Anti-atopic effect of Viola yedoensis ethanol extract against 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin dysfunction

Recent Advances in Phytochemical-Based Topical Applications for the Management of Eczema: A Review

Eczema (atopic dermatitis, AD) is a skin disease characterized by skin barrier dysfunction due to various factors, including genetics, immune system abnormalities, and environmental triggers. Application of emollients and topical drugs such as corticosteroids and calcineurin inhibitors form the mainstay of treatments for this challenging condition. This review aims to summarize the recent advances made in phytochemical-based topical applications to treat AD and the different carriers that are being used. In this review, the clinical efficacy of several plant extracts and bioactive phytochemical compounds in treating AD are discussed. The anti-atopic effects of the herbs are evident through improvements in the Scoring Atopic Dermatitis (SCORAD) index, reduced epidermal thickness, decreased transepidermal water loss, and alleviated itching and dryness in individuals affected by AD as well as in AD mouse models. Histopathological studies and serum analyses conducted in AD mouse models demonstrated a reduction in key inflammatory factors, including thymic stromal lymphopoietin (TSLP), serum immunoglobulin E (IgE), and interleukins (IL). Additionally, there was an observed upregulation of the filaggrin (FLG) gene, which regulates the proteins constituting the stratum corneum, the outermost layer of the epidermis. Carriers play a crucial role in topical drug applications, influencing dose delivery, retention, and bioavailability. This discussion delves into the efficacy of various nanocarriers, including liposomes, ethosomes, nanoemulsions, micelles, nanocrystals, solid-lipid nanoparticles, and polymeric nanoparticles. Consequently, the potential long-term side effects such as atrophy, eruptions, lymphoma, pain, and allergic reactions that are associated with current topical treatments, including emollients, topical corticosteroids, topical calcineurin inhibitors, and crisaborole, can potentially be mitigated through the use of phytochemical-based natural topical treatments.

Jiawei guomin decoction regulates the degranulation of mast cells in atopic dermatitis mice via the HIS/PAR-2 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Guomin decoction (GMD) is a traditional Chinese medicine commonly used in clinical practice. It has traditionally been used to treat all allergic diseases. Currently, Jiawei Guomin Decoction (JWGMD) is used to treat sensitive skin after initial therapy. Although it has a significant clinical therapeutic effect, the exact role of mast cell degranulation in treating atopic dermatitis (AD) is still unclear.

AIM OF THE STUDY

GMD and JWGMD can both treat allergic diseases, while JWGMD focuses on skin allergies. This study aims to explore the potential effect of JWGMD on the degranulation of mast cells in an AD mouse model induced by 2,4-dinitrofluorobenzene (DNFB) and investigate the effectiveness of JWGMD in alleviating disease progression to further provide specific therapeutic targets for treating AD.

MATERIALS AND METHODS

The scratching times and skin lesions of model mice induced by DNFB were observed, and skin tissues were collected for subsequent measurement. Histopathological changes in the back skin of mice were observed by haematoxylin eosin (H&E) staining, Toluidine blue staining was used to detect the degranulation of mouse skin mast cells, and the relationship between the expression of histamine (HIS), mast cell tryptase (MCT) and mast cell degranulation was analysed by enzyme-linked immunosorbent assay (ELISA). The expression of protease-activated receptor-2 (PAR-2), histamine 1 receptor (H1R), H2R, H4R and MCT proteins in AD mice was detected by Western blot (WB). Immunofluorescence assay (IFA) further confirmed the localization of PAR-2, H1R, H2R, H4R, and MCT proteins in the skin. Quantitative real-time PCR (qPCR) was used to determine PAR-2, H1R, H2R and H4R mRNA levels in skin lesions to further clarify the mechanism by which JWGMD amplifies mast cell degranulation in AD. In addition, a reliable ultrahigh-performance liquid chromatography-quadrupole electrostatic field orbitrap mass spectrometry (UPLC-QE-MS) nontargeted metabolomics analysis was performed to analyse the differences in metabolite abundance between GMD and JWGMD, and these results were used to identify the active components in JWGMD that may have antipruritic and anti-inflammatory properties and inhibit mast cell degranulation.

