The effects of photobiomodulation therapy on inflammatory mediators, immune infiltration, and angiogenesis in a mouse model of rosacea

Abstract

Background Rosacea is a chronic skin disorder with increasing prevalence and challenging management. Photobiomodulation therapy (PBMT) may be a promising adjuvant treatment for rosacea. Methods This study investigated the efficacy of PBMT for the treatment of rosacea lesions in a well-established mouse model using a combination of wavelengths at 590 and 830 nm. Female BALB/c mice were randomized into three groups, namely, a negative control (NC) group, a model control (MC) group, and a PBMT group. Mice were injected with LL-37 or normal saline for construction of the model and NCs, respectively. Mice in the PBMT group were administered PBMT at wavelengths of 590 nm (25 mW) and 830 nm (50 mW). The severity of erythema, inflammatory cell counts, the expression of key inflammatory mediators, and the degree of angiogenesis and immune cell infiltration of the skin lesions were evaluated by hematoxylin and eosin (H&E) staining, immunohistochemistry, and immunofluorescence staining. Results PBMT significantly decreased the erythema scores and inflammatory cell infiltration of rosacea lesions in mice. Further studies revealed that PBMT downregulated the increased expression of inflammatory mediators (S100A9 and p65) and angiogenesis markers (CD31), and attenuated the dysregulation of immune cell infiltration [including neutrophils, regulatory T cells (Treg cells), γδ T cells, and macrophages] in mice with rosacea. Conclusions This investigation suggested that PBMT can improve the rosacea condition by regulating key inflammatory mediators and dysregulating immune infiltration and angiogenesis.

Photobiomodulation for melasma treatment: Integrative review and state of the art

“…The studies we included in this review have shown that PBM could improve hyperpigmentation in clinical trials, 27,32,34 findings that have been corroborated by in vitro studies, 29,31–34 and could control inflammation, 71–73 improve the dermis structure, 67–70 and reduce angiogenesis 49 . Hence, PBM is a promising tool in the treatment of melasma.…”

“…Additionally, 590 and 830 nm light downregulated the expression of inflammatory mediators (S100A9 and p65) in a mouse model of rosacea 49 . Other studies have corroborated the hypothesis of the anti‐inflammatory action of PBM, such as by the reduction in TNF‐α, IL‐6, and IL‐8 mRNA and Nrf2 pathway stimulation in previously stressed human keratinocytes after irradiation with red (660 nm, 3 J/cm 2 , 12 ± 4 mW/cm 2 ) and green (520 nm, 3 J/cm 2 , 12 ± 4 mW/cm 2 ) light 63 .…”

“…The erythema reduction observed in this scenario may be related to the inhibitory action attributed to LED light (590 nm, 20–40 J/cm 2 ) on HMEC‐1 migration and tube formation, as well as on the synthesis and secretion of VEGF and SCF by these cells 32 . When considering the PBM effect on angiogenesis, a combination of 590 nm (25 mW, 22.5 J) and 830 nm (50 mW, 45 J) light, each for 5 min, reduced erythema and downregulated the expression of markers of angiogenesis (CD31) in a mouse model of rosacea 49 . Thus, it makes sense to consider the vascular component of melasma pathology, which is related to an increased mast cell count and elevated VEGF and CD31 expression 50,51 …”

“…32 When considering the PBM effect on angiogenesis, a combination of 590 nm (25 mW, 22.5 J) and 830 nm (50 mW, 45 J) light, each for 5 min, reduced erythema and downregulated the expression of markers of angiogenesis (CD31) in a mouse model of rosacea. 49 Thus, it makes sense to consider the vascular component of melasma pathology, which is related to an increased mast cell count and elevated VEGF and CD31 expression. 50,51 Researchers have also evaluated the effects provided by different sources of laser light on the vascular component of melasma.…”

Efficacy and tolerance of Oral minocycline combined with photobiomodulation therapy for rosacea: An evaluator‐blinded randomized, controlled clinical trial

“…PBMT maybe work on the pathogenesis of microbiome and neurovascular inflammatory responses by regulating inflammatory mediators, immune infiltration, and angiogenesis. 6 Further clinical trials can be carried out to investigate an appropriate setting of PBMT for the treatment of rosacea.…”