Cellular detection of 50 Hz magnetic fields and weak blue light: effects on superoxide levels and genotoxicity

Abstract

Purpose: We tested the hypothesis that the effects of 50 Hz magnetic fields (MFs) on superoxide levels and genotoxicity depend on the presence of blue light.

Materials and methods: Human SH-SY5Y neuroblastoma cells were exposed to a 50 Hz, 100 μT MF with or without non-phototoxic level of blue light for 24 h. We also studied whether these treatments alter responses to menadione, an agent that induces mitochondrial superoxide (O₂^{• -}) production and DNA damage. Micronuclei, proliferation, viability, cytosolic and mitochondrial O₂^{• -} levels were assessed.

Results: MF (without blue light) increased cytosolic O₂^{• -} production and blue light suppressed this effect. Mitochondrial O₂^{• -} production was reduced by both MF and blue light, but these effects were not additive. Micronucleus frequency was not affected by blue light or MF alone, but blue light (significantly when combined with MF) enhanced menadione-induced micronuclei.

Conclusions: The original simple hypothesis (blue light is needed for MF effects) was not supported, but interaction of MF and blue light was nevertheless observed. The results are consistent with MF effects on light-independent radical reactions.

Keywords:

• Extremely low frequency magnetic field
• blue light
• superoxide
• micronucleus
• in vitro

Acknowledgements

This study was supported by the strategic funding of the University of Eastern Finland. The authors wish to thank senior laboratory technician Ms Hanne Säppi for her invaluable assistance in laboratory analyses.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Additional information

Funding

This study was supported by the strategic funding of the University of Eastern Finland.