Effect of dehydroepiandrosterone on atopic dermatitis-like skin lesions induced by 1-chloro-2,4-dinitrobenzene in mouse

Eugenol-Loaded Transethosomal Gel for Improved Skin Delivery and Treatment of Atopic Dermatitis

Atopic dermatitis is a skin condition characterized by lichenification (thickening and increased skin marking), eczematous lesions, dry skin, itching, and pruritus. Eugenol is an aromatic polyphenolic compound that has attracted the attention of researchers due to its anti-inflammatory, anti-oxidant, and anti-cancer properties. The primary goal of the present study was to develop and evaluate eugenol-loaded transethosomes for the treatment of AD. Eugenol-loaded transethosomes were formulated using the ethanol injection method and subsequently subjected to particle size analysis, zeta potential, entrapment efficiency, deformability index, and HRTEM analysis. Transethosomal gel was prepared by direct-dispersion method by using Carbopol 940®. Results showed transethosomes to be lipid bilayer structures with acceptable size, and high entrapment efficiency. Transethosomal formulation showed shear-thinning behavior. Eugenol-loaded transethosomal gel was significantly able to enhance the retention of the drug in the skin. Transethosomal gel was significantly able to reduce Ear thickness, DLC, TLC, and IL-6 levels in mice model of AD. These results indicate that the eugenol-loaded transethosomal gel could be a promising carrier for the topical administration of eugenol for the treatment of AD.

Development and Evaluation of Tacrolimus Loaded Nano-Transferosomes for Skin Targeting and Dermatitis Treatment

Tacrolimus (TRL) is used for the treatment of atopic dermatitis (AD) due to its T-cell stimulation effect. However, its significantly poor water solubility, low penetration and cytotoxicity have reduced its topical applications. Herein, tacrolimus loaded nano transfersomes (TRL-NTs) were prepared, followed by their incorporation into chitosan gel to prepare tacrolimus loaded nano transfersomal gel (TRL-NTsG). TEM analysis of the TRL-NTs was performed to check their morphology. DSC, XRD and FTIR analysis of the TRL-NTs were executed after lyophilization. Similarly, rheology, spreadability and deformability of the TRL-NTsG were investigated. In vitro release, ex vivo permeation and in vitro interaction of TRL-NTsG with keratinocytes and fibroblasts as well as their co-cultures were investigated along with their in vitro cell viability analysis. Moreover, in vivo skin deposition, ear thickness, histopathology and IgE level were also determined. Besides, 6 months stability study was also performed. Results demonstrated the uniformly distributed negatively charged nanovesicles with a mean particle size distribution of 163 nm and zeta potential of -27 mV. DSC and XRD exhibited the thermal stability and amorphous form of the drug, respectively. The TRL-NTsG showed excellent deformability, spreadability and rheological behavior. In vitro release studies exhibited an 8-fold better release of TRL from the TRL-NTsG. Similarly, 6-fold better permeation and stability of the TRL-NTsG with keratinocytes and fibroblasts as well as their co-cultures was observed. Furthermore, the ear thickness (0.6 mm) of the TRL-NTsG was found significantly reduced when compared with the untreated (1.7 mm) and TRL conventional gel treated mice (1.3 mm). The H&E staining showed no toxicity of the TRL-NTsG with significantly reduced IgE levels (120 ng/mL). The formulation was found stable for at least 6 months. These results suggested the efficacy of TRL in AD-induced animal models most importantly when incorporated in NTsG.

Treating atopic-dermatitis-like skin lesions in mice with gelatin-alginate films containing 1,4-anhydro-4-seleno-d-talitol (SeTal)

New compounds and pharmacological strategies offer alternatives for treating chronic skin diseases, such as atopic dermatitis (AD). Here, we investigated the incorporation of 1,4-anhydro-4-seleno-d-talitol (SeTal), a bioactive seleno-organic compound, in gelatin and alginate (Gel-Alg) polymeric films as a strategy for improving the treatment and attenuation of AD-like symptoms in a mice model. Hydrocortisone (HC) or vitamin C (VitC) were incorporated with SeTal in the Gel-Alg films, and their synergy was investigated. All the prepared film samples were able to retain and release SeTal in a controlled manner. In addition, appreciable film handling facilitates SeTal administration. A series of in-vivo/ex-vivo experiments were performed using mice sensitized with dinitrochlorobenzene (DNCB), which induces AD-like symptoms. Long-term topical application of the loaded Gel-Alg films attenuated disease symptoms and pruritus, with suppression of the levels of inflammatory markers, oxidative damage, and the skin lesions associated with AD. Moreover, the loaded films showed superior efficiency in attenuating the analyzed symptoms when compared to hydrocortisone (HC) cream, a traditional AD-treatment, and decreased the inherent drawbacks of this compound. In short, incorporating SeTal (by itself or with HC or VitC) in biopolymeric films provides a promising alternative for the long-term treatment of AD-type skin diseases.

