-
Journal of Ethnopharmacology Mar 2024Guomin decoction (GMD) is a traditional Chinese medicine commonly used in clinical practice. It has traditionally been used to treat all allergic diseases. Currently,...
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.
Topics: Mice; Animals; Histamine; Dermatitis, Atopic; Receptor, PAR-2; Mast Cells; Dinitrofluorobenzene; Monocarboxylic Acid Transporters; Receptors, Histamine; Anti-Inflammatory Agents; RNA, Messenger
PubMed: 38008276
DOI: 10.1016/j.jep.2023.117485 -
European Journal of Pharmacology Dec 2023Programmed cell death receptor/ligand 1 (PD-1/PD-L1) blockade therapy for various cancers induces itch. However, few studies have evaluated the mechanism underlying...
Programmed cell death receptor/ligand 1 (PD-1/PD-L1) blockade therapy for various cancers induces itch. However, few studies have evaluated the mechanism underlying PD-1/PD-L1 inhibitor-induced itch. This study aimed to establish and evaluate a mouse model of acute itch induced by PD-1/PD-L1 inhibitors and to explore the role of the PD-1/PD-L1 pathway in chronic itch. The intradermal injection of the PD-1/PD-L1 small molecule inhibitors, or anti-PD-1/PD-L1 antibodies in the nape of the neck in the mice elicited intense spontaneous scratches. The model was evaluated using pharmacological methods. The number of scratches was reduced by naloxone but not by antihistamines or the transient receptor potential (TRP) channel inhibitor. Moreover, the PD-1 receptor was detected in the spinal cord of the mouse models of chronic itch that exhibited acetone, diethyl ether, and water (AEW)-induced dry skin, imiquimod-induced psoriasis, and 1-fluoro-2,4-dinitrobenzene (DNFB)-induced allergic contact dermatitis. Intrathecal PD-L1 (1 μg, 4 times a week for 1 week) suppressed the activation of the microglia in the spinal dorsal horn to relieve the chronic itch that was elicited by imiquimod-induced psoriasis and DNFB-induced allergic contact dermatitis. Although the activation of the microglia in the spinal dorsal horn was not detected in the AEW-treated mice, intrathecal PD-L1 still reduced the number of scratches that were elicited by AEW. Our findings suggest that histamine receptor inhibitors or TRP channel inhibitors have limited effects on PD-1/PD-L1 inhibitor-induced itch and that spinal PD-1 is important for the spinal activation of the microglia, which may underlie chronic itch.
Topics: Animals; Mice; Programmed Cell Death 1 Receptor; Dinitrofluorobenzene; B7-H1 Antigen; Imiquimod; Immune Checkpoint Inhibitors; Pruritus; Spinal Cord Dorsal Horn; Dermatitis, Allergic Contact; Disease Models, Animal; Psoriasis; Mice, Inbred C57BL
PubMed: 37866747
DOI: 10.1016/j.ejphar.2023.176128 -
Nutrients Sep 2023Atopic dermatitis (AD) is a chronic inflammatory disease characterized by dry and itchy skin. Recently, it has been reported that oxidative stress is involved in skin...
Atopic dermatitis (AD) is a chronic inflammatory disease characterized by dry and itchy skin. Recently, it has been reported that oxidative stress is involved in skin diseases, possibly including AD. Vitamin C, also referred to as ascorbic acid, is a vital water-soluble compound that functions as an essential nutrient. It plays a significant role as both an antioxidant and an additive in various pharmaceutical and food products. Despite the fact that vitamin C is easily oxidized, we have developed NXP081, a single-stranded DNA aptamer that selectively binds to vitamin C, thereby inhibiting its oxidation. The objective of the current research was to examine the impact of NXP081, an animal model of AD induced by 2,4-dinitrofluorobenzene (DNFB). The experimental drug NXP081, when taken orally, showed promising results in reducing inflammation and improving the skin conditions caused by DNFB. The administration of NXP081 resulted in a significant reduction in ear swelling and a noticeable improvement in the appearance of skin lesions. In addition, the administration of NXP081 resulted in a significant decrease in the migration of mast cells in the skin lesions induced by DNFB. Moreover, NXP081 inhibited the production of interferon-gamma (IFN-γ) in CD4 T cells that were activated and derived from the lymph nodes. Our findings provide useful information about the anti-inflammatory effect of NXP081 on AD.
