Recent progress in melasma pathogenesis

Dermoscopic evaluation of tranexamic acid versus Vitamin C, with microneedling in the treatment of melasma: a comparative, split-face, single-blinded study

BACKGROUND

Melasma is a complex pigmentary disorder with challenging management.

OBJECTIVES

Evaluation of efficacy of topical tranexamic acid (TXA) versus Vitamin C (Vit C) with microneedling (MN) in melasma therapy.

MATERIALS AND METHODS

In 30 females with melasma, after 4 weeks of using Modified Kligman's formula, the right side of the face was treated with MN + TXA and the left with MN + Vit C for five biweekly sessions. Wood's light, dermoscopy, Melasma Area and Severity Index (MASI), MASI malar right and malar left (MASI_MR and MASI_ML), Visual Analogue Score (VAS), and Dermatology Life Quality Index (DLQI) were evaluated at weeks 0, 4, 12, and 16.

RESULTS

Both MASI_MR and MASI_ML decreased significantly (p < .001). Both sides exhibited significant diminution in dark fine granules (p-value < .001), homogeneous pigmentation (p-value = .005) and pseudoreticular brown network (p-value = .028). However, telangiectasia significantly improved only on the TXA treated side (p = .002). DLQI improved significantly on both sides (p < .001). In some patients transformation of mixed to dermal melasma was depicted.

CONCLUSION

MN followed by Vit C or TXA is successful in melasma management, the latter being advantageous vis-a-vis dermal vascularity and epidermal pigmentation. Dermoscopic evaluation appears crucial in choosing optimum treatment in each patient.

Nootkatol prevents ultraviolet radiation-induced photoaging via ORAI1 and TRPV1 inhibition in melanocytes and keratinocytes

Skin photoaging occurs due to chronic exposure to solar ultraviolet radiation (UV), the main factor contributing to extrinsic skin aging. Clinical signs of photoaging include the formation of deep, coarse skin wrinkles and hyperpigmentation. Although melanogenesis and skin wrinkling occur in different skin cells and have different underlying mechanisms, their initiation involves intracellular calcium signaling via calcium ion channels. The ORAI1 channel initiates melanogenesis in melanocytes, and the TRPV1 channel initiates MMP-1 production in keratinocytes in response to UV stimulation. We aimed to develop a drug that may simultaneously inhibit ORAI1 and TRPV1 activity to help prevent photoaging. We synthesized nootkatol, a chemical derivative of valencene. TRPV1 and ORAI1 activities were measured using the whole-cell patch-clamp technique. Intracellular calcium concentration [Ca²⁺]_i was measured using calcium-sensitive fluorescent dye (Fura-2 AM). UV-induced melanin formation and MMP-1 production were quantified in B16F10 melanoma cells and HaCaT cells, respectively. Our results indicate that nootkatol (90 μM) reduced TRPV1 current by 94% ± 2% at –60 mV and ORAI1 current by 97% ± 1% at –120 mV. Intracellular calcium signaling was significantly inhibited by nootkatol in response to ORAI1 activation in human primary melanocytes (51.6% ± 0.98% at 100 μM). Additionally, UV-induced melanin synthesis was reduced by 76.38% ± 5.90% in B16F10 melanoma cells, and UV-induced MMP-1 production was reduced by 59.33% ± 1.49% in HaCaT cells. In conclusion, nootkatol inhibits both TRPV1 and ORAI1 to prevent photoaging, and targeting ion channels may be a promising strategy for preventing photoaging.

The Tam formula: A pilot study for a new treatment for melasma

BACKGROUND

Melasma is a common hyperpigmentation disorder with numerous, but often unsatisfactory treatment options.

AIMS

A pilot study to evaluate the efficacy and safety of a novel topical combination of 12% hydroquinone, 6% kojic acid, and 5% vitamin C cream for melasma.

PATIENTS AND METHODS

A pilot study of 6 women with melasma was conducted at an academic dermatology department and a private dermatology practice to evaluate the efficacy of a topical combination of 12% hydroquinone, 6% kojic acid, and 5% vitamin C cream, entitled the "Tam Formula." Two blinded evaluators calculated Melasma Area and Severity Index (MASI) Scores before and after treatment to evaluate change from baseline, and statistical analysis was performed.

RESULTS

Treatment with this combination topical cream resulted in an average 63.77 ± 22.10 percent reduction in MASI scores.

CONCLUSIONS

While there is a need for further investigation, this pilot study indicates the Tam Formula may provide an alternative treatment option for melasma.

Mechanistic Models of Signaling Pathways Reveal the Drug Action Mechanisms behind Gender-Specific Gene Expression for Cancer Treatments

Despite the existence of differences in gene expression across numerous genes between males and females having been known for a long time, these have been mostly ignored in many studies, including drug development and its therapeutic use. In fact, the consequences of such differences over the disease mechanisms or the drug action mechanisms are completely unknown. Here we applied mechanistic mathematical models of signaling activity to reveal the ultimate functional consequences that gender-specific gene expression activities have over cell functionality and fate. Moreover, we also used the mechanistic modeling framework to simulate the drug interventions and unravel how drug action mechanisms are affected by gender-specific differential gene expression. Interestingly, some cancers have many biological processes significantly affected by these gender-specific differences (e.g., bladder or head and neck carcinomas), while others (e.g., glioblastoma or rectum cancer) are almost insensitive to them. We found that many of these gender-specific differences affect cancer-specific pathways or in physiological signaling pathways, also involved in cancer origin and development. Finally, mechanistic models have the potential to be used for finding alternative therapeutic interventions on the pathways targeted by the drug, which lead to similar results compensating the downstream consequences of gender-specific differences in gene expression.