Fulvic Acid Attenuates Atopic Dermatitis by Downregulating CCL17/22

The main pathogenic factor in atopic dermatitis (AD) is Th2 inflammation, and levels of serum CCL17 and CCL22 are related to severity in AD patients. Fulvic acid (FA) is a kind of natural humic acid with anti-inflammatory, antibacterial, and immunomodulatory effects. Our experiments demonstrated the therapeutic effect of FA on AD mice and revealed some potential mechanisms. FA was shown to reduce TARC/CCL17 and MDC/CCL22 expression in HaCaT cells stimulated by TNF-α and IFN-γ. The inhibitors showed that FA inhibits CCL17 and CCL22 production by deactivating the p38 MAPK and JNK pathways. After 2,4-dinitrochlorobenzene (DNCB) induction in mice with atopic dermatitis, FA effectively reduced the symptoms and serum levels of CCL17 and CCL22. In conclusion, topical FA attenuated AD via downregulation of CCL17 and CCL22, via inhibition of P38 MAPK and JNK phosphorylation, and FA is a potential therapeutic agent for AD.

Novel Pullulan/Gellan Gum Bilayer Film as a Vehicle for Silibinin-Loaded Nanocapsules in the Topical Treatment of Atopic Dermatitis

In this study a novel gellan gum/pullulan bilayer film containing silibinin-loaded nanocapsules was developed for topical treatment of atopic dermatitis (AD). The bilayer films were produced by applying a pullulan layer on a gellan gum layer incorporated with silibinin nanocapsules by two-step solvent casting method. The bilayer formation was confirmed by microscopic analysis. In vitro studies showed that pullulan imparts bioadhesitvity for the films and the presence of nanocapsules increased their occlusion factor almost 2-fold. Besides, the nano-based film presented a slow silibinin release and high affinity for cutaneous tissue. Moreover, this film presented high scavenger capacity and non-hemolytic property. In the in vivo study, interestingly, the treatments with vehicle film attenuated the scratching behavior and the ear edema in mice induced by 2,4-dinitrochlorobenzene (DNCB). However, the nano-based film containing silibinin modulated the inflammatory and oxidative parameters in a similar or more pronounced way than silibinin solution and vehicle film, as well as than hydrocortisone, a classical treatment of AD. In conclusion, these data suggest that itself gellan gum/pullulan bilayer film might attenuate the effects induced by DNCB, acting together with silibinin-loaded nanocapsules, which protected the skin from oxidative damage, improving the therapeutic effect in this AD-model.

Compound traditional Chinese medicine dermatitis ointment ameliorates inflammatory responses and dysregulation of itch-related molecules in atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease accompanied with itchy and scaly rash. Compound traditional Chinese medicine dermatitis ointment (CTCMDO) consists of a mixture of extracts from five plants, which had been used in AD treatment due to good anti-inflammatory and anti-allergic effects.

MATERIALS AND METHODS

In this study, high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometer (LC/MS) were performed to analyze the active ingredients of CTCMDO in detail and to establish its HPLC fingerprint. Furthermore, the anti-inflammatory and antipruritic activities of CTCMDO were studied in the treatment of DNCB-induced AD in mice.

RESULTS

A total of 44 compounds including phenylpropionic acid compounds, alkaloid compounds, curcumin compounds and lignans were identified via combined HPLC and LC/MS. A fingerprint with 17 common peaks was established. In AD-like mice, DNCB-induced scratching behavior had been suppressed in the treatment of CTCMDO in a dose-dependent manner. Furthermore, the detailed experimental results indicated that the AD can be effectively improved via inhibiting the production of Th1/2 cytokines in serum, reversing the upregulation of substance P levels of itch-related genes in the skin, and suppressing the phosphorylation of JNK, ERK, and p38 in the skin.

CONCLUSION

This work indicated that CTCMDO can significantly improve AD via attenuating the pathological alterations of Th1/2 cytokines and itch-related mediators, as well as inhibiting the phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB).

Pullulan film incorporated with nanocapsules improves pomegranate seed oil anti-inflammatory and antioxidant effects in the treatment of atopic dermatitis in mice

This study aimed to prepare pullulan films containing pomegranate seeds oil (PSO) based nanocapsules, and evaluate the formulation efficacy in the treatment of atopic dermatitis (AD)-like lesions induced by 2,4-dinitrochlorobenzene (DNCB). The Eudragit RS 100® nanocapsules (PSONC) were prepared by the interfacial precipitation of preformed polymer, whereas the films were produced by the solvent casting method. Pomegranate seed oil nanoemulsions (PSONE) were prepared by the spontaneous emulsification method for comparative reasons. Both nanosystems presented adequate mean diameter (248 ± 16 nm for PSONE and 181 ± 6 nm for PSONC), polydispersity index (below 0.2), zeta potential (-25.63 ± 1.1 mV for PSONE and + 43.13 ± 0.7 mV for PSONC) and pH in the acid range (6.77 ± 0.27 and 5.31 ± 0.17, PSONE and PSONC). By a pre-formulation study, sorbitol (6.5%) and PEG 400 (1.5%) were considered the most suitable plasticizers for developing pullulan films (6%) intending topical application. In general, pullulan films were classified as flexible and hydrophilic, with high occlusive properties, 57.6 ± 0.8%, 64.6 ± 0.8% for vehicle, PSONCF (pullulan film containing PSONC), respectively. All formulations (films and nanocarriers) presented no irritant potential in the chorioallantoic membrane test. In the in vivo model, the treatments with free PSO and PSONCF attenuated the skin injury as well as the mechanical hypernociceptive behavioral induced by DNCB exposure to mice. Importantly, the biochemical analyses provided evidence that only the treatment with PSONCF modulated the inflammatory and the oxidative stress parameters evaluated in this study. In conclusion, these data lead us to believe that PSONC incorporation into a pullulan film matrix improved the biological properties of the PSO in this AD-model.

