In vitro study of emodin-induced nephrotoxicity in human renal glomerular endothelial cells on a microfluidic chip

Emodin is an effective component of rhubarb with positive pharmacological effects on human health. However, it is also toxic to different cells or tissues to varying degrees. The effects of emodin on glomerular endothelial cells (GECs) remain to be tested, and the documented works were always performed in vitro and hardly reflect the real physiological situation. To study the effects of emodin on GECs in a biomimetic environment, we utilized a microfluidic chip to assess the physiological reaction of human renal glomerular endothelial cells to various concentrations of emodin in this work. The results showed that emodin caused cytotoxicity, impaired glomerular filtration barrier integrity to macromolecules, and increased barrier permeability in a dose-dependent manner. With the increase in emodin concentration, the concentration of the pro-inflammatory cytokine tumor necrosis factor-alpha, interleukin (IL)-6, transforming growth factor-beta 1, and monocyte chemoattractant protein (MCP-1) increased while the production of inflammatory cytokine IL-6 first increased and then decreased with the increase in emodin concentration. Our findings shed new light on emodin-induced nephrotoxicity and provide insights for the application of microfluidic chip devices to reveal drug-cell interactions.