promising agents for skin-whitening or antimelanogenesis formulations.

Comparative study of 15% TCA peel versus 35% glycolic acid peel for the treatment of melasma

BACKGROUND

Chemical peels are the mainstay of a cosmetic practitioner's armamentarium because they can be used to treat some skin disorders and can provide aesthetic benefit.

OBJECTIVES

To compare 15% TCA peel and 35% glycolic acid peel for the treatment of melasma.

MATERIAL AND METHODS

We selected 30 participants of melasma aged between 20 and 50 years from the dermatology outpatient department and treated equal numbers with 15% TCA and 35% glycolic acid.

RESULTS

Subjective response as graded by the patient showed good or very good response in 70% participants in the glycolic acid group and 64% in the TCA group.

CONCLUSIONS

There was statistically insignificant difference in the efficacy between the two groups for the treatment of melasma.

Postinflammatory hyperpigmentation: etiologic and therapeutic considerations

Postinflammatory hyperpigmentation (PIH) is a reactive hypermelanosis and sequela of a variety of inflammatory skin conditions. PIH can have a negative impact on a patient's quality of life, particularly for darker-skinned patients. Studies show that dyschromias, including PIH, are one of the most common presenting complaints of darker-skinned racial ethnic groups when visiting a dermatologist. This is likely due to an increased production or deposition of melanin into the epidermis or dermis by labile melanocytes. A variety of endogenous or exogenous inflammatory conditions can culminate in PIH and typically most epidermal lesions will appear tan, brown, or dark brown while dermal hypermelanosis has a blue-gray discoloration. Depigmenting agents target different steps in the production of melanin, most commonly inhibiting tyrosinase. These agents include hydroquinone, azelaic acid, kojic acid, arbutin, and certain licorice (glycyrrhiza) extracts. Other agents include retinoids, mequinol, ascorbic acid (vitamin C), niacinamide, N-acetyl glucosamine, and soy, and these products depigment by different mechanisms. Certain procedures can also be effective in the treatment of PIH including chemical peeling and laser therapy. It is important to note that these same therapeutic modalities may also play a role in causing PIH. Lastly, those lesions that are not amenable to medical or surgical therapy may experience some improvement with cosmetic camouflage.

What should be considered in treatment of melasma

Melasma is a common acquired hyperpigmentary skin disorder characterized by light to dark brown macules and patches occurring in the sun-exposed areas of the face. Melasma lesional skin is characterized by epidermal hyperpigmentation through increased melanogenesis in epidermal melanocytes. Some patients have dermal melanin but its amount is not significant and its distribution is very heterogeneous in the whole melasma lesional skin. Melasma is not homogeneous disease and there are personal characteristics of patients with melasma. The pathogenesis of melasma is not fully understood, but several hypotheses have been suggested. Increased vascularity in melasma lesions has suggested the role of increased number of enlarged vessels in the development of melasma. Endogeneous and exogeneous stimuli such as sex hormones and ultraviolet irradiation respectively may stimulate the microenvironment leading to the release of various mediators that cause activation of melanocytes and/or these stimuli may directly activate the melanocytes. Melasma patients may have specialized melanocytes with an intrinsic sensitivity to these stimuli.

[Pigmentary lasers]

The pigmentary disorders are a very heterogeneous group with a high therapeutic demand from the patients. The lasers have provided a major advance in the treatment of some pigmentary lesions. The indication and the optimal parameters are actually quite well defined. However, pigmentary lasers have limits and some dermatosis can even be worsened after laser treatment. Those limitations as well as the potential side effects have to clearly be explained to the patients that often seek for a miracle cure.

A study comparing chemical peeling using modified Jessner's solution and 15% trichloroacetic Acid versus 15% trichloroacetic acid in the treatment of melasma

Background:

Melasma is a symmetric progressive hyperpigmentation of the facial skin that occurs in all races but has a predilection for darker skin phenotypes. Depigmenting agents, laser and chemical peeling as classic Jessner's solution, modified Jessner's solution and trichloroacetic acid have been used alone and in combination in the treatment of melasma.

Objectives:

The aim of the study was to compare the therapeutic effect of combined 15% Trichloroacetic acid (TCA) and modified Jessner's solution with 15% TCA on melasma.

Materials and Methods:

Twenty married females with melasma (epidermal type), with a mean age of 38.25 years, were included in this study. All were of skin type III or IV. Fifteen percent TCA was applied to the whole face, with the exception of the left malar area to which combined TCA 15% and modified Jessner's solution was applied.

Results:

Our results revealed statistically highly significant difference between MASI Score (Melasma Area and Severity Index) between the right malar area and the left malar area.

Conclusion:

Modified Jessner's solution proved to be useful as an adjuvant treatment with TCA in the treatment of melasma, improving the results and minimizing postinflammatory hyperpigmentation.

The efficacy of pimecrolimus 1% cream plus narrow-band ultraviolet B in the treatment of vitiligo: a double-blind, placebo-controlled clinical trial

BACKGROUND

Recently, narrow-band ultraviolet B (NB-UVB) and topical immunomodulators have been successfully used in the treatment of vitiligo.

OBJECTIVE

To determine whether the combination of pimecrolimus with NB-UVB accelerates the response time and/or improves the degree of response in patients with vitiligo.

METHODS

Sixty-eight patients with vitiligo enrolled in this randomized, double-blind, placebo-controlled study. The patients were randomized into two groups and treated with NB-UVB plus either pimecrolimus or placebo for 3 months. Tri-weekly radiation was started at 280 mJ/cm(2), with 15% increments for each subsequent treatment until erythema was reported or a maximum of 800 mJ/cm was achieved. At baseline and 6 and 12 weeks after commencement of therapy, vitiliginous patches were measured.