RESULTS

After intermittent stimulation with DNFB, the skin lesions showed extensive desquamation, dryness, scabbing, skin thickening, and slight bleeding. Both treatments alleviated this phenomenon and reduced the number of scratches, with JWGMD being the most effective. JWGMD can significantly reduce inflammatory cell infiltration, oedema, and some capillary neogenesis in mice and reduce the degranulation of mast cells. The ELISA results showed that JWGMD can increase the levels of MCT and HIS proteins. The WB and IFA results demonstrated that JWGMD reduced the expression levels of PAR-2, H1R, H4R, and MCT proteins in skin lesions, with protein localization mainly in the epidermal layer, while H2R protein levels were increased and mainly localized in the dermis. In addition, JWGMD downregulates the mRNA expression of PAR-2, H1R, H2R, and H4R. Interestingly, through UPLC-QE-MS nontargeted metabolomic analysis, we detected the anti-inflammatory and antiallergy active substances in JWGMD, such as methyl eugenol, dictamnine and sinapine.

CONCLUSIONS

JWGMD may alleviate itching through methyl syringol, dictamnine, sinapine and other substances, and its mechanism may be related to inhibiting the HIS/PAR-2 pathway in AD model mice and further regulating the self-amplification of mast cell degranulation. JWGMD is a potential drug for treating AD. Therefore, it deserves continuous attention and research.

Viola yedoensis Makino alleviates heat stress-induced inflammation, oxidative stress, and cell apoptosis in the spleen and thymus of broilers

ETHNOPHARMACOLOGICAL RELEVANCE

Viola yedoensis Makino (VYM) is a traditional Chinese herbal medicine widely distributed in China. It has many pharmacological effects such as anti-inflammatory, immune regulation and anti-oxidation. However, the protective effect of VYM on the spleen and thymus of broilers induced by heat stress has rarely been reported.

AIM OF THE STUDY

We established a heat stress model of broilers to explore the protective effect of VYM on spleen and thymus of broilers.

MATERIALS AND METHODS

In this experiment, a heat stress model was made by adjusting the feeding temperature of broilers. The protective effect of VYM on the spleen and thymus of heat-stressed broilers were evaluated by detecting immune organ coefficient, histological observation, Enzyme-Linked Immunosorbent Assay, production of antioxidant enzymes and peroxides, TUNEL Staining, Quantitative Real-time PCR.

RESULTS

In this study, 60 healthy male AA broilers were divided into 6 groups: Control, 4.5% VYM, HS, HS + 0.5% VYM, HS + 1.5% VYM, HS + 4.5% VYM. After 42 days of feeding, serum, spleen and thymus were collected for detection and analysis. The study revealed that heat stress can lead to pathological damage in the spleen and thymus of broilers, reduce the content of immunoglobulin and newcastle disease (ND), infectious bursal disease (IBD) antibody levels, increase the expression of inflammatory factors IL-1β, INF-γ, heat shock 70 kDa protein (HSP70), heat shock 90 kDa protein (HSP90). Heat stress inhibits the activity of antioxidant enzymes CAT and SOD, promotes the production of MDA, and then lead to oxidative damage of the spleen and thymus. In addition, apoptotic cells and the ratio of Bax/Bcl-2 was increased. However, the addition of VYM to the feed can alleviate the adverse effects of heat stress on the spleen and thymus of broilers.

CONCLUSIONS

This study showed that the addition of VYM to the diet could inhibit oxidative stress and apoptosis, and reduce the inflammatory damage of heat stress on the spleen and thymus of broilers. This study provides a basis for further exploring the regulatory role of VYM in heat stress-induced immune imbalance in broilers. In addition, this study also provides a theoretical basis for the development of VYM as a feed additive with immunomodulatory effects.

