Effect of Bacillus subtilis and Bacillus coagulans spores on induced allergic contact dermatitis in dogs

BACKGROUND

Probiotic strains have the potential to modulate immune responses, reduce intestinal inflammation, normalize intestinal mucosal function and decrease allergic reactions.

OBJECTIVE

This study aimed to investigate the effect of oral probiotic supplements containing Bacillus subtilis and Bacillus coagulans spores on clinical symptoms, haematological factors and immune responses to allergic contact dermatitis in dogs induced by dinitrochlorobenzene (DNCB).

METHODS

DNCB was injected subcutaneously into the scapular region of 20 healthy adult dogs of both sexes, divided into four groups, to induce experimental allergic contact dermatitis. Dogs in Group 1 received food without probiotics or medication. Oral prednisolone was administered to Group 2 for 30 days at a dosage of 0.25 mg/kg every other day. The dogs in Group 3 were treated with a combination of oral prednisolone and probiotics. The dogs in Group 4 were fed daily with a mixture of 109 B. subtilis and B. coagulans bacteria for 30 days. The immune system responses and related gene expression were analysed in the treated animals.

RESULTS

The administration of probiotics for 30 days resulted in a reduction in clinical symptoms and duration of wound repair. The probiotics treatment also significantly increased the serum bactericidal effects against Staphylococcus aureus and Escherichia coli. It enhanced both the classic and alternative activity of the complement, as well as lysozyme activity. Additionally, the probiotics led to higher total immunoglobulin levels and significant reductions in anti-trypsin and C-reactive protein levels. Furthermore, the expression of IgE, induction of interferon-gamma and IL-4 genes were also reduced.

CONCLUSIONS

According to the results, B. subtilis and B. coagulans can be further investigated as a viable alternative to corticosteroids in treating allergic contact dermatitis in dogs.

Evaluation of Atopic Dermatitis Improvement Caused by Low-Level, Low-Frequency Pulsed Electromagnetic Fields

This study aimed to evaluate the effectiveness of using low-level, low-frequency pulsed electromagnetic field (LLLF_PEMF) stimulation to improve atopic dermatitis induced by 2,4-dinitrochlorobenzene (DNCB). Twenty 6-week-old hairless mice were randomly divided into Normal (n = 5), PEMF 15 Hz (n = 5), PEMF 75 Hz (n = 5), and Sham (n = 5) groups. Following the onset of atopic dermatitis symptoms, PEMF groups (15 and 75 Hz) were stimulated with LLLF_PEMF (15 mT) for 8 h per day for 1 week. Sensory evaluation analysis revealed a significant difference between the PEMF 15 Hz group and Sham group (P < 0.05), but these differences were not visually obvious. While both the PEMF and Sham groups had atopic dermatitis lesions, lesion size was significantly smaller in the two PEMF groups than in the Sham group (P < 0.001). Additionally, changes in epithelial thickness because of skin inflammation significantly decreased for both PEMF groups, compared with the Sham group (P < 0.001). In conclusion, these results suggest that PEMF stimulation in vivo triggers electro-chemical reactions that affect immune response. © 2022 Bioelectromagnetics Society.

Artemisia anomala Herba Alleviates 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis-Like Skin Lesions in Mice and the Production of Pro-Inflammatory Mediators in Tumor Necrosis Factor Alpha-/Interferon Gamma-Induced HaCaT Cells

