Vitiligo: an update on systemic treatments

Methylsulfonylmethane promotes melanogenesis via activation of JNK in Mel-Ab cells

OBJECTIVE

Methylsulfonylmethane (MSM), which contains organic sulphur, has been used for a long time as a medicinal ingredient because of its benefits to human health. MSM is reported to be protective against certain skin disorders, but it is unknown whether it affects melanin synthesis. Therefore, in our current research, we examined the possibility of MSM controlling the production of melanin in Mel-Ab melanocytes.

METHODS

In Mel-Ab cells, melanin contents and tyrosinase activities were assessed and quantified. The expression of microphthalmia-associated transcription factor (MITF) and tyrosinase was evaluated using western blot analysis, while MSM-induced signalling pathways were investigated.

RESULTS

The MSM treatment significantly resulted in a dose-dependent increase in melanin production. Furthermore, MSM elevated melanin-related proteins, including MITF and tyrosinase. However, the rate-limiting enzyme of melanin production, tyrosinase, was not directly influenced by it. Therefore, we investigated potential melanogenesis-related signalling pathways that may have been triggered by MSM. Our findings showed that MSM did not influence the signalling pathways associated with glycogen synthase kinase 3β, cAMP response-element binding protein, extracellular signal-regulated kinase, or p38 mitogen-activated protein kinase. However, MSM phosphorylated c-Jun N-terminal kinases/stress-activated protein kinase (JNK/SAPK), which is known to induce melanogenesis. SP600125, a specific JNK inhibitor, inhibited MSM-induced melanogenesis.

CONCLUSION

Taken together, our study indicates that MSM induces melanin synthesis and may serve as a therapeutic option for hypopigmentary skin disorders such as vitiligo.

Combination of 308-nm excimer laser and piperine promotes melanocyte proliferation, migration, and melanin content production via the miR-328/SFRP1 axis

OBJECTIVE

Both piperine and a 308-nm excimer laser have significant curative effects on vitiligo. This study mainly explored the molecular mechanism of a 308-nm excimer combined with piperine in regulating melanocyte proliferation.

METHODS

Epidermal melanocytes were cultured in piperine solution, and the cells were irradiated by an XTRAC excimer laser treatment system at 308-nm output monochromatic light. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were for detecting the expression levels of genes or proteins. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and Transwell method was for assessing cell viability and migration capacity. The content of melanin was also detected.

RESULTS

The combination of the 308-nm excimer laser and piperine enhanced the cell proliferation, migration, and melanin production of melanocytes and upregulated the level of miR-328, and restraint of miR-328 reversed the influence of the 308-nm excimer laser and piperine. Secreted frizzled-related protein 1 (SFRP1) is a direct target gene of miR-328, and miR-328 can inhibit the expression of SFRP1 and elevate the protein level of the Wnt/β-catenin signaling pathway.

CONCLUSION

The 308-nm excimer laser combined with piperine may be more efficient than piperine alone in the remedy of vitiligo, and the miR-328/SFRP1 and Wnt/β-catenin pathways are participated in the proliferation, migration, and melanin synthesis of melanocytes.

Human Mesenchymal Stem Cell-Derived Exosomes Promote the Proliferation and Melanogenesis of Primary Melanocytes by Attenuating the H2O2-Related Cytotoxicity in vitro

Background

Mesenchymal stem cell-derived exosomes (MSC-Exo) have therapeutic potential. However, the impact of MSC-Exo on the survival and melanogenesis of human primary melanocytes following H2O2-induced damage has not been clarified. We therefore investigated the effects of MSC-Exo on the H2O2-affected survival of human primary melanocytes and their proliferation, apoptosis, senescence, and melanogenesis in vitro.

Methods

MSC-Exo were prepared from human MSCs by sequential centrifugations and characterized by Transmission Electron Microscopy, Western blot and Nanoparticle Tracking Analysis. Human primary melanocytes were isolated and treated with different concentrations of MSC-Exo, followed by exposing to H2O2. Furthermore, the impact of pretreatment with MSC-Exo on the proliferation, apoptosis, senescence and melanogenesis of melanocytes were tested by CCK-8, flow cytometry, Western blot, L-Dopa staining, tyrosinase activity and RT-qPCR.