The color of skin: brown diseases of the skin, nails, and mucosa

Brown diseases comprise disorders leading to hyperpigmentation in skin and nails. Melasma is an acquired skin disorder that is characterized by brownish macules that typically occur on the face. Schamberg disease, also known as progressive pigmented purpura, is characterized by brown pigmentation with pepper spots on their edges. We summarize the epidemiology, pathogenesis, histologic features, and treatment choices for additional brown diseases, including melasma, pigmented purpuric dermatoses, postinflammatory hyperpigmentation, drug-induced hyperpigmentation, and pigmentations due to systemic or physiologic conditions.

The role and mechanism of Asian medicinal plants in treating skin pigmentary disorders

ETHNOPHARMACOLOGICAL RELEVANCE

Chloasma, senile plaques, vitiligo and other pigmentary disorders seriously affect patients' appearance and life quality. Medicinal plant is the product of long-term medical practice worldwide, with the advantages of outstanding curative properties and less side effects. Recently, research were made to explore the value of medicinal plants in the treatment of pigmentary disorders, and remarkable results were achieved.

AIM OF THE REVIEW

This review outlines the current understanding of the role and potential mechanisms of medicinal plants (including active ingredients, extracts and prescriptions) in pigmentary disorders, especially Chinese medicinal plants, provides the preclinical evidence for the clinical benefits. This study hopes to provide comprehensive information and reliable basis for exploring new therapeutic strategies of plant drugs in the treatment of skin pigmented diseases.

METHODS

The literature information was obtained from the scientific databases (up to Oct, 2017), mainly from the PubMed, Web of Science and CNKI databases, and was to identify the experimental studies on the regulating melanogenesis role of the active agents from herbal medicine and the involved mechanisms. The search keywords for such work included: "pigmentary" or "pigmentation", "melanogenesis", and "traditional Chinese medicine" or "Chinese herbal medicine", "herb", "medicinal plant".

RESULTS

We summarized the function of medicinal plants involved in melanogenesis, especially Chinese medicine. It was reported that the active ingredients, extracts, or prescriptions of medicinal plants can regulate the expression of genes related to melanogenesis by affecting the signaling pathways such as MAPK and PKA, thereby regulating pigment synthesis. Some of them can promote melanogenesis (such as isoliquiritigenin, geniposide; Cornus officinalis Siebold & Zucc., Eclipta prostrata (L.) L.; the Bairesi complex prescription, etc.). While others have the opposite effect (such as biochanin A, Gomisin N; Panax ginseng C.A. Meyer, Nardostachys chinensis Bat.; Sanbaitang, etc.).

CONCLUSION

Asian medicinal plants, especially their active ingredients, have multilevel effects on melanogenesis by regulating melanogenesis-related genes or signaling pathways. They are of great clinical value for the treatment of skin pigmentary disorders. However, the experimental effect, safety, and functional mechanism of the medicinal plants require further determination before studying their clinical efficacy.

Clinical factors affecting the efficacy of melasma treatment using the Q-switched 1064 Nd: YAG laser mode in a group of Venezuelan female patients

The influence of melasma risk factors on the effectiveness of laser toning treatment in Venezuelan females was investigated. Clinical evaluation was performed (n = 64) including ultrasound and thyroid hormone profile. All patients underwent face exposure with laser toning, eight sessions weekly. VISIA percentiles corresponding to dark brown spots determined before and after treatment were compared by ANOVA. Differences between percentile values before and after treatment for each patient were calculated and expressed as percentages. An improvement of ≥30% was considered as significant. Spearman rank correlations between improvement and clinical parameters were determined. A significant increase (p > .005) of the median of the percentiles in the overall group was observed. However, only 62.5% of the patients exhibited an improvement of ≥30% at the right malar, 73.4% at the frontal and 71.8% at the left malar areas. Hormonal contraception during treatment (right malar: p < .0001 left malar: p = .0035), thyroid disorders (right malar: p < .0001; frontal: p = .011; left malar: p < .0001) and photoaging (right malar: p = .0235; frontal: p = .0237; left malar: p = .0137) were inversely associated to melasma improvement after treatment. Prolonged use of sunscreen improved significantly (right malar: p < .001; frontal: p = .016 and left malar: p = .025) treatment effectiveness.

Genetic Characteristic and RNA-Seq Analysis in Transparent Mutant of Carp-Goldfish Nucleocytoplasmic Hybrid

In teleost, pigment in the skin and scales played important roles in various biological processes. Iridophores, one of the main pigment cells in teleost, could produce silver pigments to reflect light. However, the specific mechanism of the formation of silver pigments is still unclear. In our previous study, some transparent mutant individuals were found in the carp-goldfish nucleocytoplasmic hybrid (CyCa hybrid) population. In the present study, using transparent mutants (TM) and wild type (WT) of the CyCa hybrid as a model, firstly, microscopic observations showed that the silver pigments and melanin were both lost in the scales of transparent mutants compared to that in wild types. Secondly, genetic study demonstrated that the transparent trait in the CyCa hybrid was recessively inherent, and controlled by an allele in line with Mendelism. Thirdly, RNA-Seq analysis showed that differential expression genes (DEGs) between wild type and transparent mutants were mainly enriched in the metabolism of guanine, such as hydrolase, guanyl nucleotide binding, guanyl ribonucleotide binding, and GTPase activity. Among the DEGs, purine nucleoside phosphorylase 4a (pnp4a) and endothelin receptor B (ednrb) were more highly expressed in the wild type compared to the transparent mutant (p < 0.05). Finally, miRNA-Seq analysis showed that miRNA-146a and miR-153b were both more highly expressed in the transparent mutant compared to that in wild type (p < 0.05). Interaction analysis between miRNAs and mRNAs indicated that miRNA-146a was associated with six DEGs (MGAT5B, MFAP4, GP2, htt, Sema6b, Obscn) that might be involved in silver pigmentation.

