Management of Atopic Dermatitis Via Oral and Topical Administration of Herbs in Murine Model: A Systematic Review

Pulsatilla koreana Nakai Extract Attenuates Atopic Dermatitis-like Symptoms by Regulating Skin Barrier Factors and Inhibiting the JAK/STAT Pathway

Atopic dermatitis is caused by various factors, including complex interactions between immune responses and imbalances in T helper cells. In order to resolve the side effects of steroid-based treatment and rapidly improve atopy symptoms, the development of preventive substances for new treatments and as food supplements is essential. Pulsatilla koreana Nakai (PKN) is traditionally used as an effective herbal medicine for pain relief, anti-inflammation, and edema, and dried PKN is boiled and drunk as a tea to prevent them; however, its effect on skin manifestations such as atopy are unclear. Therefore, we investigated the in vivo and in vitro effects of PKN extract on improving symptoms of atopy as a potential treatment. By evaluating dermatitis scores and conducting histopathological analysis in mice with Dermatophagoides farina-induced atopy-like pathology, we demonstrated that PKN extract alleviated atopy symptoms. Moreover, PKN extract restored a reduction in the protein levels of skin barrier-related factors in skin tissue. Through in vitro analysis, we examined the impact of PKN on JAK/STAT signaling in IL-4/IL-13-stimulated human keratinocytes and elucidated the mechanisms that suppress the levels of skin barrier factors and inflammation. PKN extract inhibited JAK/STAT phosphorylation stimulated by IL-4/IL-13. Furthermore, docking analysis of PKN constituents indicated binding to JNK1/2 and STAT3/6 and a subsequent inhibition of signal transduction. Therefore, this suggests that PKN extract has potential not only as a treatment but also as a food supplement to improve atopic dermatitis by strengthening skin barrier factors and inhibiting key signaling molecules.

Chlorogenic acid alleviates DNCB-induced atopic dermatitis by inhibiting the Akt1/NF-κB signaling pathway

OBJECTIVE

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease that significantly impacts patients' quality of life. Chlorogenic acid (CGA), a polyphenol present in various dietary sources and plants, has been shown to reduce skin inflammation. However, its efficacy and mechanisms of action in AD have not been thoroughly investigated. This study aimed to evaluate the therapeutic effect of CGA on AD in mice and explored its mechanism.

METHODS

To establish a BALB/c mouse model of AD induced by 2,4-dinitrochlorobenzene (DNCB) to evaluate the therapeutic potential of CGA. The anti-inflammatory effects of CGA were assessed by measuring IL-1β and IL-6 levels in TNF-α-stimulated HaCaT cells. The phosphorylation levels of PI3K, Akt, Akt1, NF-κB, and IκB-α were analyzed using Western blotting. Molecular docking was conducted to evaluate the binding affinity of CGA to Akt1.

RESULTS

Topical application of CGA significantly reduced dermatitis scores, spleen index, epidermal thickness, mast cell infiltration, and skin fibrosis. CGA reversed DNCB-induced increases in IgE, histamine, TNF-α, IL-1β, IL-6, and IL-8 levels. Western blot analysis showed that CGA inhibited the PI3K/Akt and NF-κB signaling pathways. In vitro, CGA exerts its anti-inflammatory effects by inhibiting the Akt1/NF-κB pathway, and the Akt activator (SC79) can counteract this effect. Molecular docking and dynamics simulations suggest that CGA may inhibit Akt1 activity by interacting with specific residues (ALA-50, GLY-37, TYR-326, ASP-323).

CONCLUSIONS

CGA improves AD by inhibiting the Akt1/NF-κB pathway, suggesting its potential as a natural treatment for AD.

Current utilization trend of immortalized mast cell lines in allergy research: a systematic review

Today, in the modern world, allergic diseases, also described as atopic allergies, are classified as a type of multifactorial disorder due to the complex interplay between genetics, environment, and socioeconomic factors that influence the disease's manifestation, severity, and one's predisposition to allergic diseases. It is undeniable that many reported studies have pointed out that the mast cell is one of the leading key players involved in triggering an allergic reaction. To improve our understanding of the molecular and cellular mechanisms underlying allergy, various mast cell lines have been employed in vitro to study the pathogenesis of allergic diseases for the past decades. However, there is no consensus on many fundamental aspects associated with their use, such as the effects of culture media composition and the type of inducer used for cell degranulation. As the standardization of research protocols and disease models is crucial, we present the outcome of a systematic review of scientific articles using three major immortalized in vitro mast cell lines (HMC-1, LAD2, and RBL-2H3) to study allergy. This systematic review described the cell source, culture conditions, inducers used for degranulation, and mediators released for examination. We hope that the present systematic review may help to standardize the use of immortalized in vitro mast cell lines in allergy research and serve as a user's guide to understand the fundamental aspects of allergy as well to develop an effective allergy therapy in the future for the betterment of human good health and wellbeing.

