Increased mobility and stem-cell proliferation rate in Dugesia tigrina induced by 880nm light emitting diode

J Photochem Photobiol B. 2011 Feb 7;102(2):156-60. doi: 10.1016/j.jphotobiol.2010.11.003. Epub 2010 Nov 24.


The therapeutic effects elicited by photobiostimulation in the near infrared range may be associated with increased proliferation rate of particular cell-types. The present study utilized commercial light emitting diodes to investigate the effects of low-level near-infrared radiation on the proliferation rate of stem cells in amputated planarian. Whole and amputated animals were exposed to either ambient diurnal lighting, darkness, white light, red light, or near-infrared (880 nm) light. Irradiation was consistent for the duration of the experiments and was provided using commercial 5mm light emitting diodes (∼1.0 mW/m(2) in power density and ∼0.01 J/cm(2) in radiant exposure). Compared to other groups amputated planarian exposed to near-infrared displayed increased mobility by the 3rd day of exposure (F((4,26))=4.31, p<0.04, η(2)=41%). Higher densities of stem cells were measured in these worms 84 h post injury (F((4,72))=4.78, p<0.01, η(2)=21%). These findings suggest that non-coherent light sources with power-densities about 1000 times lower than contemporary low-power laser settings remain effective in generating photobiostimulation effects and warrants further investigation on stem-cell proliferation induced by near-infrared light emitting diodes.

MeSH terms

  • Animals
  • Cell Movement
  • Cell Proliferation
  • Low-Level Light Therapy
  • Planarians / cytology
  • Planarians / radiation effects*
  • Stem Cells / cytology*
  • Time Factors