Role of epidermal γδ T-cell-derived interleukin 13 in the skin-whitening effect of Ginsenoside F1

Unexpected Extensive Hair Whitening Following Baricitinib Treatment for Alopecia Universalis: A Case Report and Mechanistic Insights

Alopecia universalis (AU) is a severe form of alopecia areata characterized by the complete loss of scalp and body hair. While Janus kinase (JAK) inhibitors like baricitinib have shown promise in promoting hair regrowth in severe cases of AU, unexpected side effects, such as hair depigmentation, have not been widely reported. We present the case of a young male with AU who experienced progressive and extensive whitening of his scalp and body hair following treatment with baricitinib. After one month of therapy, the patient observed both black and white hairs emerging, which gradually turned entirely white by the second month. Over the course of seven months, the whitening of the hair persisted, with no repigmentation observed. Laboratory tests and clinical evaluations indicated no significant adverse effects, suggesting that baricitinib was well tolerated. Dermoscopic examination revealed predominantly white terminal hairs. While the mechanisms underlying this phenomenon remain unclear, we discuss potential interactions between JAK inhibition and melanocyte function, suggesting that baricitinib's modulation of the JAK-STAT pathway may impact melanogenesis and hair pigmentation. This case highlights the need for further investigation into the effects of JAK inhibitors on hair pigmentation and the potential for hair whitening as an uncommon side effect. Understanding these mechanisms is essential for improving treatment strategies for AU and addressing patient concerns regarding pigmentation changes during therapy.

Type-2 immunity associated with type-1 related skin inflammatory diseases: friend or foe?

Chronic inflammatory skin diseases are multifactorial diseases that combine genetic predisposition, environmental triggers, and metabolic disturbances associated with abnormal immune responses. From an immunological perspective, the better understanding of their physiopathology has demonstrated a large complex network of immune cell subsets and related cytokines that interact with both epidermal and dermal cells. For example, in type-1-associated diseases such as alopecia areata, vitiligo, and localized scleroderma, recent evidence suggests the presence of a type-2 inflammation that is well known in atopic dermatitis. Whether this type-2 immune response has a protective or detrimental impact on the development and chronicity of these diseases remains to be fully elucidated, highlighting the need to better understand its involvement for the management of patients. This mini-review explores recent insights regarding the potential role of type-2-related immunity in alopecia areata, vitiligo, and localized scleroderma.

Potent pigmentation inhibitory activity of incensole-enriched frankincense volatile oil-identification, efficacy and mechanism

BACKGROUND

Frankincense volatile oil (FVO) has long been considered a side product in pharmaceutical industry since frankincense of large molecular weight is the prime target. However, the volatile oil recycled in the extract process might contain a series of functional actives, serving as promising ingredients in the cosmetic field.

METHODS

Gas chromatography-mass spectrometer was utilized to determine the species and amount of active ingredients in FVO. Subsequently, zebrafish models were used to evaluate pigmentation inhibition, ROS elimination and neutrophil activation. In vitro DPPH test was also conducted to consolidate the anti-oxidation efficacy. Based on the test results, network pharmacology was incorporated, where GO and KEGG enrichment analyses were performed to discover the interrelations between active ingredients.

RESULTS

About 40 actives molecules were identified, including incensole, acetate incensole, and acetate incensole oxide. The FVO demonstrated great depigmentation activity by suppressing melanin synthesis, as well as providing free radical scavenging and anti-inflammation effect. In network pharmacology analysis, 192 intersected targets were identified. By enrichment analysis and network construction, a series of whitening signal pathways, and hub genes, containing STAT3，MAPK3，MAPK1 were identified.

CONCLUSION

The current study quantified the components of FVO, evaluated its efficacy in skin depigmentation, and give pioneering insights on the possible mechanism. The results confirmed that the FVO could serve as whitening agent in topical uses.