Suppressive effect of 1,4-anhydro-4-seleno-D-talitol (SeTal) on atopic dermatitis-like skin lesions in mice through regulation of inflammatory mediators

BACKGROUND

Atopic dermatitis (AD) is a multifactorial chronic inflammatory disease that affects ∼20 % of children and 3% of adults globally and is generally treated by the topical application of steroidal drugs that have undesirable side-effects. The development of alternative therapies is therefore an important objective. The present study investigated the effects of topical treatment with a novel water-soluble selenium-containing carbohydrate derivative (4-anhydro-4-seleno-D-tatitol, SeTal) on the symptoms and inflammatory parameters in an AD mouse model.

METHODS

Mice were sensitized by applying 2,4-dinitrochlorobenzene (DNCB) to their dorsal skin on days 1-3, then further challenged on their ears and dorsal skin on days 14, 17, 20, 23, 26, and 29. SeTal (1 and 2%) or hydrocortisone (1%) was applied topically to the backs of the mice from days 14-29, and skin severity scores and scratching behavior determined on day 30. The mice were euthanized, and their ears and dorsal skin removed to quantify inflammatory parameters, edema, myeloperoxidase (MPO) activity, and AD-associated cytokines (tumor necrosis factor alpha (TNF-α), interleukins (IL)-18, and IL-33).

RESULTS

DNCB treatment induced skin lesions and increased the scratching behavior, ear edema, MPO activity (ear and dorsal skin), and cytokine levels in dorsal skin. Topical application of SeTal improved inflammatory markers (cytokine levels and MPO activity), cutaneous severity scores, and scratching behavior.

CONCLUSION

The efficacy of SeTal was satisfactory in the analyzed parameters, showing similar or better results than hydrocortisone. SeTal appears to be therapeutically advantageous for the treatment and control of AD.

Bis-(3-amino-2-pyridine) diselenide improves psychiatric disorders -atopic dermatitis comorbidity by regulating inflammatory and oxidative status in mice

Suppressive effect of bis (3-amino-2-pyridine) diselenide (BAPD) on psychiatric disorders - atopic dermatitis (AD) comorbidity in mice was investigated. To sensitize the animals, 2,4-dinitrochlorobenzene (DNCB) was applied to their dorsal skin on days 1-3. Mice were challenged with DNCB on their ears and dorsal skin on days 14, 17, 20, 23, 26, and 29. BAPD and Dexamethasone were administered to the animals, from days 14-29, and skin severity scores and behavioral tests were determined. Oxidative stress and inflammatory parameters were evaluated on the dorsal skin of mice. Na⁺, K⁺-ATPase activity and corticosterone levels were determined in hippocampus/cerebral cortex and plasma of mice, respectively. BAPD improved cutaneous damage, scratching behavior, inflammatory and oxidative stress markers. BAPD showed anxiolytic- and antidepressant-like effects and restored Na⁺, K⁺-ATPase activity and corticosterone levels. The present study was performed using female mice due the susceptibility for this disease. But, the evaluation of AD model in male mice would help to verify whether the male gender has the same predisposition to present this pathology. Our data demonstrated the suppressive effect of BAPD on psychiatric disorders - AD comorbidity by regulating inflammatory and oxidative status in mice.

Anti-Inflammatory Effects of M-MSCs in DNCB-Induced Atopic Dermatitis Mice

Atopic dermatitis (AD) is an inflammatory skin disease caused by an imbalance between Th1 and Th2 cells. AD patients suffer from pruritus, excessive dryness, red or inflamed skin, and complications such as sleep disturbances and depression. Although there are currently many AD treatments available there are insufficient data on their long-term stability and comparative effects. Moreover, they have limitations due to various side effects. Multipotent mesenchymal stem cells (M-MSCs) might have potential for next-generation AD therapies. MSCs are capable of immune function regulation and local inflammatory response inhibition. M-MSCs, derived from human embryonic stem cells (hESC), additionally have a stable supply. In L507 antibody array, M-MSCs generally showed similar tendencies to bone marrow-derived mesenchymal stem cells (BM-MSCs), although the immunoregulatory function of M-MSCs seemed to be superior to BM-MSCs. Based on the characteristics of M-MSCs on immunoregulatory functions, we tested a M-MSC conditioned media concentrate (MCMC) in mice with AD lesions on their dorsal skin. MCMC significantly decreased RNA expression levels of inflammatory cytokines in the mouse dorsal skin. It also suppressed serum IgE levels. In addition, significant histopathologic alleviation was identified. In conclusion, secretions of M-MSCs have the potential to effectively improve AD-related inflammatory lesions. M-MSCs showed potential for use in next-generation AD treatment.