Results

Pretreatment with lower doses of MSC-Exo protected human primary melanocytes from the H2O2-triggered apoptosis, while pretreatment with higher doses of MSC-Exo enhanced the H2O2-induced melanocyte apoptosis. Compared with the untreated control, pretreatment with a lower dose (1 µg/mL) of MSC-Exo enhanced the proliferation of melanocytes, abrogated the H2O2-increased p53, p21, IL-1β, IL-6 and IL-8 expression and partially rescued the H2O2-decreased L-dopa staining reaction, tyrosinase activity, MITF and TRP1 expression in melanocytes.

Conclusion

Our findings indicate that treatment with a low dose of MSC-Exo promotes the proliferation and melanogenesis of human primary melanocytes by ameliorating the H2O2-induced apoptosis and senescence of melanocytes. MSC-Exo may be a promising therapeutic strategy of vitiligo.

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.

Vitiligo Treated with Combined Piperine-Based Topical Treatment and Narrowband Ultraviolet B Therapy: Follow-Up with Reflectance Confocal Microscopy

BACKGROUND

Reflectance confocal microscopy (RCM) has a defined in vivo morphology of vitiligo and re-pigmentation. Combination therapies seem more effective than monotherapies.

OBJECTIVE

We aim to describe the clinical and RCM features of re-pigmentation with combined narrowband ultraviolet B (NB-UVB) and piperine-based topical treatment in localized vitiligo.

METHODS

Eight patients enrolled at a single center received combined treatment: topical treatment was applied twice daily + NB-UVB twice weekly for 2 × 2-month periods. Clinical changes were analyzed by the Vitiligo Noticeability Scale (VNS) and percentage of re-pigmentation. The evaluator agreement was assessed. Predefined RCM features had the presence/absence of (i) blood vessels, (ii) dendritic cells, and the quantity of (i) an irregular honeycombed pattern and (ii) non-pigmented papillae. Clinical and RCM monitoring was performed at the baseline, 2, 3, 5, and 7 months.

RESULTS

Macules were "slightly less noticeable" with 25-50% re-pigmentation. Irregular honeycomb patterns and non-pigmented papillae were significantly less frequently observed, and in less extended areas (T1 vs. T2, p = 0.039; T0 vs. T1, p = 0.005 and T2 vs. T4, p = 0.033). Dendritic cells and blood vessels improved, with significant changes in blood vessels (T1 vs. T2, p = 0.005 and T3 vs. T4, p = 0.008).

CONCLUSIONS

RCM confirms the morphological changes induced by combined treatment for localized vitiligo.

The role of aryl hydrocarbon receptor in vitiligo: a review

Vitiligo is an acquired autoimmune dermatosis characterized by patchy skin depigmentation, causing significant psychological distress to the patients. Genetic susceptibility, environmental triggers, oxidative stress, and autoimmunity contribute to melanocyte destruction in vitiligo. Due to the diversity and complexity of pathogenesis, the combination of inhibiting melanocyte destruction and stimulating melanogenesis gives the best results in treating vitiligo. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that can regulate the expression of various downstream genes and play roles in cell differentiation, immune response, and physiological homeostasis maintenance. Recent studies suggested that AhR signaling pathway was downregulated in vitiligo. Activation of AhR pathway helps to activate antioxidant pathways, inhibit abnormal immunity response, and upregulate the melanogenesis gene, thereby protecting melanocytes from oxidative stress damage, controlling disease progression, and promoting lesion repigmentation. Here, we review the relevant literature and summarize the possible roles of the AhR signaling pathway in vitiligo pathogenesis and treatment, to further understand the links between the AhR and vitiligo, and provide new potential therapeutic strategies.

