DNA Methyltransferases in Malar Melasma and Their Modification by Sunscreen in Combination with 4% Niacinamide, 0.05% Retinoic Acid, or Placebo

A Scoping Review on Melasma Treatments and Their Histopathologic Correlates

Melasma is an incredibly common dyschromic disorder, mostly impacting women with skin of color. There are three variants of melasma based on the depth of pathologic involvement: epidermal, mixed, and dermal. While there are many treatments for melasma, there is a paucity of research on melasma treatments and their dermatopathological correlates. A scoping review was conducted of all human trials on melasma with histopathologic analysis, including 37 trials in the final analysis. Most studies were conducted on women with a Fitzpatrick skin type of III or greater. Strong histologic evidence supports the utilization of retinols/retinoids for epidermal melasma and microneedling for dermal melasma. There is a paucity of trials conducted on melasma utilizing histologic correlates, and fewer still that are comprehensive to include analyses on quality of life.

Nicotinamide: A Multifaceted Molecule in Skin Health and Beyond

Nicotinamide (NAM), the amide form of vitamin B3, is a precursor to essential cofactors nicotinamide adenine dinucleotide (NAD⁺) and NADPH. NAD⁺ is integral to numerous cellular processes, including metabolism regulation, ATP production, mitochondrial respiration, reactive oxygen species (ROS) management, DNA repair, cellular senescence, and aging. NAM supplementation has demonstrated efficacy in restoring cellular energy, repairing DNA damage, and inhibiting inflammation by suppressing pro-inflammatory cytokines release. Due to its natural presence in a variety of foods and its excellent safety profile-even at high doses of up to 3 g/day-NAM is extensively used in the chemoprevention of non-melanoma skin cancers and the treatment of dermatological conditions such as blistering diseases, atopic dermatitis, rosacea, and acne vulgaris. Recently, its anti-aging properties have elevated NAM's prominence in skincare formulations. Beyond DNA repair and energy replenishment, NAM significantly impacts oxidative stress reduction, cell cycle regulation, and apoptosis modulation. Despite these multifaceted benefits, the comprehensive molecular mechanisms underlying NAM's actions remain not fully elucidated. This review consolidates recent research to shed light on these mechanisms, emphasizing the critical role of NAM in cellular health and its therapeutic potential. By enhancing our understanding, this work underscores the importance of continued exploration into NAM's applications, aiming to inform future clinical practices and skincare innovations.

Niacinamide: a review on dermal delivery strategies and clinical evidence

Niacinamide, an active form of vitamin B3, is recognised for its significant dermal benefits including skin brightening, anti-ageing properties and the protection of the skin barrier. Its widespread incorporation into cosmetic products, ranging from cleansers to serums, is attributed to its safety profile and proven efficacy. Recently, topical niacinamide has also been explored for other pharmaceutical applications, including skin cancers. Therefore, a fundamental understanding of the skin permeation behaviour of niacinamide becomes crucial for formulation design. Given the paucity of a comprehensive review on this aspect, we provide insights into the mechanisms of action of topically applied niacinamide and share the current strategies used to enhance its skin permeation. This review also consolidates clinical evidence of topical niacinamide for its cosmeceutical uses and as treatment for some skin disorders, including dermatitis, acne vulgaris and actinic keratosis. We also emphasise the current exploration and perspectives on the delivery designs of topical niacinamide, highlighting the potential development of formulations focused on enhancing skin permeation, particularly for clinical benefits.

An Update on New and Existing Treatments for the Management of Melasma

Melasma is a chronic, acquired disorder of focal hypermelanosis that carries significant psychosocial impact and is challenging for both the patient and the treating practitioner to manage in the medium to long term. Multiple treatments have been explored, often in combination given the many aetiological factors involved in its pathogenesis. Therapeutic discoveries to treat melasma are a focal topic in the literature and include a range of modalities, with recent developments including updates on visible light photoprotection, non-hydroquinone depigmenting agents, oral tranexamic acid, chemical peels, and laser and energy-based device therapy for melasma. It is increasingly important yet challenging to remain up-to-date on the arsenal of treatments available for melasma to find an efficacious and well-tolerated option for our patients.