Poly-γ-Glutamate microneedles as transdermal immunomodulators for ameliorating atopic dermatitis-like skin lesions in Nc/Nga mice

Atopic dermatitis (AD), a common, relapsing, inflammatory disorder of the skin, is associated with T helper type 2 (Th2)-biased immune responses. Despite the efficacy of existing drugs for AD treatment, their safety and side effects cause concern. The present study describes the use of dissolvable poly-γ-glutamate (γ-PGA) microneedles (MNs) with immunomodulatory effects for effectively relieving AD-like symptoms in Nc/Nga mice. γ-PGA MNs can easily penetrate the epidermis and release γ-PGA into the dendritic cell-rich dermis to interact with dendritic cells for modulating immune responses. Transdermal administration of high-molecular-weight (HMW, 1100 kDa) γ-PGA MNs significantly reduced clinical dermatitis scores, epidermal thickness, and mast cell infiltration in mice by downregulating immunoglobulin (Ig)E and IgG1 levels (Th2-associated antibodies) compared with the AD control group. However, low-molecular-weight (200-400 kDa) γ-PGA MNs ameliorated AD-like skin lesions less effectively than HMW γ-PGA MNs, thus indicating that the MW of γ-PGA may affect its immunomodulatory properties. Notably, the mouse skin quickly recovered its barrier function within 4 h after MN application. No weight loss or abnormality was observed in the MN-treated mice during the 8-week treatment period. These results suggest that the γ-PGA MNs represent an innovative, safe, and reliable therapeutic strategy for AD management. STATEMENT OF SIGNIFICANCE: This study is the first to explore the feasibility of using poly-γ-glutamate (γ-PGA) microneedles (MNs) as transdermal immunomodulators for improving atopic dermatitis (AD) symptoms and to evaluate their immunomodulatory effect in mice with spontaneously developed AD. Transdermal administration of γ-PGA MNs enables the γ-PGA to localize in the skin for activation of dermal dendritic cells, thus modulating immune responses. We demonstrate that high-molecular-weight γ-PGA MNs can be retained in the skin for at least 6 days and effectively suppress AD-like skin lesions in mice by reducing infiltration of mast cells and downregulating Th2-associated antibody production (IgE and IgG1). The developed MN device has the potential to replace conventional therapy and to become an innovative treatment strategy for AD.

Huang-Lian-Jie-Du extract ameliorates atopic dermatitis-like skin lesions induced by 2,4-dinitrobenzene in mice via suppression of MAPKs and NF-κB pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Huang-Lian-Jie-Du Decoction (HLJDD), is a well-known traditional Chinese herbal formula first written in the Tang dynasty. In Chinese medicine practice, HLJDD is commonly prescribed to treat various inflammatory skin diseases, such as atopic dermatitis (AD) and psoriasis.

AIM OF THE STUDY

The present study aimed at investigating the therapeutic effect of HLJDD extract (HLJDE) and to elucidate the underlying molecular mechanisms of action in the 1-chloro-2,4-dinitrobenzene (DNCB)-induced AD-like mice.

MATERIALS AND METHODS

Female Balb/c mice were sensitized with DNCB for three days. After sensitization, mice were challenged with DNCB every three days and orally administrated with HLJDE (150, 300 and 600 mg/kg) daily from day 14 to day 29 for consecutive 16 days. At the end of experiment, the clinical AD scores of the mice were calculated to evaluate the therapeutic effect of HLJDE, and serum, ears and dorsal skin of the mice were collected for unravelling molecular mechanisms.

RESULTS

HLJDE significantly reduced the clinical symptoms in the AD-like mice by inhibiting eosinophil and mast cell infiltration, suppressing the production of Th2-associated cytokine (IL-4) and pro-inflammatory cytokines (TNF-α). In addition, HLJDE significantly suppressed the NF-κB and MAPKs pathways. Moreover, HLJDE was able to accentuate filaggrin expression in the skin lesion when compared to the sensitized mouse without treatment.

CONCLUSION

HLJDE significantly improved the AD-like symptoms on the DNCB-sensitized mice through mitigating the production of inflammatory mediators via suppressing MAPKs and NF-κB pathways. Additionally, the elevated expression of filaggrin in the skin lesion by HLJDE contributes to the recovery of dysfunctional skin barrier on the DNCB-sensitized mice.

Berberine Inhibits Pro-inflammatory Cytokine-induced IL-6 and CCL11 Production via Modulation of STAT6 Pathway in Human Bronchial Epithelial Cells

Berberine is an isoquinoline alkaloid isolated from various Chinese herbs that has potential of anti-inflammatory, anti-lipidemic, anti-neoplastic, and anti-diabetic activity. In this study, we evaluated the anti-inflammatory efficacy of berberine on allergic airway inflammation by targeting epithelial cells. Allergic airway inflammation driven by T helper 2 (Th2)-type immunity is characterized by airway hyperresponsiveness, elevated IgE production, and eosinophilic infiltration. For eosinophil recruitment, major chemoattractant CCL11 (eotaxin-1) was secreted by lung epithelial cells. BEAS-2B cells, a human bronchial epithelial cell line, were pre-treated with berberine and then activated by IL-4 plus TNF-α. The viability of BEAS-2B cells was assessed. Expression levels of IL-6 and CCL11 were determined using ELISA and real-time PCR. The signaling pathways of MAP kinases, NF-κB, and STAT6 were analyzed by western blot. Berberine treatment (≤1 μM) didn't significantly affect the viability of BEAS-2B cells with or without IL-4 plus TNF-stimulation. Berberine significantly inhibited the secretion of IL-6 and CCL11 from pro-inflammatory cytokine-activated BEAS-2B cells. NF-κB and MAP kinase pathways were seemingly unaffected in BEAS-2B cells with berberine treatment. Significant reduction of nuclear STAT6 protein expression in activated BEAS-2B cells with berberine treatment was observed. Current study reveals that berberine has inhibitory effect in pro-inflammatory cytokine-activated BEAS-2B cells through reducing IL-6 and CCL11 production, which is possibly modulated by suppressing STAT6 signaling pathway.