Artemisia anomala S. Moore is a perennial herbaceous plant classified as Asteraceae of the genus Artemisia. Many species of Artemisia have been used as medicinal materials. Artemisia anomala S. Moore has been widely used in China to treat inflammatory diseases. However, the mechanism of its action on the keratinocyte inflammatory response is poorly understood. Here, we investigated the anti-inflammatory reaction of Artemisia anomala S. Moore ethanol extract (EAA) using human keratinocyte (HaCaT) cells, which involved investigating the nuclear factor kappa B (NF-κB), signal transducer, and activator of transcription-1 (STAT-1), as well as mitogen-activated protein kinase (MAPK) signaling pathways and atopic dermatitis-like skin lesions in mice. We elucidated the anti-inflammatory effects of EAA on tumor necrosis factor-α/interferon-γ (TNF-α/IFN-γ)-treated human keratinocyte cells and 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD)-like mice. The levels of chemokines and cytokines (IL-8, IL-6, TARC, and RANTES) were determined by an enzyme-linked immunosorbent assay. The NF-κB, STAT-1, and MAPK signaling pathways in HaCaT cells were analyzed by western blotting. Thickening of the mice dorsal and ear skin was measured and inflammatory cell infiltration was observed by hematoxylin and eosin staining. Results showed that EAA suppressed IL-8, IL-6, TARC, and RANTES production. EAA inhibited nuclear translocation of NFκB and STAT-1, as well as reduced the levels of phosphorylated ERK MAPKs. EAA improved AD-like skin lesions in DNCB-treated mice. These findings suggest that EAA possesses stronger anti-inflammatory properties and can be useful as a functional food or candidate agent for AD.

Cell-penetrating heme oxygenase-1 in the therapy of atopic dermatitis in mice

Atopic dermatitis (AD), also referred to as atopic eczema, is a long-term inflammatory condition that is characterized by itchy, red, swollen and cracked skin. Accumulating evidence suggests that AD is caused by genetic factors, environmental exposure and immune system dysfunction; however, its underlying molecular mechanism remains unclear. Current treatment strategies aim to decrease the severity and frequency of flares. Heme oxygenase-1 (HO-1) is a nuclear factor erythroid 2-related factor 2 (Nrf2)-regulated gene that plays crucial roles against stress, inflammation and oxidation, and exerts cytoprotective effects. Previous studies have reported that treatment of AD induces high expression levels of HO-1 and Nrf2, indicating that HO-1 may play an important role in the treatment of AD. The present study constructed the recombinant protein, cell-penetrating peptide-HO-1 (CPP-HO-1), which was expressed in Escherichia coli and isolated with a 6xHis-tag using HiTrap His column (1 ml). AD was established using 4-dinitrochlorobenzene (DNCB) in mice. It was observed that the CPP-HO-1 fusion protein decreased the severity of AD, inhibited scratching in mice and decreased skin inflammation. Taken together, the results of the present study suggested that the CPP-HO-1 fusion protein may play a protective role against DNCB-induced AD in mice.

Application of Topical Immunotherapy in the Treatment of Alopecia Areata: A Review and Update

Treatment of extensive or recalcitrant alopecia areata (AA) is a major clinical challenge. Even after thorough investigation of several medications, its treatment outcomes have remained unsatisfactory. While there is no US Food and Drug Administration-approved medication for AA yet, topical immunotherapy has been a well-documented treatment option. Dinitrochlorobenzene, squaric acid dibutylester, and diphenylcyclopropenone are three substances that have demonstrated efficacy in the treatment of extensive or recalcitrant AA. Despite being commonly used, the mechanism underlying topical immunotherapy is not well-elucidated and a wide range of clinical efficacies have been reported in the literature. The aim of this review was to summarize and update the pharmacology, mechanism of action, therapeutic efficacy, and tolerability of topical immunotherapy in the treatment of AA.

extract Ento-B by Dinitrochlorobenzene combined with acetic acid induced UC in rats

PURPOSE

To study the Periplaneta americana L. extract Ento-B on the treatment of chronic ulcerative colitis induced by 2,4-dinitrochlorobenzene and acetic acid in rats and to explore its primary mechanism of action.

