Department of Biochemistry and Molecular Biology, Federal University of Ceara, 60020-181 Fortaleza, CE, Brazil.
WFSR, Wageningen University and Research Centre, P.O. Box 230, 6700 AE Wageningen, the Netherlands.
Toxicol In Vitro. 2020 Jun;65:104824. doi: 10.1016/j.tiv.2020.104824. Epub 2020 Mar 10.
Soybean toxin (SBTX) is a protein isolated from soybean seeds and composed of two polypeptide subunits (17 and 27 kDa). SBTX has in vitro activity against phytopathogenic fungi such as Cercospora sojina, Aspergillus niger, and Penicillium herguei, and yeasts like Candida albicans, C. parapsilosis, Kluyveromyces marxiannus, and Pichia membranifaciens. The present study aimed to analyze in vitro whether SBTX causes any side effects on non-target bacterial and mammalian cells that could impede its potential use as a novel antifungal agent. SBTX at 100 μg/mL and 200 μg/mL did not hinder the growth of the bacteria Salmonella enterica (subspecies enterica serovar choleraesuis), Bacillus subtilis (subspecies spizizenii) and Staphylococcus aureus. Moreover, SBTX at concentrations up to 500 μg/mL did not significantly affect the viability of erythrocytes, neutrophils, and human intestinal Caco-2 cells. To study whether SBTX could induce relevant alterations in gene expression, in vitro DNA microarray experiments were conducted in which differentiated Caco-2 cells were exposed for 24 h to 100 μg/mL or 200 μg/mL SBTX. SBTX up-regulated genes involved in cell cycle and immune response pathways, but down-regulated genes that play a role in cholesterol biosynthesis and platelet degranulation pathways. Thus, although SBTX did not affect bacteria, nor induced cytotoxity in mammalian cells, it affected some biological pathways in the human Caco-2 cell line that warrants further investigation.
大豆毒素（SBTX）是从大豆种子中分离得到的一种蛋白质，由两个多肽亚基（17 和 27 kDa）组成。SBTX 在体外对植物病原菌真菌如大豆褐斑病菌、黑曲霉和青霉属有活性，对酵母如白色念珠菌、近平滑念珠菌、马克斯克鲁维酵母和膜毕赤酵母也有活性。本研究旨在分析 SBTX 在体外是否对非靶标细菌和哺乳动物细胞产生任何副作用，从而阻碍其作为新型抗真菌剂的潜在用途。SBTX 在 100 μg/mL 和 200 μg/mL 时不会抑制细菌肠炎沙门氏菌（亚种 enterica 血清型 choleraesuis）、枯草芽孢杆菌（亚种 spizizenii）和金黄色葡萄球菌的生长。此外，SBTX 浓度高达 500 μg/mL 时，对红细胞、嗜中性粒细胞和人肠道 Caco-2 细胞的活力没有显著影响。为了研究 SBTX 是否能诱导相关基因表达的改变，进行了体外 DNA 微阵列实验，其中分化的 Caco-2 细胞暴露于 100 μg/mL 或 200 μg/mL 的 SBTX 24 小时。SBTX 上调了参与细胞周期和免疫反应途径的基因，但下调了参与胆固醇生物合成和血小板脱颗粒途径的基因。因此，尽管 SBTX 不影响细菌，也不诱导哺乳动物细胞的细胞毒性，但它影响了人 Caco-2 细胞系中的一些生物学途径，这需要进一步研究。