Rosmarinic Acid Ameliorates Dermatophagoides farinae Extract-Induced Atopic Dermatitis-like Skin Inflammation by Activating the Nrf2/HO-1 Signaling Pathway

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases. AD pathogenesis is associated with increased oxidative stress, impairment of the skin barrier, and activation of the immune response. Rosmarinic acid (RA), a caffeic acid ester, is known for its anti-inflammatory and antioxidant properties. However, the effects of RA on Dermatophagoides farinae extract (DfE)-induced AD-like skin inflammation, as well as its ability to regulate oxidative stress through the Nrf2/HO-1 pathway in TNF-α/IFN-γ-treated keratinocytes, remain unclear. We investigated RA activity in a DfE-induced AD-like skin inflammation mouse model and IFN-γ/TNF-α-stimulated keratinocytes. We found that RA attenuates DfE-induced inflammation by decreasing dermatitis scores and serum inflammatory marker levels and mast cell infiltration. Additionally, RA significantly suppressed IFN-γ/TNF-α-induced chemokine production in keratinocytes and reduced Th cytokine levels in concanavalin A-stimulated splenocytes. Importantly, RA also increased Nrf2/HO-1 expression in TNF-α/IFN-γ-treated keratinocytes. In conclusion, this study demonstrated that RA effectively alleviates DfE-induced AD-like skin lesions by reducing the levels of inflammatory cytokines and chemokines. Furthermore, RA promotes Nrf2/HO-1 signaling in keratinocytes, which may help mitigate DfE-induced oxidative stress, thereby alleviating AD-like skin inflammation. These findings highlight the potential of RA as a therapeutic agent for treating AD and other skin inflammation.

Oral Administration of Taurodeoxycholate, A GPCR19 Agonist, Effectively Ameliorates Atopic Dermatitis in A Mouse Model

Atopic dermatitis (AD) is the most prevalent chronic inflammatory skin disorder, characterised by intense pruritus and recurrent eczematous lesions. Recently, the US FDA has approved Janus kinase (JAK) inhibitors for oral treatment in AD patients. However, oral immunomodulatory agents have demonstrated adverse effects. In previous studies, we demonstrated the efficacy of topical taurodeoxycholate (TDCA), a G protein-coupled receptor 19 (GPCR19) agonist, on AD. In this study, we further evaluated the efficacy of orally administered TDCA on MC903- and dinitrochlorobenzene (DNCB)-induced AD mouse models. Oral administration of TDCA significantly ameliorated AD symptoms and reduced both epidermal and dermal thickness. Additionally, oral TDCA treatment inhibited the infiltration of myeloid and lymphoid cells into AD lesions. TDCA also suppressed the expression of thymic stromal lymphopoietin (TSLP), interleukin (IL)-4, IL-13, IL-33, IL-1β, tumour necrosis factor-alpha (TNF-α) and chemokine (C-C motif) ligand 17 in the skin and blood. Given the previously demonstrated safety profiles of TDCA, oral TDCA may offer a beneficial and safer alternative for AD patients.

Nano-based formulations of thymoquinone are new approaches for psoriasis treatment: a literature review

Psoriasis, a persistent immune-mediated inflammatory skin condition, affects approximately 2-3% of the global population. Current treatments for psoriasis are fraught with limitations, including adverse effects, high costs, and diminishing efficacy over time. Thymoquinone (TQ), derived from Nigella sativa seeds, exhibits promising anti-inflammatory, antioxidant, and immunomodulatory properties that could prove beneficial in managing psoriasis. However, TQ's hydrophobic nature and poor bioavailability have hindered its usefulness as a therapeutic agent. Recent research has strategically addressed these challenges by developing nano-thymoquinone (nano-TQ) formulations to enhance delivery and efficacy in treating psoriasis. Preclinical studies employing mouse models have demonstrated that nano-TQ effectively mitigates inflammation, erythema, scaling, epidermal thickness, and cytokine levels in psoriatic lesions. Various nano-TQ formulations, including nanoemulsions, lipid vesicles, nanostructured lipid carriers, and ethosomes, have been explored to improve solubility, facilitate skin penetration, ensure sustained release, and achieve site-specific targeting. Although clinical trials are currently scarce, the outcomes from in vitro and animal models are promising. The potential co-delivery of nano-TQ with other anti-psoriatic agents also presents avenues for further investigation.

