백서 치주질환모델을 이용한 석류추출물 분말의 치주질환 억제 효과

Abstract

Periodontal disease is a common infectious disease that causes the loss of supporting tissue surrounding the tooth. This destruction process is caused by bacterial plaque products and the inflammatory and immune functions of the patient. Scaling and root planing are insufficient to completely remove periodontal pathogens. Therefore, various drugs are additionally applied to promote the complete eradication of bacteria. Pomegranate extract is a compound that has a significant clinical value, indicating antibacterial, antioxidant, anti-inflammatory, anti-proliferative, and DNA therapeutic activities. Pressed pomegranate seed oil inhibits cyclooxygenase (COX) , which are important enzymes involved in the production of various inflammatory mediators. Pomegranate extract also has broad inhibitory effects on matrix metalloproteinase (MMP) expression and IL-1β-induced tissue destruction. The purpose of this study was to evaluate the effect of pomegranate extract (Pomegranate Extract Powder, GNC, Pittsburgh, Pennsylvania, USA) on the progression of periodontal disease in an experimental rat model of periodontitis. Forty Sprague-Dawley rats were used in this study. They were grouped as follows: (1) group 1: no ligation + Distilled water(DW); (2) group 2: silk ligation + pgLPS + DW; (3) group 3: silk ligation + pgLPS + 22 μg/ml pomegranate extract solution; and (4) group 4: silk ligation + pgLPS + 44 μg/ml pomegranate extract solution. Periodontitis was induced by placing a 5-0 black silk ligature around the maxillary second molar and injecting 1 μg/ml pgLPS into the gingiva every week. Pomegranate extract solution or DW was orally administered daily. The animals were sacrificed at 3 weeks, and tissue specimens around the maxillary second molar were harvested from these animals. The specimens were analyzed using enzyme-linked immunosorbent assay(ELISA), micro-CT imaging and histometric measurements. Among the inflammation-related cytokines, COX-1 showed a significantly lower expression in the group 3, 4 than in the group 2. COX-2 expression was significantly lower in the group 3, 4 than in the group 1, 2. No significant difference was observed in MMP-2 expression. Micro-CT revealed significant alveolar bone resorption inhibition in the group 3, 4 than in the group 2. Histometric evaluation showed little gingival recession and alveolar bone loss; moreover, the length of the junctional epithelium increased and the amount of connective tissue attachment decreased in the group 4. In rats administered the pomegranate extract, the expression of COX-1 and COX-2, which mediate the inflammatory response in periodontal tissues, was significantly reduced, and alveolar bone loss due to inflammation was statistically significantly inhibited. In other words, pomegranate extract has an effect of inhibiting the progression of alveolar bone loss due to periodontal inflammation by reducing the expression of COX-1 and COX-2 in the process of periodontal disease.