Suppression of dust mite extract and 2,4-dinitrochlorobenzene-induced atopic dermatitis by the water extract of Lindera obtusiloba

Ethnopharmacological relevance

The Lindera obtusiloba has been used in traditional medicine for the treatment of inflammation and dermatitis. In this study, we investigated the effect of topical application of Lindera obtusiloba water extract (LOWE) on the house dust mite extract (Dermatophagoides farinae extract, DFE) and 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD).

Materials and methods

We established AD model in BALB/c mice by repeated local exposure of DFE/DNCB to the ears. After a topical application of LOWE on the skin lesions, the epidermal thickness, mast cell infiltration, and serum immunoglobulin E (IgE) and histamine were measured. In addition, the gene expression of interleukin (IL)-4, IL-13, IL-31, and tumor necrosis factor (TNF)-α in the ears was assayed.

Results

LOWE reduced AD symptoms based on ear thickness, histopathological analysis, and serum IgE levels. LOWE inhibited mast cell infiltration into the ear and elevation of serum histamine in AD model. Moreover, LOWE suppressed DFE/DNCB-induced expression of IL-4, IL-13, IL-31, and TNF-α in the ears.

Conclusions

Our results showed that topical application of LOWE exerts beneficial effects in AD symptoms, suggesting that LOWE might be a candidate for the treatment of AD.     

Inhibitory effects of Chelidonium majus extract on atopic dermatitis-like skin lesions in NC/Nga mice

Aim of the study

Chelidonium majus (CM) has traditionally been used for treatment of various inflammatory diseases including atopic dermatitis (AD). However its action on atopic dermatitis (AD) is unclear. Therefore, we investigated the effect of CM on AD using NC/Nga mice as an AD model.

Materials and methods

The effect of CM on 1-chloro-2,4-dinitrobenzene (DNCB) induced NC/Nga mice was evaluated by examining skin symptom severity, itching behavior, ear thickness, levels of serum immunoglobulin E (IgE), tumor necrosis factor-α (TNF-α), and interlukin-4 (IL-4), skin histology.

Results

The CM significantly reduced the total clinical severity score, itching behavior, ear thickness and the level of serum IgE in AD mouse model. CM not only decreased TNF-α but also IL-4.

Conclusion

These results suggest that CM may be a potential therapeutic modality for AD.     

The synergistic anti-inflammatory effect of the combination of sodium ferulate and oxymatrine and its modulation on inflammation-associated mediators in RAW 264.7 cells

Ethnopharmacological relevance

The combination of Radix Angelicae sinensis (Oliv.) Diels and Radix Sophora flavescens Ait. was extensively used in traditional Chinese medicine to treat inflammatory diseases, such as acne, heart disease, and hepatitis. Sodium ferulate (SF) and oxymatrine (OMT) were effective component of Radix Angelicae sinensis (Oliv.) Diels and Radix Sophora flavescens Ait., respectively.

Aim of the study

In this study, we investigated the synergistic anti-inflammatory effect of the combination of SF and OMT, and its modulation on inflammation-associated mediators in RAW 264.7 cells.

Materials and methods

In vivo, the anti-inflammatory effects of the combination of SF and OMT were evaluated with the xylene-induced mouse ear edema model and the carrageenan-induced rat paw edema model. In vitro, chemokines and cytokines mRNA expressions in lipopolysaccharide (LPS)-activated RAW 264.7 cells were determined by real-time PCR (RT-PCR) microarray analysis. The levels of interleukin-11 (IL-11), C-reactive protein (CRP) and interferon-γ (INF-γ) in the supernatant of LPS-stimulated RAW 264.7 cells were measured by enzyme-linked immune-sorbent assay (ELISA).