Topics: Mice; Animals; Dermatitis, Atopic; Dinitrofluorobenzene; Mice, Inbred BALB C; Aptamers, Nucleotide; Ascorbic Acid; CD4-Positive T-Lymphocytes; Skin Diseases; Vitamins; Skin; Cytokines
PubMed: 37836456
DOI: 10.3390/nu15194172 -
International Journal of Molecular... Oct 2023The management of abdominal pain in patients affected by inflammatory bowel diseases (IBDs) still represents a problem because of the lack of effective treatments....
The management of abdominal pain in patients affected by inflammatory bowel diseases (IBDs) still represents a problem because of the lack of effective treatments. Acetyl L-carnitine (ALCAR) has proved useful in the treatment of different types of chronic pain with excellent tolerability. The present work aimed at evaluating the anti-hyperalgesic efficacy of ALCAR in a model of persistent visceral pain associated with colitis induced by 2,4-dinitrobenzene sulfonic acid (DNBS) injection. Two different protocols were applied. In the preventive protocol, ALCAR was administered daily starting 14 days to 24 h before the delivery of DNBS. In the interventive protocol, ALCAR was daily administered starting the same day of DNBS injection, and the treatment was continued for 14 days. In both cases, ALCAR significantly reduced the establishment of visceral hyperalgesia in DNBS-treated animals, though the interventive protocol showed a greater efficacy than the preventive one. The interventive protocol partially reduced colon damage in rats, counteracting enteric glia and spinal astrocyte activation resulting from colitis, as analyzed by immunofluorescence. On the other hand, the preventive protocol effectively protected enteric neurons from the inflammatory insult. These findings suggest the putative usefulness of ALCAR as a food supplement for patients suffering from IBDs.
Topics: Humans; Rats; Animals; Acetylcarnitine; Visceral Pain; Hyperalgesia; Colitis; Neuroglia; Central Nervous System
PubMed: 37834289
DOI: 10.3390/ijms241914841 -
Journal of Ethnopharmacology Jan 2024Mahuang-Lianqiao-Chixiaodou decoction (MLCD) is a traditional Chinese medicinal (TCM) formula recorded in the Treatise on Febrile Diseases. It is commonly used for...
ETHNOPHARMACOLOGICAL RELEVANCE
Mahuang-Lianqiao-Chixiaodou decoction (MLCD) is a traditional Chinese medicinal (TCM) formula recorded in the Treatise on Febrile Diseases. It is commonly used for clinical treatment of atopic dermatitis (AD). However, the potential mechanisms of MLCD intervention in AD combined with mental disorders behaviors such as anxiety and depression remain elusive and deserves further investigation.
AIM OF THE STUDY
The study aims to observe the effect of MLCD on anxiety- and depression-like behaviors in AD mice and explore the possible neuroinflammatory mechanism of NOD-like receptor 3 (NLRP3) inflammasome.
MATERIALS AND METHODS
The chemical components of MLCD extracts were identified using UHPLC-MS. The AD mice were induced by 2,4-dinitrofluorobenzene and treated with MLCD or mometasone furoate (MF, as a positive control) for 7 days. The pathological changes in their skin tissue and brain hippocampus were observed by hematoxylin-eosin staining. Elevated plus-maze test (EPM), open field test (OFT), and the suspended tail (TST) were used to measure the anxiety- and depressive-like behaviors in AD mice. Expression of NLRP3 inflammasome-related proteins in brain hippocampus were measured by the quantitative real-time polymerase chain reaction (qPCR) and western blotting (WB).
RESULTS
We found that MLCD contain many active ingredients, including ephedrine, Forsythoside A, phillyrin, glycyrrhizic acid, etc. Both MLCD and MF alleviated skin lesions and promoted positive histopathological changes in the hippocampus of AD mince to varying degrees. MLCD however, could further increase their proportion of open arm entry times (Oentries%) in EPM, residence time in the central area (Ctime) and the proportion of the number of times in the central area (Centries%) in OFT significantly. MLCD also reduces their immobility time in TST considerably. Mechanistically, MLCD downregulated the relative mRNA expression and protein level of NLRP3, Caspase-1, IL-1β, and IL-18 in hippocampal tissue compared to the model group.
CONCLUSIONS
MLCD can alleviate anxiety-like and depression-like behaviors in AD mice by intervening in the gene and protein expression of NLRP3 inflammasome-related factors, thus treating AD.
