Isoflurane and sevoflurane increase interleukin-6 levels through the nuclear factor-kappa B pathway in neuroglioma cells.

BACKGROUND Isoflurane can increase pro-inflammatory cytokine interleukin (IL)-6 levels. However, the up-stream mechanism remains unknown. Nuclear factor-kappa B (NF-κB) promotes the generation of pro-inflammatory cytokines. We examined the effects of isoflurane and sevoflurane on the NF-κB signalling pathway and its association with IL-6 levels in cultured cells. METHODS H4 human neuroglioma cells (H4 cells), and mouse primary neurones and microglia were treated with 2% isoflurane or 4.1% sevoflurane for 6 h, for analysis of IL-6 and NF-κB. Pyrrolidine dithiocarbamate (an NF-κB inhibitor) or 2-deoxy-d-glucose (2-DG) (an inhibitor of glucose glycolysis) was applied 1 h before anaesthetic treatment. RESULTS Isoflurane or sevoflurane treatment increased the levels of IL-6 [isoflurane: 410% (54); sevoflurane: 290% (24)], the nuclear levels of NF-κB [isoflurane: 170% (36); sevoflurane: 320% (30)], and the transcription activity of NF-κB in H4 cells. Moreover, isoflurane enhanced the transcription activity of NF-κB in mouse microglia, but not primary neurones. Finally, pyrrolidine dithiocarbamate and 2-DG attenuated isoflurane-induced increases in IL-6 and NF-κB, and the transcription activity of NF-κB. CONCLUSIONS These studies in H4 cells suggest that the NF-κB signalling pathway could contribute to isoflurane or sevoflurane-induced neuroinflammation. This could lead to the targeted intervention of anaesthetic-induced neuroinflammation.