The Roles of Sex Hormones in the Course of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by T helper 2 cell (Th2)-shifted abnormal immunity, skin barrier impairment, and pruritus. The prevalence of AD in childhood is slightly higher in boys than in girls; after puberty, the sexual difference is reversed. The female preponderance in all generations exists in intrinsic AD with enhanced Th1 activity and nickel allergy, lacking increased serum IgE or filaggrin mutation. AD is often deteriorated before menstruation. We review the effects of sex hormones on immune responses and skin permeability barrier and propose possible hypotheses for the above phenomena. After puberty, the immune responses of patients are remarkably influenced by sex hormones. Estrogen and progesterone enhance the activities of Th2/regulatory T cell (Treg) but suppress Th1/Th17. Androgens suppress Th1/Th2/Th17 and induce Treg. The skin permeability barrier is fortified by estrogen but is impaired by progesterone and androgens. Dehydroepiandrosterone suppresses Th2 but enhances Th1. The amount of steroid sulfatase converting dehydroepiandrosterone sulfate to dehydroepiandrosterone is higher in women than in men, and thus, women might be more susceptible to the influence of dehydroepiandrosterone. The balance of modulatory effects of sex hormones on immune responses and skin barrier might regulate the course of AD.

Effects and mechanism of action of Huang-Lian-Jie-Du-Tang in atopic dermatitis-like skin dysfunction in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD), a disorder prevalent during childhood and adulthood, seriously affects the patient's quality of life. Although Huang-Lian-Jie-Du-Tang (HLJDT) has shown anti-inflammatory effects in previous studies, its effects and mechanism of action underlying AD disorder are still largely unknown.

OBJECTIVE

This study explored the anti-inflammatory and immunomodulatory effects of HLJDT on the AD-like dermal disorder, induced in vitro by lipopolysaccharide (LPS)-triggered inflammation, and in vivo by 2,4-dinitrochlorobenzene (DNCB).

MATERIALS AND METHODS

In vivo HLJDT effects were investigated by determining the severity of dermatitis, which consisted of observing signs of skin lesions, visually and through haematoxylin and eosin (HE) staining, in mouse ears and dorsal skin, measuring serum levels of interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, interferon (IFN)-γ, the tumour necrosis factor (TNF)-α, and determining the splenic index, number of splenic CD4⁺/CD8⁺ T-lymphocytes, as well as the phosphorylation levels of mitogen-activated protein kinases (including MAPKs-p38, ERK, and JNK), IκB-α, and nuclear factor kappa B (NF-κB) (p65) within dermal lesions. Morphological changes in LPS-induced inflammation were observed under a microscope, and ELISA and qPCR assays were used to measure IL-1α, IL-1β, IL-6, and TNF-α expression levels. The protein expression levels of P-ERK/ERK, P-p38/p38, P-JNK/JNK, P-IKβ-α, and P-p65 were measured through western blotting. Additionally, p65 expression was assessed by immunofluorescence, and LPS binding to RAW264.7 cell membrane was studied with laser confocal microscopy.

RESULTS

HLJDT could remarkably mitigate DNCB-induced AD-like lesion symptoms, alleviating inflammatory mediator infiltration in mouse ears and dorsal skin tissue, down-regulating serum expression levels of IL-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IFN-γ, and TNF-α, normalising the splenic CD4⁺/CD8⁺ T-lymphocyte ratio, and inactivating MAPKs (including p38, ERK, and JNK), IκB-α, and NF-κB (p65) in dorsal skin. Furthermore, HLJDT inhibited LPS-induced differentiation of RAW264.7 cells, as evidenced by the decreased protein and mRNA expression of IL-1α, IL-1β, IL-6, and TNF-α. Additionally, it decreased ERK, p38, JNK, IKβ-α, and p65 phosphorylation levels in the MAPKs/NF-κB pathway, inhibited p65 nuclear translocation, and reduced LPS binding to the RAW264.7 cell membrane.

CONCLUSIONS

HLJDT significantly improved AD-like symptoms via inhibition of the MAPKs/NF-κB pathway. Therefore, administration of HLJDT might be a potential treatment for AD in the clinical setting.

Integrating tacrolimus into eutectic oil-based microemulsion for atopic dermatitis: simultaneously enhancing percutaneous delivery and treatment efficacy with relieving side effects

Background: Topical application of tacrolimus (FK506) was effective in treating atopic dermatitis (AD); however, the therapeutic efficiency is hampered by its poor penetration into the skin and local side effects of transient irritation symptoms with a burning sensation, a feeling of warmth or heat. Menthol and camphor have been widely used in topical compound formulations for adjunctive pharmacotherapy for antipruritics and analgesics owing to their cool nature, and both present skin penetration enhancing effects. Moreover, they can form a liquid eutectic oil to solubilize hydrophobic drugs.

Purpose: Taking advantages of menthol/camphor eutectic (MCE), this work aims to integrate FK506 into MCE to construct a microemulsion system, i.e., FK506 MCE ME, which simultaneously enhances the percutaneous delivery and treatment efficacy, while reduces the side effects of FK506.

Methods: The formulation of FK506 MCE ME was optimized and characterized. Different formulations containing FK506 were topically administered to treat 1–chloro–2, 4–dinitrobenzene (DNCB)-induced murine AD.

