In vitro studies on radioprotective efficacy of silymarin against γ-irradiation
In vitro studies on radioprotective efficacy of silymarin against γ-irradiation
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DOI：
10.3109/09553002.2013.741285
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发表时间：
2013-03-01
影响因子：
2.6
通讯作者：
Arora, Rajesh
中科院分区：
文献类型：
--
作者：
Adhikari, Manish;Dhaker, Atlar;Arora, Rajesh
目的：水飞蓟素因其肝保护作用而被广泛开发。本研究旨在评价水飞蓟素对γ辐射的保护作用。材料与方法：采用不同的测定方法研究水飞蓟素的防辐射性能。采用3-（4,5-二甲基噻唑-2-基）-2,5-二苯基溴化四氮唑（MTT）法评价水飞蓟素对人胚胎肾（HEK）细胞的细胞毒性。通过研究使用2',7'-二氯二氢氟素双乙酸酯（H(2)DCFDA）减少微核频率和自由基生成来评估对γ辐射的保护效果。通过膜联蛋白V-PI（碘化丙啶）分析和细胞周期分析评估辐射诱导的细胞凋亡。采用流式细胞术和彗星法分别测定γ辐射诱导的线粒体膜电位（MMP）变化和DNA损伤。结果：MTT试验和Annexin V-PI研究表明，水飞蓟素对HEK细胞有保护作用。细胞凋亡明显减少（76.36%）。水飞蓟素还能降低辐射诱发微核率（>69%）（p < 0.05）。H(2)DCFDA测定细胞内活性氧（ROS）在0.5 H时减少了21%。细胞周期分析显示，未照射对照组的G(1)阻滞在水飞蓟素预处理照射组（0.5 H）下降。水飞蓟素处理导致MMP （2 h）显著高于辐射对照。此外，水飞蓟素在辐照期间的存在显著降低了DNA损伤（通过彗星测定）。结论：水飞蓟素对辐射诱导的细胞死亡和DNA损伤的保护作用可能归因于γ辐射诱导的ROS的减少。体外HEK细胞实验明确证明水飞蓟素是一种有前途、有效、安全的辐射对抗剂。
Purpose : Silymarin has been widely exploited for its hepatoprotective activities. This study aimed to evaluate the protective efficacy of silymarin against gamma-radiation.Materials and methods: The radioprotective properties of silymarin were studied using different assays. Cytotoxicity of silymarin on Human embryonic kidney (HEK) cells was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Protective efficacy against gamma-radiation was assessed by studying reduction in micronuclei frequency and free radical generation using 2',7'-dichlorodihydroflurescin diacetate (H(2)DCFDA). Radiation-induced apoptosis was estimated by Annexin V-PI (propidium iodide) analysis and cell cycle analysis. gamma-radiation induced changes in mitochondrial membrane potential (MMP) and DNA damage was estimated employing flow-cytometry and comet assay respectively.Results : MTT assay and Annexin V-PI studies showed that pre-incubation of HEK cells with silymarin protected them from gamma-irradiation. Significant reduction in apoptosis (76.36%) was observed. Silymarin also decreased the percentage of radiation-induced micronuclei (>69%) (p < 0.05). Measurement of intracellular reactive oxygen species (ROS) by H(2)DCFDA revealed a reduction in ROS (21%) at 0.5 h. Cell cycle analysis revealed G(1) block in the unirradiated control, which declined in the silymarin pretreated irradiated group (0.5 h). Silymarin treatment resulted in a significant increase in MMP (2 h) against the radiation control. Moreover, the presence of silymarin during irradiation significantly decreased the DNA damage (as measured by comet assay).Conclusions : Protection against radiation-induced cell-death and DNA damage by silymarin could be attributed to a reduction in ROS induced by gamma-radiation. In vitro experiments on HEK cells explicitly prove that silymarin is a promising, effective and safe radiation countermeasure agent.