Results

The combination of SF and OMT could significantly inhibit the edema in the xylene-induced mouse ear edema and carrageenan-induced rat paw edema, but no effect was found when each drug was used alone according to above doses. The combination exhibited a better effect in down-regulating mRNA expressions of inflammation-associated mediators in LPS-stimulated RAW 264.7 cells than SF or OMT alone. The ELISA results showed that the combination synergistically inhibited LPS-induced IL-11, CRP and INF-γ production in a dose-dependent manner.

Conclusion

The combination of SF and OMT showed synergistic anti-inflammatory effect, and the activity was probably related to its modulation on inflammation-associated mediators, especially IL-11, CRP and INF-γ.     

Anti-atherogenic effect of San-Huang-Xie-Xin-Tang, a traditional Chinese medicine, in cultured human aortic smooth muscle cells

Aim of the study

San-Huang-Xie-Xin-Tang (SHXXT) is a traditional Chinese medicine and it has been shown to have an anti-inflammatory effect. Since inflammation is one of the major mechanisms of atherosclerosis, we aimed to investigate anti-atherosclerotic effect of SHXXT in human aortic smooth muscle cells (HASMCs).

Materials and methods

Human aortic smooth muscle cells (HASMCs) were used in the present study, and rendered atherosclerosis by adding lipopolysaccharides. We first tested the effects of SHXXT on HASMC migration and proliferation as they present the major morphological change of atherosclerosis. We also examined whether SHXXT can influence the production of several biomarkers of inflammation and atherosclerosis including reactive oxygen species (ROS), COX-2, ERK1/2, IL-1β, IL-6, IL-8 and MCP-1.

Results

Using the dimethyl-thiazol-diphenyltetrazoliumbromide (MTT) and wound repair assay, SHXXT was shown to significantly reduce HASMC proliferation and migration, respectively. From the fluorometric assay, SHXXT significantly reduced ROS production. SHXXT down regulated mRNA and protein levels for the COX-2 gene. In addition, phosphorylated ERK1/2 levels were suppressed by SHXXT suggesting HASMC division can be inhibited under pro-inflammatory condition. SHXXT significantly inhibited the production of IL-1β, IL-6, IL-8 and MCP-1 after LPS stimulation.

Conclusions

Our results indicated that SHXXT can influence several mechanisms involved in atherosclerosis, which suggests that SHXXT may have a therapeutic potential for cardiovascular disease associated with atherosclerosis.     

Procyanidin-rich fractions from Parkia biglobosa (Mimosaceae) leaves cause redox-sensitive endothelium-dependent relaxation involving NO and EDHF in porcine coronary artery

Aim of the study

Parkia biglobosa leaves are traditionally used as an antihypertensive agent in Benin. The present study assessed the vasorelaxant activity of different Parkia biglobosa leaf extracts using isolated porcine coronary artery rings.

Materials and methods

A hydroalcoholic leaf extract was submitted to a multi-step liquid-liquid fractionation with solvents of increasing polarity and the polyphenolic content of the different fractions was analyzed. Vascular reactivity of the different extracts was assessed using porcine coronary artery rings, in the presence or absence of specific pharmacological inhibitors.

Results

The hydroalcoholic, ethyl acetate and butanolic extracts contained mainly procyanidins and monomeric flavonoids. Parkia biglobosa leaf crude extract induced a redox-sensitive endothelium-dependent relaxation mediated by both nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF). The fractionation of the butanolic extract generated 6 fractions, two of which induced stronger vasorelaxation than the original extract and they had a higher phenolic content.

Conclusions

Parkia biglobosa leaf extract is able to induce endothelium-dependent NO- and EDHF-mediated relaxation in porcine coronary artery rings. The vasorelaxant activity is dependent on their phenolic content and appears to involve mainly procyanidins.     

Inhibition of 2,4-dinitrofluorobenzene-induced atopic dermatitis by topical application of the butanol extract of Cordyceps bassiana in NC/Nga mice

Ethnopharmacological significance

The Cordyceps species are insect-borne mushrooms that have been ethnopharmacologically used for skin diseases such as eczema and dermatitis.