Topics: Humans; Mice; Animals; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Dermatitis, Atopic; NLR Proteins; Mental Disorders
PubMed: 37783411
DOI: 10.1016/j.jep.2023.117263 -
Biochemical Pharmacology Nov 2023The aryl hydrocarbon receptor (AhR) is widely expressed in the skin. It controls immune-mediated skin responses to various external environmental signals, promote...
The aryl hydrocarbon receptor (AhR) is widely expressed in the skin. It controls immune-mediated skin responses to various external environmental signals, promote terminal differentiation of epidermal keratinocytes and participates the maintenance of the skin barrier function. As a therapeutic target, AhR activation modulates many diseases progression driven by immune/inflammatory processes such as atopic dermatitis (AD) and psoriasis. In this study, we revealed that GDU-952 is a novel AhR agonist, which is able to decreases IgE serum levels, to inhibit pro-inflammatory cytokines such as IL-6 and TNF-α and to induce immunoregulatory effects through restoring Th1/Th2 immune balance and promoting CD4FOXP3regulatory T (Treg) populations in AD skin lesions. Furthermore, GDU-952 can strengthen the skin barrier function through upregulating epidermal differentiation-related and tight junction proteins. This may alleviate AD symptoms, such as dermatitis scores, epidermal hyperplasia and mast cell infiltration. These results offer a rationale for further preclinical/clinical studies to evaluate the possible use of GDU-952 in the management of AD.
Topics: Animals; Mice; Dermatitis, Atopic; Dinitrofluorobenzene; Receptors, Aryl Hydrocarbon; Skin; Keratinocytes; Cytokines
PubMed: 37778446
DOI: 10.1016/j.bcp.2023.115835 -
Antioxidants (Basel, Switzerland) Aug 2023Berries have gained widespread recognition for their abundant natural antioxidant, anti-inflammatory, and immunomodulatory properties. However, there has been limited...
Berries have gained widespread recognition for their abundant natural antioxidant, anti-inflammatory, and immunomodulatory properties. However, there has been limited research conducted thus far to investigate the role of the active constituents of berries in alleviating contact hypersensitivity (CHS), the most prevalent occupational dermatological disease. Our study involved an ex vivo investigation aimed at evaluating the impact of black raspberry extract (BRB-E) and various natural compounds found in berries, such as protocatechuic acid (PCA), proanthocyanidins (PANT), ellagic acid (EA), and kaempferol (KMP), on mitigating the pathogenicity of CHS. We examined the efficacy of these natural compounds on the activation of dendritic cells (DCs) triggered by 2,4-dinitrofluorobenzene (DNFB) and lipopolysaccharide (LPS). Specifically, we measured the expression of activation markers CD40, CD80, CD83, and CD86 and the production of proinflammatory cytokines, including Interleukin (IL)-12, IL-6, TNF-α, and IL-10, to gain further insights. Potential mechanisms through which these phytochemicals could alleviate CHS were also investigated by investigating the role of phospho-ERK. Subsequently, DCs were co-cultured with T-cells specific to the OVA peptide to examine the specific T-cell effector responses resulting from these interactions. Our findings demonstrated that BRB-E, PCA, PANT, and EA, but not KMP, inhibited phosphorylation of ERK in LPS-activated DCs. At higher doses, EA significantly reduced expression of all the activation markers studied in DNFB- and LPS-stimulated DCs. All compounds tested reduced the level of IL-6 in DNFB-stimulated DCs in Flt3L as well as in GM-CSF-derived DCs. However, levels of IL-12 were reduced by all the tested compounds in LPS-stimulated Flt3L-derived BMDCs. PCA, PANT, EA, and KMP inhibited the activated DC-mediated Interferon (IFN)-γ and IL-17 production by T-cells. Interestingly, PANT, EA, and KMP significantly reduced T-cell proliferation and the associated IL-2 production. Our study provides evidence for differential effects of berry extracts and natural compounds on DNFB and LPS-activated DCs revealing potential novel approaches for mitigating CHS.
PubMed: 37759970
DOI: 10.3390/antiox12091667 -
Brain Sciences Aug 2023The eyes provide themselves with immune tolerance. Frequent skin inflammatory diseases in young blind people suggest, nonetheless, that the eyes instruct a systemic...
