The Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China.
The Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China.
Carbohydr Polym. 2018 Sep 1;195:576-585. doi: 10.1016/j.carbpol.2018.04.110. Epub 2018 Apr 30.
Selenium (Se) is an essential element nutrient for human and animal health. Biogenic selenium nanoparticles (SeNPs) by microorganism possesses unique physical and chemical properties and biological activities compared to inorganic selenium and organic selenium. The study was conducted to establish a green, efficient and low-cost biotechnology for biogenic synthesis of SeNPs by Lactobacillus casei ATCC 393 (L. casei 393), and investigate its characteristics and antioxidant activities in vitro. The results showed that L. casei 393 transforms sodium selenite to SeNPs under anaerobic conditions. Moreover, 50-80 nm SeNPs were accumulated in the intracellular L. casei 393. The whole bacteria present distinct bright red color. SeNPs were isolated and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray photoelectron spectroscopy (XPS), and fourier transform infrared spectroscopy (FT-IR). The results showed that the extracted SeNPs were capped by proteins and polysaccharides. Extracted biogenic SeNPs by L. casei 393 at a concentration less than 25 μg Se/mL had no cytotoxicity on the growth and proliferation of human normal epithelial cell (NCM460). The toxicity order of different selenium forms was: Sodium selenite > Selenium methionine > SeNPs synthesized by L. casei 393. Moreover, biogenic SeNPs by L. casei 393 induced HepG2 cells apoptosis via caspase cascade signaling and endocytosis of SeNPs. Moreover, SeNPs alleviated diquat or hydrogen peroxide (HO)-caused oxidative damage in intestinal epithelial cells, and reduced malondialdehyde (MDA) concentration and increased glutathione peroxidase (GPx) activity in culture medium. The findings suggest that biomolecules capped-SeNPs synthesized by probiotic L. casei 393 possess significant antioxidant and anticancer activities, and probiotic bacteria can provide a better alternative to synthesize biogenic elemental selenium particles with potential applications as anticancer and antioxidant agents.
硒（Se）是人体和动物健康所必需的元素营养素。与无机硒和有机硒相比，微生物产生的生物硒纳米粒子（SeNPs）具有独特的物理化学性质和生物活性。本研究旨在建立一种绿色、高效、低成本的生物技术，通过干酪乳杆菌 ATCC 393（L. casei 393）生物合成 SeNPs，并研究其在体外的特性和抗氧化活性。结果表明，L. casei 393 在厌氧条件下将亚硒酸钠转化为 SeNPs。此外，在细胞内 L. casei 393 中积累了 50-80nm 的 SeNPs。整个细菌呈现出明显的鲜红色。通过透射电子显微镜（TEM）、扫描电子显微镜（SEM）、能量色散 X 射线能谱（EDX）、X 射线光电子能谱（XPS）和傅里叶变换红外光谱（FT-IR）对 SeNPs 进行了分离和表征。结果表明，提取的 SeNPs 被蛋白质和多糖包裹。L. casei 393 提取的浓度低于 25μg Se/mL 的生物合成 SeNPs 对人正常上皮细胞（NCM460）的生长和增殖没有细胞毒性。不同硒形态的毒性顺序为：亚硒酸钠＞硒蛋氨酸＞L. casei 393 合成的 SeNPs。此外，L. casei 393 合成的生物 SeNPs 通过半胱天冬酶级联信号和 SeNPs 的内吞作用诱导 HepG2 细胞凋亡。此外，SeNPs 减轻了百草枯或过氧化氢（HO）引起的肠上皮细胞氧化损伤，降低了培养基中丙二醛（MDA）浓度，增加了谷胱甘肽过氧化物酶（GPx）活性。研究结果表明，益生菌干酪乳杆菌 393 合成的生物被包裹的 SeNPs 具有显著的抗氧化和抗癌活性，益生菌可以提供更好的替代方法来合成具有潜在应用价值的生物元素硒颗粒作为抗癌和抗氧化剂。