Effect of anti-skin disorders of ginsenosides- A Systematic Review

Ginsenosides are bioactive components of Panax ginseng with many functions such as anti-aging, anti-oxidation, anti-inflammatory, anti-fatigue, and anti-tumor. Ginsenosides are categorized into dammarane, oleanene, and ocotillol type tricyclic triterpenoids based on the aglycon structure. Based on the sugar moiety linked to C-3, C-20, and C-6, C-20, dammarane type was divided into protopanaxadiol (PPD) and protopanaxatriol (PPT). The effects of ginsenosides on skin disorders are noteworthy. They play anti-aging roles by enhancing immune function, resisting melanin formation, inhibiting oxidation, and elevating the concentration of collagen and hyaluronic acid. Thus, ginsenosides have previously been widely used to resist skin diseases and aging. This review details the role of ginsenosides in the anti-skin aging process from mechanisms and experimental research.

Hair repigmentation and regrowth in a dupilumab-treated paediatric patient with alopecia areata and atopic dermatitis: a case report

Alopecia areata (AA) is a chronic inflammatory disease mainly involving Th1 immunoreaction, but Th2 is also involved. A 9-year-old girl presented to our clinic with severe alopecia for 2 months and pruritus-related rashes for 8 years. She was diagnosed with AA and atopic dermatitis (AD), and the Severity of Alopecia Tool (SALT) score was 98. She used a 0.05% halometasone cream (occlusive dressing) topically applied overnight (6 days weekly) for 10 months. After 2 months of treatment, she had regrowth of both black and white hair. However, relapse occurred and she gradually lost all black terminal hair, but white terminal hair remained, with a SALT score of 70. Continuous topical occlusion resulted in white hair regrowth with a SALT score of 20 at the end of month 10. Dupilumab was initially prescribed as a 600-mg subcutaneous injection and maintained at 300 mg every 4 weeks thereafter. Hair repigmentation (10% of whole hair density) started, with black hair shaft appearing at the proximal end in parietal-occipital and occipital areas after three injections at week 12 of dupilumab therapy, with a SALT score of 10. After seven injections at week 28, the percentage of black hair shaft reached up to 90, and she regained her black hair and the pigmented section of hair shaft continued to grow longer at the rate of normal hair growth. Nevertheless, 4 months after termination of dupilumab therapy, the black terminal hair began to fall off, and white vellus hair gradually regrew on the scalp, with a SALT score of 80. Dupilumab induces hair regrowth and repigmentation of white terminal hair without disturbing the anagen phase of hair follicles. Therefore, melanocytes in AA may be a potential target of Th2-related factors. Persistent regrowth of white hair may be used as a signal of Th2 dominance in AA management.

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.

Depigmenting topical therapy based on a synergistic combination of compounds targeting the key pathways involved in melasma pathophysiology

Melasma has a complex pathophysiology with different cell types and signalling pathways involved. Paracrine factors secreted by keratinocytes, fibroblasts and endothelial cells act on melanocytes and stimulate melanogenesis. These paracrine factors are involved in the oxidative stress, inflammatory, vascular and hormonal pathways, among others. Damage of the dermoepidermal barrier also occurs and facilitates melanin deposition in the dermis, also known as dermal or mixed melasma. We used artificial intelligence tools to define the best combination of compounds for skin pigmentation inhibition. Mathematical models suggested the combination of retinol, diosmin and ferulic acid to be the most effective one. In vitro cellular tyrosinase activity assay proved that this combination had a synergistic depigmenting effect. Further assays proved that the combination could inhibit key pathways involved in melasma by downregulating ET-1 and COX-2 gene expression and IBMX-induced dendricity in human melanocytes, and upregulated the gene expression of IL-1b, TIMP3 and several endogenous antioxidant enzymes. The combination also reduced melanin levels in a phototype VI 3D epidermis model. These results indicate that the combination of retinol, diosmin and ferulic acid is an effective synergistic complex for the treatment of melasma by regulating the key molecular pathways involved in skin hyperpigmentation pathophysiology.

Inflammatory response: The target for treating hyperpigmentation during the repair of a burn wound

Hyperpigmentation is a common complication in patients with burn injuries during wound healing; however, the mechanisms underlying its occurrence and development remain unclear. Recently, postinflammatory hyperpigmentation (PIH) was found to result from overproduction of melanin. Local or systemic inflammatory responses are often observed in patients who develop hyperpigmentation. However, we lack studies on the relationship between PIH and burn injury. Therefore, we comprehensively reviewed the existing literature on the melanogenesis of the skin, inflammatory mechanisms in pigmentation, and local or systemic alteration in inflammatory cytokines in patients suffering from burn trauma to elucidate the relationship between PIH and burn injury. We believe that this review will guide further research on regulating melanin production in the burn management process.

