Excessive reactive oxygen radicals (ROS) produced by ionizing radiation (IR) can cause human body to serious oxidative damage, leading to oxidation-reduction (REDOX) system imbalance and immune system damage. Here, the radioprotection of EGCG was studied through a model of oxidative damage in 60Coγ radiation mice. Firstly, the weights and the main organs indexes of mice, including the liver index, spleen index and pancreas index, indicated preliminarily the safety and protection of EGCG. Then, the radioprotection of EGCG based on immune-regulation on radiation mice was further investigated. Results suggested that EGCG could prevent significantly the immune system damage caused by 60Coγ via increasing the immune organ index, inducing the transformation of spleen cells into T- and B-lymphocytes, and enhancing the macrophage phagocytosis, compared with model group. In addition, EGCG could also protect spleens of radiation mice from 60Coγ-induced the imbalance of REDOX system by enhancing the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), increasing the level of glutathione (GSH), suppressing lipid peroxidation (Malondialdehyde, MDA). The antioxidant enzymes activities of serum and livers were also increased markedly. Taken together, our results indicated that EGCG possessed the excellent potential to serve as a natural radioprotector against IR-induced damage.

中文翻译：

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基于免疫调节作用和抗60Coγ辐射诱发的小鼠抗氧化活性的EGCG的放射防护。

电离辐射（IR）产生的过多的活性氧自由基（ROS）会导致人体严重氧化损伤，从而导致氧化还原（REDOX）系统失衡和免疫系统受损。在这里，通过60Coγ辐射小鼠的氧化损伤模型研究了EGCG的放射防护。首先，小鼠的体重和主要器官指标，包括肝脏指标，脾脏指标和胰腺指标，初步表明了EGCG的安全性和保护性。然后，进一步研究了基于免疫调节的辐射小鼠对EGCG的辐射防护作用。结果表明，EGCG可通过提高免疫器官指数，诱导脾细胞转化为T淋巴细胞和B淋巴细胞以及增强巨噬细胞吞噬作用来显着预防60Coγ引起的免疫系统损害，与模型组相比。此外，EGCG还可以通过增强抗氧化酶超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）的活性，增加谷胱甘肽（GSH）的水平来保护60Coγ引起的REDOX系统失衡的辐射小鼠的脾脏，抑制脂质过氧化（丙二醛，MDA）。血清和肝脏的抗氧化酶活性也明显增加。综上所述，我们的结果表明，EGCG具有出色的潜力，可作为天然的辐射防护剂抵抗IR诱导的损伤。增加谷胱甘肽（GSH）的水平，抑制脂质过氧化（丙二醛，MDA）。血清和肝脏的抗氧化酶活性也明显增加。综上所述，我们的结果表明，EGCG具有出色的潜力，可作为天然的辐射防护剂抵抗IR诱导的损伤。增加谷胱甘肽（GSH）的水平，抑制脂质过氧化（丙二醛，MDA）。血清和肝脏的抗氧化酶活性也明显增加。综上所述，我们的结果表明，EGCG具有出色的潜力，可作为天然的辐射防护剂抵抗IR诱导的损伤。