Results: MCE solubilized FK506. FK506 in MCE ME penetrated skin in vitro more than in the commercial ointment, and MCE predominantly exerted the enhancing effects in MCE ME. FK506 MCE ME or FK506 MCE ME gel had greater effects on clinical symptoms, histological analysis, and IgE than did commercial FK506. The anti-pruritic and down-regulation of substance P effects of MCE ME vehicle mitigated the side effects of FK506 application.

Conclusion: MCE ME presented the excellent properties of simultaneously enhancing the percutaneous delivery and treatment efficacy, while reducing the side effects of FK506 for AD. Therefore, MCE ME is a promising nanoscale system for FK506 to effectively treating AD with low irritation and high medication adherence.

Chemical compounds studied in this article: Tacrolimus (PubChem CID: 445643); menthol (PubChem CID: 1254); camphor (PubChem CID: 2537)

Topical Spilanthol Inhibits MAPK Signaling and Ameliorates Allergic Inflammation in DNCB-Induced Atopic Dermatitis in Mice

Atopic dermatitis (AD) is a recurrent allergic skin disease caused by genetic and environmental factors. Patients with AD may experience immune imbalance, increased levels of mast cells, immunoglobulin (Ig) E and pro-inflammatory factors (Cyclooxygenase, COX-2 and inducible NO synthase, iNOS). While spilanthol (SP) has anti-inflammatory and analgesic activities, its effect on AD remains to be explored. To develop a new means of SP, inflammation-related symptoms of AD were alleviated, and 2,4-dinitrochlorobenzene (DNCB) was used to induce AD-like skin lesions in BALB/c mice. Histopathological analysis was used to examine mast cells and eosinophils infiltration in AD-like skin lesions. The levels of IgE, IgG1 and IgG2a were measured by enzyme-linked immunosorbent assay (ELISA) kits. Western blot was used for analysis of the mitogen-activated protein kinase (MAPK) pathways and COX-2 and iNOS protein expression. Topical SP treatment reduced serum IgE and IgG2a levels and suppressed COX-2 and iNOS expression via blocked mitogen-activated protein kinase (MAPK) pathways in DNCB-induced AD-like lesions. Histopathological examination revealed that SP reduced epidermal thickness and collagen accumulation and inhibited mast cells and eosinophils infiltration into the AD-like lesions skin. These results indicate that SP may protect against AD skin lesions through inhibited MAPK signaling pathways and may diminish the infiltration of inflammatory cells to block allergic inflammation.

Therapeutic effects of bee venom and its major component, melittin, on atopic dermatitis in vivo and in vitro

BACKGROUND AND PURPOSE

Atopic dermatitis (AD) is a multifactorial skin condition with complex interactions of innate and adaptive immune responses. There are several existing therapies for AD, including topical glucocorticosteroids, emollients, phototherapies, calcineurin inhibitors and immunosuppressants, such as cyclosporine A. Although these therapies reduce inflammation, they also cause serious side effects. Therefore, it is necessary to develop new therapeutic approaches for AD treatment without side effects. There are several studies on natural materials or toxins, such as herbs, ginseng extract and snake venom, for AD treatment. However, treatment of AD with bee venom and its major component, melittin has rarely been studied.

EXPERIMENTAL APPROACH

Effects of bee venom and melittin were studied in a model of AD in vivo induced by 1-chloro-2,4-dinitrobenzene (DNCB) in female Balb/c mice and in cultures of human keratinocytes, stimulated by TNF-α/IFN-γ. The potential pharmacological effects of bee venom and melittin on these in vivo and in vitro AD-like skin disease models were studied.

KEY RESULTS

Bee venom and melittin exhibited potent anti-atopic activities, shown by decreased AD-like skin lesions, induced by DNCB in mice. In vitro studies using TNF-α/IFN-γ-stimulated human keratinocytes showed that bee venom and melittin inhibited the increased expression of chemokines, such as CCL17 and CCL22, and pro-inflammatory cytokines, including IL-1β, IL-6 and IFN-γ, through the blockade of the NF-κB and STAT signalling pathways.

CONCLUSIONS AND IMPLICATIONS

Our results suggest that bee venom and melittin would be suitable for epicutaneous application, as topical administration is often appropriate for the treatment of AD.

Anti-inflammatory and immune response regulation of Si-Ni-San in 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin dysfunction

ETHNOPHARMACOLOGICAL RELEVANCE

Si-Ni-San (SNS) is a well-known decoction in traditional Chinese medicine. Although studies have indicated that the anti-inflammatory and anti-allergic properties of SNS and its components can account for their therapeutic effects, the role and mechanism of SNS in treating skin dysfunction remain unclear.

AIM OF THE STUDY

Atopic dermatitis (AD), a disorder known for its prevalence in infants and adults, severely influences the quality of life of affected patients. In this study, we aimed to investigate the anti-inflammatory and immune response modulations of SNS in 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin dysfunction.

MATERIALS AND METHODS

Dermatitis was induced in Kunming mice by the topical application of DNCB. SNS or dexamethasone (positive control) was topically applied every day over the course of the 21-day study. The following were assessed: dermatitis severity scores; ear and dorsal skin haematoxylin and eosin staining; interleukin (IL)- 1α, IL-1β, IL-2, IL-4, IL-6, and tumour necrosis factor (TNF)-α cytokine levels in the serum; spleen index; spleen CD4 + /CD8 + T lymphocyte ratio; and phosphorylation levels of mitogen-activated protein kinases (MAPKs- p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK)), IκB-α, and nuclear factor (NF)-κB (p65) in skin lesions.