The eyes provide themselves with immune tolerance. Frequent skin inflammatory diseases in young blind people suggest, nonetheless, that the eyes instruct a systemic immune tolerance that benefits the whole body. We tested this premise by using delayed skin contact hypersensitivity (DSCH) as a tool to compare the inflammatory response developed by sighted (S) and birth-enucleated (BE) mice against oxazolone or dinitrofluorobenzene at the ages of 10, 30 and 60 days of life. Adult mice enucleated (AE) at 60 days of age were also assessed when they reached 120 days of life. BE mice displayed exacerbated DSCH at 60 but not at 10 or 30 days of age. AE mice, in contrast, show no exacerbated DSCH. Skin inflammation in 60-day-old BE mice was hapten exclusive and supported by distinct CD8 lymphocytes. The number of intraepidermal T lymphocytes and migrating Langerhans cells was, however, similar between S and BE mice by the age of 60 days. Our observations support the idea that the eyes instruct systemic immune tolerance that benefits organs outside the eyes from an early age. The higher prevalence of inflammatory skin disorders reported in young people might then reflect reduced immune tolerance associated with the impaired functional morphology of the eyes.
PubMed: 37759864
DOI: 10.3390/brainsci13091261 -
Scientific Reports Sep 2023Nanoparticle (NP) skin exposure is linked to an increased prevalence of allergic contact dermatitis. In our prior studies using the mouse contact hypersensitivity (CHS)...
Nanoparticle (NP) skin exposure is linked to an increased prevalence of allergic contact dermatitis. In our prior studies using the mouse contact hypersensitivity (CHS) model, we reported that silica 20 nm (SiO) NPs suppressed the allergic response and titanium dioxide NPs doped with manganese (mTiO) exacerbated it. In this work, we conducted in vitro experiments using bone marrow-derived dendritic cells (BMDCs) to study the combinatorial effect of the potent 2,4-dinitrofluorobenzene (DNFB) hapten sensitizer with SiO and mTiO NPs on BMDC cytotoxicity, cytokine secretion and phenotype using the B7 family ligands. Results show that DNFB and mTiO behave similarly and exhibit proinflammatory characteristics while SiO promotes a naive phenotype. We observe that the B7-H3 (CD276) ligand is only expressed on CD80 + (B7-1) BMDCs. Results from adoptive transfer CHS studies, combined with BMDC phenotype analysis, point to the importance of PD-L2 expression in modulating the adaptive immune response. This work identifies metrics that can be used to predict the effects of NPs on contact allergy and to guide efforts to engineer cell-based therapies to induce hapten specific immune tolerance.
Topics: Animals; Mice; Dinitrofluorobenzene; Silicon Dioxide; Dermatitis, Allergic Contact; Immunomodulation; B7-1 Antigen; Disease Models, Animal; Dendritic Cells
PubMed: 37749142
DOI: 10.1038/s41598-023-42797-5 -
Journal of the American Podiatric... 2023There is a long-standing stigma associated with the use of epinephrine in digital nerve blocks (DNBs) over the concern of digital necrosis. We conducted a systematic...
There is a long-standing stigma associated with the use of epinephrine in digital nerve blocks (DNBs) over the concern of digital necrosis. We conducted a systematic review to assess the duration of anesthesia, onset of anesthesia, and complications of lidocaine with epinephrine compared with plain lidocaine for DNBs in adults. We searched Medline via Ovid, Cochrane Library, and ClinicalTrials.gov on January 28, 2020. We included randomized controlled trials that examined lidocaine with epinephrine 1:80,000 to 1:1,000,000 (1-12.5 µg/mL) and plain lidocaine for DNBs of fingers or toes in adults. We completed a blinded review of all unique articles, followed by full-text reviews, data extraction, and quality assessment of all eligible trials. Risk of bias was assessed to inform qualitative data analysis. We identified seven studies with a combined 363 adults and 442 DNBs that met the inclusion criteria. All five studies that reported duration of anesthesia established longer duration in the epinephrine-supplemented lidocaine group, with significant increases in three. Two of the three studies that reported the onset of anesthesia demonstrated significant differences. The two studies that reported complications did not have a single case of digital necrosis. In adults, the use of lidocaine with epinephrine 1:80,000 to 1:1,000,000 (1-12.5 µg/mL) for DNB yields a longer duration of anesthetic effect and seems to be as safe as plain lidocaine in healthy adults. Several studies had some concern for bias, and additional studies are warranted.
Topics: Adult; Humans; Lidocaine; Anesthetics, Local; Epinephrine; Nerve Block; Necrosis
PubMed: 37713411
DOI: 10.7547/21-066