The melanin inhibitory effect of plants and phytochemicals: A systematic review

BACKGROUND

Melanin plays an important role in protecting human skin, while excessive synthesis of melanin can cause abnormal pigmentation and induce skin diseases. Long-term use of commercial whitening agents in managing skin melanin such as kojic acid and arbutin can lead to some negative effects such as dermatitis and liver cancer. Although past studies have researched the melanin inhibitory effect of plant extracts, the effective dose and mechanisms are not well summarized and discussed. This study aims to explore the melanin inhibitory property of phytochemicals and tries to answer the following research questions: (1) Which plant extracts and phytochemicals could inhibit melanin biosynthesis in the skin? what is the mechanism of action? (2) Have human trials been conducted to confirm their melanin inhibitory effect? (3) If not, which phytochemicals are recommended for further human trials? This article would provide information for future research to develop natural and safe skin whitening products.

METHODS

A preferred reporting items for systematic reviews and meta-analyses (PRISMA) systematic review method and OHAT risk-of-bias tool were applied to screen literature from 2000 to 2021 and 50 research articles met the selection criteria.

RESULTS

Flavonoids, phenolic acids, stilbenes and terpenes are main classes of phytochemicals responsible for the melanin inhibitory effects. The in vitro/in vivo melanin inhibitory effects of these plant extracts/phytochemicals are achieved via three main mechanisms: (1) the ethyl acetate extract of Oryza sativa Indica cv., and phytochemicals such as galangin and origanoside could manage melanin biosynthesis through competitive inhibition, non-competitive inhibition or mixed-type inhibition of tyrosinase; (2) phytochemicals such as ginsenoside F1, ginsenoside Rb1 and 4‑hydroxy-3-methoxycinnamaldehyde could inhibit melanogenesis through down-regulating microphthalmia-related transcription factor (MITF) gene expression via different signalling pathways; (3) the ethanolic extracts of Dimorphandra gardneriana, Dimorphandra gardneriana, Lippia microphylla and Schinus terebinthifolius have a good ultraviolet absorption ability and high sun protective factor (SPF) values, thereby inhibiting UV induced melanogenesis in the skin.

CONCLUSION

Although many plant extracts and phytochemicals have been found to inhibit melanin production, most of the results were only proved in cellular and/or animal models. Only the ethyl acetate extract of Oryza sativa Indica cv. panicle, and ginsenoside F1 were proved effective in human trials. Animal studies proved the effectiveness of galangin, origanoside, ginsenoside Rb1 and 4‑hydroxy-3-methoxycinnamaldehyde with effective dose below 3 mM, and therefore recommended for future human trial. In addition, cellular studies have demonstrated the effectiveness of oxyresveratrol, mulberroside A, kurarinol, kuraridinol, plumbagin, (6aR,11aR)-3,8-dihydroxy-9‑methoxy pterocarpan, ginsenoside Rh4, cardamonin, nobiletin, curcumin, β-mangostin and emodin in inhibiting melanin synthesis at low concentrations of 20 µM and proved the low SPF values of Dimorphandra gardneriana, Dimorphandra gardneriana, Lippia microphylla and Schinus terebinthifolius extracts, and therefore recommended for further animal and human trials.

Chemical Distance Measurement and System Pharmacology Approach Uncover the Novel Protective Effects of Biotransformed Ginsenoside C-Mc against UVB-Irradiated Photoaging

