Costa S, Utan A, Cervellati R, Speroni E, Guerra M C
Department of Pharmacology, Bologna University, via Irnerio 48, 40126 Bologna, Italy.
Food Chem Toxicol. 2007 Oct;45(10):1910-7. doi: 10.1016/j.fct.2007.04.008. Epub 2007 May 4.
Besides aflatoxin B1, recent findings suggested that oxidative stress plays an important role in the toxicity of an other mycotoxin: ochratoxin A (OTA). The protective effect of two catechins (epigallocatechin gallate, EGCG, and epicatechin gallate, ECG) against OTA-induced cytotoxicity was investigated in a pig kidney cell line (LLC-PK1). The ability of the catechins to reduce ROS production and DNA fragmentation induced by OTA was also investigated. Our experiments proved the significant cytoprotective effects of the molecules in vitro from OTA-induced cell damage. In particular a 24h pre-treatment with EGCG or ECG restored cell viability with respect to OTA alone. Pre-treatment with EGCG at low concentration for 8 days protected cells from OTA-induced cell death. Moreover both catechins reduced OTA-induced ROS production. A reduction of OTA-induced DNA fragmentation was found for LLC-PK1 cells pre-treated with EGCG and ECG. The free-radical scavenging capacity of both catechins was tested with the Briggs-Rauscher oscillating method (pH approximately 2) and the TEAC assay (pH 7.4). The results show a good scavenging power according with inhibition of ROS production. Catechins could be useful to develop alimentary strategies for both humans and animals to prevent OTA-induced cytotoxicity.
除黄曲霉毒素B1外，最近的研究结果表明，氧化应激在另一种霉菌毒素——赭曲霉毒素A（OTA）的毒性作用中起着重要作用。在猪肾细胞系（LLC-PK1）中研究了两种儿茶素（表没食子儿茶素没食子酸酯，EGCG，和表儿茶素没食子酸酯，ECG）对OTA诱导的细胞毒性的保护作用。还研究了儿茶素减少OTA诱导的活性氧（ROS）产生和DNA片段化的能力。我们的实验证明了这些分子在体外对OTA诱导的细胞损伤具有显著的细胞保护作用。特别是，用EGCG或ECG进行24小时预处理相对于单独使用OTA恢复了细胞活力。用低浓度EGCG预处理8天可保护细胞免受OTA诱导的细胞死亡。此外，两种儿茶素都减少了OTA诱导的ROS产生。在用EGCG和ECG预处理的LLC-PK1细胞中发现OTA诱导的DNA片段化减少。用Briggs-Rauscher振荡法（pH约为2）和TEAC测定法（pH 7.4）测试了两种儿茶素的自由基清除能力。结果表明，根据对ROS产生的抑制作用，它们具有良好的清除能力。儿茶素可能有助于开发针对人类和动物的饮食策略，以预防OTA诱导的细胞毒性。