Polygonum perfoliatum L. ethanol extract ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum perfoliatum L. (PP) is classified as a heat-clearing and detoxifying agent in traditional Chinese medicine, and is believed to possess therapeutic properties for treating eczema, furuncles, and venomous snake bites. Previous studies have demonstrated that PP extract exhibits multiple bioactivities, including antibacterial, anti-inflammatory, antitumor, antioxidation, and antiviral properties. However, no existing studies have evaluated the effects of PP on animal models of atopic dermatitis (AD)-like skin symptoms, which are closely associated with traditional ethnic usage.

AIM OF THE STUDY

In present study, therefore, we aimed to explore the potential anti-atopic effect of Polygonum perfoliatum L. ethanol extract (PPE) in 2,4-Dinitrochlorobenzene (DNCB)-induced dermatitis-like skin lesions.

MATERIALS AND METHODS

For reaching this aim, DNCB-induced mice with AD-like skin inflammation were subjected to topical administration of PPE gels for a period of 21 days, and subsequently, the biological impacts of PPE were evaluated.

RESULTS

PPE gels effectively mitigated AD-like skin symptoms induced by DNCB in mice, as demonstrated by a marked reduction in epidermal thickness and dermatitis severity. Moreover, PPE significantly decreased the production of various cytokines, including TNF-α, IL-6, IL-1β, IL-4, IL-5, IL-13 and IgE, in addition to suppressed the production of key inflammation-related enzymes (iNOS and COX-2) and decreased the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB in AD-like skin samples. Furthermore, PPE treatment inhibited the abnormally elevated CD4+/CD8+ ratio in DNCB-induced AD mice. The results of the skin irritation test revealed that PPE exhibited no adverse toxicity in mice at dose of 10 mg/day.

CONCLUSIONS

PPE exhibits potential as a safe therapeutic agent for atopic dermatitis by efficiently mitigating DNCB-induced atopic symptoms and diminishing inflammation, and does not carry the risk of over-immunosuppression or treatment-associated adverse effects.

Cymbaria daurica L.: A Mongolian herbal medicine for treating eczema via natural killer cell-mediated cytotoxicity pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Cymbaria daurica L. (C. daurica) is a perennial herb known commonly as "Xinba" (Chinese) and "Kanba-Arong" (Mongolian). In Mongolia, it is used as a traditional medicine to treat eczema and other skin diseases due to its anti-swelling, anti-inflammatory, anti-hemorrhagic, and anti-itching properties. However, the potential mechanism of action for eczema treatment has not been reported.

AIM OF THE STUDY

To investigate the effect of C. daurica on 1-chloro-2,4-dinitrobenzene (DNCB)-induced eczema in rats and the associated action mechanism.

MATERIALS AND METHODS

Qualitative analysis of C. daurica was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on information obtained from compound identification and relevant literature, the possible targets of C. daurica against eczema were analyzed using network pharmacology and molecular docking methods. The DNCB-induced eczema rat models were treated with different dosages of C. daurica extract (10, 50, and 250 mg/mL per day), and the therapeutic effects subsequently evaluated based on the degree of skin inflammation, spleen index, and hematoxylin and eosin staining (H&E staining). Enzyme-linked immunosorbent assay (ELISA), reverse transcription quantitative polymerase chain reaction (RT-qPCR), and western blotting were used to analyze the relevant target effects. The C. daurica mechanism of action on eczema was verified by animal experiments. High-performance liquid chromatography (HPLC) was carried out to determine the content of active ingredients in C. daurica. In addition, the physicochemical properties of the extract were evaluated.