Long-term exposure to ultraviolet light induces photoaging and may eventually increase the risk of skin carcinogenesis. Rare minor ginsenosides isolating from traditional medicine Panax (ginseng) have shown biomedical efficacy as antioxidation and antiphotodamage agents. However, due to the difficulty of component extraction and wide variety of ginsenoside, the identification of active antiphotoaging ginsenoside remains a huge challenge. In this study, we proposed a novel in silico approach to identify potential compound against photoaging from 82 ginsenosides. Specifically, we calculated the shortest distance between unknown and known antiphotoaging ginsenoside set in the chemical space and applied chemical structure similarity assessment, drug-likeness screening, and ADMET evaluation for the candidates. We highlighted three rare minor ginsenosides (C-Mc, Mx, and F2) that possess high potential as antiphotoaging agents. Among them, C-Mc deriving from American ginseng (Panax quinquefolius L.) was validated by wet-lab experimental assays and showed significant antioxidant and cytoprotective activity against UVB-induced photodamage in human dermal fibroblasts. Furthermore, system pharmacology analysis was conducted to explore the therapeutic targets and molecular mechanisms through integrating global drug-target network, high quality photoaging-related gene profile from multiomics data, and skin tissue-specific expression protein network. In combination with in vitro assays, we found that C-Mc suppressed MMP production through regulating the MAPK/AP-1/NF-κB pathway and expedited collagen synthesis via the TGF-β/Smad pathway, as well as enhanced the expression of Nrf2/ARE to hold a balance of endogenous oxidation. Overall, this study offers an effective drug discovery framework combining in silico prediction and in vitro validation, uncovering that ginsenoside C-Mc has potential antiphotoaging properties and might be a novel natural agent for use in oral drug, skincare products, or functional food.

Anti-Photoaging and Anti-Inflammatory Effects of Ginsenoside Rk3 During Exposure to UV Irradiation

Ginseng is a widely cultivated perennial plant in China and Korea. Ginsenoside Rk3 is one of the major active components of ginseng and is a promising candidate to regulate skin pigments and exert anti-photoaging effects on skin physiology. Ginsenoside Rk3 was mixed with a cream (G-Rk3 cream) and smeared on the skin of mice. Then, the mice were exposed to ultraviolet (UV) A (340 nm and 40 W) and UVB (313 nm and 40 W) radiation. Special attention was given to the anti-photoaging and anti-inflammatory effects of ginsenoside Rk3 on the mouse skin. Macroscopic evaluation indicated that the mouse dorsal skin looked smooth and plump even under UV irradiation for 12 weeks. Pathological analysis indicated that there was no obvious photoaging or inflammation in the mouse skin that was treated with the G-Rk3 cream. More healthy, intact, and neat collagen fibers were observed in mice treated with the G-Rk3 cream than in untreated mice. Further analysis proved that ginsenoside Rk3 could inhibit the decrease in water and hydroxyproline levels in skin tissues and the loss of superoxide dismutase and glutathione peroxidase activities in the blood. Moreover, ginsenoside Rk3 slowed or halted increases in malondialdehyde, matrix metalloproteinase (MMP)-1, and MMP-3 levels in the blood and levels of interleukin 1, interleukin 6, and tumor necrosis factor α in skin tissues. In conclusion, ginsenoside Rk3 plays a significant role in inhibiting photoaging and inflammation to protect skin health.

Vitiligo skin T cells are prone to produce type 1- and type 2-cytokines to induce melanocyte dysfunction and epidermal inflammatory response through JAK signaling

Vitiligo is a T cell-mediated inflammatory skin disorder characterized by the loss of epidermal melanocytes. However, the contribution of melanocytes to the physiopathology of the disease in response to the T cell microenvironment remains unclear. Here, using NanoString technology and multiplex ELISA, we show that active vitiligo perilesional skin is characterized by prominent type 1 and 2 associated immune responses. The vitiligo skin T cell secretome downregulated melanocyte function and adhesion, while increasing melanocyte mitochondrial metabolism and expression of inflammatory cytokines and chemokines by epidermal cells. The JAK1/2 inhibitor ruxolitinib strongly inhibited such effects on epidermal cells. Our data highlight that vitiligo is more complex than previously thought with prominent combined activities of both Th1- and Th2-related cytokines inducing inflammatory responses of epidermal cells. Melanocytes do not appear only to be a target of T cells in vitiligo but could actively contribute to perpetuate inflammation. JAK inhibitors could prevent the impact of T cells on epidermal cells and pigmentation, highlighting their potential clinical benefit in vitiligo.