Exposure factors in the occurrence and development of melasma (Review)

Melasma is an acquired pigmentation disease that mainly involves the development of symmetrical yellow-brown facial patches. The incidence rate of the disease is increasing yearly. Therefore, actively studying the exposure factors that induce melasma could contribute to the prevention and treatment of this disease. In the present review, the possible exposure factors were summarized.

The Impact of Antioxidants on Vitiligo and Melasma: A Scoping Review and Meta-Analysis

Reactive oxygen species (ROS) generated during melanogenesis make melanocytes particularly vulnerable to oxidative stress, influencing their survival and melanin synthesis. Oxidative stress, significantly present in vitiligo and recently also detected in melasma, triggers inflammatory cascades and melanogenesis, making antioxidants a promising therapeutic avenue. A systematic search was conducted on Embase and Pubmed to study the efficacy of antioxidants for treating vitiligo and/or melasma. Meta-analysis was performed to assess the difference in Melasma Severity Index (MASI) scores between baseline and follow-up. Various antioxidants like polypodium leucotomos, ginkgo biloba, catalase/superoxide dismutase, and vitamin E have potential in vitiligo. For melasma, vitamin C, silymarin, and niacinamide were among those showing promise in reducing pigmentation, with vitamin C displaying significant effects in meta-analysis. Different antioxidants improve both vitiligo and melasma, with an increased minimal erythema dose (MED) following UV exposure being significant for vitiligo and tyrosinase inhibition being crucial for melasma. However, the efficacy of individual antioxidants varies, and their exact mechanisms, especially in stimulating melanocyte proliferation and anti-inflammatory pathways, require further investigation to understand better and optimize their use.

Targeting Tyrosinase in Hyperpigmentation: Current Status, Limitations and Future Promises

Hyperpigmentation is a common and distressing dermatologic condition. Since tyrosinase (TYR) plays an essential role in melanogenesis, its inhibition is considered a logical approach along with other therapeutic methods to prevent the accumulation of melanin in the skin. Thus, TYR inhibitors are a tempting target as the medicinal and cosmetic active agents of hyperpigmentation disorder. Among TYR inhibitors, hydroquinone is a traditional lightening agent that is commonly used in clinical practice. However, despite good efficacy, prolonged use of hydroquinone is associated with side effects. To overcome these shortcomings, new approaches in targeting TYR and treating hyperpigmentation are desperately requiredessentialneeded. In line with this purpose, several non-hydroquinone lightening agents have been developed and suggested as hydroquinone alternatives. In addition to traditional approaches, nanomedicine and nanotheranostic platforms have been recently proposed in the treatment of hyperpigmentation. In this review, we discuss the available strategies for the management of hyperpigmentation with a focus on TYR inhibition. In addition, alternative treatment options to hydroquinone are discussed. Finally, we present nano-based strategies to improve the therapeutic effect of drugs prescribed to patients with skin disorders.

5-Azacytidine promotes HCC cell metastasis by up-regulating RDH16 expression

The level of DNA methylation could affect the expression of tumor promoting and tumor suppressor genes. DNA methyltransferase inhibitors could reduce high methylation levels in cancer and inhibit the progression of a variety of cancers, including HCC. However, the pro-metastatic effect of DNA methyltransferase inhibitors in some cancers suggest the potential risk of their use. Whether DNA methyltransferase inhibitors also promote metastasis in HCC remains unclear. Our study will explore the effect of DNA methyltransferase inhibitor 5-Azacytidine on HCC metastasis. Our study found that 5-Azacytidine inhibited the proliferation of HCC cells while promoting in vitro and in vivo metastasis of HCC. Mechanistically, our study showed that 5-Azacytidine increased the expression of RDH16 by decreasing the methylation of RDH16 gene promoter. RDH16 is a highly methylated gene and its expression is very low in hepatocellular carcinoma. 5-Azacytidine promoted the migration of hepatocellular carcinoma cells by increasing the expression of RDH16. Our results suggest that 5-Azacytidine up-regulates the expression of RDH16 by decreasing the methylation level of RDH16, and then promoting HCC metastasis. These findings suggest that 5-Azacytidine and even other DNA methyltransferase inhibitors may have the risk of promoting metastasis in HCC treatment. RDH16 could be used as a pro-metastasis biomarker in the treatment of HCC with DNA methyltransferase inhibitors.