RESULTS

Our analysis of the 173 targets included in the protein-protein interaction (PPI) network identified tumor necrosis factor (TNF) and interleukin 2 (IL-2) as key targets involved in the treatment of eczema with C. daurica extract. Furthermore, the 173 targets were associated with the natural killer cell-mediated cytotoxicity pathway. Our results showed that C. daurica significantly reduced IL-2 and TNF-α serum levels in eczema rat models (P < 0.0001); thus, playing an important role in the anti-inflammatory response. Furthermore, according to the p-value, RT-qPCR and western blotting showed that the expression of Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1), Vav guanine nucleotide exchange factor (Vav), and growth factor receptor-bound protein 2 (Grb2) changed in the skin of the eczema model rats after treatment with the C. daurica extract.

CONCLUSION

Our study confirms that C. daurica can inhibit SHP-1, Vav, and Grb2 expression; thereby, inhibiting the natural killer cell-mediated cytotoxicity pathway. These results provide insight into the mechanism of C. daurica in treating eczema.

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.

Integrated transcriptomic and metabolomic analyses of DNCB-induced atopic dermatitis in mice

AIMS

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder that affects up to 20 % of children and 10 % of adults worldwide; however, the exact molecular mechanisms remain largely unknown.

MATERIALS AND METHODS

In this study, we used integrated transcriptomic and metabolomic analyses to study the potential mechanisms of 1-chloro-2,4-dinitrobenzene (DNCB)-induced AD-like skin lesions.

KEY FINDINGS

We found that DNCB induced AD-like skin lesions, including phenotypical and histomorphological alterations and transcriptional and metabolic alterations in mice. A total of 3413 differentially expressed metabolites were detected between DNCB-induced AD-like mice and healthy controls, which includes metabolites in taurine and hypotaurine metabolism, phenylalanine metabolism, biosynthesis of unsaturated fatty acids, tryptophan metabolism, arachidonic acid metabolism, pantothenate and CoA biosynthesis, pyrimidine metabolism, and glycerophospholipid metabolism pathways. Furthermore, the differentially expressed genes associated (DEGs) with these metabolic pathways were analyzed using RNA sequencing (RNA-seq), and we found that the expression of pyrimidine metabolism-associated genes was significantly increased. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the glycolysis/gluconeogenesis, glucagon signaling pathway and pentose phosphate pathway-associated metabolic genes were dramatically altered.

SIGNIFICANCE

Our results explain the possible mechanism of AD at the gene and metabolite levels and provide potential targets for the development of clinical drugs for AD.

A comprehensive review of phytochemistry, pharmacology and quality control of plants from the genus Viola

OBJECTIVES

The genus Viola belongs to the family Violaceae, and the plants from this genus are essential folk herb medicine extensively used in many areas. The plants from the genus Viola are used to treat various diseases and exert a significant role in protecting people's health. This review summarized the genus Viola plants' phytochemistry, pharmacology, and quality control methods.

KEY FINDINGS

The information on chemical constituents and pharmacological effects of the genus Viola was obtained by searching the Web of Science, Pubmed, CNKI, and other databases. A total of 208 valuable articles were selected and analyzed in this review. The main chemical components of plants from the genus Viola consist of flavonoids, coumarins, alkaloids, lignans, sesquiterpenes, cyclotides, etc. The active chemical components of medicinal plants from this genus exert antibacterial, antiviral, antioxidant, anti-inflammatory, anti-tumor, neuroprotective, hepatoprotective activities, and so on. The quality control of these plants is not sufficient and needs further research.

SUMMARY

The chemical constituents, pharmacological effects, and quality control of plants from the genus Viola were systematically summarized in this paper, and this review provides a literature basis for the further research of plants from this genus.

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.

Artemisia annua water extract attenuates DNCB-induced atopic dermatitis by restraining Th2 cell mediated inflammatory responses in BALB/c mice

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia annua L. (A. annua) is a traditional Chinese medicine that has been used since ancient times to treat malaria, eczema, dermatomycosis, jaundice, and boils. Modern pharmacological studies show that it has immunosuppressive and anti-inflammatory effects. However, the mechanism of A. annua in the treatment of atopic dermatitis (AD) remains unclear.