Diversified Stimuli-Induced Inflammatory Pathways Cause Skin Pigmentation

The production of melanin pigments by melanocytes and their quantity, quality, and distribution play a decisive role in determining human skin, eye, and hair color, and protect the skin from adverse effects of ultraviolet radiation (UVR) and oxidative stress from various environmental pollutants. Melanocytes reside in the basal layer of the interfollicular epidermis and are compensated by melanocyte stem cells in the follicular bulge area. Various stimuli such as eczema, microbial infection, ultraviolet light exposure, mechanical injury, and aging provoke skin inflammation. These acute or chronic inflammatory responses cause inflammatory cytokine production from epidermal keratinocytes as well as dermal fibroblasts and other cells, which in turn stimulate melanocytes, often resulting in skin pigmentation. It is confirmed by some recent studies that several interleukins (ILs) and other inflammatory mediators modulate the proliferation and differentiation of human epidermal melanocytes and also promote or inhibit expression of melanogenesis-related gene expression directly or indirectly, thereby participating in regulation of skin pigmentation. Understanding of mechanisms of skin pigmentation due to inflammation helps to elucidate the relationship between inflammation and skin pigmentation regulation and can guide development of new therapeutic pathways for treating pigmented dermatosis. This review covers the mechanistic aspects of skin pigmentation caused by inflammation.

γδT cells contribute to type 2 inflammatory profiles in eosinophilic chronic rhinosinusitis with nasal polyps

Eosinophilic chronic rhinosinusitis with nasal polyps (ECRS) is a condition linked with type 2 inflammation, poor treatment outcomes, and high recurrence tendency. Although γδT cells have been reported to induce type 2 immune responses and eosinophilic infiltration in several diseases, their role in ECRS has not been fully explored. We aimed to evaluate the association of γδT cells with the type 2 inflammatory profiles in ECRS. Nasal tissue samples obtained from patients with chronic rhinosinusitis with nasal polyps (CRSwNP) (51 eosinophilic and 48 non-eosinophilic), 50 patients with chronic rhinosinusitis without nasal polyps (CRSsNP), and 58 control subjects were examined for γδT cells, inflammatory markers and eosinophils using HE, RT-qPCR, ELISA, immunofluorescence, and flow cytometry. In parallel, studies were also conducted in an ECRS murine model induced by anti-γδT cells neutralizing antibody administration. γδT cells expression was significantly increased in tissues from patients with ECRS compared with non-ECRS, CRSsNP and control subjects. Moreover, inflammatory markers including type 2 proinflammatory cytokines (IL-4, IL-5, IL-13), GATA3, eosinophil cationic protein (ECP), and eotaxin levels were also increased in nasal tissues of patients with ECRS, and Vγ1+ γδT cells mRNA expression was positively correlated with type 2 cytokines, GATA3, and ECP. In the ECRS murine model, anti-Vγ1+ γδT antibody treatment reduced the infiltration of eosinophils and expression of type 2 cytokines, GATA3, and ECP in nasal mucosae. In conclusion, the results of the present study suggest that γδT cells play a crucial role in the type 2 inflammatory profiles and nasal tissue eosinophilic infiltration in patients with ECRS.

Traditional Chinese Herbal Medicine for Whitening

Melanin is the chief pigment responsible for the pigmentation of human skin. Increasing evidence indicates that traditional Chinese drugs with skin-whitening effects are attracting the attention of consumers and researchers because they are perceived to be milder, safer, and healthier than synthetic alternatives. This commentary summarizes the current research on Chinese herbal medicines that inhibit melanin and their biological activities. The findings presented in this study suggest that these traditional Chinese herbal medicines might be potential candidates for novel skin-whitening agents.

Acremonidin E produced by Penicillium sp. SNF123, a fungal endophyte of Panax ginseng, has antimelanogenic activities

Background

Ginseng extracts and ginseng-fermented products are widely used as functional cosmetic ingredients for their whitening and antiwrinkle effects. Recently, increasing attention has been given to bioactive metabolites isolated from endophytic fungi. However, little is known about the bioactive metabolites of the fungi associated with Panax ginseng Meyer.

Methods

An endophytic fungus, Penicillium sp. SNF123 was isolated from the root of P. ginseng, from which acremonidin E was purified. Acremonidin E was tested on melanin synthesis in the murine melanoma cell line B16F10, in the human melanoma cell line MNT-1, and in a pigmented 3D-human skin model, Melanoderm.

