Picture of boy being examining by doctor at a tuberculosis sanatorium

Understanding our future through Open Access research about our past...

Strathprints makes available scholarly Open Access content by researchers in the Centre for the Social History of Health & Healthcare (CSHHH), based within the School of Humanities, and considered Scotland's leading centre for the history of health and medicine.

Research at CSHHH explores the modern world since 1800 in locations as diverse as the UK, Asia, Africa, North America, and Europe. Areas of specialism include contraception and sexuality; family health and medical services; occupational health and medicine; disability; the history of psychiatry; conflict and warfare; and, drugs, pharmaceuticals and intoxicants.

Explore the Open Access research of the Centre for the Social History of Health and Healthcare. Or explore all of Strathclyde's Open Access research...

Image: Heart of England NHS Foundation Trust. Wellcome Collection - CC-BY.

Cytotoxic responses to 405 nm light exposure in mammalian and bacterial cells : involvement of reactive oxygen species

Ramakrishnan, Praveen and Maclean, Michelle and MacGregor, Scott J. and Anderson, John G. and Grant, M. Helen (2016) Cytotoxic responses to 405 nm light exposure in mammalian and bacterial cells : involvement of reactive oxygen species. Toxicology in Vitro, 33. pp. 54-62. ISSN 0887-2333

[img]
Preview
Text (Ramakrishnan-etal-TiV2016-cytotoxic-responses-to-405-nm-light-exposure-in-mammalian-and-bacterial-cells)
Ramakrishnan_etal_TiV2016_cytotoxic_responses_to_405_nm_light_exposure_in_mammalian_and_bacterial_cells.pdf
Final Published Version
License: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 logo

Download (1MB) | Preview

Abstract

Light at wavelength 405 nm is an effective bactericide. Previous studies showed that exposing mammalian cells to 405 nm light at 36 J/cm2 (a bactericidal dose) had no significant effect on normal cell function, although at higher doses (54 J/cm2), mammalian cell death became evident. This research demonstrates that mammalian and bacterial cell toxicity induced by 405 nm light exposure is accompanied by reactive oxygen species production, as detected by generation of fluorescence from 6-carboxy-2’,7’- dichlorodihydrofluorescein diacetate. As indicators of the resulting oxidative stress in mammalian cells, a decrease in intracellular reduced glutathione content and a corresponding increase in the efflux of oxidised glutathione was observed from 405 nm light treated cells. The mammalian cells were significantly protected from dying at 54 J/cm2 in the presence of catalase, which detoxifies H2O2. Bacterial cells were significantly protected by sodium pyruvate (H2O2 scavenger) and by a combination of free radical scavengers (sodium pyruvate, dimethyl thiourea (OH scavenger) and catalase) at 162 and 324 J/cm2. Results herefore suggested that the cytotoxic mechanism of 405 nm light in mammalian cells and bacteria could be oxidative stress involving predominantly H2O2 generation, with other ROS contributing to the damage.