粥狀動脈硬化的形成是心臟血管疾病一個重要疾病，而粥狀動脈硬化主要是因為血液中膽固醇及低密度脂蛋白在血漿中的含量過高，受到自由基氧化，形成氧化態的脂質，進而形成內皮增生及粥狀動脈斑塊之現象。若能降低血中膽固醇、低密度脂蛋白及提高抗氧化能力，則可以有效預防粥狀動脈硬化形成。因此本實驗的目的主要在探討中藥山藥在高血脂中抗粥狀動脈硬化、抗氧化作用。本實驗利用含有2％山藥的膽固醇飼料，餵食體重約2-3公斤的紐西蘭白兔12週，分別於不同時間測量血液中膽固醇、低密度脂蛋白、自由基含量、觀察主動脈粥狀動脈硬化情形、及測量組織內自由基含量及抗氧化酵素之活性。結果發現膽固醇組血中膽固醇含量為1522.5 mg/dl，山藥組血中膽固醇含量為700-740 mg/dl，統計上顯著下降之情形，其P < 0.05，除了膽固醇外，血液中LDL含量也有明顯的差異；在主動脈粥狀動脈硬化斑塊堆積方面膽固醇組堆積面積約81％，山藥組堆積約為38％；在組織自由基含量方面，膽固醇組含量為3989.36 ± 98.39，山藥組含量為2869.83 ± 689.87，統計上P<0.05有顯著差異；山藥可有效增加抗氧化酵素活性，例如：SOD、catalase，進而減低粥狀動脈硬化之形成。根據實驗結果顯示山藥對於粥狀動脈硬化及抗氧化具有良好的作用，對於應用在人體抗粥狀動脈硬化可提供進一步探討。; New Zealand White (NZW) rabbits were assigned randomly into four dietary groups. The normal group was fed with regular rabbit chow and the cholesterol group was fed with a chow containing 0.5 % cholesterol. The Dioscorea Rhizoma (DR) group and the probucol group were fed with the same diet as the control group plus 2% DR or 200mg/kg/day probucol, respectively. The plasma level of total cholesterol and LDL were increased in the cholesterol group compared to the normal group, and decrease in the probucol group and DR group compared to the cholesterol group. The emzyme activities of SOD and catalase were increased in the DR group as compared to the cholesterol group. Eighty-one percent of the intimal surface of the thoracic aorta was covered with atherosclerotic plaque in the cholesterol group but only 38 % of the surface was covered in the DR group. Therefore, the atherosclerotic plaque can be significantly reduced with subsequent prevention of atheroma formation. A 28 % increase in antioxidation activity was also noted, as measured by lucigenin -chemiluminscence and luminal- chemiluminscence. These results suggest that the antioxidant and antiatherogenic effects of DR can be useful in the prevention of the atherosclerotic formation.
