Soft Laser Radiation Effects On Polyphenol Exposed Human T Leukemic Jurkat Cells

Beneficial effects in various pathological conditions of low power laser irradiation within the tissue transparency window of 600-1000 nm are yet far from being explained, as there are many aspects of polyphenols cellular effects. The aim of this study was to supply new data concerning changes occurring in viability and proliferation of Jurkat cells under the influence of various concentrations of hypericin or coumarin, as well as soft laser irradiation effects thereon. Jurkat cells were cultured in standard conditions, in presence/absence of Hypericin or Coumarin. We used radiations emitted by semiconductor lasers, and exposed the T cell suspensions to doses and irradiation regimes of therapeutic significance. Selecting appropriate molecular probes (JC-1, PI, Hoechst, AnnexinV-FITC, 7-AAD) the mitochondrial reticulum state, cell viability, proliferation rate, cell cycle progression, and percentage of apoptotic and necrotic cells were assessed by conventional, phase contrast, fluorescence microscopy, and flow cytometry. The data obtained demonstrate cell state, radiation wavelength, radiation dose, and irradiation regime dependent soft laser irradiation effects, as well as dose-dependent hypericin and coumarin influence on Jurkat cells behavior.Partial financial support of the Romanian Ministry of Education and Research (grants CNCSIS 924/2006, CEEX 6109/2005 and PN2-42139/2008) is gratefully acknowledged.