The physiology of melanin deposition in health and disease

Eumelanin is the major pigment responsible for human skin color. This black/brown pigment is localized in membrane-bound organelles (melanosomes) found in specialized cells (melanocytes) in the basal layer of the epidermis. This review highlights the steps involved in melanogenesis in the epidermis and the disorders in skin pigmentation that occur when specific steps critical for this process are defective. Melanosomes, which contain tyrosinase, a major enzyme involved in melanin synthesis, develop through a series of steps in the melanocyte. They are donated from the melanocyte dendrites to the surrounding keratinocytes in the epidermis. In the keratinocytes, the melanosomes are found singly or packaged into groups, and as the keratinocytes move upward in the epidermis, the melanosomes start to degrade. This sequence of events is critical for melanin pigmentation in the skin and can be influenced by genetic, hormonal, and environmental factors, which all play a role in levels of melanization of the epidermis. The effects these factors have on skin pigmentation can be due to different underlying mechanisms involved in the melanization process leading to either hypo- or hyperpigmentary disorders. These disorders highlight the importance of mechanistic studies on the specific steps involved in the melanization process.

p44/42 MAPK signaling is a prime target activated by phenylethyl resorcinol in its anti-melanogenic action

BACKGROUND

Melanin plays a crucial role in protecting human skin against exposure to ultraviolet (UV) radiation. However, its overproduction induces hyperpigmentation disorders of the skin.

PURPOSE

To investigate effects of phenylethyl resorcinol as one resorcinol derivative on melanogenesis and its mechanisms using B16F10 mouse melanoma cells and human epidermal melanocytes.

METHODS

Effects of phenylethyl resorcinol on melanogenesis and its mechanism of action were examined using several in vitro assays (i.e., cell survival, melanin content, cellular tyrosinase activity, real-time PCR analysis, luciferase-reporter assay, Western blot analysis, and ELISAs for cyclic AMP (cAMP), protein kinase A (PKA), cAMP response element binding (CREB) protein, and mitogen-activated protein kinases (MAPKs)).

RESULTS

Phenylethyl resorcinol reduced both melanin content and tyrosinase activity in these cells. Phenylethyl resorcinol also suppressed tyrosinase activity in cell-free tyrosinase enzyme assay. Although phenylethyl resorcinol decreased mRNA levels of tyrosinase and tyrosinase-related protein (TRP)-2, it did not affect mRNA levels of melanogenic gene microphthalmia-associated transcriptional factor (MITF) or TRP-1. Phenylethyl resorcinol had no effects on cAMP signaling or NF-κB signaling based on results of cyclic AMP response element (CRE)-luciferase reporter assay, cAMP production, protein kinase A (PKA) activity, Western blot assays for phosphorylated CRE-binding protein (CREB), NF-κB-luciferase reporter assay, and Western blot assays for phosphorylated NF-κB. However, phenylethyl resorcinol induced activation of activator protein-1 (AP-1) signaling. Specifically, phenylethyl resorcinol increased AP-1 reporter activity and increased phosphorylation of p44/42 MAPK, but not p38 MAPK or c-Jun N-terminal kinase (JNK). MEK1/2 and Src, upstream molecules of p44/42 MAPK were also phosphorylated by phenylethyl resorcinol. In addition, phenylethyl resorcinol-induced decreases in melanin content, tyrosinase activity, and MITF protein levels were attenuated by PD98059, a p44/42 MAPK inhibitor.

CONCLUSION

These data indicate that the anti-melanogenic activity of phenylethyl resorcinol is mediated by activation of p44/42 MAPK, indicating that phenylethyl resorcinol may be a potential therapeutic agent for treating hyperpigmentation skin disorders.

Efficacy and Safety of an Oral Nutritional (Dietary) Supplement Containing Pinus pinaster Bark Extract and Grape Seed Extract in Combination with a High SPF Sunscreen in the Treatment of Mild-to-Moderate Melasma: A Prospective Clinical Study

Background: Melasma is a common hyperpigmentation disorder, characterized by light-to-dark brown patches, usually distributed on sun-exposed areas of the body. The objective of this study was to evaluate the efficacy and tolerability of an oral nutritional supplement containing Pinus pinaster and Grape seed extract, vitamins and minerals, used concomitantly with a high SPF sunscreen in 30 women with mild-to-moderate facial melasma. Methods: Efficacy was assessed by measurement of the Melasma Area and Severity Index (MASI), instrumental analysis of the lesions (Mexameter®, VISIA®)) and Patient’s and Physician’s Global Assessment (PGA). Results: The MASI score decreased significantly compared with baseline at days 28, 56, and 84. Mexameter® analysis showed a significant decrease of ∆M (difference in the melanin index between melasma and adjacent area). VISIA® results also showed a reduction in the number and areas of UV pigmented spots and in the areas of melasma overtime. Both the Patient’s and Physician’s Global Assessment showed that the product led to an improvement of the lesions in terms of depigmentation and had positive cosmetic features without adverse events. Conclusion: The oral supplement subject of this study in combination with high SPF sunscreen was effective and well-tolerated for treatment of mild to moderate facial melasma.

A Face-Split Study to Evaluate the Effects of Microneedle Radiofrequency with Q-Switched Nd:YAG Laser for the Treatment of Melasma

Background

Laser toning using a low-fluence 1,064 nm Q-switched Nd:YAG laser is one of the most frequently used treatment modalities for melasma. However, this therapy is time consuming because it requires a lot of treatment sessions. Recently, it has been reported that transdermal radiofrequency (RF) is effective for the treatment of melasma.

Objective

To determine whether microneedle RF conduction could be an adjunct therapy for melasma, we have studied the effect of simultaneous treatments with laser toning and RF for melasma.

Methods

Fifteen patients with melasma underwent five sessions of laser toning and microneedle RF on the right side of the face, and only laser toning on the left side. Responses to treatments were evaluated using the Mexameter® (Courage Khazaka, Germany) score, the pigmentation and severity index (PSI) score, and the patient's overall assessment. Additionally, an electron microscopic study of a skin biopsy was performed.