Results

Acremonidin E reduced melanogenesis in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 cells with minimal cytotoxicity. qRT–PCR analysis demonstrated that acremonidin E downregulated melanogenic genes, including tyrosinase and tyrosinase-related protein 1 (TRP-1), while their enzymatic activities were unaffected. The antimelanogenic effects of acremonidin E were further confirmed in MNT-1 and a pigmented 3D human epidermal skin model, Melanoderm. Immunohistological examination of the Melanoderm further confirmed the regression of both melanin synthesis and melanocyte activation in the treated tissue.

Conclusion

This study demonstrates that acremonidin E, a bioactive metabolite derived from a fungal endophyte of P. ginseng, can inhibit melanin synthesis by downregulating tyrosinase, illuminating the potential utility of microorganisms associated with P. ginseng for cosmetic ingredients.

Synthesis of a Novel α-Glucosyl Ginsenoside F1 by Cyclodextrin Glucanotransferase and Its In Vitro Cosmetic Applications

Ginsenosides from Panax ginseng (Korean ginseng) are unique triterpenoidal saponins that are considered to be responsible for most of the pharmacological activities of P. ginseng. However, the various linkage positions cause different pharmacological activities. In this context, we aimed to synthesize new derivatives of ginsenosides with unusual linkages that show enhanced pharmacological activities. Novel α-glycosylated derivatives of ginsenoside F1 were synthesized from transglycosylation reactions of dextrin (sugar donor) and ginsenoside F1 (acceptor) by the successive actions of Toruzyme^®3.0L, a cyclodextrin glucanotransferase. One of the resultant products was isolated and identified as (20S)-3β,6α,12β-trihydroxydammar-24ene-(20-O-β-D-glucopyranosyl-(1→2)-α-D-glucopyranoside) by various spectroscopic characterization techniques of fast atom bombardment-mass spectrometry (FAB-MS), infrared spectroscopy (IR), proton-nuclear magnetic resonance (¹H-NMR), ¹³C-NMR, gradient heteronuclear single quantum coherence (gHSQC), and gradient heteronuclear multiple bond coherence (gHMBC). As expected, the novel α-glycosylated ginsenoside F1 (G1-F1) exhibited increased solubility, lower cytotoxicity toward human dermal fibroblast cells (HDF), and higher tyrosinase activity and ultraviolet A (UVA)-induced inhibitory activity against matrix metalloproteinase-1 (MMP-1) than ginsenoside F1. Since F1 has been reported as an antiaging and antioxidant agent, the enhanced efficacies of the novel α-glycosylated ginsenoside F1 suggest that it might be useful in cosmetic applications after screening.

Microemulsion-based hydrogels for enhancing epidermal/dermal deposition of topically administered 20(S)-protopanaxadiol: in vitro and in vivo evaluation studies

BACKGROUND

20(S)-Protopanaxadiol (20S-PPD) is a fully deglycosylated ginsenoside metabolite and has potent dermal antiaging activity. However, because of its low aqueous solubility and large molecular size, a suitable formulation strategy is required to improve its solubility and skin permeability, thereby enhancing its skin deposition. Thus, we optimized microemulsion (ME)-based hydrogel (MEH) formulations for the topical delivery of 20S-PPD.

METHODS

MEs and MEHs were formulated and evaluated for their particle size distribution, morphology, drug loading capacity, and stability. Then, the deposition profiles of the selected 20S-PPD-loaded MEH formulation were studied using a hairless mouse skin model and Strat-M membrane as an artificial skin model.

RESULTS

A Carbopol-based MEH system of 20S-PPD was successfully prepared with a mean droplet size of 110 nm and narrow size distribution. The formulation was stable for 56 d, and its viscosity was high enough for its topical application. It significantly enhanced the in vitro and in vivo skin deposition of 20S-PPD with no influence on its systemic absorption in hairless mice. Notably, it was found that the Strat-M membrane provided skin deposition data well correlated to those obtained from the in vitro and in vivo mouse skin studies on 20S-PPD (correlation coefficient r 2 = 0.929‒0.947).

CONCLUSION

The MEH formulation developed in this study could serve as an effective topical delivery system for poorly soluble ginsenosides and their deglycosylated metabolites, including 20S-PPD.

