Introduction: Neutrophil Extracellular Traps (NETs) are extracellular structures produced by neutrophils. It’s generally consist of fibrous decondensed chromatins and antimicrobial proteins.The molecules externalized through NETs formation are considered to be key auto-antigens and might be involved in the generation of autoimmune responses.
Objective: This study aims to evaluate the inhibitory effect of oleuropein, phenylethanol, tyrosol and tysrosol3 on ROS dependent NETs production.
Methods: The natural molecules (oleuropein , phenylethanol , tyrosol and tyrosol3) were assessed for their capacity to inhibit NET formation on primary human neutrophils in vitro. First,we evaluated the toxic effects of the 4 molecules on neutrophils using the Trypan blue exclusion test. Since NETs formation is mostly ROS dependent we used the luminol-amplified chemiluminescence assay to detect the sum of intra and extracellular ROS. Fluorescence Microscopy was used to detect the presence of NETs with Hoechst as a DNA intercalating dye.
Results: Our results showed that our four molecules do not have an acute cytotoxic effect on neutrophils maintained in culture for 48 hours. A high anti-radical effect of these four molecules was translated by a strong inhibition of the production of superoxide anion by neutrophils. Fluroescence microscopy showed that the treatment of neutrophils with the four molecules has significantly reduced the production of NETs .
Conclusion: Our results revealed for the first time an inhibitory effect of four natural molecules on ROS-dependent NET release. These four molecules could be considered in the future as a palliative treatment for patients with autoimmune diseases.
