The Main Event
« Looking for some hot stuff… | Main | Best in show »
A closer look at low-light therapy
Monday 14.00 PT: On Sunday, prompted by Rox Anderson’s talk at the Hot Topics session (see previous post, “Looking for some hot stuff…”), I went along to listen to a couple of invited papers in a dedicated BiOS session on mechanisms for low-light-level therapy.
First up, Darayash Tata of the US Food and Drug Administration reported on an in vitro study of laser-induced modulations of the metabolic activities of malignant human-brain-cancer (glioblastoma) cells.
Tata and fellow investigator Ronald Waynant evaluated the efficacy of two light sources: a continuous-wave 633 nm wavelength helium-neon laser and a 1552 nm pulsed picosecond laser. During the study, glioblastoma cells were exposed in their growth-culture medium at several energy doses, with cellular metabolic activities measured via colorimetric assay three days after photo exposure.
Taken together, said Tata, “our findings reveal that optical or near-infrared low-level light exposures could potentially be a viable tool in reducing the metabolic activity of cancers.”
In terms of a working hypothesis, the current thinking is that laser-induced changes in metabolism may result from laser-generated production of hydrogen peroxide (a natural by-product of cell respiration). More research is needed, however, to work out the exposure parameters that would optimize metabolic and cellular-growth suppression in vivo.
A second invited paper, presented by Juanita Anders, a professor in the department of anatomy, physiology and genetics at the Uniformed Services University of the Health Sciences (Bethesda, MD), highlighted the regenerative effects of laser light in the treatment of spinal-cord injury (i.e. severe central-nervous-system trauma for which there are currently no treatments).
Worldwide, it’s estimated that there are 2.5 million people living with spinal-cord injury, with 130,000 new cases reported annually. All told, that equates to billions of dollars in acute and long-term care.
In recent years, Anders and her colleagues have carried out a number of light-therapy studies on rat models with spinal cord injury. The group’s latest in vivo data, presented here at BiOS, demonstrate that light delivered transcutaneously promotes regeneration of axons (nerve fibres) and functional recovery.
It’s early days, but Anders reckons the results are further evidence that low-level light is emerging as a “promising non-invasive therapy for acute spinal-cord injury”.