Epidermal Overexpression of Xenobiotic Receptor PXR Impairs the Epidermal Barrier and Triggers Th2 Immune Response

The skin is in daily contact with environmental pollutants, but the long-term effects of such exposure remain underinvestigated. Many of these toxins bind and activate the pregnane X receptor (PXR), a ligand-activated transcription factor that regulates genes central to xenobiotic metabolism. The objective of this work was to investigate the effect of constitutive activation of PXR in the basal layer of the skin to mimic repeated skin exposure to noxious molecules. We designed a transgenic mouse model that overexpresses the human PXR gene linked to the herpes simplex VP16 domain under the control of the keratin 14 promoter. We show that transgenic mice display increased transepidermal water loss and elevated skin pH, abnormal stratum corneum lipids, focal epidermal hyperplasia, activated keratinocytes expressing more thymic stromal lymphopoietin, a T helper type 2/T helper type 17 skin immune response, and increased serum IgE. Furthermore, the cutaneous barrier dysfunction precedes development of the T helper type 2/T helper type 17 inflammation in transgenic mice, thereby mirroring the time course of atopic dermatitis development in humans. Moreover, further experiments suggest increased PXR signaling in the skin of patients with atopic dermatitis when compared with healthy skin. Thus, PXR activation by environmental pollutants may compromise epidermal barrier function and favor an immune response resembling atopic dermatitis.

Recent development of signaling pathways inhibitors of melanogenesis

Human skin, eye and hair color rely on the production of melanin, depending on its quantity, quality, and distribution, Melanin plays a monumental role in protecting the skin against the harmful effect of ultraviolet radiation and oxidative stress from various environmental pollutants. However, an excessive production of melanin causes serious dermatological problems such as freckles, solar lentigo (age spots), melasma, as well as cancer. Hence, the regulation of melanin production is important for controlling the hyper-pigmentation. Melanogenesis, a biosynthetic pathway to produce melanin pigment in melanocyte, involves a series of intricate enzymatic and chemical catalyzed reactions. Several extrinsic factors include ultraviolet radiation and chemical drugs, and intrinsic factors include molecules secreted by surrounding keratinocytes or melanocytes, and fibroblasts, all of which regulate melanogenesis. This article reviews recent advances in the development of melanogenesis inhibitors that directly/indirectly target melanogenesis-related signaling pathways. Efforts have been made to provide a description of the mechanism of action of inhibitors on various melanogenesis signaling pathways.

A Retrospective Analysis of γδ T Cell Expression in Chronic Rhinosinusitis and Its Association with Recurrence of Nasal Polyps

BACKGROUND/AIMS

To examine whether γδ T cell is expressed in the nasal mucosa of chronic rhinosinusitis (CRS) patients and its potential association with recurrence of nasal polyps.

METHODS

Thirty-six patients with CRS with nasal polyps (CRSwNP) and 25 patients with CRS without nasal polyps (CRSsNP) were recruited. Twenty-six patients with other nasal diseases served as controls. The CRSwNP group was divided into the eosinophilic CRSwNP and noneosinophilic CRSwNP groups. The expression of γδ T cells was detected by immunohistochemistry. The expression of each subtype of γδ T cells was detected by using qRT-PCR. All patients underwent nasal endoscopy, and postoperative follow-up lasted over 12 months. CRS patients were evaluated by preoperative VAS scores of symptoms and nasal endoscopy Lund-Kennedy scores.

RESULTS

The expression of γδ T cells in the CRSwNP groups was stronger than in the CRSsNP and the control group (p < 0.05, p < 0.05). The expression of Vγ1+γδ T cells in the eosinophilic CRSwNP group was higher than that in the CRSsNP group and the control group (p < 0.05, p < 0.05). The expression of γδ T cells was associated with high rate of recurrence, tissue eosinophil infiltration, worse symptom score of nasal obstruction, and higher Lund-Kennedy score (all p < 0.05).

CONCLUSIONS

Increased expression of γδ T cells in CRSwNP may be associated with recurrence of nasal polyps.