Topical Treatments for Melasma and Their Mechanism of Action

OBJECTIVE

We conducted a review of topical agents currently used in melasma, discussing their mechanism of action, efficacy, safety, and tolerability, with an update on newer treatments.

METHODS

A systematic review from PubMed database was performed, using PRISMA guidelines. The search was limited to English and Spanish studies that were double or single blinded, prospective, controlled or randomized clinical trials, reviews of literature, and meta-analysis studies.

RESULTS

348 studies were analyzed; 80 papers met inclusion criteria. Triple combination (TC) therapy and hydroquinone (HQ) are still the most well-studied agents with strong evidence-based recommendation. TC therapy remains the gold standard of care based on efficacy and patient tolerability. Evidence has shown ascorbic acid, azelaic acid, glycolic acid, kojic acid, salicylic acid, and niacinamide to be effective as adjuvant therapies with minimal side effects. Tranexamic acid (TA) and cysteamine have become recent agents of interest due to their good tolerability, however more trials and studies are warranted. Less evidence exists for other topical agents, such as linoleic acid, mulberry extract oil, rucinol, 2% undecylenoyl phenylalanine, and epidermal growth factors agents.

LIMITATIONS

Some studies discussed represented a low sample size, and there is an overall lack of recent studies with larger populations and long-term follow up.

CONCLUSIONS

TC therapy continues to be the gold standard of care. Topical cysteamine and TA are newer options that can be incorporated as adjuvant and maintenance treatments into a patient's regimen. Cysteamine and topical TA have no known severe adverse effects. Evidence comparing other topical adjuvant treatments to HQ, maintains HQ as the gold standard of care.

Association of testosterone level with melasma in men: a case-control study in Indonesia

Introduction

melasma is a common acquired hypermelanosis which occurs mostly in face that caused by many factors. One of the pathogenesis of melasma in men is affected by testosterone. This study aimed to investigate the relationship between testosterone levels and melasma in men and its association with the severity of melasma as measured by the melasma area and severity index (MASI) score.

Methods

a case-control study involving 30 subjects with melasma and 30 subjects without melasma who were treated at the outpatient clinic of Dermatovenereology of Ngoerah General Hospital from June to August 2022. Descriptive statistical analysis is to determine frequencies and percentages. Bivariate analysis was used to find any risk factor between testosterone level and melasma. Data obtained from the two groups then analyzed for correlation between the MASI score and testosterone levels.

Results

mean age of the subjects in the melasma group was 43.83±6.30 and in control group was 43.80±6.09. Mean testosterone level in the melasma group (7.55±1.77) was significantly lower than the control group (21.07±6.65; p = 0.001). Subject with testosterone level ≥8.92 nmol/L has 6.9 times risk of melasma compare to control (aOR: 6.986, 95% CI 1.905-25.622; p = 0.003).

Conclusion

low testosterone levels possibly have a role in pathogenesis of melasma in men.