Results

Both laser toning and combination therapy showed significant decreases in the Mexameter® and PSI score after five treatment sessions. Combination therapy showed a more significant improvement of melasma than laser toning. No remarkable side effects were reported. Electron microscopic analysis showed a greater number of vacuolar changes and increased loosening of melanocytes and adjacent epidermal cells after combination therapy.

Conclusion

The combination treatment of laser toning and microneedle RF therapy showed a better therapeutic effect for melasma than laser toning alone. Therefore, the microneedle RF technique could be a new and safe adjunct therapy for the treatment of melasma.

Melasma: How hormones can modulate skin pigmentation

We described-along with a genetic predisposition and exposure to sunlight, as the main factors for melasma development-pregnancy, hormonal therapies, and oral contraceptive pills. Whilst hormonal alteration or therapies are frequently reported in literature in association with melasma, studies analyzing the laboratoristic correlation are limited. We review data published on hormones variations both in women and males with melasma and report some peculiar clinical cases that further demonstrate how the relationship between hormone secretion and melasma development is difficult to be defined.

New oral and topical approaches for the treatment of melasma

Melasma is a common, therapeutically challenging, and universally relapsing disorder of hyperpigmentation that is most often observed in women and individuals with Fitzpatrick Skin Types III through VI. The pathogenesis of melasma is complex and protean. Contributing factors that are often implicated in the etiopathogenesis of this condition include a genetic predisposition, intense ultraviolet radiation exposure, and hormonal influences. Therapeutic interventions for melasma include a multimodality approach incorporating photoprotection agents, topical and oral skin lighteners, and resurfacing procedures. Given our expanding knowledge of the pathogenesis of melasma, new and effective treatments are expanding our therapeutic armamentarium. This article reviews new and emerging oral and topical treatments for melasma.

Laser Toning in Melasma

Melasma is a common acquired disorder of hyperpigmentation. A variety of treatment options has been suggested for the management of melasma. A range of different lasers had been tried in the treatment of melasma. Q-switched Nd-YAG laser (QSL) is the most commonly used laser in the treatment of melasma. Recently, laser toning or low-fluence, multi-pass technique has become popular in treatment of melasma. Authors aimed to review the procedure, its effectiveness, combination therapies using laser toning, and complications of laser toning. A PubMed search was made using keywords such as laser toning, QSL, melasma, and lasers in melasma, and relevant articles were reviewed.

Tranexamic Acid for Adults with Melasma: A Systematic Review and Meta-Analysis

Objective

Melasma is a highly prevalent, chronic, and pigmentary disorder. This systematic review aims to evaluate the efficacy and safety of tranexamic acid (TA) for the treatment of adults with melasma.

Methods

We independently searched 3 databases from beginning to 26 April, 2018. The study included 21 eligible trials. Two writers extracted data at the same time independently. Study outcomes were calculated by standardized mean differences (SMD) with 95% confidence intervals (CIs). All statistical analyses were performed using Review Manager Version 5.3 and STATA Version 15.1.

Results

The combined results showed that the use of TA was associated with reduced Melasma Area and Severity Index (MASI) and Melanin Index (MI). No significant difference in Erythema Index (EI) was observed with TA treatment. Side effects were minor, with a few cases reporting mild gastrointestinal reaction, oligomenorrhoea, hypopigmentation, urticarial rash, and skin irritation xerosis.

Conclusion

The meta-analysis suggested that TA treatment appeared to be a promising therapeutic approach for melasma.

Combined treatment of melasma involving low-fluence Q-switched Nd:YAG laser and fractional microneedling radiofrequency

Background: While low fluence Q-switched Nd:YAG laser (QSNY) demonstrates moderate efficacy in the melasma treatment for darker skin types, this single regimen still remains challenges. Fractional microneedling radiofrequency (FMR) is known to enhance dermal microenvironment, possibly offsetting pathogenic factors of melasma aggravation. Objectives: To compare the effectiveness and safety of combination therapy using low-fluence QSNY and FRM with QSNY monotherapy in Asian melasma patients Methods: A retrospective study was undertaken for melasma patients to compare clinical data between 56 patients receiving combination regimen and 58 patients with QSNY only. For the 10 sessions at 1-week intervals, combination group was consecutively treated with QSNY and FRM, while QS toning group with QSNY alone. Two blinded dermatologists evaluated the efficacy based on modified Melasma Area and Severity Index (mMASI) and the physician's global assessment (PGA) at baseline and 3 months after the final treatment. Treatment-related side effects and disease course was recorded in detail. Results: Combination group demonstrated better efficacy compared with QS toning only group. Both median degrees of mMASI decrease (2.9 vs. 1.8) and proportions of PGA achieving better than 'good' grades (68% vs. 54%) showed superior efficacies of combination group. No significant difference was observed for treatment-related side effects between two groups, while the prevalence of mottle hypopigmentation and rebound hyperpigmentation was higher in QSNY only group. Conclusion: A novel dual mode of low-fluence QSNY and FRM represents a safe and effective treatment for melasma in Asian melasma patients.

Complex segregation analysis of facial melasma in Brazil: evidence for a genetic susceptibility with a dominant pattern of segregation

Despite high prevalence, the etiopathology of melasma is not fully understood. Nevertheless, many factors have been associated with the disease, including: sun exposure, sex steroids hormones, drugs, stress, and pregnancy. The high occurrence within familiars (40-60%) suggests a genetic predisposition to the disease. This study explored, through complex segregation analysis (CSA), the inheritance model that best fit the family segregation pattern of facial melasma when accounting for the main epidemiological risk factors. We evaluated 686 subjects from 67 families, and 260 (38%) of them had facial melasma. The CSA model, adjusted for age, skin phototype, sex, sun exposure at work, hormonal oral contraceptive, and pregnancy, evidenced a genetic component that was best fitted to a dominant pattern of segregation. Melasma results from an interaction between exposure factors (e.g. pregnancy, hormones, and sun exposure) over genetically predisposed individuals.

