Lee Tung-Kwang, O'Brien Kevin F, Wang Weidong, Sheng Chao, Wang Tao, Johnke Roberta M, Allison Ron R
Department of Radiation Oncology, Leo W. Jenkins Cancer Center, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA.
Open Nucl Med J. 2009 Jan 1;1(1):1-8. doi: 10.2174/1876388X00901010001.
The multifold bioactive medicinal properties of ginseng have been closely linked to its antioxidative ability, which is related to its ginsenoside content. Since the key mechanism of radiation-induced cell death and tissue damage is the generation of reactive oxygen species (ROS) that attack cellular DNA, this study focuses on the impact of a standardized North American ginseng extract (NAGE) on (137)Cs-induced oxidative stress in human peripheral lymphocytes (PBL) obtained from 10 healthy individuals (6M/4F), 42.7 +/- 4.6 years of age. At two different time points (0 h and 24 h before irradiation), we applied NAGE (250 - 1000 microg ml(-1)) to mononuclear cell cultures for cytokinesis-block micronuclei (MN) assay and determination of the state of oxidative stress in PBL. We found that at both time points, NAGE significantly reduced the MN yields in PBL after irradiation (1 and 2 Gy) in a concentration-dependent manner (P<0.001). Compared with radiation alone, the maximum reduction rate of MN yield were 51.1% and 49.1% after 1 Gy and 2 Gy exposures, respectively. We also found that before irradiation the presence of NAGE in the culture medium resulted in a significant increased intracellular total antioxidant capacity (TAC) in PBL. At both time points, the increment of (137)Cs-induced MN yields in PBL was positively correlated with the increment of intracellular ROS production (R = 0.6 - 0.7, P = 0.002), but negatively correlated with the reduction of TAC levels (R = -0.4 -0.5, P = 0.02 - 0.004). However, the presence of NAGE in the culture medium significantly increased the TAC levels, while concomitantly decreasing both ROS production and MN yields in PBL (P<0.001). Our findings that NAGE is effective in protecting human PBL against radiation-induced oxidative stress should encourage further in vivo study of dietary supplementation with NAGE as an effective natural radiation countermeasure.
人参的多种生物活性药用特性与其抗氧化能力密切相关，而抗氧化能力又与其人参皂苷含量有关。由于辐射诱导细胞死亡和组织损伤的关键机制是产生活性氧（ROS）攻击细胞DNA，本研究聚焦于标准化北美人参提取物（NAGE）对从10名健康个体（6名男性/4名女性）获取的人外周血淋巴细胞（PBL）中137Cs诱导的氧化应激的影响，这些个体年龄为42.7±4.6岁。在两个不同时间点（照射前0小时和24小时），我们将NAGE（250 - 1000微克/毫升）应用于单核细胞培养物，用于胞质分裂阻滞微核（MN）试验以及测定PBL中的氧化应激状态。我们发现，在两个时间点，NAGE均以浓度依赖方式显著降低了照射（1和2 Gy）后人PBL中的MN产量（P<0.001）。与单纯辐射相比，1 Gy和2 Gy照射后MN产量的最大降低率分别为51.1%和49.1%。我们还发现，照射前培养基中存在NAGE会导致PBL中细胞内总抗氧化能力（TAC）显著增加。在两个时间点，PBL中137Cs诱导的MN产量增加与细胞内ROS产生的增加呈正相关（R = 0.6 - 0.7，P = 0.002），但与TAC水平的降低呈负相关（R = -0.4 - 0.5，P = 0.02 - 0.004）。然而，培养基中存在NAGE会显著提高TAC水平，同时降低PBL中的ROS产生和MN产量（P<0.001）。我们的研究结果表明，NAGE能有效保护人PBL免受辐射诱导的氧化应激，这应促使进一步开展将NAGE作为有效的天然辐射防护措施进行膳食补充的体内研究。