METHODS

Using 2,4-dinitrochlorobenzene combined with acetic acid to induce chronic ulcerative colitis (chronic UC) in rats. The sulfasalazine (400 mg/kg) and Ento-B (200 mg/kg, 100 mg/kg,50 mg/kg) were given by intragastric administration and the effect was evaluated according to the disease activity index (DAI) score, colon mucosal injury index (CMDI) score, histopathological score (HS) and the serum levels of Interleukin-4(IL-4), Interleukin-10(IL-10), Tumor necrosis factor-α(TNF-α), Malondialdehyde(MDA), Superoxide dismutase(SOD) and Inducible nitric oxide synthase(iNOS.).

RESULTS

Compared with the model group, all doses of Ento-B could reduce the score of CMDI (p < 0.05), HS(p < 0.05 or p < 0.01), significantly increased the expression of IL-4, IL-10, SOD (p < 0.01) and decreased the levels of TNF-α, MDA, iNOS in serum of UC rats, significantly improving the degree of colon lesionsin UC rats.

CONCLUSIONS

Ento-B may play an important role in the treatment of ulcerative colitis induced byUC rats. The mechanism may be related to the increased expression of IL-4, IL-10, SOD and reduced expression of TNF-α, MDA, iNOS.

Effect of Resveratrol-Enriched Rice on Skin Inflammation and Pruritus in the NC/Nga Mouse Model of Atopic Dermatitis

Resveratrol-enriched rice (RR) was developed using genetic engineering to combine the properties of resveratrol and rice. To evaluate the effect of RR on pruritic skin inflammation in atopic dermatitis (AD)-like skin lesions, we used dinitrochlorobenzene (DNCB)-induced NC/Nga mice and an in vitro 3D skin model. Normal rice (NR), resveratrol, and RR were topically applied to mice dorsal skin, following which the dermatitis index and scratching frequency were calculated. Histological examination was performed by hematoxylin and eosin and immunohistochemistry staining of IL-31 level. The level of immunoglobulin E (IgE) and IL-31 in the serum was determined by enzyme-linked immunosorbent assay (ELISA). The cytotoxicity of RR and the expression levels of pro-inflammatory cytokines were also determined in cultured human keratinocytes and a 3D skin model. RR significantly reduced scratching frequency, decreased the dermatitis severity and trans-epidermal water loss (TEWL) and improved skin hydration in DNCB-induced NC/Nga mice. RR also significantly decreased serum IL-31 and IgE levels and suppressed the production of IL-6 in human keratinocytes and the 3D skin model. Our study indicates that the synergistic effect of rice and resveratrol manifested by the topical application of RR can serve as a potential alternative therapy for chronic skin inflammatory diseases such as AD.

Bleomycin Aggravates Atopic Dermatitis via Lung Inflammation in 2,4-Dinitrochlorobenzene-Induced NC/Nga Mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease. Bleomycin (BLM) contributes to the induction of pulmonary inflammation and fibrosis in animals. Although skin and lung tissue inflammation is closely related in the pathogenesis of allergic diseases, a proper animal model for investigating the relationship between skin and lung inflammation is lacking. Therefore, we developed a mouse model of AD with relapsing dermatitis and pulmonary fibrosis caused by the administration of allergen and BLM. The present study determined whether lung injury caused by the bronchial application of BLM would exacerbate AD-like allergic inflammation induced by 2, 4-dinitrochlorobenzene (DNCB) in NC/Nga mice. NC/Nga mice treated with BLM and DNCB had increased severity of clinical symptoms and airway hyperresponsiveness as well as increased inflammatory cell infiltration and collagen deposition in the dorsal skin and lung. Compared to normal mice, interleukin (IL)-6 and tumor necrosis factor (TNF)-α production in bronchoalveolar lavage fluid were increased in NC/Nga mice treated with both DNCB and BLM and in animals treated with DNCB alone. Administration of BLM and DNCB increased the levels of IL-4 and IL-13 production in spleen cells and eotaxin-2 mRNA expression in dorsal skin, compared to NC/Nga mice treated with DNCB alone. The total cell numbers in axillary lymph node, bronchoalveolar lavage, and thymus were increased in DNCB-BLM mice compared to those in mice treated with DNCB alone. Administration of BLM and DNCB increased the numbers of cluster of differentiation 4 (CD4)+ T cells and CD11b+granulocyte-differentiation antigen-1 (Gr-1)+ cells among peripheral blood mononuclear cells, CD4+ cells in bronchoalveolar lavage, CD4+ and B220+CD23+ B cells in the axillary lymph node, and CD4+ cells in thymus, compared to DNCB-treated mice. The number of total, CD4+, and CD11b+Gr-1+ cells in the lung were increased in both DNCB and DNCB-BLM mice. These results demonstrate that BLM aggravates allergic skin inflammation and promotes airway hyperreactivity and lung inflammation when combined with DNCB in NC/Nga mice.

