Effects of Angelicae dahuricae Radix on 2, 4-Dinitrochlorobenzene-Induced Atopic Dermatitis-Like Skin Lesions in mice model

Abstract

Background: Atopic dermatitis (AD) is an inflammatory, chronically relapsing, and intensively pruritic skin disease that affect 10-30% of the global population. Angelicae dahuricae Radix (ADR) has been reported to be anti-inflammatory in Korean Medicine. In the present study, we investigated whether ADR suppresses the progression of AD in animal model.

Methods: AD was induced by 2, 4-Dinitrochlorobenzene (DNCB). ADR was orally administered to mice to study the effect of ADR on AD. Histological Analysis, immunohistochemistry, blood analysis, RT-PCR, and ELISA assay were performed.

Results: ADR significantly suppressed AD-like symptoms in BALB/c mice: ADR decreased skin thickness and spleen weight of mice. ADR reduced infiltration of mast cells, inflammatory cells and CD4+ cells into mouse skin. ADR lowered the number of WBCs in the blood of mice. ADR reduced the levels of IgE, IL-6, IL-10 and IL-12 in mice serum. ADR down-regulated mRNA expression of IL-4, IL-6 and TNF-α in mouse skin tissue.

Conclusion: Our present study clearly indicates that ADR suppresses the progression of AD induced by DNCB in BALB/c mice. This suggests that ADR might be a useful drug for the treatment of AD.

Keywords: 2, 4-Dinitrocholrlbenzene; Angelicae dahuricae Radix; Atopic dermatitis; BALB/c mice; Cytokine; Inflammation.

Fig. 1

General schematic diagram of studies

Fig. 2

Changes in body weight (a) and Food intake (b) during treatment with ADR (200 mg/kg). After induction of AD by DNCB, mice were orally administered with ADR. Values are expressed as mean ± SEM (n = 8)

Fig. 3

Observations of skin lesions in ADR (200 mg/kg) treated DNCB-induced AD mice. The photograph shows the back of mice on day 28 after sensitization (a). The measurement of skin thickness (b) spleen weight (c) in DNCB-induced AD mice model treated with ADR. Values are expressed as mean ± SEM (n = 8)

Fig. 4

ADR (200 mg/kg) reduced infiltration of mast cells, inflammatory cells and CD4+ cells into skin. The skin sections were stained with toluidine blue (a). Sections were evaluated using microscope at an original magnification of 200x. The skin sections were stained with hematoxylin and eosin (c). Sections were evaluated using microscope at an original magnification of 200x. The skin sections were immunostained with CD4+ antibody. CD4+ cells were shown as brown color (e). b, d, f Sections were evaluated and graphed from the results of (a), (c), (e). Sections were evaluated using microscope at an original magnifiation of 1000x. Data are presented as mean ± SEM. ∗P< 0.05, ∗∗P< 0.01, and ∗∗∗ < 0.001

Fig. 5

ADR (200 mg/kg) reduced the levels of leukocytes in the blood. WBC (a), Neutrophil (b), Lymphocyte (c), Monocyte (d), Eosinophil (e), Basophil (f) were analyzed using HEMAVET 950 hematology analyzer. Data are presented as mean ± SEM. ∗P< 0.05, ∗∗P< 0.01, and ∗∗∗P< 0.001

Fig. 6

ADR (200 mg/kg) reduced the levels of cytokines in the serum. The release of IgE (a), IL-6 (b), IL-10 (c) and IL-12 (d) was measured by sandwich ELISA assay. Data are presented as mean ± SEM. ∗P< 0.05, ∗∗P< 0.01, and ∗∗∗P< 0.001

Fig. 7

Effect of ADR (200 mg/kg) on the cytokine mRNA expression in mouse skin tissue. The IL-4, IL-6 and TNF-α mRNA expression were measured by RT-PCR (a), (b), (c) in mouse skin tissue. The columns and the error bars represent mean ± SD (n = 8 mice/group). ∗P< 0.05, ∗∗P< 0.01, and ∗∗∗ < 0.001