Aim of the study

In this study, we investigated the curative effects of the butanol fraction (CBBF) of Cordyceps bassiana on atopic dermatitis.

Materials and methods

Dermatitis was induced by repeated application of 2,4-dinitrofluorobenzene (DNFB) in NC/Nga mice. After a topical application of CBBF on the skin lesions, the dermatitis score, epidermal thickness, mast cell number, and interleukin (IL)-4 and interferon (IFN)-γ, as well as the levels of histamine and immunoglobulin E (IgE) in the serum, were measured. Moreover, effect of CBBF on histamine release was examined using RBL-2H3 under stimulation with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA).

Results

CBBF inhibited atopic dermatitis symptoms and signs in the DNFB-treated NC/Nga mice. The suppressive activity of topically applied CBBF may be due to the dose-dependent blockade of a series of immunopathological events, including the release of histamine, the production of IgE, and the secretion of IL-4 and IFN-γ. However, this extract did not directly suppress the degranulation process, assessed by measuring β-hexosaminidase release.

Conclusions

Our results suggest that CBBF can be applied as an effective herbal remedy to treat atopic dermatitis.     

Effect of Alnus japonica extract on a model of atopic dermatitis in NC/Nga mice

Aim of the study

The bark of Alnus species has long been used in traditional oriental medicine in the treatment of many pathological conditions, including fever, hemorrhage, diarrhea, alcoholism, various skin diseases (e.g. chronic herpes, eczema and prurigo), and inflammation. In order to assess the immunomodulatory efficacy of a novel herbal medicine in treating atopic dermatitis, we measured serum levels of several allergic and inflammatory biomarkers in NC/Nga mice before and after treatment with this experimental agent.

Materials and methods

Gene and protein expression analyses of iNOS and COX-2 were quantified by real time PCR and Western blot analysis and serum levels of IL-4, -5 and -13 were also measured by ELISA, all of which were reduced after treatment with the experimental agent. Additionally, serum concentrations of IgE and blood eosinophil counts were reduced in treated mice.

Results

The topical application of leaf and bark extract from Alnus japonica suppressed the development of AD-like skin lesions. The percent of blood eosinophils was decreased after treatment with leaf and bark extract from Alnus japonica. The serum IgE and Th2-related cytokine levels were decreased after treatment with leaf and bark extract from Alnus japonica compared with those treated with base cream (vehicle treated AD group). The IL-4, IL-5 and IL-13 were lower than those of vehicle treated AD group.

Conclusions

We contend that leaf and bark extract from Alnus japonica may prove useful in the treatment of atopic dermatitis and other allergic skin diseases, although more in-depth clinical studies are necessary before clinical implementation.     

Inhibitory effects of Drynaria fortunei extract on house dust mite antigen-induced atopic dermatitis in NC/Nga mice

Ethnopharmacological relevance

Drynaria fortunei (Kunze) J. Sm has been widely used in traditional medicine for the treatment of inflammation, hyperlipidemia, arteriosclerosis, rheumatism, and bone healing. We investigated the anti-inflammatory effects of a 70% ethanol extract of Drynaria fortunei (DFE).

Materials and methods

We evaluated the anti-inflammatory effects of topically applied DFE on house dust mite Dermatophargoides farinae-induced atopic dermatitis-like skin lesions in NC/Nga mice.

Results

Treatment of NC/Nga mice with DFE reduced the dermatitis score, ear thickness, and serum levels of IgE, IgG1, and IL-6. Histopathological analyses of ear and skin lesions showed inhibition of the thickening of the epidermis and reduced epidermal/dermal infiltration of inflammatory cells. In ear lesions, mRNA expression levels of IL-4, IL-6, and tumor necrosis factor-α were reduced by DFE treatment.

Conclusions

DFE inhibited the development of dermatitis-like skin lesions in NC/Nga mice. These results suggest that DFE may be a therapeutic candidate for the treatment of AD.