Evaluation of corticosterone and IL-1β, IL-6, IL-10 and TNF-α expression after 670-nm laser photobiomodulation in rats

Abstract

The literature has shown that low-level laser therapy accelerates the repair of cutaneous wounds. However, there is a scarcity of scientific studies that characterise the possible systemic interference of laser photobiomodulation. The aim of this research was to quantitatively evaluate blood corticosterone levels and tissue cytokine expression in cutaneous wounds of rats treated with low-level laser therapy (semiconductor diode AsGaAl, continuous emission, 9 mW, 670 nm, 0.031 W/cm(2), beam with an output area of 0.28 cm(2)) and normal controls. A total of 36 male Wistar rats were used and randomly divided into two groups of 18 rats each. A standardised circular 6-mm-diameter wound was made in the dorsal skin region of each rat, and they were euthanised at 1, 6 and 12 h after cutaneous surgery. The blood was collected, and portions of cutaneous tissue and subcutaneous muscle were removed and cryopreserved. Corticosterone levels in the blood were measured by a radioimmunoassay technique; histological sections were submitted to the ELISA technique for analysis of tissue cytokine expression levels. At 6 h after surgery, a significant increase in corticosterone and a significant reduction in the levels of IL-1β and IL-6 in tissues of irradiated wounds were observed when compared to controls (p < 0.05). The levels of TNF-α and IL-10 expression were not significantly different between the groups at different time intervals. Thus, this study strongly suggests a systemic and local biomodulation of low-level laser therapy as indicated by the blood levels of corticosterone and the tissue expression of IL-1β and IL-6, respectively.

Complicated Effect of He-Ne Laser Therapy on Pro-/Anti-Inflammatory Cytokines from Serum in Rats

“…As to the IL-6, in this study, the level of IL-6 was increased significantly compared with the NC and ER groups, which were different from the result reported by Lima that the concentrations of IL-6 were measured at 6 h and 12 h after 31 s of LLLT treatment [12]. While the level of IL-6 after 10 days of treatment with 30 min every day were tested in this experiment, and the reason for the difference of the result could be due to the period of treatment time.…”

“…Levels of anti-inflammatory cytokines (TGF-β and IL-10) from LA group were increased when compared with both of NC and ER groups, in additionally, level of IL-10 also higher in LA group than in PC group. All these results indicate that the effects of He-Ne laser on pro-/anti-inflammatory cytokines were not always consistent as reported before [11][12][13].…”

“…The same effects of LLLT on IL-1β were demonstrated by other researchers using different treating conditions. Studies carried out by Anuska et al in 2014 also demonstrated reduction of IL-1β expression post-treatment [12]. In the previous study, animals were treated with LLLT (semiconductor diode AsGaAl, continuous emission, 9 mW, 670 nm, 0.031 W/cm 2 , beam with an output area of 0.28 cm 2 ) at a dose of 1 J/cm2, immediately following cutaneous surgery, then the tissues were collected at 1, 6 and 12 h post-surgery for detecting the pro-inflammatory cytokines by ELISA.…”

“…The expression of IL-10 in wound healing mice could be used to determine the wound age, as it began to enhance 1-3 h after injury, returned to lower level by 24 h, increased again at 48 h after injury [27]. Previous study observed a reduction of IL-10 at 6 and 12 h after laser treatment, without statistically significant [12]. Level of IL-10 produced by mesenteric and periaortic lymph node cells from mice after 6 days of laser treatment was also reduced [28].…”

IFN-τDisplays Anti-Inflammatory Effects onStaphylococcus aureusEndometritis via Inhibiting the Activation of the NF-κB and MAPK Pathways in Mice

“…A key component of the host immune response to infection is the upregulation of cytokine production [30]. To further study the effect of IFN- τ on S. aureus endometritis, the levels of TNF- α , IL-1 β , IL-6, and IL-10 production were evaluated.…”