Effects of magnetic stimulation on tumors and immune functions

We investigate the effects of repetitive magnetic stimulation on tumors and immune functions. A circular coil (inner diameter=15mm, outer diameter=75 mm) is used in the experiments. Stimulus conditions are: peak magnetic field=0.25 T (at the center of the coil), frequency =25 pulses/s, 1000 pulses/sample/day, and magnetically induced eddy currents in mice=0.79-1.54 A/m². The sham group mice are placed in the same holders and exposed to the same noise produced during the stimulation. The tumor growth study shows a significant tumor weight decrease due to the application of magnetic stimulation (54% versus the sham group). An immunological assay is also performed to examine the effects of the magnetic stimulation on immune functions. An in vivo study, TNF-α and IL-2 productions in the spleen are measured after exposure of the magnetic stimulation three or seven times. TNF-α production significantly increases in the stimulated group (146%-164% versus the sham group). In an in vitro study, isolated spleen cells (lymphocytes) are exposed to the magnetic stimulation (25 pulses/s, 1000 pulses/sample, and eddy currents: 2.36-2.90 A/m²) and a proliferation assay is performed. The poliferation activity of the lymphocytes is up-regulated in the exposed samples. These results indicate that the immune functions might be activated by repetitive magnetic stimulation exposure, resulting in a tumor weight decrease.