School of Life Sciences, Zhengzhou University, Zhengzhou, Henan 450001, China.
Zhengzhou Mindtek Biological Technology Co. Ltd., Zhengzhou, Henan 450001, China.
J Dairy Sci. 2021 Sep;104(9):9532-9542. doi: 10.3168/jds.2021-20291. Epub 2021 Jul 1.
Ionizing radiation (IR) is widely used in the diagnosis and treatment of various cancers. However, IR can cause damage to human health by producing reactive oxygen species. Lactococcus lactis is a type of microorganism that is beneficial to human health and has a strong antioxidant capacity. In this study, the protective effect of normal and IR-induced L. lactis IL1403 cell-free extracts (CFE and IR-CFE, respectively) against oxidative damage in vitro and the radioprotective effect of IR-CFE in vivo was evaluated using Coγ-induced oxidative damage model in mice. Results showed that IR-CFE exhibited a stronger oxidative damage-protective effect than CFE for L. lactis IL1403 under HO in vitro. Moreover, IR-CFE also showed strong radioprotective effect on hepatocyte cells (AML-12) under radiation condition, and the effect was better than that of CFE. Animal experiment indicated that IR-CFE could reduce the IR-induced damage to the hematopoietic system by increasing the number of white blood cells and red blood cells in peripheral blood of irradiated mice. It was also observed that IR-CFE could markedly alleviate the Coγ-induced oxidative stress via increasing the activities of superoxide dismutase and glutathione peroxidase, enhancing the levels of glutathione, and decreasing the contents of malondialdehyde in serum, liver, and spleen. In addition, IR-CFE also could reduce the activities of alanine transaminase and aspartate aminotransferase in serum, thereby reducing radiation damage to the liver. These results suggested that IR-CFE could be considered as potential candidates for natural radioprotective agents. This study provides a theoretical basis for improving the application of lactic acid bacteria.
电离辐射（IR）广泛应用于各种癌症的诊断和治疗。然而，IR 通过产生活性氧物种会对人体健康造成损害。乳球菌（Lactococcus lactis）是一种有益于人类健康且具有强大抗氧化能力的微生物。在这项研究中，使用 Coγ 诱导的小鼠氧化损伤模型，评估了正常和 IR 诱导的乳球菌 IL1403 无细胞提取物（CFE 和 IR-CFE）对体外氧化损伤的保护作用和 IR-CFE 的体内放射保护作用。结果表明，IR-CFE 在体外 HO 条件下对 L. lactis IL1403 的氧化损伤保护作用强于 CFE。此外，IR-CFE 对辐射条件下的肝细胞（AML-12）也具有很强的放射保护作用，效果优于 CFE。动物实验表明，IR-CFE 可以通过增加辐照小鼠外周血白细胞和红细胞的数量来减少 IR 对造血系统的损伤。还观察到，IR-CFE 可以通过增加超氧化物歧化酶和谷胱甘肽过氧化物酶的活性、提高谷胱甘肽水平、降低血清、肝脏和脾脏中丙二醛的含量，显著减轻 Coγ 诱导的氧化应激。此外，IR-CFE 还可以降低血清中丙氨酸转氨酶和天冬氨酸转氨酶的活性，从而减轻肝脏的辐射损伤。这些结果表明，IR-CFE 可以被认为是天然放射保护剂的潜在候选物。本研究为提高乳酸菌的应用提供了理论依据。
