| 摘要: | 中文摘要 前言: 粥狀動脈硬化形成的主要原因是由於血液中膽固醇濃度過高，導致脂質特別是低密度脂蛋白，進入到血管內皮細胞中，被具有活性的氧分子氧化，進而形成泡沫細胞及內皮增生現象。粥狀動脈硬化與血中膽固醇濃度及自由基的存在有高度相關性，因此預防粥狀動脈硬化可以從降低血膽固醇及提高抗氧化能力著手。厚朴、澤瀉及葛根在中醫上用來治療心血管疾病，具有舒張平滑肌、抑制血小板聚集及抗氧化等作用，文獻指出澤瀉及葛根還有降血脂的藥效。 實驗方法與材料: 本實驗以2％膽固醇飼料誘導紐西蘭白兔成為高血脂症兔子並同時分別給予厚朴、澤瀉及葛根三種中藥，測量第0、2、4週血清中生化值，血液中超氧自由基及一氧化氮;並利用RT-PCR assay, 西方點墨法(Wesern blot assay)及免疫組織化學染色（IHC）測量兔子肝臟中CuZn-SOD及GSH-Px mRNA 及蛋白質表現。 結果: 澤瀉組血中膽固醇明顯降低;葛根組及厚朴組無明顯降低血脂之作用。在第2週時，厚朴、澤瀉及葛根均有清除血液中超氧自由基之能力。此外厚朴、澤瀉及葛根亦均有提高肝臟中抗氧化酵素CuZn-SOD mRNA及蛋白質表現之能力（55%, 18%, 50%）。在本實驗對於三種中藥: 厚朴、澤瀉及葛根的抗氧化和降血脂的研究，期望能對於傳統中醫預防心血管疾病或粥狀動脈硬化作用提供進一步瞭解。; 英文摘要 Hypercholesterolemia plays a cruical role in the development of atherosclerosis. The risk of atherosclerotic progression to coronary heart disease increases with high levels of total serum cholesterol or low density lipoprotein (LDL). Several endogenous antioxidative enzymes, such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px), are known to protect against lipid peroxidation. In previous studies, it was found that three Chinese medicinal herbs: Magnolia Officinalis、Rhizoma Alismatis and Pueraria Root, were able to inhibit lipid peroxidation in rat liver injury. In this study, we fed New Zealand white rabbits with 2% cholesterol and herbal extracts to explore the molecular mechanisms of Magnolia Officinalis、Rhizoma Alismatis and Pueraria Root in those antioxidative effects. Cholesterol、TG、HDL and LDL in blood were measured as indexes of lipid-lowing. We also isolated the liver for RNA and protein extraction to study the gene expression of antioxidative enzymes. With RT-PCR analysis, we found that the mRNA levels of Cu,Zn-SOD were significantly potentiated by Magnolia Officinalis、Rhizoma Alismatis and Pueraria Root, however, the mRNA levels of GSH-Px were increased by Magnolia Officinalis and Rhizoma Alismatis. With Western blot assay, we found that the protein levels of SOD were increased (55%, 19%,50%, respectively). These preliminary data suggested that SOD gene expression can be upregulated by Magnolia Officinalis、Rhizoma Alismatis and Pueraria Root which in turn scavenged superoxide anion to reduce the hypercholesterolemic injury in livers. Application of Magnolia officinalis、Rhizoma Alismatis and Pueraria Root can then be developed as a remedy in atherosclerotic prevention in the near future. |
