氧化还原平衡是细胞完成正常生理活动的重要基础。由硫氧还蛋白（Thioredoxin，Trx）、硫氧还蛋白还原酶（Thioredoxin reductase，TrxR）和还原性辅酶Ⅱ（NADPH）构成的小分子蛋白系统在人和哺乳类细胞内的氧化还原平衡维持中起非常重要的作用。大量研究表明Trx和TrxR在肿瘤细胞中过表达，因而是目前肿瘤药物设计的靶标蛋白。甘肃多种道地药材如黄芪、当归等报导具有明显的抗癌药效，但抗癌机理不明。本研究拟采用生物化学、分子生物学及免疫组化等方法，以多种肿瘤细胞系及荷瘤小鼠为材料，以是否抑制TrxR活性为选择标准，对分离纯化得到的药材成分逐一进行抑癌活性筛选，以期得到甘肃道地药材的抗肿瘤有效成分，并揭示这些有效成分在细胞和整体水平、体内和体外环境抑制TrxR表达和活性的规律。研究结果对阐明甘肃道地药材抗癌机理、针对性开发地方药材品种和加快中药材走向国际市场具有重要意义。

The homeostasis of redox is a crucial foundation for the cells to undertake the normal physiological activites. It has been demonstrated that the small protein system, which is composed of the thioredoxin(Trx), the thioredoxin reductase (TrxR) and the reductive coenzymes II(NADPH) in cells of human and mammalian, plays a cardinal role in maintaining the redox balance. The massive evidence showed that over-expression of Trx and TrxR have been observed in tumor cells and it has emerged as a target of the drug design. It has been reported that the Gansu geoherbs such as Radix Astragali and Radix Angelicae Sinensis displayed the remarkable effectiveness to the anti-cancer assay. However, the mechanism underlying the anti-cancer is currently still elusive. In this study, the anticancer screening will be performed in a variety of tumor cell lines and tumor-bearing mice via determination of the inhibition of TrxR by the various components isolated from Gansu genuine herbs using the biochemistry, molecular biology and immunohistochemical etc. strategies. This research aims to obtain the anti-tumor effective ingredients from Gansu geoherbs and investigate the expression and activity of TrxR in vitro and in vivo within cells as well as whole organism treated with the active ingredients. The results of this study will elucidate the anticancer mechanism of Gansu genuine herbs and be the potentiality for promoting the development of local herbs medicines. Moreover, it possesses the significance for accelerating the Chinese medicinal herbs into the international market.