Chronic exposure of low dose salinomycin inhibits MSC migration capability in vitro

Salinomycin is a polyether antiprotozoal antibiotic that is used as a food additive, particularly in poultry farming. By consuming animal products, there may be a chronic human exposure to salinomycin. Salinomycin inhibits the differentiation of preadipocytes into adipocytes. As human mesenchymal stem cells (MSC) may differentiate into different mesenchymal cells, it thus appeared worthwhile to investigate whether chronic salinomycin exposure impairs the functional properties of MSC and induces genotoxic effects. Bone marrow MSC were treated with low-dose salinomycin (100 nM) (MSC-Sal) for 4 weeks, while the medium containing salinomycin was changed every other day. Functional changes were evaluated and compared to MSC without salinomycin treatment (MSC-control). MSC-Sal and MSC-control were positive for cluster of differentiation 90 (CD90), CD73 and CD44, and negative for CD34. There were no differences observed in cell morphology or cytoskeletal structures following salinomycin exposure. The differentiation into adipocytes and osteocytes was not counteracted by salinomycin, and proliferation capability was not inhibited following salinomycin exposure. The migration of MSC-Sal was attenuated significantly as compared to the MSC-control. There were no genotoxic effects after 4 weeks of salinomycin exposure. The present study shows an altered migration capacity as a sign of functional impairment of MSC induced by chronic salinomycin exposure. Further in vitro toxicological investigations, particularly with primary human cells, are required to understand the impact of chronic salinomycin consumption on human cell systems.