Oral and topical administration of a geranyl acetophenone attenuates DNCB-induced atopic dermatitis-like skin lesions in BALB/c mice

Atopic dermatitis (AD) is a chronic, allergic inflammatory skin disorder that lacks a definite cure. Using a mouse DNCB-induced AD-like skin lesions model, this study evaluated the potential therapeutic utility of tHGA as an oral and topical treatment for AD. Male BALB/c mice were sensitised and challenged with 1% and 0.5% DNCB on their shaved dorsal skin. Mice in the treatment group were administered tHGA (20, 40, and 80 mg/kg) orally three times per week for 2 weeks, or tHGA (0.2%, 1%, and 5%) topically once daily for 12 days. On day 34, the mice were euthanized, and blood and dorsal skin samples were obtained for analysis. All doses of orally and topically administered tHGA significantly improved scratching, epidermal thickness, blood eosinophilia and mast cell infiltration. There was a minor discrepancy between the two routes of administration, with orally treated tHGA showing significant reductions in Scoring of Atopic Dermatitis (SCORAD), tissue eosinophil infiltration, serum IgE and skin IL-4 levels with treatment of 40 and 80 mg/kg tHGA, whereas topically applied tHGA showed significant reductions in all dosages. These findings suggest that tHGA exhibited therapeutic potential for AD as both oral and topical treatment ameliorates AD-like symptoms in the murine model.

Reynoutria japonica consisted of emodin-8-β-D-glucoside ameliorates Dermatophagoides farinae extract-induced atopic dermatitis-like skin inflammation in mice by inhibiting JAK/STAT signaling

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by skin barrier dysfunction and chronic inflammatory responses. Reynoutria japonica, known as Huzhang in traditional Chinese Medicine, can enhance blood circulation to eliminate wind pathogens and terminate coughing. Despite pharmacological evidence supporting the efficacy of R. japonica in suppressing edema-induced skin inflammation or connective tissue diseases, its pharmaceutical potential for treating AD-like skin inflammation remains unexplored. This study investigated the possible effects of R. japonica ethanol extract (RJE) on Dermatophagoides farinae extract (DfE)-induced AD-like skin inflammation in NC/Nga mice. To elucidate the underlying mechanisms by which RJE inhibits skin inflammation, we examined the effect of RJE on IFN-γ/TNF-α-induced signal transducer and activator of transcription (STAT) signaling in human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDFs). Our findings revealed that RJE mitigates DfE-induced AD-like symptoms and skin barrier disruptions in mouse skin lesions. Moreover, RJE attenuated DfE-induced mast cell infiltration and serum levels of inflammatory cytokines (IL-1α, IL-1β, IL-6, IL-23, IFN-γ, TNF-α, and GM-CSF). RJE also inhibited IFN-γ/TNF-α-induced chemokine levels and STAT3 phosphorylation in HEKs and HDFs. Virtual binding analysis of the RJE components suggested that emodin-8-β-D-glucoside binds to Janus kinase (JAK) 1/2, thereby suppressing STAT signaling, which was confirmed by Western blot analysis. In conclusion, our results suggest that RJE may alleviate DfE-induced skin barrier dysfunction by inhibiting JAK/STAT signaling and the proinflammatory immune response through the suppression of inflammatory mediators in AD-like skin disease. These findings suggest that RJE has potential as an effective therapy for AD management.

Efficacy of Topical Palmitoylethanolamide (Levagen+) for the Management of Eczema Symptoms: A Double-Blind, Comparator-Controlled, Randomized Clinical Trial

INTRODUCTION

Eczema is a debilitating skin disorder clinically characterised by the development of itchy, dry, rough, and scaling skin caused by a series of rudimentary clinical phenotypes.

METHODS

This double-blind, randomised, comparator-controlled trial evaluated the effectiveness of topical application of a novel palmitoylethanolamide formulation (Levagen+) compared with a standard moisturiser (comparator) to reduce eczema severity and improve patient outcomes. Seventy-two participants aged over 18 years old with atopic eczema (symptoms including redness, dry skin, scaling, and/or itchiness) on their hands or arm were recruited. Participants were randomly allocated to one of two treatment groups (Levagen + or comparator). Treatment was applied to the affected area twice daily for 4 weeks. Outcome measures included Self-Assessed Eczema Area Severity Index (SA-EASI) scoring and Patient-Oriented Eczema Measure (POEM) from baseline to week 4.

RESULTS

Levagen+ was effective at alleviating symptom severity of eczema over 4 weeks. Levagen+ significantly reduced redness, dryness, and total POEM score compared to a comparator cream.

CONCLUSION

Levagen+ can significantly reduce eczema symptom severity compared to a comparator product, supporting its use as a potential treatment for eczema.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT05003453.

