Korean J Dermatol.  2009 Nov;47(11):1213-1219.

The Effect of Blue Light on Propionibacterium acnes and the Expression of Inflammatory Cytokines in HaCaT Cells

• Par YD
• Lee KS

Abstract

BACKGROUND
Acne is a multifactorial disease. Particularly, Propionibacterium acne acts on triglycerides and releases cytokines, which trigger inflammatory reactions and alter the infundibular keratinization status. Recently, visible light, especially blue light, has been shown to activate the endogenous porphyrins of P. acne, which results in a photodynamic reaction that destroys the bacteria. However, the effect of blue light on inflamed lesion, inflammatory papules, pustules, are largely unknown.
OBJECTIVE
We investigated the bactericidal effect of blue light on P. acnes as well as the inhibitory effect on the expression of inflammatory cytokines in HaCaT cells.
METHODS
We performed the colony count assay in blue light irradiated-culture media of P. acnes and RT-PCR analysis in blue light irradiated-HaCaT immortalized keratinocytes.
RESULTS
A 7 minute irradiation with blue light was bactericidal to P. acnes. It decreased the expression of tumor necrosis factor (TNF)-alphaand toll-like receptor (TLR) 2 in HaCaT cells. Expression of TNF-alpha-induced TNF-alpha and TLR 2 were down-regulated by blue light in HaCaT cells.
CONCLUSION
Blue light is a potential anti-acne treatment.

Keyword

Blue light; Cytokine; HaCaT cell; Propionibacterium acnes

MeSH Terms

Acne Vulgaris
Bacteria
Cytokines
Keratins
Light
Polyenes
Porphyrins
Propionibacterium
Propionibacterium acnes
Toll-Like Receptors
Triglycerides
Tumor Necrosis Factor-alpha
Cytokines
Keratins
Polyenes
Porphyrins
Toll-Like Receptors
Triglycerides
Tumor Necrosis Factor-alpha