Abstract 1342: Effects of the plasticizer metabolite 2 ethyl-1-hexanol on human lymphoblast cells

Abstract

Abstract The study main objective was to determine the toxicity of 2-ethyl-1-hexanol (EH) and to compare them to its precursor di-ethylhexyl phthalate (DEHP) on the TK6 human lymphoblast cell line. EH is an organic alcohol produced in cells as result of the biotransformation of DEHP. Release of EH from lung cancer cells was also reported recently. Environmental human exposure to the parent DEHP can result through interaction with personal care products, paint lacquer, inks, rubber, dry cleaning and plasticizers such as PVC. Analyzed effects in this study included doses that inhibit cell growth (IC50), damage to the mitochondrial membrane, generation of Reactive Oxygen Species (ROS), and activation of caspase 3 and 7. TK6 cells were cultured on 12.5cm2 flasks with modified RPMI 1640 culture media with 10% FBS, and incubated at 37°C with 5% CO2. IC50 was determined by trypan blue exclusion and mitochondrial membrane permeability applying the Mito PT JC-1 assay from Immunochemistry. For ROS determination the fluorescent dye 2,7-dichlorofluorescein diacetate (DCFH-DA) was applied. For caspases 3 and 7 analysis the Magic RedTM assay from Immunochemistry was applied. Results indicated that IC50s of DEHP and EH on TK6 cells were 234 μM and 75nM respectively. Cells where then exposed to the identified IC50 for 48 hours to measure effects on mitochondria and ROS generation. ROS results indicated that EH generated an average of 96.31 Fluorescence Standard Units (FSU), the negative control Dimethyl Sulphoxide (DMSO) generated 58.22 FSU, the compound used as positive control cis-Di ammine platinum (II) dichloride (Cisplatin) generated 1309.67 FSU and for DEHP the ROS analysis resulted on 793.27 FSU. The level of ROS generated between the parent and this metabolite are not consistent with the degree of toxicity observed. Determination and comparison of the mitochondrial membrane permeabilization as well as Caspases 3 and 7-activation assays of EH are still developing. The preliminary results, however indicates a wide difference in citotoxicity between the parent compound and its metabolite clearly supporting the need for prevention strategies reducing exposure to these controversial plasticizer and therefore potential health effects. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1342. doi:10.1158/1538-7445.AM2011-1342