Epigenetic regulation of melanogenesis

Melanogenesis is a complex process in which melanin is synthesized in melanocytes and transported to keratinocytes, which involves multiple genes and signaling pathways. Epigenetics refers to the potential genetic changes that affect gene expression without involving changes in the original sequence of DNA nucleotides. DNA methylation regulates the expression of key genes such as tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), dopachrome tautomerase (DCT) and microphthalmia-associated transcription factor (MITF), as well as paracrine factors such as stem cell factor (SCF) and endothelin-1 (ET-1) in melanogenesis. Potential DNA methylation sites are present in the genes of melanogenesis-related signaling pathways such as "Wnt", "PI3K/Akt/CREB" and "MAPK". H3K27 acetylation is abundant in melanogenesis-related genes. Both the upstream activation and downstream regulation of MITF depend on histone acetyltransferase CBP/p300, and pH-induced H3K27 acetylation may be the amplifying mechanism of MITF's effect. HDAC1 and HDAC10 catalyze histone deacetylation of melanogenesis-related gene promoters. Chromatin remodelers SWI/SNF complex and ISWI complex use the energy of ATP hydrolysis to rearrange nucleosomes, while their active subunits BRG1, BRM and BPTF, act as activators and cofactors of MITF. MicroRNAs (miRNAs) can directly target a large number of melanogenesis-related genes, while long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) regulate melanogenesis in a variety of ways. Interactions exist among the epigenetic mechanisms of melanogenesis. For example, the methyl CpG binding domain protein 2 (MeCP2) links DNA methylation, histone deacetylation, and histone methylation. Epigenetic-based therapy provides novel opportunities for treating dermatoses that are caused by pigmentation disturbances. This review summarizes the epigenetic regulation mechanisms of melanogenesis, and examines the pathogenesis and treatment of epigenetics in pigmentation disorders.

Melasma treatment: a systematic review

Melasma is a common chronic refractory disorder of pigmentation affecting people with darker skin types. Overall prevalence varies between 8.8% and 40%, depending on the ethnicity of the population and the geographical area. Therapeutic management of melasma is challenging, with high recurrence rates which significant impacts on the quality of life. No single treatment is universally efficacious. Systemic treatments with tranexamic acid and polypodium leucotmatous had promising results, although the former was related to systemic side effects. Microneedling and peeling were also efficacious, although their superiority to topical hydroquinone, the gold standard in melasma treatment, remains to be established. Similarly, laser and light devices have been beneficial. However, recurrence rates remain high in all treatment groups. Combination therapies, either in double or triple combinations yielded the best results when compared to single terapies. Treatment choice should be made after Wood's lamp examination, as well as dermatoscopic evaluation, in order to select the best treatment option, targeted at each melasma subtype.

Melasma: A Condition of Asian Skin

Melasma is a benign yet psychologically debilitating skin condition that is prevalent among women of darker phenotypes, and particularly in Asian women. This potentially preventable condition can lead to skin discoloration that is hard to treat and can frequently recur. This review aims to (1) highlight the pathophysiology of melasma, (2) describe its important risk factors, and (3) identify prevention methods, available treatment options, and potential complications of melasma. By raising awareness of this condition, we hope that physicians and patients will be able to be better informed to discuss screening options and to avoid preventable risk factors, especially in patients who are predisposed to the disease.

Treatment of melasma: a review of less commonly used antioxidants

Melasma, a common cause for seeking dermatologic care, is a chronic condition of skin hyperpigmentation. With a poorly understood pathogenesis, and no universal cure, melasma is a challenge for many dermatologists. For decades, there has been investigation into the role of oxidative stress in melasma. In this literature review, we introduce the role of oxidative stress in melasma and discuss the function of various topical and oral antioxidant therapies for patients suffering from melasma. Numerous studies have shown efficacy of various antioxidant therapies for treatment of hyperpigmentation, and in this review, we focus primarily on those with less widespread use. Vitamin E, niacinamide, polypodium leucotomos, pycnogenol, grape seed extract, amino fruit acids, phytic acid, zinc, silymarin, Korean red ginseng powder, plant extracts, and parsley all have well-demonstrated evidence of antioxidant properties, and these substances have been studied in the context of skin hyperpigmentation. Although there is conflicting evidence of their therapeutic efficacy, the use of these naturally occurring substances is promising for patients and medical providers seeking alternative therapeutic options.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.