Topical ruxolitinib: A new treatment for vitiligo

Vitiligo is a chronic autoimmune skin disorder whose diagnosis is often psychologically upsetting. The efficacy of the available therapies, including topical corticosteroids and topical calcineurin inhibitors, has historically been limited and the management of vitiligo is still challenging. As vitiligo is a chronic disease limited to the skin, topical rather than systemic therapies may be preferable (especially among patients with localised lesions) to avoid the long-term side-effects of the latter. A topical formulation of ruxolitinib, a selective JAK1/2 inhibitor, has recently been approved in the United States for the treatment of non-segmental vitiligo in patients aged >12 years based on data from the phase III TRuE-V1 and TRuE-V2 clinical trials. The aim of this review is to describe the current evidence concerning the efficacy and safety of topical ruxolitinib in the treatment of vitiligo, and discuss issues regarding its use in younger children and pregnant or breastfeeding women, as well as the duration and durability of treatment. The promising results obtained so far suggest that 1.5% ruxolitinib cream is an effective means of treating vitiligo.

Combining network pharmacology, molecular docking, molecular dynamics simulation, and experimental verification to examine the efficacy and immunoregulation mechanism of FHB granules on vitiligo

Background

Fufang Honghua Buji (FHB) granules, have proven efficacy against vitiligo in long-term clinical practice. However, its major active chemical components and molecular mechanisms of action remain unknown. The purpose of this study was to confirm the molecular mechanism of FHB's therapeutic effect on vitiligo utilizing network pharmacology, molecular docking, and molecular dynamics simulation prediction, as well as experimental verification.

Methods

Traditional Chinese Medicine Systems Pharmacology (TCMSP) and HERB databases were used to obtain the chemical composition and action targets of FHB. Online Mendelian Inheritance in Man (OMIM), DrugBank, DisGeNET, GeneCards, and Therapeutic Target Database (TTD) databases were applied to screen for vitiligo-related targets. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed through the Matascape database. Molecular docking and dynamics simulation methods were for the analysis of the binding sites and binding energies between the FHB's active components and the targets. Finally, a vitiligo mouse model was created, and the therapeutic effect and molecular mechanism of action of FHB were validated using enzyme linked immunosorbent assay (ELISA), western blot (WB), and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Additionally, hematoxylin-eosin staining (HE) and blood biochemical assays were conducted to assess the biosafety of FHB.

Result

The screening of chemical composition and targets suggested that 94 genetic targets of FHB were associated with vitiligo. The bioinformatics analysis suggested that luteolin, quercetin, and wogonin may be major active components, and nuclear factor-kappa B p65 subunit (RELA), signal transducer, and activator of transcription (STAT) 3 and RAC-alpha serine/threonine-protein kinase (AKT) 1 may be potential targets of FHB-vitiligo therapy. Molecular docking and dynamics simulation further demonstrated that luteolin, quercetin, and wogonin all bound best to STAT3. Through experimental verification, FHB has been demonstrated to alleviate the pathogenic characteristics of vitiligo mice, suppress the JAK-STAT signaling pathway, reduce inflammation, and increase melanogenesis. The in vivo safety evaluation experiments also demonstrated the non-toxicity of FHB.

Conclusions

FHB exerts anti-inflammatory and melanogenesis-promoting effects via the effect of multi-component on multi-target, among which the JAK-STAT pathway is a validated FHB-vitiligo target, providing new ideas and clues for the development of vitiligo therapy.

Pharmacological inhibition of demethylzeylasteral on JAK-STAT signaling ameliorates vitiligo

BACKGROUND

The activation of CD8⁺ T cells and their trafficking to the skin through JAK-STAT signaling play a central role in the development of vitiligo. Thus, targeting this key disease pathway with innovative drugs is an effective strategy for treating vitiligo. Natural products isolated from medicinal herbs are a useful source of novel therapeutics. Demethylzeylasteral (T-96), extracted from Tripterygium wilfordii Hook F, possesses immunosuppressive and anti-inflammatory properties.

METHODS

The efficacy of T-96 was tested in our mouse model of vitiligo, and the numbers of CD8⁺ T cells infiltration and melanocytes remaining in the epidermis were quantified using whole-mount tail staining. Immune regulation of T-96 in CD8⁺ T cells was evaluated using flow cytometry. Pull-down assay, mass spectrum analysis, molecular docking, knockdown and overexpression approaches were utilized to identify the target proteins of T-96 in CD8⁺ T cells and keratinocytes.

