Photobiomodulation at Multiple Wavelengths Differentially Modulates Oxidative Stress In Vitro and In Vivo

Figure 3

Real-time evaluation of the effect of PBM on the redox status in HaCaT cells using genetically encoded fluorescent sensors. (a–d) Cells were treated with PBM at the indicated wavelength (660 nm in (a), 800 nm in (b), and 970 nm in (c) and the combination of the three wavelengths in (d)) and subsequently exposed to 0.5 mM H₂O₂. Measurement of fluorescence started immediately after exposure to oxidative stress. Data are the means ± SD. Signals recorded in treated cells and in cells treated only with PBM are also plotted. (e) Representative images of the fluorescence intensity at 405 nm (left) and 488 nm (center) and transmitted light (right) of the same cells at baseline (upper raw) and upon treatment with 0.5 mM H₂O₂ (lower raw). (f–i) Cells were first treated with 0.5 mM H₂O₂ and subsequently exposed to PBM at the indicated wavelength (660 nm in (a), 800 nm in (b), and 970 nm in (c) and the combination of the three wavelengths in (d)). Measurement of fluorescence started 20 seconds prior to the exposure to oxidative stress. Data are the means ± SD.

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