Inhibitory Effects of Far-Infrared Irradiation Generated by Ceramic Material on Murine Melanoma Cell Growth

Abstract

The biological effects of specific wavelengths, so-called “far-infrared radiation” produced from ceramic material (cFIR), on whole organisms are not yet well understood. In this study, we investigated the biological effects of cFIR on murine melanoma cells (B16-F10) at body temperature. cFIR irradiation treatment for 48 h resulted in an 11.8% decrease in the proliferation of melanoma cells relative to the control. Meanwhile, incubation of cells with cFIR for 48 h significantly resulted in 56.9% and 15.7% decreases in the intracellular heat shock protein (HSP)70 and intracellular nitric oxide (iNO) contents, respectively. Furthermore, cFIR treatment induced 6.4% and 12.3% increases in intracellular reactive oxygen species stained by 5-(and 6)-carboxyl-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>2</mml:mn><mml:mo>′</mml:mo></mml:msup></mml:math>,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>7</mml:mn><mml:mo>′</mml:mo></mml:msup></mml:math>-dichlorodihydrofluorescein diacetate and dihydrorhodamine 123, respectively. Since malignant melanomas are known to have high HSP70 expression and iNO activity, the suppressive effects of cFIR on HSP70 and NO may warrant future interest in antitumor applications.