Comparison of NB-UVB combination therapy regimens for vitiligo: A systematic review and network meta-analysis

5,7-Dihydroxy-4-Methylcoumarin as a Functional Compound for Skin Pigmentation and Human Skin Safety

Background/Objectives: This study aims to investigate the effects of 5,7-dihydroxy-4-methylcoumarin (5,7D-4MC) on melanogenesis in B16F10 murine melanoma cells and to evaluate its safety as a potential ingredient for functional cosmetics and therapeutic agents targeting pigmentation-related disorders. Method: The cytotoxicity of 5,7D-4MC was assessed using an MTT assay, and melanin content and tyrosinase activity were measured at different concentrations (25, 50, 100 µM). Western blot analyses were conducted to evaluate the expression of key melanogenesis-related proteins (TYR, TRP-1, TRP-2, and MITF) and to investigate the regulation of major signaling pathways, including PKA/cAMP, GSK3β, and PI3K/AKT. Additionally, a human primary skin irritation test was performed on 32 participants to assess the dermatological safety of 5,7D-4MC. Results: 5,7D-4MC did not affect cell viability at concentrations below 100 µM and significantly promoted melanin production in a dose-dependent manner. Tyrosinase activity and the expression levels of melanogenic proteins increased significantly following 5,7D-4MC treatment. PKA and GSK3β pathways were activated, while the PI3K/AKT pathway was downregulated. The skin irritation test showed that 5,7D-4MC exhibited low irritation potential at concentrations of 50 µM and 100 µM. Conclusions: 5,7D-4MC enhances melanogenesis and demonstrates low skin irritation, making it a promising candidate for therapeutic applications in treating hypopigmentation disorders, such as vitiligo, as well as a functional cosmetic ingredient. However, further studies involving human melanocytes and clinical trials are required to validate their efficacy.

Comparison of various excimer laser (EL) combination therapies for vitiligo: a systematic review and network meta-analysis

AIM

This study aimed to compare the efficacy and safety of excimer laser (EL)-based combination regimens in improving repigmentation.

METHODS

A comprehensive search was conducted in PubMed, Web of Science, Cochrane Library, and Embase on July 1, 2023, to include randomized controlled trials of EL combination treatments for vitiligo that met the criteria. The primary outcome measure was a repigmentation rate ≥ 75%, and the secondary outcome measures were a repigmentation rate of ≤ 25% and adverse events.

RESULTS

Eleven studies involving 348 patients were included. Network Meta-Analysis showed that EL combined with antioxidants (SUCRA = 98.8%), EL combined with calcipotriol (SUCRA = 59.8%) and EL combined with tacalcitol (SUCRA = 59.6%) were the three optimal interventions achieving repigmentation rates ≥ 75%. EL alone (SUCRA = 77.6%), EL combined with tacalcitol (SUCRA = 61.7%) and EL combined with antioxidants (SUCRA = 57.2%) were the three interventions with the highest rates of treatment failure. Adverse events in all groups mainly included erythema, burning sensation and hyperpigmentation. Based on the results of the current study, EL combination therapies were safe with mild adverse events.

CONCLUSION

EL combined with antioxidants was the preferred regimen for vitiligo, whereas EL alone was the regimen with the highest rate of treatment failure in vitiligo.

Impact of Combined Phototherapy and Melanocyte Transplantation on Indicators of Vitiligo Activity

OBJECTIVE

To investigate the effect of phototherapy combined with melanocyte transplantation on the activity index of vitiligo.

METHODS

One hundred twenty patients with stable vitiligo were selected and divided into 2 groups: phototherapy group ( n = 60) and phototherapy combined with melanocyte therapy group ( n = 60). Patients' vitiligo activity scores before and 6 months after treatment, patients' skin pigmentation responses 6 months after treatment, and patients' new Koebner cases 6 months after treatment were compared. The expression of tyrosinase and Melan-A in the skin samples was analyzed by immunohistochemistry.

