Effects of thermal therapy combined with blue light‐emitting diode irradiation on trimellitic anhydride-induced acute contact hypersensitivity mouse model

Abstract

Backgroud

The biological effect of phototherapy, which involves using visible light for disease treatment, has attracted recent attention, especially in dermatological practice. Light-emitting diode (LED) irradiation increases dermal collagen level and reduces inflammation. It has been suggested that thermal therapy and LED irradiation can modulate inflammatory processes. However, little is known about the molecular mechanism of the anti-inflammatory effects of thermal therapy and LED irradiation.

Objective

This study was to determine the anti-inflammatory effect of thermal therapy combined with LED irradiation on trimellitic anhydride (TMA)-induced acute contact hypersensitivity (CHS) mouse model.

Methods

Twenty-four BALB/c mice were randomly divided into the following groups: Vehicle group, TMA group, TMA + alternating thermal therapy group (Alternating group), and TMA + alternating + LED group (LED group). Ear swelling was measured based on the thickness of ear before and after each TMA challenge. Vascular permeability was evaluated by the extravasation of Evans blue dye. Serum IgE level, Th1/Th2/Th17 cytokines, and related transcription factors were measured using ELISA kits, and histological examination was illustrated in ear tissue.

Results

The LED group showed reduction in ear swelling response, vascular permeability, serum IgE levels, Th2/Th17 cytokine levels, and inflammatory cell infiltration. Moreover, the LED group showed increased Th1 cytokine levels.

Conclusions

These results indicate that thermal therapy combined with LED irradiation alleviated TMA-induced acute CHS in the mouse model. Thermal therapy and phototherapy should be considered as a novel therapeutic tool for the treatment of skin inflammation.

Keywords:

• Light-emitting diode (LED)
• allergic contact dermatitis (ACD)
• contact hypersensitivity (CHS)
• thermal therapy
• cytokines

Author contributions

H-JJ and OHC designed the experiments. CHP, TVN, and YJF performed the experiments. CHP and YJF stimulated temperature distribution during the heating process. H-JJ and OHC coordinated the project. CHP and CHS analyzed the data and performed a biological analysis. The manuscript was written by CHP, H-JJ, and OHC. All authors discussed the results and reviewed the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding authors upon request.

Additional information

Funding

This paper was supported by Fund of Biomedical Research Institute, Jeonbuk National University Hospital.