He-Ne laser irradiation protects B-lymphoblasts from UVA-induced DNA damage

Abstract

The effect of He-Ne laser (632.8 nm) pre-irradiation on UVA (343 nm)-induced DNA damage in the human B-lymphoblast cell line NC37 was investigated using the comet assay. He-Ne laser pre-irradiation was observed to result in a dose-dependent decrease in UVA-induced DNA damage. This effect was also found to be dependent on the incubation period between He-Ne laser pre-irradiation and the UVA exposure. Whereas the control cells with a higher DNA damage point to an initial ability of faster repair, both the control and the He-Ne laser pre-irradiated cells subsequently show the same rate of DNA repair. The results suggest that He-Ne laser irradiation protect the cells from UVA-induced DNA damage primarily through an influence on processes that prevent an initial DNA damage.

Direct 1O2 optical excitation: A tool for redox biology

“…Several experimental aspects are detailed in each entry (see footnotes for more information). Each set of conditions has been obtained from a publication, with the particular reference provided in each case. Transition Biological model Light source Wavelength Power Spectral control 1 O 2 scavenging 1 O 2 enhancement Thermal control Reference 633 nm Human erythrocytesDye laser (pulsed)633 nm–YesNoNoNo[108]Human erythrocytesHe-Ne laser (cw)632.8 nm38–50 mWNopArpO 2 Yes[108]NC-37 lymphoblast lineHe-Ne laser (cw)633 nm1.2 mWNoNoNoNo[177]A2058 melanoma lineHe-Ne laser (cw)632.8 nm7 mWNoNoNoYes[178]Human skin fibroblastsHe-Ne laser (cw)632.8 nm18.8 mWYesNoNoYes[143]MCF-7 breast cancer lineHe-Ne laser (cw)632.8 nm14 mWNoNoNoNo[141]-A549Diode laser (cw)635 nm–No-SODNoNo[181]-EMT6-NAC-ASTC-a-1-EMT6 tumors in miceDiode laser (cw)635 nm–NoNoNoNo[181]-ASTC-a-1 tumors in mice-A549 adenocarcinomaLED (cw)637±17 nm–YesNoNoYes[146]-PtK2 renal line-U2OS osteosarcomaClinical trials in womenDiode laser (cw)…”

Multiple roles of cytochrome c oxidase in mammalian cells under action of red and IR‐A radiation

“…At the present-day level of knowledge, one can suggest that the stimulating action of visible-to-near IR region of the optical spectrum on cytochrome c oxidase may perform, under certain circumstances, a protective function on cells against the harmful effects of c-rays (21-23) or environmental pollution (e.g., various chemicals, (11), or else other spectral regions of sunlight, e.g. UV (24)(25)(26). It was suggested that radioprotective action of He-Ne laser irradiation before c-irradiation might occur due to a shift in the cellular redox state by laser preirradiation (11).…”

He–Ne laser (632.8 nm) pre‐irradiation gives protection against DNA damage induced by a near‐infrared trapping beam

“…In this context it is important to note that pre-irradiation with He--Ne laser has been observed to protect wild type E. coli [6,7] against UVC and B-lymphoblast cells against UVA [8] radiation induced damage, which is also believed to be mediated predominantly via ROS generation [9]. Therefore we investigated the possibility of using He--Ne laser pre-irradiation to minimize 1064 nm trapping beam induced adverse effects in cell.…”

“…Since pre-irradiation with He--Ne laser beam is expected to generate singlet oxygen at a sub-lethal concentration leading to activation of the DNA repair machinery [6,8], the incubation time (duration for which the cells are grown at 37 C temperature after He--Ne laser pre-irradiation and before irradiation with trapping beam) can influence the observed protection. Hence, the impact of incubation time on the protective effect of He--Ne laser preirradiation was investigated and the results are shown in figure 3.…”