RESULTS

SNS significantly alleviated the symptoms of AD-like lesions induced by DNCB, decreased the infiltration of inflammatory cells in the ear and dorsal tissues, suppressed the increased cytokine levels in the serum, reduced the CD4 + /CD8 +T lymphocyte ratio in the spleen, and downregulated the activation of MAPKs, IκB-α, and NF-κB (p65) in the dorsal skin. The effects were similar to those of dexamethasone.

CONCLUSIONS

SNS alleviated the DNCB-induced AD-like skin dysfunction in mice through anti-inflammatory and immune system modulation, indicating that SNS shows potential for AD treatment in clinical settings.

Nucleophosmin modulates the alleviation of atopic dermatitis caused by the marine-derived compound dihydroaustrasulfone alcohol

Atopic dermatitis (AD) is a chronic inflammatory skin disease, and its prevalence is increasing. AD usually elicits skin barrier dysfunction, dry skin and itching. As the mechanisms of AD remain unknown, there is an urgent need to find effective therapies. Because of the diversity and complexity of marine environments, the discovery of drugs from marine organisms as novel therapeutic agents for human diseases has seen renewed interest. Dihydroaustrasulfone alcohol (WA-25), the synthetic precursor of austrasulfone, which is a natural product isolated from a Formosan soft coral, has been shown to possess many therapeutic effects in our previous studies. However, the detailed mechanisms and therapeutic effects of WA-25 on AD are incompletely understood. We performed in vitro and in vivo studies to examine the effects of WA-25 on AD. We showed that WA-25 blocks inflammation and oxidative stress. Simultaneously, we also found that WA-25 reduces the AD scores and AD-induced transepidermal water loss (TEWL), scratching behavior, and alloknesis. WA-25 is more effective in cases of AD than are the drugs that are currently used clinically. Importantly, we also found that when nucleophosmin (NPM) was inhibited or when its expression was reduced, the anti-inflammatory and anti-AD effects of WA-25 were blocked. These data suggest that NPM plays dual roles in inflammation and AD. Overall, these results suggest that WA-25 is a potential anti-inflammatory and AD therapeutic agent that is modulated by NPM.

Tacrolimus nanoparticles based on chitosan combined with nicotinamide: enhancing percutaneous delivery and treatment efficacy for atopic dermatitis and reducing dose

Background

Topical application of tacrolimus (FK506) was effective in the treatment of atopic dermatitis (AD); however, adverse effects frequently occurred with the increase of FK506 dose during long–term treatment.

Objective

The objective of this project was to develop a hybrid skin targeting system encapsulating FK506 based on nicotinamide (NIC) and chitosan nanoparticles (CS–NPs), ie, FK506–NIC–CS–NPs, which took advantages of both of NIC and CS–NPs to obtain the synergetic effects of percutaneous delivery and treatment efficacy enhancement along with dose reduction.

Methods

The formulation of FK506–NIC–CS–NPs was optimized and characterized. In vitro and in vivo skin permeation studies were performed. AD–like skin lesions were constructed with BALB/c mice by 1–chloro–2, 4–dinitrobenzene (DNCB)–induced, and FK506–NIC–CS–NPs containing different dose of FK506 were topically administered to treat AD–like skin lesions in comparison with Protopic.

Results

NIC was found to significantly increase the FK506 EE to 92.2% by CS–NPs. In comparison with commercial FK506 ointment (Protopic), in vitro and in vivo skin permeation studies demonstrated that NIC–CS–NPs system significantly enhanced FK506 permeation through and into the skin, and deposited more FK506 into the skin. The treatment efficacy on clinical symptoms, histological analysis, and molecular biology of the AD–mice demonstrated that NIC–CS–NPs with ~1/3 dose of FK506 of Protopic was superior to that of Protopic, and NIC–CS–NPs vehicle exhibited the adjuvant therapy and moderate anti–AD effects.

Conclusion

The system of NIC–CS–NPs enhances the permeability of FK506, plays an adjuvant role in anti-AD, reduces the dose of FK506 in treating AD, and is therefore a promising nanoscale system of FK506 for the effective treatment of AD.

Gamma-irradiated black ginseng extract inhibits mast cell degranulation and suppresses atopic dermatitis-like skin lesions in mice

Gamma irradiation is able to affect various structural modification and an increase of the biological properties of biomaterials. This study was conducted to investigate the anti-allergenic effect of γ-irradiated black ginseng extract (BGE) using in vitro and in vivo experiments. IgEantigen complex-induced degranulation was measured in RBL-2H3 mast cells. In addition, an anti-atopic dermatitis (AD) test was carried out by spreading γ-irradiated BGE on the dorsal skin of 2,4-dinitrochlorobenzene (DNCB)-induced BALB/c mice. The content of arginylfructose (AF) of gamma-irradiated BGE was higher than that of BGE. In RBL-2H3 mast cells, γ-irradiated BGE treatments significantly reduced the IgE-antigen complex-induced release of β-hexosaminidase, histamine, intracellular ROS, and Ca2+ influx. A western blot analysis showed that γ-irradiated BGE had an inhibitory activity on the FcεRI-mediated signaling in mast cells. In the DNCB-induced AD model, γ-irradiated BGE significantly alleviated the ADlike skin symptoms and clinical signs. The suppression of AD by γ-irradiated BGE was accompanied by a decrease in the serum level of IgE and IL-4, as well as the number of leukocyte. Gamma-irradiated BGE also suppressed IL-4 and increased IFN-γ in splenocytes. Our data suggests that γ-irradiated BGE may be effective therapeutic agents for the treatment of AD.

