School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, 264005, People's Republic of China.
School of Chemistry and Chemical Engineering, Yantai University, Yantai, 264005, People's Republic of China.
Part Fibre Toxicol. 2023 Mar 10;20(1):8. doi: 10.1186/s12989-023-00519-9.
Montmorillonite (Mt) and its derivatives are now widely used in industrial and biomedical fields. Therefore, safety assessments of these materials are critical to protect human health after exposure; however, studies on the ocular toxicity of Mt are lacking. In particular, varying physicochemical characteristics of Mt may greatly alter their toxicological potential. To explore the effects of such characteristics on the eyes, five types of Mt were investigated in vitro and in vivo for the first time, and their underlying mechanisms studied.
The different types of Mt caused cytotoxicity in human HCEC-B4G12 corneal cells based on analyses of ATP content, lactate dehydrogenase (LDH) leakage, cell morphology, and the distribution of Mt in cells. Among the five Mt types, Na-Mt exhibited the highest cytotoxicity. Notably, Na-Mt and chitosan-modified acidic Na-Mt (C-H-Na-Mt) induced ocular toxicity in vivo, as demonstrated by increases corneal injury area and the number of apoptotic cells. Na-Mt and C-H-Na-Mt also induced reactive oxygen species (ROS) generation in vitro and in vivo, as indicated by 2',7'-dichlorofluorescin diacetate and dihydroethidium staining. In addition, Na-Mt activated the mitogen-activated protein kinase signaling pathway. The pretreatment of HCEC-B4G12 cells with N-acetylcysteine, an ROS scavenger, attenuated the Na-Mt-induced cytotoxicity and suppressed p38 activation, while inhibiting p38 activation with a p38-specific inhibitor decreased Na-Mt-induced cytotoxicity.
The results indicate that Mt induces corneal toxicity in vitro and in vivo. The physicochemical properties of Mt greatly affect its toxicological potential. Furthermore, ROS generation and p38 activation contribute at least in part to Na-Mt-induced toxicity.
蒙脱石（Mt）及其衍生物目前广泛应用于工业和生物医学领域。因此，这些材料在暴露后对人体健康的安全性评估至关重要；然而，关于 Mt 的眼毒性研究还很缺乏。特别是，Mt 的不同物理化学特性可能会极大地改变其毒理学潜力。为了探讨这些特性对眼睛的影响，首次在体外和体内研究了五种类型的 Mt，并研究了它们的潜在机制。
基于对 ATP 含量、乳酸脱氢酶（LDH）泄漏、细胞形态和 Mt 在细胞中分布的分析，五种类型的 Mt 均导致人 HCEC-B4G12 角膜细胞的细胞毒性。在这五种 Mt 类型中，Na-Mt 的细胞毒性最高。值得注意的是，Na-Mt 和壳聚糖修饰的酸性 Na-Mt（C-H-Na-Mt）在体内引起眼毒性，表现为角膜损伤面积和凋亡细胞数量增加。Na-Mt 和 C-H-Na-Mt 还在体外和体内诱导活性氧（ROS）的产生，如 2'，7'-二氯荧光素二乙酸酯和二氢乙啶染色所示。此外，Na-Mt 激活丝裂原活化蛋白激酶信号通路。HCEC-B4G12 细胞用 ROS 清除剂 N-乙酰半胱氨酸预处理可减轻 Na-Mt 诱导的细胞毒性，并抑制 p38 激活，而用 p38 特异性抑制剂抑制 p38 激活可降低 Na-Mt 诱导的细胞毒性。
这些结果表明 Mt 在体外和体内引起角膜毒性。Mt 的物理化学性质极大地影响其毒理学潜力。此外，ROS 的产生和 p38 的激活至少部分导致了 Na-Mt 诱导的毒性。
