A method to determine reactive oxygen species production in intestinal and liver cell cultures using the 2′,7′-dichlorodihydrofluorescein diacetate assay

Exposure to xenobiotics can increase the production of reactive oxygen species (ROS). When detoxification organs such as the intestines and liver cannot neutralise these xenobiotics, it can induce oxidative stress and cause damage to tissues. Therefore, cell-based bioassays that indicate intracellular ROS production are a useful screening tool to evaluate the effect of these chemicals. Although flow cytometry is commonly used to measure ROS in cells, many research laboratories in the Global South do not always have access to such specialised instrumentation. Therefore, we describe a sensitive but low-cost method that can easily be used to determine ROS production in vitro. This method employs the fluorogenic dye, 2′,7′-dichlorodihydrofluorescein diacetate (H2DCF-DA), which emits fluorescence after being oxidised to a fluorescent derivative. Since the H2DCF-DA bioassay indicates non-specific ROS production it can be used as a marker of overall oxidative stress. This method was validated by exposing human duodenum epithelial adenocarcinoma (HuTu-80) and rat liver epithelial hepatoma (H4IIE-luc) cells to agricultural soil samples. • Production of ROS can be determined in vitro in intestinal and liver cells. • This method is inexpensive and can be easily performed in standard laboratories. • The method provides a tool for the high-throughput screening of environmental samples.