Copper-induced non-monotonic dose response in Caco-2 cells

  • Charles O’DohertyEmail author
  • Joanne Keenan
  • Karina Horgan
  • Richard Murphy
  • Finbarr O’Sullivan
  • Martin Clynes


Copper is an essential dietary micronutrient in humans for proper cell function; however, in excess, it is toxic. The human cell line Caco-2 is popular as an in vitro model for intestinal absorption and toxicology. This study investigated the response of exponentially growing Caco-2 cells to prolonged copper exposure (120 h). An unexpected non-monotonic dose-response profile was observed in Caco-2 cells. Exposure to media supplemented with 3.125 μM CuSO4 resulted in decreased cell yield vs. untreated. However, toxicity was progressively reduced from 90% at 3.125 μM to 60% at 25 μM. This effect was documented between 48 and 120 h continuous exposure (p < 0.05). This triphasic toxicity curve was observed to be specific to copper in Caco-2 cells, as iron, manganese and zinc displayed monotonic dose-response profiles. Two inorganic copper forms, copper sulphate and copper chloride, were shown to conserve the non-monotonic dose-response curve. The triphasic effect was shown to be specific to Caco-2 cells. These results have implications for research investigating the effect of copper and other micronutrients using Caco-2 cells.


Dose response Copper Caco-2 Triphasic Trace elements Toxicity 


Funding information

This work was funded by a joint Enterprise Ireland Innovative Partnership programme (IP/2015/0375).

Supplementary material

11626_2019_333_MOESM1_ESM.xlsx (10 kb)
ESM 1 (XLSX 10 kb)


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Copyright information

© The Society for In Vitro Biology 2019

Authors and Affiliations

  1. 1.National Institute for Cellular BiotechnologyDublin City UniversityDublinIreland
  2. 2.AlltechMeathIreland

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