치주염 랫드 모델에서 Pimpinella brachycarpa 추출물의 항염증 및 골보호 효과 = Anti-Inflammatory and Bone-Protective Effects of Pimpinella brachycarpa Extract in a Rat Model

다국어 초록 (Multilingual Abstract)

Periodontitis is a chronic inflammatory disease characterized by progressive destruction of the periodontal tissues, including the periodontal ligament and alveolar bone, driven by dysregulated host immune responses to bacterial challenge. Although conventional periodontal therapies focus on mechanical debridement and infection control, these approaches have limitations in preventing sustained inflammation and subsequent bone loss. Therefore, there is growing interest in host-modulatory strategies using natural products with anti-inflammatory and bone-protective properties.
Pimpinella brachycarpa is a traditional medicinal plant known for its anti-inflammatory and antioxidant activities; however, its therapeutic potential and underlying mechanisms in periodontitis remain insufficiently understood. The present dissertation aimed to comprehensively evaluate the anti-inflammatory and bone-protective effects of Pimpinella brachycarpa extract (PBE) using complementary rat models of periodontitis and to elucidate its mechanistic basis through integrated in vivo and in vitro approaches.
First, the therapeutic efficacy of PBE was evaluated in a ligature-induced rat model of periodontitis, which closely mimics the complex pathological features of clinical periodontal disease. PBE administration significantly attenuated alveolar bone loss and preserved periodontal tissue architecture. Histological and immunohistochemical analyses demonstrated reduced osteoclast activity, decreased infiltration of inflammatory immune cells, and suppressed expression of pro-inflammatory cytokines in periodontal tissues. These findings indicate that PBE exerts protective effects against periodontal tissue destruction under multifactorial inflammatory conditions.
To further investigate the inflammation-driven mechanisms of PBE, an LPS-induced rat model of periodontitis and cell-based experiments were employed. In this model, PBE significantly reduced alveolar bone loss, osteoclast activation, and disease activity scores. In vitro studies using macrophages and human periodontal ligament fibroblasts revealed that PBE suppressed the production of inflammatory mediators and cytokines induced by LPS or interleukin-1β stimulation. Moreover, PBE inhibited the activation of key inflammatory signaling pathways, including the PI3K/AKT and NF-κB pathways, and reduced the expression of matrix metalloproteinases associated with extracellular matrix degradation.
Collectively, this dissertation demonstrates that PBE effectively mitigates periodontal inflammation and alveolar bone destruction in rat models of periodontitis by modulating inflammatory responses and osteoclast activity. These findings provide both phenotypic and mechanistic evidence supporting the potential of PBE as a natural host-modulatory agent for the adjunctive management of periodontitis.

목차 (Table of Contents)

• CHAPTER 1
• Anti-Inflammatory and Bone-Protective Effects of Pimpinella brachycarpa Extract in a Ligature-induced Rat Model of Periodontitis
• 1. INTRODUCTION 1
• 2. MATERIALS AND METHODS 6
• 2.1 Phytochemical analysis of Pimpinella brachycarpa extract (PBE) 6
• 2.2 Ligature-induced periodontitis assays 9
• 2.3 Gross morphological assessment and bone loss quantification 10
• 2.4 Histological analysis (H&E staining) 10
• 2.5 TRAP staining for osteoclast detection 10
• 2.6 Immunohistochemistry (IHC) 11
• 2.7. Statistical analysis 11
• 3. RESULTS 13
• 3.1. Quantification of marker compounds of PBE 13
• 3.2 PBE attenuates ligature-induced alveolar bone loss 18
• 3.3 PBE attenuates ligature-induced alveolar bone destruction in histological analysis 20
• 3.4 PBE reduces osteoclast activity in ligature-induced periodontitis 23
• 3.5 PBE suppresses immune cell infiltration and inflammatory cytokine expression 26
• 3.6. CGA contributes to the protective effect of PBE against bone loss 29
• 3.7. CGA alleviates alveolar bone destruction in histological analysis 31
• 3.8. CGA reduces osteoclast activity 33
• 4. DISCUSSION 36
• 5. REFERENCES 40
• CHAPTER 2
• Anti-Inflammatory and Bone-Protective Effects of Pimpinella brachycarpa Extract through Modulation of Inflammatory Signaling in an LPS-induced Periodontitis Model
• 1. INTRODUCTION 49
• 2. MATERIALS AND METHODS 53
• 2.1 Phytochemical analysis of Pimpinella brachycarpa extract 53
• 2.2 LPS-induced periodontitis assays 53
• 2.3 Histological analysis and scoring 54
• 2.4 Immunohistochemistry (IHC) 55
• 2.5 TRAP staining 55
• 2.6 Cell culture 55
• 2.7 Cell Viability and Enzyme-Linked Immunosorbent Assay 56
• 2.8 Western blotting analysis 57
• 2.9 Quantitative RT-PCR 57
• 2.10 Statistical analysis 60
• 3. RESULTS 61
• 3.1. PBE attenuates LPS-induced alveolar bone destruction in histological analysis 61
• 3.2 PBE tends to reduce LPS-induced superficial root resorption in histological analysis 63
• 3.3 PBE reduced disease activity in LPS-induced periodontitis 65
• 3.4 PBE reduced CD45-positive inflammatory cell infiltration in LPS-induced periodontitis 68
• 3.5 PBE suppresses LPS-induced osteoclast activation in TRAP staining analysis 71
• 3.6. Regulatory effects of PBE on secretion of inflammatory mediators and cytokines in Raw264.7 macrophages and PDLF Cells 74
• 3.7. PBE inhibited IL-1β-induced activation of the PI3K/AKT and NF-κB signaling pathways in PDLF cells 76
• 3.8. PBE reduced IL-1β-induced MMP expression in PDLF cells 79
• 4. DISCUSSION 82
• 5. REFERENCES 86
• 국문초록 93
• ACKNOWLEDGEMENT 95