Radioprotective Potential of Ginseng

描述(申请人提供)：辐射在医疗、农业和工业等领域的广泛使用，以及核恐怖主义威胁的上升，使辐射引起的正常组织损伤日益成为平民和军方关注的焦点。因此，确定能有效减少辐射的生物效应，但又没有现有辐射防护剂所带来的不良副作用的辐射防护剂的需求变得越来越迫切。在这方面，我们最近报道了亚洲人参提取物与体外人外周血淋巴细胞(PBL)辐射防护之间的剂量依赖关系。我们认为，这种体外辐射防护表明人参在体内具有作为有效辐射防护剂的潜力。我们的具体假设是，人参在体内具有成为有效的辐射防护剂的潜力，由于自由基在辐射损伤中起着如此重要的作用，因此这种辐射防护的机制直接或间接地与其抗氧化能力有关。使用标准化的北美人参提取物(NAGE)作为我们的辐射防护剂，其具体目的是：1.使用我们的体外PBL模型，根据DNA损伤的程度，通过测定NAG对照射前后PBL的影响来确定NAGE的辐射防护潜力；2.通过评估辐射暴露和/或给药前后PBL中细胞的氧化/抗氧化状态，确定NAGE的辐射防护机制是否与其抗氧化作用相关；3.通过比较口服NAG前后受试者外周血淋巴细胞中辐射诱导的DNA损伤，以及体外暴露于一定范围的辐射剂量(0-2Gy值)，确定健康受试者每日口服NAG是否对其PBL产生辐射防护作用。实现这些目标将为NAGE发展成为有效的辐射防护剂提供必要的先决条件。

DESCRIPTION (provided by applicant): The widespread use of radiation in such areas as medicine, agriculture and industry, along with the elevating threat of nuclear terrorism, has made radiation-induced normal tissue damage an increasing focus of concern for both civilians and the military. Thus, the need to identify radioprotectors that effectively reduce the biological effects of radiation, but lack the unwanted side effects associated with current radioprotectors, has taken on increasing urgency. In this regard, we have recently reported a dose-dependent relationship between Asian ginseng extracts and radioprotection in human peripheral blood lymphocytes (PBL) ex vivo. We believe this ex vivo radioprotection is indicative of ginseng's potential to function as an effective radioprotector in vivo. Our specific hypothesis is that ginseng possesses the potential to be an effective radioprotector in vivo, and, since free radicals play such an important role in radiation-induced damage, the mechanism underlying this radioprotection is linked, either directly or indirectly, to its antioxidative ability. Using a standardized North American Ginseng extract (NAGE) as our radioprotective agent, the specific aims are to: 1. Define the radioprotective potential of NAGE using our ex vivo PBL model by determining the effect of NAGE on PBL, before and after exposure to radiation, based on the degree of DNA damage; 2. Identify whether the mechanism underlying NAGE's radioprotection is correlated with its antioxidative action by assessing the cellular oxidative/antioxidative status in PBL before and after the radiation exposure and/or NAGE administration; and 3. Determine whether oral, daily supplementation of NAGE to healthy human subjects results in radioprotection of their PBL by comparing, both before and after administration of NAGE, the radiation-induced DNA damage in PBL drawn from subjects and exposed ex vivo to a range of radiation doses (0-2 Gy). Accomplishing these aims will provide an essential prerequisite to the development of NAGE as an effective radioprotector.