RESULTS

The effect of skin surface repigmentation in the observation group was better than that in the control group ( p < .05). The expression of tyrosinase and Melan-A in the observation group was higher than that in the control group ( p < .05), indicating that the combined treatment could enhance the function of melanocytes. After 6 months of treatment, the incidence of the Koebner phenomenon in the observation group was lower than that in the control group ( p < .05).

CONCLUSION

The combination of phototherapy and melanocyte transplantation can obviously improve the activity index of vitiligo, slow down the spread of white spots, reduce the formation of new white spots, and reduce the occurrence of the Koebner phenomenon.

Bridging Molecular Mechanism and Clinical Practice in Vitiligo Treatment: An Updated Review

BACKGROUND

Treatment of vitiligo seeks to achieve three goals: cessation of disease progression, regeneration of pigmentation, and prevention of recurrence.

SUMMARY

Number of nonsurgical interventions are available that suppress the autoimmune response and regenerate the melanocytes from the reservoir: phototherapy including psoralen and ultraviolet A, narrowband ultraviolet B, and 308-nm excimer and 311-nm Titanium:Sapphire lasers; topical agents including topical calcineurin inhibitors, topical corticosteroids, and topical 5-fluorouracil; and systemic agents including corticosteorids, mycophenolate mofetil, cyclosporine, methotrexate, minocycline, afamelanotide, and antioxidants. In recent years, a great advance has been made in the understanding of pathogenesis of vitiligo, and JAK inhibitors are being investigated as a new treatment. Minimally invasive procedures such as fractional lasers or microneedling can help achieve the optimal treatment outcome when used properly.

KEY MESSAGES

Our review describes various treatment modalities for vitiligo based on their molecular mechanism of action. Bridging the gap between molecular mechanisms and therapeutic options would be a valuable reference for physicians in clinical practice.

Comparison of the efficacy of tacrolimus 0.1% ointment vs calcipotriol/betamethasone in combination with NBUVB in treatment of vitiligo

Purpose: Vitiligo is an idiopathic depigmenting skin disorder. The study compares the efficacy of topical tacrolimus 0.1% with calcipotriol/betamethasone dipropionate in vitiligo patients receiving NB-UVB treatment.Materials and methods: Forty-one adult patients with generalized type vitiligo were recruited. Patients were assigned to phototherapy and then classified into either group one (20 patients), receiving calcipotriol/betamethasone dipropionate cream (D group), or group two (21 patients), receiving tacrolimus 0.1% ointment (T group). They were followed-up at 3 and 6 months.Results: The D group witnessed an increase in the repigmentation area from 35.4% in the third month to 54.7% in the sixth month (p = 0.001) and the T group from 32.2% to 45.6% (p = 0.011). However, the differences between the treatment groups were not statistically significant. Body sites demonstrated different levels of improvement ranging from the highest in the face to the lowest in the Hand & Feet with the other body sites in between. A negative correlation was identified between the duration since diagnosis and the response to D treatment (3 months: r = -0.612, p = 0.007; 6 months: r = -0.755, p = 0.001).Conclusions: Although both combinations are efficacious, they did not significantly differ in efficacy at three and six months follow-up points.Clinical trial registration: The study was registered at clinicaltrials.gov (NCT04440371).

Understanding of Pathomechanisms and Clinical Practice for Vitiligo

Vitiligo is a disease caused by the acquired depletion of melanocytes and/or melanocyte precursor cells in response to genetic and environmental factors, resulting in depigmentation of the entire body. It is roughly divided into segmental and non-segmental vitiligo, and it has been found that abnormalities of melanocytes themselves and dysregulation of autoimmune responses to melanocytes are greatly involved in the pathology of non-segmental vitiligo. Segmental vitiligo pathology is largely unknown; however, it has been suggested that it may be caused by skin or melanocyte mosaicism. Treatments for vitiligo include topical therapy, ultraviolet therapy, and surgical transplantation, and it is extremely important to correctly understand the pathology to perform optimal treatment. In recent years, the development of vitiligo treatments using Janus kinase (JAK) inhibitors has progressed rapidly. We herein outline the latest pathology of vitiligo, from general vitiligo treatment to the progress of clinical trials using JAK inhibitors, along with what clinicians should consider in archiving precision medicine, including my own ideas thereon.