AIM OF THE STUDY

This study was aimed to investigate the effect of A. annua water extract (AWE) on 2,4-dinitrochlorobenzene (DNCB)-induced AD mouse model and tried to explore its possible underlying mechanisms.

MATERIALS AND METHODS

AD was induced in BALB/c mice by the topical repeated application of DNCB. Oral drug intervention of AWE and dexamethasone (DEX, positive control) began from the 7th day and continued for 13 consecutive days. The clinical skin score, ear thickness and the weight of ear and spleen were assessed. The ear tissue were stained with toluidine blue and hematoxylin and eosin (H&E) to detect inflammatory cell infiltration. IgE, terleukin (IL)-4 and IL-13 levels in the serum and IgE level in splenocytes were quantified by enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of IL-4, IL-6, IL-13, IL-17, tumor necrosis factor (TNF)-α and thymic stromal lymphopoietin (TSLP) were measured by quantitative real time polymerase chain reaction. The phosphorylation levels of mitogen-activated protein kinases (MAPKs)-p38 and nuclear factor (NF)-κB in ear tissue were detected by Western blot.

RESULTS

Results demonstrated that AWE treatment significantly attenuated the AD-like symptoms in DNCB-induced BALB/c mice, including the skin dermatitis severity and ear edema. Further study disclosed that AWE treatment suppressed the expressions of IgE, IL-4, IL-6, IL-13, IL-17, TNF-α and TSLP at mRNA and protein levels. Moreover, AWE showed inhibitory effect on the phosphorylation of p38 MAPK and NFκB in ear tissues of AD mice.

CONCLUSIONS

Collectively, our results suggested that AWE suppressed DNCB-induced AD in mice probably by restraining Th2 type inflammatory response. These findings might pave the road for the potential clinical application of AWE for AD treatment.

Topical delivery of pluronic F127/TPGS mixed micelles-based hydrogel loaded with glycyrrhizic acid for atopic dermatitis treatment

OBJECTIVE

The purpose of this study was to develop pluronic F127/D-a-tocopheryl polyethylene glycol 1000 succinate mixed micelles-based hydrogel (MMs-gel) for topical delivery of GL to improve its skin permeability and atopic dermatitis (AD) treatment.

SIGNIFICANCE

GL loaded MMs-gel (GL-MMs-gel) could be potentially used as a promising nanocarrier for the treatment of AD.

METHODS

GL-MMs were prepared by thin film hydration method and then loaded into carbopol gel. The formulation of GL-MMs-gel was optimized by full factorial design and systematically characterized for drug content, pH, spreadability, in vitro drug release and percutaneous permeation, etc. The therapeutic effect of GL-MMs-gel was also investigated in AD-like skin lesion model in BALB/c mice and compared with GL solution-based gel (GL-sol-gel).

RESULTS

Spherical GL-MMs with particle size of ∼30 nm were successfully incorporated into carbopol gel to form GL-MMs-gel with drug content of (98.80 ± 1.30) %, pH of 6.0 ± 0.08, and spreadability of (7.1 ± 0.2) cm. In vitro drug release profile of GL-MMs-gel exhibited a sustained-release behavior. The permeation flux for GL-MMs-gel (5.15 ± 0.33 µg/cm²/h) was significantly higher than that of GL-sol-gel (3.08 ± 0.34 µg/cm²/h) and GL-MMs-gel increased the accumulative amounts of GL in rats' skin 8.41 times than GL-sol-gel. The GL-MMs-gel was more effective than GL-sol-gel in suppressions of various AD symptoms including skin lesions, edema, high IgE levels, epidermal hyperplasia, and mast cell infiltration.

CONCLUSION

All results revealed that MMs-gel could be a promising carrier for topical delivery of GL for the treatment of AD.

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).