CD1d knockout mice exhibit aggravated contact hypersensitivity responses due to reduced interleukin-10 production predominantly by regulatory B cells

Conflicting observations have been reported concerning the role of CD1d-dependent natural killer T (NKT) cells in contact hypersensitivity (CHS), supporting either a disease-promoting or downregulatory function. We studied the role of NKT cells in CHS by comparing the immune response in CD1d knockout (CD1d KO) and wild-type (Wt) mice after contact allergen exposure. For induction of CHS, C57BL/6 CD1d KO mice (n = 6) and C57BL/6 Wt mice (n = 6) were sensitised with 1% (w/v) dinitrochlorobenzene (DNCB) or vehicle for three consecutive days and subsequently challenged with a single dose of 0.5% DNCB (w/v) on the ears fifteen days later. We demonstrate that CD1d KO mice, as compared with Wt littermates, have more pronounced infiltration of mononuclear cells in the skin (29.1% increase; P < 0.001), lower frequencies of interleukin-10(+) B cells (B(regs) ) in the spleen (53.2% decrease; P < 0.05) and peritoneal cavity (80.8% decrease; P < 0.05) and increased production of interferon-γ (3-fold; P < 0.05) after DNCB sensitisation and challenge, which suggests an important regulatory and protective role of CD1d-dependent NKT cells in CHS in our model, at least in part via regulation of IL-10 producing B(regs) .

A diterpenoid derivate compound targets selenocysteine of thioredoxin reductases and induces Bax/Bak-independent apoptosis

We have previously shown that the natural diterpenoid derivative S3 induced Bim upregulation and apoptosis in a Bax/Bak-independent manner. However, the exact molecular target(s) of S3 and the mechanism controlling Bim upregulation are still not clear. Here, we identify that S3 targets the selenoproteins TrxR1 and TrxR2 at the selenocysteine residue of the reactive center of the enzymes and inhibits their antioxidant activities. Consequently, cellular ROS is elevated, leading to the activation of FOXO3a, which contributes to Bim upregulation in Bax/Bak-deficient cells. Moreover, S3 retards tumor growth in subcutaneous xenograft tumors by inhibiting TrxR activity in vivo. Our studies delineate the signaling pathway controlling Bim upregulation, which results in Bax/Bak-independent apoptosis and provide evidence that the compounds can act as anticancer agents based on mammalian TrxRs inhibition.

Topical immunotherapy in alopecia areata

Alopecia Areata (AA) is a common non-scarring alopecia directed against the anagenic hair follicle. Various treatment modalities have been used for the treatment of severe AA. Topical immunotherapy is the best documented treatment so far for severe and refractory AA. Dinitrochlorobenzene (DNCB), squaric acid dibutylester (SADBE), and diphencyprone (DPCP) are the contact allergens used for this purpose. DNCB has been found to be mutagenic by the Ames test and is largely replaced by DPCP and SADBE. DPCP and SADBE are both known to be non-mutagenic compounds and have comparable efficacy results and relapse rates. SADBE requires special solvents and additives to maintain its potency and is more expensive than the rest. DPCP has a response rate varying from 60% in severe Alopecia Areata to 17% in patients with alopecia totalis or universalis, and shows about 88 to 100% high response rate in patients with patchy Alopecia Areata.