Study type: Medical/biological study (experimental study)

Extremely low frequency electromagnetic fields modulate expression of inducible nitric oxide synthase, endothelial nitric oxide synthase and cyclooxygenase-2 in the human keratinocyte cell line HaCat: potential therapeutic effects in wound healing. med./bio.

Published in: Br J Dermatol 2010; 162 (2): 258-266

Aim of study (acc. to author)

To study the effect of extremely low frequency electromagnetic fields on the human keratinocytes cell line HaCaT in order to assess the mechanisms of action of extremely low frequency electromagnetic fields and to provide further support for their therapeutical use in wound healing.

Background/further details

It is known that expression and regulation of nitric oxide synthases and cyclooxygenase-2 are vital for wound healing, however, no reports demonstrated a direct action of extremely low frequency electromagnetic fields in the modulation of these inflammatory molecules in human keratinocytes.
In order to evaluate the effect of the electromagnetic field on the modulation of the cellular responses to an inflammatory stimulus, the HaCaT cells were partly treated with lipopolysaccharides.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 3 hr, 18 hr or 48 hr

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 3 hr, 18 hr or 48 hr
Exposure setup
Exposure source
Setup 22 cm long solenoid with 6 cm radius and 160 turns of 1.25 x 10-5 cm copper wire placed inside an incubator with constant temperature; cell cultures positioned in the center of the solenoid where the field was highly homogeneous (98%)
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT effective value measured - -

Reference articles

  • Vianale G et al. (2008): Extremely low frequency electromagnetic field enhances human keratinocyte cell growth and decreases proinflammatory chemokine production.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The exposure of HaCaT cells to extremely low frequency electromagnetic fields increased iNOS (in LPS-stimulated cells, 3 h exposure) and eNOS expression levels (in LPS-stimulated cells, all exposures). These exposure-dependent increased protein expressions were paralled by increased nitric oxide synthase enzyme activities (with and without LPS stimulation, all exposure durations), i.e. increased nitric oxide production. In addition, higher levels of activator protein-1 expression (with and without LPS stimulation) as well as a higher cell proliferation rate were associated to electromagnetic field exposure. In contrast, exposure decreased COX-2 expression (in LPS-stimulated cells, 3 h exposure), prostaglandin-E2 production (in LPS-stimulated cells) and catalase enzyme activity and O2- (superoxide) production (both with and without LPS stimulation).
The authors conclude that mediators of inflammation, such as reactive nitrogen, prostaglandin-E2 and keratinocytes cell proliferation are critical for the tissue regenerative processes. The ability of extremely low frequency electromagnetic field to upregulate nitric oxide synthase enzyme activities, thus nitrogen intermediates, as well as cell proliferation and to downregulate COX-2 expression and the downstream intermediate prostaglandin-2 highlights the potential therapeutic role of extremely low frequency electromagnetic field in wound healing processes.

Study character:

Study funded by

Related articles