MITF and UV responses in skin: From pigmentation to addiction

Ultraviolet radiation (UVR) has numerous effects on skin, including DNA damage, tanning, vitamin D synthesis, carcinogenesis, and immunomodulation. Keratinocytes containing damaged DNA secrete both α-melanocyte-stimulating hormone (α-MSH), which stimulates pigment production by melanocytes, and the opioid β-endorphin, which can trigger addiction-like responses to UVR. The pigmentation (tanning) response is an adaptation that provides some delayed protection against further DNA damage and carcinogenesis, while the opioid response may be an evolutionary adaptation for promoting sun-seeking behavior to prevent vitamin D deficiency. Here, we review the pigmentation response to UVR, driven by melanocytic microphthalmia-associated transcription factor (MITF), and evidence for UVR-induced melanomagenesis and addiction. We also discuss potential applications of a novel approach to generate protective pigmentation in the absence of UVR (sunless tanning) using a topical small-molecule inhibitor of the salt-inducible kinase (SIK) family.

Methyl-2-acetylamino-3-(4-hydroxyl-3,5-dimethoxybenzoylthio)propanoate suppresses melanogenesis through ERK signaling pathway mediated MITF proteasomal degradation

BACKGROUND

Microphthalmia-associated transcription factor (MITF) is regulated by expression and/or degradation pathway, controlling to the expression of melanogenic enzymes for melanin synthesis. Methyl-2-acetylamino-3-(4-hydroxyl-3,5-dimethoxybenzoylthio)propanoate (MAHDP) is reported to anti-melanogenesis effect but its mechanism remain unclear.

OBJECTIVE

To investigate the effects of MAHDP on melanogenesis and elucidate its mechanism.

METHODS

Tyrosinase activity, melanogenic proteins and gene expression levels were measured with MAHDP treatment in B16F1 cells, human melanocytes, reconstructed skin and clinical trial.

RESULTS

MAHDP attenuated melanin production in α-MSH (melanocyte stimulating hormone) stimulated-B16F1 cells. MAHDP decreased the expression of tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). But, MADPH did not affect the phosphorylation of p38 MAPK, JNK and AKT, which are associated with the regulation of MITF expression. These results suggest that MITF downstream is regulated not transcriptionally but translationally. Treatment of MG132 (a proteasomal degradation inhibitor) almost abolished the decrease of MITF protein levels by MAHDP. Phosphorylation and ubiquitination of MITF for proteasomal degradation were increased by treatment of MAHDP. Treatment of PD98059 (an ERK phosphorylation inhibitor) abrogated ERK phosphorylation, downregulation of MITF and tyrosinase as well as the decrease of melanin contents by MAHDP. Therefore, the degradation of MITF proteins by MAHDP is regulated to the ERK signaling. Finally, MAHDP improved the pigmentation in human epidermal melanocytes, a UVB-irradiated the reconstructed skin model and clinical trial without cytotoxicity and skin irritation.

CONCLUSION

These results clearly demonstrate that MAHDP suppresses the expression of melanogenic enzymes through ERK phosphorylation-mediated MITF proteasomal degradation, and suggest that MAHDP may be efficient as a therapeutic agent for hyperpigmentation.

Modulation of human melanoma cell proliferation and apoptosis by hydatid cyst fluid of Echinococcus granulosus

Objective

The objective of this paper was to assess the effects of hydatid cyst fluid (HCF) of Echinococcus granulosus on melanoma A375 cell proliferation and apoptosis.

Methods

A375 cells were classified into five groups by in vitro culture: normal group, control group, 10% HCF group, 20% HCF group and 30% HCF group. Trypan blue staining method was employed to detect the toxicity of HCF. Effects of different concentrations of HCF on melanoma A375 cell proliferation at different time points were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry and propidium iodide (PI) staining were used to detect cell cycle, and Annexin-V/PI double staining method was used to determine A375 cell apoptotic rate. Western blotting was applied to detect the expression of phosphorylated extracellular regulated protein kinases, proliferating cell nuclear antigen (PCNA), cell-cycle-related proteins (cyclin A, cyclin B1, cyclin D1 and cyclin E) and apoptosis-related proteins (Bcl-2, Bax and caspase-3).

Results

HCF with a high concentration was considered as atoxic to A375 cells. HCF promoted A375 cell proliferation, and the effects got stronger with an increase in concentrations but was retarded after reaching a certain range of concentrations. HCF increased phosphorylation level and expression of extracellular regulated protein kinase, as well as PCNA expression. HCF also promoted the transferring progression of A375 cells from the G0/G1 phase to the S phase to increase the cell number in S phase and increased the expression of cyclin A, cyclin D1 and cyclin E. HCF increased the expression of procaspase-3 (the precursor of apoptosis-related protein caspase-3) and antiapoptotic protein-Bcl-2, and decreased the expression of proapoptotic factor Bax, thereby inhibiting cell apoptosis.

Conclusion

As a result, this study confirmed that HCF promotes proliferation and inhibits apoptosis of melanoma A375 cells.

Combined treatment for skin laxity of the aging face with monopolar radiofrequency and intense focused ultrasound in Korean subjects

BACKGROUND

Although various minimal invasive approaches are available for aging skin laxity, they alone may not lead to notably satisfactory results.

OBJECTIVE

To evaluate the effectiveness and safety of combination regimen with monopolar radiofrequency (MRF) and intense-focused ultrasound (IFUS) in facial lifting and tightening.

METHODS

Twenty-two Korean participants with aging face received a sequential single session of MRF and IFUS treatment. Objective and subjective assessments for improvement were performed at the 20-week post-treatment. Safety profiles were also recorded, and skin biopsies were taken at baseline and follow-up visit.

