The effects of alternating magnetic field (AMF) stimulation on the proliferation of human liver cancer cells
(HepG2) under varying frequencies from 500 Hz to 2 kHz were investigated. The AMF stimulator generated a
magnetic field of 5 mT with a saw tooth pulse waveform, the frequency of alternating pulses was controlled by
the duty factor of the digital control circuit. HepG2 cells were cultured in a 6-well plate over a magnetic coil
using a cooling system while been kept for 48 hours in an incubator. After magnetic stimulation of 0.5, 1 and 2
kHz, the proliferation rates of the HepG2 cells saw almost no difference compared to liver cancer cells that
were not stimulated. However, the proliferation rates at 1.4 kHz were reduced by up to 66 % compared to the
non-stimulated cells. In other words, HepG2 cancer cells can be suppressed by magnetic stimulation of a certain
frequency. These results are in good agreement with those from analysis of cell viability using MTT assay,
a colorimetric assay used for assessing cell metabolic activity. This phenomenon of a suppression frequency
may be related with various ionic flows that occur in the ion channels of cell membranes.