The use of light-emitting diodes to stimulate mitochondrial function and liver regeneration of partially hepatectomized rats

Abstract

The biostimulating effect of laser radiation has been observed in many areas of Medicine. However, there are still several questions to be answered, among them the importance of light coherence in the stimulatory process. In the present study, we used light-emitting diodes (LED) to promote the stimulation of liver regeneration after partial hepatectomy in rats. Fourteen male Wistar rats weighing 200-250 g were submitted to partial hepatectomy (70%) followed by LED light irradiation (630 nm) of the remaining part of the liver at two doses, i.e., 10 (N = 7) and 140 (N = 7) J/cm 2 . A group irradiated with laser, 590 nm (N = 7, 15 J/cm 2 ) was performed for the study of proliferating cell nuclear antigen-labeling index. Data are reported as mean ± SEM. Statistical comparisons of the groups were performed by analysis of variance for parametric measurements followed by the Bonferroni post-test, with the level of significance set at P < 0.05. Respiratory mitochondrial activity was increased in the irradiated groups (states 3 and 4; P < 0.05), with better results for the group exposed to the lower LED dose (10 J/cm 2 ). The proliferating cell nuclear antigen-labeling index, by immunohistochemical staining, was similar for both LED-exposed groups (P > 0.05) and higher than for the control group (P < 0.05). The cell proliferation index obtained with LED and laser were similar (P > 0.05). In conclusion, the present results suggest that LED irradiation promotes biological stimulatory effects during the early stage of liver regeneration and that LED is as effective as laser light, independent of the coherence, divergence and cromaticity.

Effect of irradiation with different laser wavelengths on oxidative stress of non-hepatectomized rats

“…In the present study we assessed hepatic mitochondrial function and MDA levels in intact livers in response to the use of laser as a source of light in a simulation of laser therapy at two different wavelengths applied separately or in combination, based on the basic understanding of some fundamental elements of the interaction between light and matter 1,6 . The main objective was to determine the effect of laser light on hepatic energy capacity based on previous studies from our laboratory about hepatic function and mitochondrial function 5,18,19 .…”

“…Several studies have shown an effective interaction between light and biological tissues, the liver in particular [1][2][3][4][5] .Conventional light, as well as light-emitting diodes (LED) and laser, with their different optical properties concerning light production and delivery have similar effects on cell organelles, leading to increased efficiency of wound healing, of hepatocellular mitochondrial energy capacity, and of hepatic regeneration 2,[3][4][5][6] . The partial loss of hepatic tissue rapidly triggers the regenerative process until the original weight is recovered 7,8 .…”

Mechanisms of repigmentation induced by photobiomodulation therapy in vitiligo

“…[19] Monochromatic radiation in the visible and infrared A (IRA) range sustains matrix metalloproteinase (MMP), improves mitochondrial function, and increases adenosine triphosphate (ATP) synthesis and O 2 consumption, which leads to cellular regenerative pathways. [20][21][22] We have reported that the mitochondrial-related signalling pathway is responsible for biological effects induced by He-Ne laser in pigmented cells. More specifically, He-Ne irradiation immediately induced an increase in mitochondrial membrane potential, ATP and cyclic adenosine monophosphate (cAMP), as well as JNK/AP1 activity via enhanced cytochrome c oxidase activity in A2058 melanoma cells.…”

The correlation between radiative surface defect states and high color rendering index from ZnO nanotubes

“…The solid-state lighting holds tremendous prospective for future illumination, backlight panel display industry and biomedical applications due to their brightness and durability [1-3]. Over the past decade, much attention has been drawn towards white-light-emitting diodes (WLEDs) as new light sources due to their reliability with great economic and ecological consequences.…”