RESULTS

Based on the objective assessment for the overall facial skin tightening and laxity, 19 patients (90%) demonstrated "moderate" or better improvements (more than 25%) compared with baseline. Specifically, improvements of skin laxity and sagging, and droopy jaw line were more noticeable compared with that of superficial skin texture (P < 0.05). Subjective satisfactions were generally consistent with objective findings, and no serious adverse effect was observed. Histologic evaluation showed increased dermal collagen fibers throughout the dermis after treatments (P < 0.05).

CONCLUSION

Combination treatment of MRF and IFUS has cumulative benefits for skin lifting and tightening with satisfactory safety profiles in Asian subjects.

Histopathological findings in pregnancy associated cutaneous hyperpigmentation

Hyperpigmentation in pregnancy is a common phenomenon, experienced to some degree by up to 90% of pregnant women. It mainly involves sun-exposed areas, but it can extend to non-exposed zones. Cases with extensive hyperpigmentation are rarely reported. In this paper, we describe the case of a 30-year-old phototype V woman in her 37th week of pregnancy, who presented with brownish hyperpigmentation of the skin in extensive areas, including both axillae, the abdomen and the lowest part of the back. In the abdomen, there was a reinforcement of the hyperpigmentation through the linea nigra and the umbilicus. The hyperpigmentation affected the buttocks as well and involved the intertriginous area between them. Histopathologic analysis showed a hyperpigmented basal layer of the epidermis with no melanocytic atypia or melanocytic nests. Histochemical staining for iron did not show any deposits. Immunohistochemical studies for HMB-45, Melan A and SOX10 demonstrated an increased number of melanocytes. There was hyperpigmentation of basal layer keratinocytes. We also performed immunohistochemical stains for estrogen and progesterone receptors, which were both negative. The patient was examined 3 months after delivery, evidencing a significant clearing of the lesions.

Assessment of the effects of skin microneedling as adjuvant therapy for facial melasma: a pilot study

BACKGROUND

Melasma is a common chronic and relapsing acquired dyschromia. Skin microneedling was reported resulting sustained long-term improvement of recalcitrant melasma, however, the exact mechanism that promotes this skin lightening is not known. This study aimed to investigate clinical and histologic alterations promoted by skin microneedling in facial melasma.

METHODS

Open pilot trial including six women with facial refractory melasma submitted to two sessions of microneedling (1.5 mm) each 30 days followed by daily triple combination and broad-spectrum sunscreen. Comparison of pretreatment (T0) and 15 days after last microneedling procedure (T45) was made by standardized pictures, skin colorimetry, MASI, MELASQoL and histological parameters (haematoxylin-eosin, picrosirius-red, periodic acid Schiff and Fontana-Masson staining).

RESULTS

The age of the subjects varied from 34 to 46 years-old, the phototypes were III and IV (Fitzpatrick), and age of melasma onset was 20 to 38 years. Improvement of melasma was perceived in all subjects. There was a significant reduction of MASI score (-70%), MELASQoL (-55%) and increase in L* (+13%) colorimetric value (p < 0.03). All cases evidenced epithelium thickening, decrease in melanin pigmentation and densification of upper dermis collagen (p = 0.03). Patients were followed by 6 months under broad-spectrum sunscreen and triple combination without relapse.

CONCLUSION

In addition to classic treatment (broad-spectrum sunscreen and triple combination), skin microneedling promoted clinical and histological improvement of refractory facial melasma.

Arginase-2, a miR-1299 target, enhances pigmentation in melasma by reducing melanosome degradation via senescence-induced autophagy inhibition

Expression profiles revealed miR-1299 downregulation concomitant with arginase-2 (ARG2) upregulation in hyperpigmented skin of melasma patients. Opposite regulation of tyrosinase and PMEL17 by miR-1299 and inverse relationship between miR-1299 and ARG2 expression denoted a role of miR-1299 in pigmentation with ARG2 as a miR-1299 target. ARG2 overexpression or knock-down in keratinocytes, the main source of ARG2 in epidermis, positively regulated tyrosinase and PMEL17 protein levels, but not mRNA levels or melanosome transfer. ARG2 overexpression in keratinocytes reduced autophagy equivalent to 3-MA, an autophagy inhibitor which also increased tyrosinase and PMEL17 protein levels, whereas ARG2 knock-down induced opposite results. Autophagy inducer rapamycin reduced ARG2-increased tyrosinase and PMEL17 protein levels. Also, autophagy was reduced in late passage-induced senescent keratinocytes showing ARG2 upregulation. ARG2, but not 3-MA, stimulated keratinocyte senescence. These results suggest that ARG2 reduces autophagy in keratinocytes by stimulating cellular senescence, resulting in skin pigmentation by reducing degradation of transferred melanosomes.

Precise role of dermal fibroblasts on melanocyte pigmentation

Dermal fibroblasts are traditionally recognized as synthesizing, remodeling and depositing collagen and extracellular matrix, the structural framework for tissues, helping to bring thickness and firmness to the skin. However, the role of fibroblasts on skin pigmentation arouses concern recently. More is known about the interactions between epidermal melanocytes and keratinocytes. This review highlights the importance of fibroblast-derived melanogenic paracrine mediators in the regulation of melanocyte activities. Fibroblasts act on melanocytes directly and indirectly through neighboring cells by secreting a large number of cytokines (SCF), proteins (DKK1, sFRP, Sema7a, CCN, FAP-α) and growth factors (KGF, HGF, bFGF, NT-3, NRG-1, TGF-β) which bind to receptors and modulate intracellular signaling cascades (MAPK/ERK, cAMP/PKA, Wnt/β-catenin, PI3K/Akt) related to melanocyte functions. These factors influence the growth, the pigmentation of melanocytes via the expression of melanin-producing enzymes and melanosome transfer, as well as their dendricity, mobility and adhesive properties. Thus, fibroblasts are implicated in both skin physiological and pathological pigmentation. In order to investigate their contribution, various in vitro models have been developed, based on cellular senescence. UV exposure, a major factor implicated in pigmentary disorders, may affect the secretory crosstalk between dermal and epithelial cells. Therefore, identification of the interactions between fibroblasts and melanocytes could provide novel insights not only for the development of melanogenic agents in the clinical and cosmetic fields, but also for a better understanding of the melanocyte biology and melanogenesis regulation.

