Light emitting diode irradiation protect against the amyloid beta 25-35 induced apoptosis of PC12 cell in vitro

Background and Objectives: Whether light emitting diode (LED) irradiation has effects on beta-amyloid (Abeta) induced apoptosis, a leading hypothesis of the cause of Alzheimer's disease (AD), or not? Study Design/Materials and Methods: Monolayer cell cultures of PC12 were subjected to Abeta or/and LED irradiation at various intensity. Cell apoptosis was confirmed by morphological criteria, DNA fragmentation assay, and FAScan flow cytometer assay. Results: Treatment of the cells with LED irradiation significantly diminished Abeta induced apoptosis within 24 hours. Conclusions: The LED irradiation, when utilized at power of 0.9W/m(2) and 60 minutes has significantly diminished Abeta induced apoptosis of PC12 cells. (C) 2003 Wiley-Liss, Inc.