Online Measurement of Real-Time Cytotoxic Responses Induced by Multi-Component Matrices, such as Natural Products, through Electric Cell-Substrate Impedance Sensing (ECIS)

Abstract

Natural products are complex matrices of compounds that are prone to interfere with the label-dependent methods that are typically used for cytotoxicity screenings. Here, we developed a label-free Electric Cell-substrate Impedance Sensing (ECIS)-based cytotoxicity assay that can be applied in the assessment of the cytotoxicity of natural extracts. The conditions to measure the impedance using ECIS were first optimized in mice immortalized hypothalamic neurons GT1-7 cells. The performance of four natural extracts when tested using three conventional cytotoxicity assays in GT1-7 cells, was studied. Betula pendula (silver birch tree) was found to interfere with all of the cytotoxicity assays in which labels were applied. The silver birch extract was also proven to be cytotoxic and, thus, served as a proof-of-concept for the use of ECIS. The extract was fractionated and the ECIS method permitted the distinction of specific kinetic patterns of cytotoxicity on the fractions as well as the extract’s pure constituents. This study offers evidence that ECIS is an excellent tool for real-time monitoring of the cytotoxicity of complex extracts that are difficult to work with using conventional (label-based) assays. Altogether, it offers a very suitable cytotoxicity-screening assay making the work with natural products less challenging within the drug discovery workflow.

SEM and ECIS Investigation of Cells Cultured on Nanopillar Modified Interdigitated Impedance Electrodes for Analysis of Cell Growth and Cytotoxicity of Potential Anticancer Drugs

“…Consequently, a drastic change in the measured impedance due to the cell attachment and spreading can be measured [15][16][17]. ECIS is able to provide quantitative information with respect to cell morphological changes, cell movements, and alteration in cellular function in cultures exposed to various drugs, chemicals, and biochemical treatments [18][19][20][21]. Since cells are sensitive to pollutants, drugs, and toxins, this type of biosensor has been proven as a reliable predictor of cytotoxicity to represent the general cell response resulting from a variety of inhibition mechanisms [22].…”