Efficacy of functional microarray of microneedles combined with topical tranexamic acid for melasma: A randomized, self-controlled, split-face study

To evaluate the efficacy of a functional microarray of microneedles (MNs) plus topical tranexamic acid (TA) for melasma in middle-aged women in China.Thirty female subjects with melasma were enrolled in this study. The left or right side of the face was chosen randomly to be pretreated with a functional microarray of MNs, followed by topical 0.5% TA solution once per week for 12 weeks. The other half-face was the control, treated with a sham device plus topical 0.5% TA solution. At baseline and at weeks 4, 8, and 12 of treatment, clinical (photographic) evaluations and parameters determined by Visia were recorded. At baseline and week 12, patient satisfaction scores and the biophysical parameters measured by Mexameter were also recorded. Side effects were evaluated at baseline and at the end of the 12 weeks.In total, 28 women (93.3%) completed the study. The brown spots' scores measured by Visia were significantly lower on the combined therapy side than on the control side at 12 weeks after starting treatment; there was no significant difference between sides at 4 or 8 weeks. After 12 weeks, melanin index (MI) decreased significantly in both 2 groups, and the MI was significantly less on the combined side at week 12. Transepidermal water loss, roughness, skin hydration, skin elasticity, and erythema index showed no significant differences between 2 sides at baseline, 4, 8, and 12 weeks after treatment. Physicians' evaluations of photographs showed better results at week 12 with combined therapy: >25% improvement was observed in the MNs plus TA side in 25 patients, and in the TA side in only 10 patients. Subjective satisfaction scores on both sides increased significantly. The participants were more satisfied with the results of the combined therapy side than the control side. No obvious adverse reactions were observed throughout the study.Combined therapy with a functional microarray of MNs and topical TA solution is a promising treatment for melasma.

A review of laser and light therapy in melasma

Melasma is a dysregulation of the homeostatic mechanisms that control skin pigmentation and excess pigment is produced. Traditional treatment approaches with topical medications and chemical peels are commonly used but due to the refractory and recurrent nature of melasma, patients often seek alternative treatment strategies such as laser and light therapy. Several types of laser and light therapy have been studied in the treatment of melasma. Intense pulsed light, low fluence Q-switched lasers, and non-ablative fractionated lasers are the most common lasers and light treatments that are currently performed. They all appear effective but there is a high level of recurrence with time and some techniques are associated with an increased risk for postinflammatory hyper- or hypopigmentation. The number and frequency of treatments varies by device type but overall, Q-switched lasers require the greatest number of treatment applications to see a benefit. Vascular-specific lasers do not appear to be effective for the treatment of melasma. Ablative fractionated lasers should be used with caution because they have a very high risk for postinflammatory hypo- and hyperpigmentation. The use of nonablative fractionated laser treatments compared with other laser and light options may result in slightly longer remission intervals. Picosecond lasers, fractional radiofrequency, and laser-assisted drug delivery are promising future approaches to treat melasma. The goal of this review is to summarize the efficacy and safety of the most commonly used laser and light therapies to treat melasma, briefly present future laser-based treatment options for patients with melasma, and provide recommendations for treatment on the basis of the reviewed information.

Gomisin N Inhibits Melanogenesis through Regulating the PI3K/Akt and MAPK/ERK Signaling Pathways in Melanocytes

Gomisin N, one of the lignan compounds found in Schisandra chinensis has been shown to possess anti-oxidative, anti-tumorigenic, and anti-inflammatory activities in various studies. Here we report, for the first time, the anti-melenogenic efficacy of Gomisin N in mammalian cells as well as in zebrafish embryos. Gomisin N significantly reduced the melanin content without cellular toxicity. Although it was not capable of modulating the catalytic activity of mushroom tyrosinase in vitro, Gomisin N downregulated the expression levels of key proteins that function in melanogenesis. Gomisin N downregulated melanocortin 1 receptor (MC1R), adenylyl cyclase 2, microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). In addition, Gomisin N-treated Melan-A cells exhibited increased p-Akt and p-ERK levels, which implies that the activation of the PI3K/Akt and MAPK/ERK pathways may function to inhibit melanogenesis. We also validated that Gomisin N reduced melanin production by repressing the expression of MITF, tyrosinase, TRP-1, and TRP-2 in mouse and human cells as well as in developing zebrafish embryos. Collectively, we conclude that Gomisin N inhibits melanin synthesis by repressing the expression of MITF and melanogenic enzymes, probably through modulating the PI3K/Akt and MAPK/ERK pathways.

African ancestry is associated with facial melasma in women: a cross-sectional study

Background

Melasma is a chronic acquired focal hypermelanosis affecting photoexposed areas, especially for women during fertile age. Several factors contribute to its development: sun exposure, sex steroids, medicines, and family history. Melanic pigmentation pathway discloses several SNPs in different populations. Here, we evaluated the association between genetic ancestry and facial melasma.

Methods

A cross-sectional study involving women with melasma and an age-matched control group from outpatients at FMB-Unesp, Botucatu-SP, Brazil was performed. DNA was extracted from oral mucosa swabs and ancestry determined by studying 61 INDELs. The genetic ancestry components were adjusted by other known risk factors by multiple logistic regression.

