Intravenous laser wavelength radiation effect on LCAT, PON1, catalase, and FRAP in diabetic rats

The main purpose of this study is to evaluate the effect of intravenous irradiation of different low-level laser wavelengths on the activity of lecithin-cholesterol acyltransferase (LCAT), paraoxonase (PON1), catalase, and ferric reducing ability of plasma (FRAP) in diabetic rats. First, diabetes was induced in rats using streptozotocin (STZ). Enzymes’ activity was measured in the blood samples and compared before and after intravenous laser blood irradiation. We used four continuous-wave lasers—IR (λ = 808 nm), Red (λ = 638 nm), Green (λ = 532 nm), and Blue (λ = 450 nm)—to compare the wavelength’s effect on different enzymes’ activity. Laser power was fixed at 0.01 mW and laser energy was changed by 2-, 4-, 6-, and 8-min time of radiations.

The enzymes’ activity of blood samples was measured 2, 6, and 24 h after radiation. The results show an increase in the activity of different enzymes when compare with diabetic non-radiated samples. More importantly, with a constant laser energy, the enzymes’ activity increased with decreasing laser wavelength. It is important to note that with a constant laser energy, as the wavelength decreases, the photon energy increases and the number of photons decrease, while the enzyme’s activity elevation increases. As a result, we can conclude that in intravenous low-level laser therapy, photon energy is more important than the number of photons even if their product, energy, is kept constant.