Anti-atopic dermatitis effect of fish collagen on house dust mite-induced mice and HaCaT keratinocytes

Collagen, a major structural protein in mammalian tissues, is effective against skin wounds and osteoarthritis. Although bovine and porcine collagens have mainly been used, several potential risks of mammalian collagen have led to the use of fish collagen (FC) as an alternative. FC and its peptides are used as common cosmeceutical products because of their antihypertensive, anti-bacterial, and antioxidant activities. Despite the effects of FC on wrinkle reduction, UV-protection, and wound healing, the relationship between FC and atopic dermatitis (AD) has not yet been reported. Therefore, we investigated the anti-AD effects of FC against house dust mite (Dermatophagoides farinae, HDM)-induced AD in NC/Nga mice and TNF-α/IFN-γ-stimulated HaCaT keratinocytes. FC alleviated AD apparent symptoms, such as dermatitis score, transepidermal water loss, epidermal thickness, and mast cell infiltration upon declining pro-inflammatory cytokines and mediators, IL-6, IL-5, IL-13, TSLP, and TNF-α. The skin barrier protein, filaggrin, was also recovered by FC administration in vivo and in vitro. Immune response and skin barrier dysfunction are both mitigated by three routes of FC administration: oral, topical, and both routes via the regulation of IκB, MAPKs, and STATs pathways. In summary, FC could be a potential therapeutic agent for AD by regulating immune balance and skin barrier function.

Veronica persica Ethanol Extract Ameliorates Dinitrochlorobenzene-Induced Atopic Dermatitis-like Skin Inflammation in Mice, Likely by Inducing Nrf2/HO-1 Signaling

Atopic dermatitis (AD) is chronic allergic contact dermatitis with immune dysregulation. Veronica persica has pharmacological activity that prevents asthmatic inflammation by ameliorating inflammatory cell activation. However, the potential effects of the ethanol extract of V. persica (EEVP) on AD remain elusive. This study evaluated the activity and underlying molecular pathway of EEVP in two AD models: dinitrochlorobenzene (DNCB)-induced mice and interferon (IFN)-γ/tumor necrosis factor (TNF)-α-stimulated human HaCaT keratinocytes. EEVP attenuated the DNCB-induced increase in serum immunoglobulin E and histamine levels, mast cell counts in toluidine-blue-stained dorsal skin, inflammatory cytokine (IFN-γ, interleukin [IL]-4, IL-5, and IL-13) levels in cultured splenocytes, and the mRNA expression of IL6, IL13, IL31 receptor, CCR-3, and TNFα in dorsal tissue. Additionally, EEVP inhibited the IFN-γ/TNF-α-induced mRNA expression of IL6, IL13, and CXCL10 in HaCaT cells. Furthermore, EEVP restored the IFN-γ/TNF-α-induced downregulation of heme oxygenase (HO)-1 in HaCaT cells by inducing nuclear factor erythroid 2-related factor 2 (Nrf2) expression. A molecular docking analysis demonstrated that EEVP components have a strong affinity to the Kelch-like ECH-associated protein 1 Kelch domain. In summary, EEVP inhibits inflammatory AD by attenuating immune cell activation and inducing the Nrf2/HO-1 signaling pathway in skin keratinocytes.

Ursolic acid ameliorates DNCB-induced atopic dermatitis-like symptoms in mice by regulating TLR4/NF-κB and Nrf2/HO-1 signaling pathways

BACKGROUND

Ursolic acid (UA) is a triterpenoid compound found in natural plants. It has been reported to have anti-inflammatory, antioxidant, and immunomodulatory properties. However, its role in atopic dermatitis (AD) is unknown. This study aimed to evaluate the therapeutic effect of UA in AD mice and explore the underlying mechanisms.

METHODS

Balb/c mice were treated with 2, 4-dinitrochlorobenzene (DNCB) to induce AD-like lesions. During modeling and medication administration, dermatitis scores and ear thickness were measured. Subsequently, histopathological changes, levels of T helper cytokines, and oxidative stress markers levels were evaluated. Immunohistochemistry staining was used to assess changes in the expression of the nuclear factor of kappa B (NF-κB) and NF erythroid 2-related factor 2 (Nrf2). Furthermore, CCK8 assay, reactive oxygen species (ROS) assay, real-time PCR, and western blotting were employed to evaluate the effects of UA on ROS levels, inflammatory mediator production, and the NF-κB and Nrf2 pathways in TNF-α/IFN-γ-stimulated HaCaT cells.

RESULTS

The results showed that UA significantly reduced dermatitis score and ear thickness, effectively inhibited skin proliferation and mast cell infiltration in AD mice, and decreased the expression level of T helper cytokines. Meanwhile, UA improved oxidative stress in AD mice by regulating lipid peroxidation and increasing the activity of antioxidant enzymes. In addition, UA inhibited ROS accumulation and chemokine secretion in TNF-α/IFN-γ-stimulated HaCaT cells. It might exert anti-dermatitis effects by inhibiting the TLR4/NF-κB pathway and activating the Nrf2/HO-1 pathway.

CONCLUSION

Taken together, our results suggest that UA may have potential therapeutic effects on AD and could be further studied as a promising drug for AD treatment.