Photobiomodulation reduces hippocampal apoptotic cell death and produces a Raman spectroscopic "signature"

• Published in: PloS one Vol. 17; no. 3; p. e0264533
• Main Authors: Davies, David J, Hadis, Mohammed, Di Pietro, Valentina, Lazzarino, Giuseppe, Forcione, Mario, Harris, Georgia, Stevens, Andrew R, Soon, Wai Cheong, Goldberg Oppenheimer, Pola, Milward, Michael, Belli, Antonio, Palin, William M
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03.03.2022; Public Library of Science (PLoS)
• Subjects: Aging; Animal tissues; Animals; Apoptosis; Biochemistry; Bioengineering; Biology and Life Sciences; Brain; Brain Injuries, Traumatic - metabolism; Brain research; Cell death; Contusions; Dentistry; Fibroblasts; Head injuries; Health aspects; Hippocampus; Hippocampus - metabolism; Hospitals; Inflammation; Injuries; Injury prevention; Irradiation; Light; Light therapy; Low-Level Light Therapy - methods; Medical research; Medicine and Health Sciences; Methods; Neurosciences; Ophthalmology; Photobiology; Physical Sciences; Radiation; Raman spectroscopy; Rats; Research and Analysis Methods; Spectroscopic observation; Spectrum Analysis, Raman; Traumatic brain injury; Wound healing; United Kingdom; United Kingdom > UK
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0264533

Apoptotic cell death within the brain represents a significant contributing factor to impaired post-traumatic tissue function and poor clinical outcome after traumatic brain injury. After irradiation with light in the wavelength range of 600-1200 nm (photobiomodulation), previous investigations have reported a reduction in apoptosis in various tissues. This study investigates the effect of 660 nm photobiomodulation on organotypic slice cultured hippocampal tissue of rats, examining the effect on apoptotic cell loss. Tissue optical Raman spectroscopic changes were evaluated. A significantly higher proportion of apoptotic cells 62.8±12.2% vs 48.6±13.7% (P<0.0001) per region were observed in the control group compared with the photobiomodulation group. After photobiomodulation, Raman spectroscopic observations demonstrated 1440/1660 cm-1 spectral shift. Photobiomodulation has the potential for therapeutic utility, reducing cell loss to apoptosis in injured neurological tissue, as demonstrated in this in vitro model. A clear Raman spectroscopic signal was observed after apparent optimal irradiation, potentially integrable into therapeutic light delivery apparatus for real-time dose metering.