| 摘要: | 廣藿香 (Pogostemon cablin)是臨床上常用的芳香化濕藥，中醫常用來治療中暑嘔瀉、頭痛寒熱；外用敷治瘡疔腫痛、刀傷、燙傷等症狀。研究指出廣藿香甲醇萃取物具有良好的抗氧化效果，並且具有止吐、鎮痛及抑制子宮收縮作用，因此本研究採用廣藿香為研究材料。以醋酸扭體及福馬林舔足試驗，探討廣藿香甲醇萃取物之鎮痛作用，另外體外實驗以LPS誘導RAW 264.7細胞株發炎試驗，以及體內實驗以λ-角叉菜膠誘發小鼠足蹠浮腫試驗，研究抗發炎之效果；檢測其肝臟抗氧化酵素SOD、GSH-Rd、GSH-Px等活性及測定腳組織MDA、IL-1β、IL-6與TNF-α等cytokines含量，並以quartz crystal microbalance(QCM)、西方點墨法與組織染色切片等不同的實驗方法驗證COX-2與iNOS的變化，藉以探討其鎮痛及抗發炎之分子機轉。
結果顯示，廣藿香甲醇萃取物 (1.0 g/kg)及廣藿香油 (10, 20 mg/kg)對於醋酸誘導的扭體反應有明顯的抑制效果，對於福馬林誘導的舔足反應，廣藿香甲醇萃取物 (0.5, 1.0 g/kg)及廣藿香油 (10, 20 mg/kg)可明顯的減少小鼠後期舔足時間，另外抗發炎方面，體外實驗，廣藿香甲醇萃取物 (500, 1000 μg/kg)可明顯抑制LPS誘導RAW 264.7生成NO與發炎介質 (iNOS、COX-2)以及cytokines (IL-1β與TNF-α)；廣藿香甲醇萃取物 (0.5, 1.0 g/kg)及廣藿香油 (10, 20 mg/kg)可明顯抑制λ-角叉菜膠誘導小鼠的足蹠腫脹反應，並且增加肝臟抗氧化酵素 (SOD、GSH-Rd、GSH-Px)的活性以及抑制腳組織發炎介質 (COX-2、iNOS)與cytokines (IL-6、TNF-α)的含量。
上述結果顯示，廣藿香甲醇萃取物及其主成分廣藿香油均具有鎮痛及抗發炎作用。而其機轉研究顯示，鎮痛方面由於其可抑制醋酸誘導扭體反應及抑制福馬林所誘導的後期發炎性疼痛，因此我們推論其鎮痛效果與抑制發炎反應有關；而在抗發炎方面，檢測可增強肝臟抗氧化酵素活性以及抑制足蹠發炎介質的濃度，其作用之機轉可能與提升肝臟中抗氧化酵素，以清除自由基，減少發炎足蹠組織中脂質過氧化的傷害；減少cytokines (IL-1β、IL-6、TNF-α)的濃度，以抑制COX-2的產生；及減少cytokines含量及抑制iNOS的濃度，進而減少NO的生成，而達到抗發炎作用。
Pogostemon cablin (PC) is used as aromatic eliminating dampness herb by traditional Chinese physicians. In traditional Chinese medicine, it is often used for treating summer vomiting and diarrhea, headache fever and chills, furuncle, cut and scald. The methanol extract of PC (PCMeOH) has significantly efficient anti-oxidative activity in some studies. Moreover, the antiemetic, analgesic and constriction effects were also demonstrated by treatment with PC. Therefore, this study investigated the analgesic effect of the PCMeOH and Pogostemon cablin Oil (PCO) by acetic acid-induced writhing response and formalin test. The anti-inflammatory effect of the PCMeOH was examined by LPS induced RAW 264.7 cells. In the vivo, PCMeOH and PCO were examined by λ-carrageenan-induced paw edema in mice. To investigate the possible anti-inflammatory mechanisms of the PCMeOH and PCO, we further measured the activities of SOD, GSH-Rd and GSH-Px in the liver tissue, the levels of MDA and cytokines such as IL-1β, IL-6 and TNF-α in the edema paw of mice, the expressions of COX-2 and iNOS by Western blot, and immunohistochemical stain.
The results showed that the PCMeOH (1.0 g/kg) and PCO (10, 20 mg/kg) significantly inhibited the acetic acid-induced writhing response. The PCMeOH (0.5, 1.0 g/kg) and PCO (10, 20 mg/kg) significantly inhibited formalin (0.5%, 0.1 ml/ 10 g) induced the licking time in the late phase. Moreover, PCMeOH (500, 1000 μg/kg) significantly inhibited the levels of NO, iNOS, COX-2 and cytokines such as IL-1β and TNF-α induced by LPS in RAW 264.7 cells. In vivo, PCMeOH (0.5, 1.0 g/kg) and PCO (10, 20 mg/kg) also significantly inhibited λ-carrageenan-induced paw edema, and increased the activities of SOD, GSH-Rd and GSH-Px in the liver tissue.
The results show that the PCMeOH and PCO possessed significant analgesic and anti-inflammatory effects. There are three possible anti-inflammatory mechanisms of the PCMeOH and PCO. One is associated with enhancing anti-oxidative enzymes in liver for cleaning the free radicals and diminishing the damage of lipid peroxidation in inflammatory paw tissue. Another is associated with decreasing the levels of cytokines (IL-1β, IL-6 and TNF-α) that resulted in inhibition of COX-2 activity. The other is associated with inhibiting iNOS activity which resulted in decreasing NO production. |