Dehydroepiandrosterone (DHEA) restrains intestinal inflammation by rendering leukocytes hyporesponsive and balancing colitogenic inflammatory responses

Dehydroepiandrosterone (DHEA) is a hormone that plays an important role in the modulation of inflammatory responses. However, the precise mechanisms that link the actions of this androgen with protection or susceptibility to inflammatory bowel diseases (IBD) remain uknown. Here we showed that low dose DHEA inhibited proliferation of spleen cells and IFN-у production. The hormone was not toxic to myeloid lineage cells, although it caused necrosis of spleen cells at the intermediate and highest doses in vitro (50 and 100μM). The treatment of C57BL/6 mice with DHEA during colitis induction by dextran sodium sulfate (DSS) led to a reduction in weight loss and clinical signs of disease. There were decreased peripheral blood monocytes on day 6 of DSS exposure and treatment, besides increase in circulating neutrophils in the tissue repair phase. DHEA also led to reduced lamina propria cellularity and restoration of normal colon length. These results were accompanied by decreased expression of IL-6 and TGF-β mRNA, while IL-13 was augmented in the colon on day 6, which was probably related to attenuation of inflammation. There was retention of CD4(+) cells in the spleen after use of DHEA, along with augmented frequency of CD4(+)IL-4(+) cells, decreased CD4(+)IFN-ɣ(+) in spleen and constrained CD4(+)IL-17(+) population in the mesenteric lymph nodes. Moreover, splenocytes of mice treated with DHEA became hyporesponsive, as observed by reduced proliferation after re-stimulation ex-vivo. In conclusion, DHEA modifyies leukocyte activity and balances the exacerbated immune responses which drive local and systemic damages in IBD.

Dehydroepiandrosterone (DHEA): hypes and hopes

Dehydroepiandrosterone (DHEA) and its sulfated form dehydroepiandrosterone sulfate (DHEAS) are the most abundant circulating steroid hormones in humans. In animal studies, their low levels have been associated with age-related involuntary changes, including reduced lifespan. Extrapolation of animal data to humans turned DHEA into a 'superhormone' and an 'anti-aging' panacea. It has been aggressively marketed and sold in large quantities as a dietary supplement. Recent double-blind, placebo-controlled human studies provided evidence to support some of these claims. In the elderly, DHEA exerts an immunomodulatory action, increasing the number of monocytes, T cells expressing T-cell receptor gamma/delta (TCRγδ) and natural killer (NK) cells. It improves physical and psychological well-being, muscle strength and bone density, and reduces body fat and age-related skin atrophy stimulating procollagen/sebum production. In adrenal insufficiency, DHEA restores DHEA/DHEAS and androstenedione levels, reduces total cholesterol, improves well-being, sexual satisfaction and insulin sensitivity, and prevents loss of bone mineral density. Normal levels of CD4+CD25(hi) and FoxP3 (forkhead box P3) are restored. In systemic lupus erythematosus, DHEA is steroid-sparing. In an unblinded study, it induced remission in the majority of patients with inflammatory bowel disease. DHEA modulates cardiovascular signalling pathways and exerts an anti-inflammatory, vasorelaxant and anti-remodelling effect. Its low levels correlate with increased cardiovascular disease and all-cause mortality. DHEA/DHEAS appear protective in asthma and allergy. It attenuates T helper 2 allergic inflammation, and reduces eosinophilia and airway hyperreactivity. Low levels of DHEAS accompany adrenal suppression. It could be used to screen for the side effects of steroids. In women, DHEA improves sexual satisfaction, fertility and age-related vaginal atrophy. Many factors are responsible for the inconsistent/negative results of some studies. Overreliance on animal models (DHEA is essentially a human molecule), different dosing protocols with non-pharmacological doses often unachievable in humans, rapid metabolism of DHEA, co-morbidities and organ-specific differences render data interpretation difficult. Nevertheless, a growing body of evidence supports the notion that DHEA is not just an overrated dietary supplement but a useful drug for some, but not all, human diseases. Large-scale randomised controlled trials are needed to fine-tune the indications and optimal dosing protocols before DHEA enters routine clinical practice.

Danggui buxue tang inhibits 2,4-dinitrochlorobenzene: induced atopic dermatitis in mice

Danggui Buxue Tang (DBT) is a herbal decoction that has been used in Chinese medicine to enhance qi and blood circulation. Previously, we found that DBT can suppress allergy-related asthma in mice, leading us to hypothesize that DBT might ameliorate allergy disease. In this study, we evaluated whether DBT can attenuate atopic dermatitis (AD) symptoms and have an anti-inflammatory effect on AD-like mice. The dorsal skin of female mice was shaved and sensitized cutaneously (skin smear) with 1-chloro-2,4-dinitrobenzene. Mice were then given various doses of DBT from days 14 to 29 cutaneously. DBT treatment suppressed ear swelling and skin inflammation and decreased mast cell and eosinophil infiltration into skin and ear tissue. DBT also inhibited levels of IgE and Th2-associated cytokine levels in serum. These results demonstrate that cutaneous administration of DBT reduced the development of AD-like skin lesions in mice.