RESULTS

Fifty patients completed the 3-month study. No significant side effects except self-limited erythema and pruritus were observed. After 12 weeks of treatment, repigmentation of the facial lesions was higher in patients treated with combined pimecrolimus and NB-UVB compared with the placebo plus NB-UVB group (64.3 vs 25.1%) (p < 0.05%). There was no statistically significant difference in the repigmentation rate between the two groups on other body areas.

CONCLUSION

On the face, NB-UVB works better if combined with pimecrolimus 1% cream rather than used alone.

The efficacy of pimecrolimus 1% cream combined with microdermabrasion in the treatment of nonsegmental childhood vitiligo: a randomized placebo-controlled study

Recently, topical immunomodulators have been successfully used in monotherapy or in combination with other therapeutic modalities in vitiligo. To determine whether combination pimecrolimus 1% cream and microdermabrasion enhances response time and repigmentation rate in children with vitiligo. Sixty-five children diagnosed with vitiligo enrolled in this randomized placebo-controlled study. Three vitiliginous patches were chosen in each patient. The first lesion was treated by pimecrolimus 1% cream. On the second lesion after doing microdermabrasion on day 1, pimecrolimus 1% cream was applied. On the third lesion placebo was applied. The course of treatment was 10 days. Vitiliginous patches were measured at baseline, day 10, and months 1, 2, and 3. Sixty patients completed the 3-month study period. Clinical response (pigmentation >50%) was observed in 60.4% of the patches treated by combined pimecrolimus plus microdermabrasion at the third month of follow-up, compared with 32.1% and 1.7% for pimecrolimus alone and placebo, respectively (p = 0.000). No significant side effect was observed. Microdermabrasion exerts an additive effect in enhancing the rate and degree of repigmentation by pimecrolimus. This new combined approach appears to be safe and effective in childhood vitiligo.

Modifying skin pigmentation - approaches through intrinsic biochemistry and exogenous agents

Rates of skin cancer continue to increase despite the improved use of traditional sunscreens to minimize damage from ultraviolet radiation. The public perception of tanned skin as being healthy and desirable, combined with the rising demand for treatments to repair irregular skin pigmentation and the desire to increase or decrease constitutive skin pigmentation, arouses great interest pharmaceutically as well as cosmeceutically. This review discusses the intrinsic biochemistry of pigmentation, details mechanisms that lead to increased or decreased skin pigmentation, and summarizes established and potential hyper- and hypo-pigmenting agents and their modes of action.

Pigmentary Disorders in Latin America

Pigmentary disorders with hypopigmentation/depigmentation or hyperpigmentation may have special manifestations in Latin America. Most pigmentary disorders are commonly observed in all areas of Latin America, but a few are particularly seen in tropical and subtropical regions. In most pigmentary disorder ailments described, multiple factors involved in their pathogenesis are known, but etiology remains elusive. Some pigmentary disorders have peculiar clinical expressions and, in spite of being restricted to certain geographical areas, they may be observed in other world areas because of frequent traveling of affected patients. Therapy of most of these ailments is difficult or remains unknown.

Superficial dermabrasion and suction blister epidermal grafting for postburn dyspigmentation in Asian skin

BACKGROUND The effective treatment of postburn dyspigmentation, which is more common in non-Caucasian populations, is a challenge for all surgeons. OBJECTIVE We tried to evaluate an alternative surgical method of superficial dermabrasion and suction blister epidermal grafting, its efficacy, and its outcome, for the treatment of postburn dyspigmentation disorders in Asians. METHODS We applied superficial dermabrasion as a deepithelialization process on dyspigmented areas of skin and simultaneous suction blister epidermal grafting to providing pure epidermis. Twenty-three cases were included in our study. RESULTS All of the epidermal grafts took completely within 4 or 5 days after surgery without hematoma or delayed wound healing in any case. Skin color and surface irregularity improved remarkably in all cases and blended in well with the surrounding skin. Postoperative complications, such as peripheral hypopigmentation, delayed hyperpigmentation, milia, inclusion cysts, achromic fissures, prolonged erythema, and scar deformity, were not observed in any of the cases during the follow-up period. CONCLUSION Our method of combined modalities had a synergistic effect on the treatment of postburn dyspigmentation. The authors suggest that superficial dermabrasion with simultaneous epidermal grafting should be considered as an alternative method for the treatment of postburn dyspigmentation disorders.

Hypopigmenting agents: an updated review on biological, chemical and clinical aspects

An overview of agents causing hypopigmentation in human skin is presented. The review is organized to put forward groups of biological and chemical agents. Their mechanisms of action cover (i) tyrosinase inhibition, maturation and enhancement of its degradation; (ii) Mitf inhibition; (iii) downregulation of MC1R activity; (iv) interference with melanosome maturation and transfer; (v) melanocyte loss, desquamation and chemical peeling. Tyrosinase inhibition is the most common approach to achieve skin hypopigmentation as this enzyme catalyses the rate-limiting step of pigmentation. Despite the large number of tyrosinase inhibitors in vitro, only a few are able to induce effects in clinical trials. The gap between in-vitro and in-vivo studies suggests that innovative strategies are needed for validating their efficacy and safety. Successful treatments need the combination of two or more agents acting on different mechanisms to achieve a synergistic effect. In addition to tyrosinase inhibition, other parameters related to cytotoxicity, solubility, cutaneous absorption, penetration and stability of the agents should be considered. The screening test system is also very important as keratinocytes play an active role in modulating melanogenesis within melanocytes. Mammalian skin or at least keratinocytes/melanocytes co-cultures should be preferred rather than pure melanocyte cultures or soluble tyrosinase.