RESULTS

Here, we found that T-96 reduced CD8⁺ T cell infiltration in the epidermis using whole-mount tail staining and alleviated the extent of depigmentation to a comparable degree of tofacitinib (Tofa) in our vitiligo mouse model. In vitro, T-96 decreased the proliferation, CD69 membrane expression, and IFN-γ, granzyme B, (GzmB), and perforin (PRF) levels in CD8⁺ T cells isolated from patients with vitiligo. Pull-down assays combined with mass spectrum analysis and molecular docking showed that T-96 interacted with JAK3 in CD8⁺ T cell lysates. Furthermore, T-96 reduced JAK3 and STAT5 phosphorylation following IL-2 treatment. T-96 could not further reduce IFN-γ, GzmB and PRF expression following JAK3 knockdown or inhibit increased immune effectors expression upon JAK3 overexpression. Additionally, T-96 interacted with JAK2 in IFN-γ-stimulated keratinocytes, inhibiting the activation of JAK2, decreasing the total and phosphorylated protein levels of STAT1, and reducing the production and secretion of CXCL9 and CXCL10. T-96 did not significantly inhibit STAT1 and CXCL9/10 expression following JAK2 knockdown, nor did it suppress upregulated STAT1-CXCL9/10 signaling upon JAK2 overexpression. Finally, T-96 reduced the membrane expression of CXCR3, and the culture supernatants pretreated with T-96 under IFN-γ stressed keratinocytes markedly blocked the migration of CXCR3⁺CD8⁺ T cells, similarly to Tofa in vitro.

CONCLUSION

Our findings demonstrated that T-96 might have positive therapeutic responses to vitiligo by pharmacologically inhibiting the effector functions and skin trafficking of CD8⁺ T cells through JAK-STAT signaling.

Ayurvedic Doctors Cannot Prescribe Allopathic Medicines-National Consumer Dispute Redressal Commission Judgement

Purvish M. ParikhWe describe the facts of the matter and the court's decision in a case of an Ayurveda, Yoga & Naturopathy, Unani, Siddha, and Homeopathy (AYUSH) doctor being found guilty of deficiency of service by prescribing allopathic medicines that were associated with known complications. The case details include the allegation, the defense, and the court's judgement. Details of the concerned acts, circulars, and regulations, as well as court case laws, are described. The regulations allow AYUSH doctors to prescribe allopathic medicines under certain circumstances, which were not adhered to in this case.

Meta-analysis of the efficacy of adding platelet-rich plasma to 308-nm excimer laser for patients with vitiligo

Objective

Platelet-rich plasma (PRP) is a novel treatment option for vitiligo. PRP has been reported to be effective in combination with 308-nm excimer laser therapy, but there is no consensus on their combination use. Therefore, this meta-analysis assessed the efficacy and safety of the combination regimen in patients with vitiligo compared with laser therapy alone.

Methods

The meta-analysis was performed by searching PubMed, EMBASE, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, and WanFang to identify relevant publications published through 1 February 2022.

Results

Six studies involving 302 patients were included. Compared with phototherapy alone, combination treatment with PRP and 308-nm excimer laser therapy significantly improved the total response rate and reduced the no response rate. Additionally, the proportions of patients with repigmentation rates of ≥75%, ≥50%, and ≥25% were significantly higher in the combination group than in the monotherapy group. In addition, the rates of adverse events for combination therapy were comparable to those for laser therapy alone, and the recurrence rates were low.

Conclusions

This meta-analysis provided evidence supporting the combined use of PRP and 308-nm excimer laser therapy as a valuable treatment modality for patients with vitiligo based on its superiority to monotherapy.

Strategies to Develop a Suitable Formulation for Inflammatory Skin Disease Treatment

Skin barrier functions, environmental insults, and genetic backgrounds are intricately linked and form the basis of common inflammatory skin disorders, such as atopic dermatitis, psoriasis, and seborrheic dermatitis, which may seriously affect one’s quality of life. Topical therapy is usually the first line of management. It is believed that successful topical treatment requires pharmaceutical formulation from a sufficient dosage to exert therapeutic effects by penetrating the stratum corneum and then diffusing to the target area. However, many factors can affect this process including the physicochemical properties of the active compound, the composition of the formulation base, and the limitations and conditions of the skin barrier, especially in inflammatory skin. This article briefly reviews the available data on these issues and provides opinions on strategies to develop a suitable formulation for inflammatory skin disease treatment.