엉겅퀴 에탄올 추출물의 항염·항산화 작용에 따른 아토피 피부염 보호 효과 = Protective effects of Cirsium japonicum ethanol extract on atopic dermatitis via anti-inflammatory and antioxidant activities

다국어 초록 (Multilingual Abstract)

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by severe pruritus and dryness. This condition arises from the complex interplay of genetic and environmental factors, and its major pathogenic mechanisms involve skin barrier dysfunction and immune imbalance. In particular, excessive activation of T helper type 2 (Th2) immune responses and increased immunoglobulin E (IgE) levels promote the secretion of inflammatory cytokines, leading to chronic skin inflammation.

Cirsium japonicum extract has been reported to possess anti-inflammatory and antioxidant activities. However, its effects on AD have not yet been investigated. To evaluate the anti-AD effects of Cirsium japonicum ethanol extract (CJEE), this study employed an LPS-induced inflammatory model in RAW 264.7 macrophages and a 2,4-dinitrochlorobenzene (DNCB)-induced AD model in BALB/c mice.

To evaluate the cytotoxicity of CJEE, an MTT assay was performed, and nitric oxide (NO) production was measured. CJEE showed no cytotoxicity in RAW 264.7 macrophages while significantly inhibiting NO production. In the mouse model, AD was induced using 1% DNCB, followed by oral administration of CJEE for 10 days. Epidermal and dermal thickness and mast cell infiltration in dorsal skin tissues were assessed histologically. The CJEE-treated group exhibited markedly reduced epidermal and dermal hyperplasia and decreased mast cell infiltration compared with the negative control (NC) group.

Molecular analyses using RT-qPCR and Western blotting demonstrated reduced expression of inflammation-related factors, including TSLP, IL-1β, TNF-α, IL-6, iNOS, and COX-2. Among mitochondrial antioxidant factors, SOD2 expression was increased, whereas CAT showed normalization following CJEE treatment. In addition, lipid peroxidation–regulating and stress-responsive antioxidant factors, including GPX4 and HO-1, were upregulated.

These findings suggest that CJEE may alleviate the pathological symptoms of AD by modulating anti-inflammatory and antioxidant pathways.

목차 (Table of Contents)

• ABSTRACT 1
• 1. INTRODUCTION 3
• 2. MATERIALS AND METHODS 6
• 2.1. Preparation of Cirsium japonicum ethanol extract (CJEE) 6
• 2.2. Cell culture 6
• 2.3. Cell viability 6
• 2.4. Nitric oxide detection assay 7
• 2.5. Animals 8
• 2.6. Induction of ADlike skin inflammation and administration of CJEE 8
• 2.7. Histological analysis 9
• 2.7.1. Hematoxylin and eosin (H&E) staining 9
• 2.7.2. Toluidine blue staining 10
• 2.8. RT-qPCR 10
• 2.9. Western blot analysis 11
• 2.10. Statistical analysis 12
• 3. RESULT 13
• 3.1. Cytotoxicity and nitric oxide production in RAW 264.7 macrophages treated with CJEE 13
• 3.2. Therapeutic effect of CJEE on DNCB-induced AD-like skin lesions 13
• 3.3. Effects of CJEE on histopathological changes in H&E-stained skin lesions 14
• 3.4. Effects of CJEE on mast cell infiltration in toluidine bluestained skin tissues 14
• 3.5. Effects of CJEE on cytokine expression in AD mice 15
• 3.6. Effects of CJEE on inflammation- and lipid peroxidationrelated proteins in AD mice 15
• 3.7. Effects of CJEE on antioxidant defenserelated proteins in AD mice 16
• 4. DISCUSSION 17
• 5. CONCLUSION 22
• REFERENCES 23
• FIGURES 29
• FIGURE LEGENDS 37
• 국문초록 41