Results

We evaluated 119 women with facial melasma and 119 controls. Mean age was 39 ± 9 years. Mean age at beginning of disease was 27 ± 8 years. Pregnancy (40%), sun exposure (37%), and hormonal oral contraception (22%) were the most frequently reported melasma triggers. All subjects presented admixed ancestry, African and European genetic contributions were significantly different between cases and controls (respectively 10% vs 6%; 77% vs 82%; p < 0.05). African ancestry (OR = 1.04; 95% CI 1.01 to 1.07), first generation family history (OR = 3.04; 95% CI 1.56 to 5.94), low education level (OR = 4.04; 95% CI 1.56 to 5.94), and use of antidepressants by individuals with affected family members (OR = 6.15; 95% CI 1.13 to 33.37) were associated with melasma, independently of other known risk factors.

Conclusions

Facial melasma was independently associated with African ancestry in a highly admixed population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-017-0378-7) contains supplementary material, which is available to authorized users.

4-n-butylresorcinol enhances proteolytic degradation of tyrosinase in B16F10 melanoma cells

OBJECTIVE

4-n-butylresorcinol is a competitive inhibitor of tyrosinase and has been used as an antimelanogenic agent. However, its inhibition mechanism in intact cells is not fully understood. To elucidate the cellular mechanism, we compared in vitro and in vivo inhibitory effects of 4-n-butylresorcinol on tyrosinase activity.

METHODS

B16F10 melanoma cells were cultured in media containing α-MSH in the presence or absence of 4-n-butylresorcinol. Tyrosinase mRNA levels, protein levels and activity in B16F10 cells were compared by real-time PCR, immunostaining combined with western blot and colorimetric analysis, respectively. Melanin concentration was measured by colorimetry both in the cells and in the media. Tyrosinase glycosylation and proteolytic degradation were analysed by immunoblotting after cells were treated with Endo H/PNGase F and E64/proteasome inhibitors, respectively.

RESULTS

4-n-butylresorcinol inhibited tyrosinase activity and melanin synthesis more effectively in intact cells than in cell lysates. Western blotting and real-time RT-PCR showed that 4-n-butylresorcinol reduced protein levels, but not mRNA levels, of tyrosinase in B16F10 cells. 4-n-butylresorcinol showed no effect on the processing of tyrosinase glycosylation or on trafficking to melanosomes. However, treatment of B16F10 cells with E64 or proteasome inhibitor abrogated the 4-n-butylresorcinol-induced decrease of tyrosinase. Moreover, 4-n-butylresorcinol activated p38 MAPK, resulting in increased ubiquitination of tyrosinase.

CONCLUSION

4-n-butylresorcinol inhibits melanogenesis by enhancing proteolytic degradation of tyrosinase as well as competitive binding to tyrosinase. These findings will help to develop new, effective and safe chemicals for the treatment of hyperpigmentation disorders.

Demethyleugenol β-Glucopyranoside Isolated from Agastache rugosa Decreases Melanin Synthesis via Down-regulation of MITF and SOX9

Agastache rugosa (Fisch. & C. A. Mey.) Kuntze has been well-known for its antioxidative properties. This study investigated the anti-melanogenesis effect of demethyleugenol β-d-glucopyranoside (1) from A. rugosa by studying molecular regulation of melanogenesis in melan-a mouse melanocytes and normal human epidermal melanocytes (NHEMs) and in in vivo models. The SRY (sex-determining region on the Y chromosome)-related high-mobility group (HMG) box 9 (SOX9), one of the critical factors that affect skin pigmentation, is up-regulated. Interestingly, 1 down-regulated the expression of SOX9 and microphthalmia-associated transcription factor (MITF). Reduction of these two transcription factors resulted in a decrease in melanogenic enzymes such as tyrosinase, tyrosinase-related protein 1, and dopachrome tautomerase. As a result, 1 significantly inhibited melanin synthesis in melan-a mouse melanocytes and NHEMs. In addition, the anti-melanogenic effect of 1 was confirmed in zebrafish and reconstructed skin tissue models. In conclusion, 1, as a potent SOX9 regulator, ameliorates skin pigmentation.

Skin Hyperpigmentation in Indian Population: Insights and Best Practice

Skin pigmentation is one of the most strikingly variable phenotypes in humans, therefore making cutaneous pigmentation disorders frequent symptoms manifesting in a multitude of forms. The most common among them include lentigines, postinflammatory hyperpigmentation, dark eye circles, and melasma. Variability of skin tones throughout the world is well-documented, some skin tones being reported as more susceptible to pigmentation disorders than others, especially in Asia and India. Furthermore, exposure to ultraviolet radiation is known to trigger or exacerbate pigmentation disorders. Preventive strategies for photoprotection and treatment modalities including topical and other medical approaches have been adopted by dermatologists to mitigate these disorders. This review article outlines the current knowledge on pigmentation disorders including pathophysiology, molecular profiling, and therapeutic options with a special focus on the Indian population.

Randomized clinical trial of facial acupuncture with or without body acupuncture for treatment of melasma

OBJECTIVE

To evaluate the efficacy of acupuncture treatments in treating facial melasma, contrasting treatments involving facial acupuncture with facial/body acupuncture.

METHOD

Women suffering with melasma were randomly assigned into: 1) facial acupuncture (n = 20); or 2) facial/body acupuncture (n = 21). Each group was given 2 sessions per week for 8 weeks. Melasma area and darkness of its pigmentation were assessed using digital images.

RESULTS

95.2% and 90% of participants in facial/body and facial acupuncture, respectively, had decreased melasma areas, with a mean reduction area being 2.6 cm(2) (95%CI 1.6-3.6 cm(2)) and 2.4 cm(2) (95%CI 1.6-3.3 cm(2)), respectively. 66.7% (facial/body acupuncture) and 80.0% (facial acupuncture) of participants had lighter melasma pigmentation compared to their baselines (p-value = 0.482).

CONCLUSIONS

Facial acupuncture, with or without body acupuncture, was shown to be effective in decreasing the size of melasma areas. This study is registered with the Thai Clinical Trial Registry (TCTR20140903004).