生物活性導向分離鑑定山苦瓜葉抑制牙齦卟啉單胞菌誘導發炎反應的活性物質

Abstract

牙齦卟啉單胞菌Porphyromonas gingivalis (P. gingivalis)，為厭氧革蘭氏陰性菌，黑色、短桿狀，引起慢性牙周炎的致病菌之一。當宿主受到P. gingivalis感染，入侵口腔表皮細胞後，宿主將啟動免疫反應，刺激細胞激素、化學趨化素分泌，例如：介白素-8 (Interukin-8 ; IL-8)，誘導嗜中性白血球移動至發炎處浸潤，而產生了紅、腫的發炎現象。 山苦瓜（Momordica charantia L. var. abbreviate Seinge） 俱有多種功效，降血糖、降血脂、抗菌、抗發炎等功效。本研究室先前研究自苦瓜葉萃取物分離鑑定數種俱有抗發炎的活性物質，例如：beta-ionone, momordicoside aglycone等。 本研究以牙齦卟啉單胞菌（P. gingivalis）刺激人類單核球細胞（THP-1）細胞模式，以生成細胞激素介白素-8 (Interukin-8 ; IL-8)作為篩選指標。自山苦瓜葉萃取物分離並鑑定抗發炎活性的組成分：Charantadiol A ( 5β,19-epoxycucurbita-6,23(E),25(26)-triene-3β,19(R)-diol )—苦瓜二醇。細胞實驗結果顯示能夠抑制P. gingivalis 誘導THP-1細胞分泌IL-6、IL-8；而在動物實驗發現可抑制P. gingivalis 誘導小鼠牙齦組織IL-6和TNF-α mRNA表現。 本研究結果證實Charantadiol A俱有抗發炎的活性，故推測Charantadiol A俱有抑制牙周病炎和其他P. gingivalis 誘導發炎之相關疾病。

Porphyromonas gingivalis, a gram-negative anaerobic rod bacterium, is a major periodonto-pathogen that plays a role in the pathogenesis of periodontal disease, which is considered a typical chronic inflammatory disease. Wild bitter melon (WBM; Momordica charantia L. var. abbreviate Seinge) possesses hypoglycemic, hypolipidemic, antibacterial, and anti-inflammatory properties. The aim of this study was to identify the anti-inflammatory active compounds from WBM leaf using P. gingivalis-stimulated human monocytic THP-1 cells in vitro. WBM leaves were extracted with ethanol and separated into five fractions by elution of n-hexane/acetone. Among them, the fra5 significantly inhibited P. gingivalis-induced interleukin (IL)-8 by THP-1 cells. Hence, fra5 was subjected to separation and purification by using various chromatographic techniques. Charantadiol A (5β,19-epoxycucurbita-6,23(E),25(26)-triene-3β,19(R)-diol) was identified by comparing spectral data. Treatment of charantadiol A effectively reduced IL-6 and IL-8 production by P. gingivalis-stimulated human monocytic THP-1 cells in vitro. In addition, charantadiol A also significantly inhibited heat-killed P. gingivalis-induced IL-6 and TNF-a mRNA levels in gingival tissue of mice. In summary, these findings suggest that charantadiol A P. gingivalis-induced cytokine production or expression, suggesting its therapeutic potential in P. gingivalis-related inflammatory diseases.