IL-33-driven ILC2/eosinophil axis in fat is induced by sympathetic tone and suppressed by obesity

Group 2 innate lymphoid cells (ILC2s) in white adipose tissue (WAT) promote WAT browning and assist in preventing the development of obesity. However, how ILC2 in adipose tissue is regulated remains largely unknown. Here, our study shows that ILC2s are present in brown adipose tissue (BAT) as well as subcutaneous and epididymal WAT (sWAT and eWAT). The fractions of ILC2s, natural killer T (NKT) cells and eosinophils in sWAT, eWAT and BAT are significantly decreased by high-fat-diet (HFD) feeding and leptin deficiency-induced obesity. Consistent with this, the adipose expression and circulating levels of IL-33, a key inducing cytokine of ILC2, are significantly downregulated by obesity. Furthermore, administration of IL-33 markedly increases the fraction of ILC2 and eosinophil as well as the expression of UCP1 and tyrosine hydroxylase (TH), a rate-limiting enzyme in catecholamine biosynthesis, in adipose tissue of HFD-fed mice. On the other hand, cold exposure induces the expression levels of IL-33 and UCP1 and the population of ILC2 and eosinophil in sWAT, and these promoting effects of cold stress are reversed by neutralization of IL-33 signaling in vivo Moreover, the basal and cold-induced IL-33 and ILC2/eosinophil pathways are significantly suppressed by sympathetic denervation via local injection of 6-hydroxydopamine (6-OHDA) in sWAT. Taken together, our data suggest that the ILC2/eosinophil axis in adipose tissue is regulated by sympathetic nervous system and obesity in IL-33-dependent manner, and IL-33-driven ILC2/eosinophil axis is implicated in the development of obesity.

Antimelanogenesis Activity of Hydrolyzed Ginseng Extract (GINST) via Inhibition of JNK Mitogen-activated Protein Kinase in B16F10 Cells

GINST is a hydrolyzed ginseng extract produced by an in vitro process that imitates the metabolic function of bacteria in the human digestive track and has approved by the Ministry of Food and Drug Safety of Korea for the management of postprandial hyperglycemia. Additionally, GINST has been reported to have other physiological functions including anti-aging and antioxidant effects. The objectives of this study are to compare the antimelanogenic effects of fresh ginseng extract (FGE) and GINST extract and to elucidate the functional mechanism. The concentration of total ginsenosides in FGE and GINST was measured using ultraperformance liquid chromatography with a C18 column. B16F10 cells were treated with FGE and GINST for 72 h to assess melanin content, tyrosinase activity, and protein levels of microphthalmia-associated transcription factor (MITF) and tyrosinase-related protein-1 (TRP-1). The activity of kinases involved in mitogen-activated protein kinase (MAPK) signaling, such as extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK), and p38 mitogen-activated protein kinases (p38), were measured using western blots. While neither FGE nor GINST inhibited the activity of mushroom tyrosinase directly, GINST decreased melanogenesis and tyrosinase activity markedly. Furthermore, our results indicate that GINST downregulated the levels of MITF and TRP-1 possibly by suppressing JNK signaling. We concluded that, when compared to FGE, GINST has a superior antimelanogenic effect mediated by the downregulation of MITF, TRP-1, and intracellular tyrosinase activity via the JNK signaling pathway. Thus, we suggest that GINST has the potential to be used as a novel skin whitening agent.

Effect of ginseng and ginsenosides on melanogenesis and their mechanism of action

Abnormal changes in skin color induce significant cosmetic problems and affect quality of life. There are two groups of abnormal change in skin color; hyperpigmentation and hypopigmentation. Hyperpigmentation, darkening skin color by excessive pigmentation, is a major concern for Asian people with yellow–brown skin. A variety of hypopigmenting agents have been used, but treating the hyperpigmented condition is still challenging and the results are often discouraging. Panax ginseng has been used traditionally in eastern Asia to treat various diseases, due to its immunomodulatory, neuroprotective, antioxidative, and antitumor activities. Recently, several reports have shown that extract, powder, or some constituents of ginseng could inhibit melanogenesis in vivo or in vitro. The underlying mechanisms of antimelanogenic properties in ginseng or its components include the direct inhibition of key enzymes of melanogenesis, inhibition of transcription factors or signaling pathways involved in melanogenesis, decreasing production of inducers of melanogenesis, and enhancing production of antimelanogenic factor. Although there still remain some controversial issues surrounding the antimelanogenic activity of ginseng, especially in its effect on production of proinflammatory cytokines and nitric oxide, these recent findings suggest that ginseng and its constituents might be potential candidates for novel skin whitening agents.