Context-dependent effects of high-frequency pulsed electromagnetic fields on cytokine responses in human THP-1...

High-frequency pulsed electromagnetic fields (HF-EMF) are increasingly encountered in modern environments, yet their potential immunomodulatory effects remain unclear. Here, we investigated whether L-band pulsed HF-EMF modulate cytokine responses in human THP-1 monocytes under basal conditions or during lipopolysaccharide (LPS)-induced inflammation. Cells were exposed to pulsed electric fields at 4.6 or 7.3 kV/m, with two exposure regimens applied at each intensity (intermittent 30 s bursts or continuous 1 h exposure). Cell viability, morphology and lipid peroxidation (MDA) were assessed, and cytokine secretion was profiled by cytokine array and multiplex immunoassay, complemented by PCA and correlation network analyses. HF-EMF exposure did not induce cytotoxicity or marked oxidative damage. Under LPS stimulation, HF-EMF produced subtle yet consistent shifts in cytokine patterns, with trends toward attenuation of LPS-elevated mediators including VEGF, IL-6 and CCL17/TARC at higher field intensity. In unstimulated cells, cytokine levels remained largely unchanged, except for a reproducible decrease in basal VEGF under the highest exposure condition. Overall, these data support a context-dependent immunomodulatory effect of pulsed HF-EMF in human monocytes, warranting follow-up studies in more physiological models and with refined exposure characterization.