Helium–Neon Laser Irradiation Stimulates Migration and Proliferation in Melanocytes and Induces Repigmentation in Segmental-Type Vitiligo

Abstract

Low-energy helium-neon lasers (632.8 nm) have been employed in a variety of clinical treatments including vitiligo management. Light-mediated reaction to low-energy laser irradiation is referred to as biostimulation rather than a thermal effect. This study sought to determine the theoretical basis and clinical evidence for the effectiveness of helium-neon lasers in treating vitiligo. Cultured keratinocytes and fibroblasts were irradiated with 0.5-1.5 J per cm2 helium-neon laser radiation. The effects of the helium-neon laser on melanocyte growth and proliferation were investigated. The results of this in vitro study revealed a significant increase in basic fibroblast growth factor release from both keratinocytes and fibroblasts and a significant increase in nerve growth factor release from keratinocytes. Medium from helium-neon laser irradiated keratinocytes stimulated [3H]thymidine uptake and proliferation of cultured melanocytes. Furthermore, melanocyte migration was enhanced either directly by helium-neon laser irradiation or indirectly by the medium derived from helium-neon laser treated keratinocytes. Thirty patients with segmental-type vitiligo on the head and/or neck were enrolled in this study. Helium-neon laser light was administered locally at 3.0 J per cm2 with point stimulation once or twice weekly. The percentage of repigmented area was used for clinical evaluation of effectiveness. After an average of 16 treatment sessions, initial repigmentation was noticed. Marked repigmentation (>50%) was observed in 60% of patients with successive treatments. Basic fibroblast growth factor is a putative melanocyte growth factor, whereas nerve growth factor is a paracrine factor for melanocyte survival in the skin. Both nerve growth factor and basic fibroblast growth factor stimulate melanocyte migration. It is reasonable to propose that helium-neon laser irradiation clearly stimulates melanocyte migration and proliferation and mitogen release for melanocyte growth and may also rescue damaged melanocytes, therefore providing a microenvironment for inducing repigmentation in vitiligo.

The use of low-level light therapy in supportive care for patients with breast cancer: review of the literature

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The survival of Escherichia coli upon exposure to irradiation with non-coherent polychromatic polarized light

“…The favourable effects of polarized light rays were discovered during studies on laser light rays, and in 1981 a group of physicists from Hungary proved that polarized light has a stimulating effect on the natural defence and repair functions of organisms and cells (Kertesz et al, 1982;Fenyo, 1984;Kubasova et al, 1988). These cells include endothelial cells (Moore et al, 2005), keratinocytes (Yu et al, 2003), macrophages (Fujimaki et al, 2003), and several classes of leukocytes such as neutrophils (Young et al, 1989). Earlier research on bacteria showed a significant difference (P < 0.05) in the number of Bacillus subtilis after treatment with non-coherent polarized light, darkness or visible light .…”

Role of Corticosteroids in Treatment of Vitiligo

“…In vitro study on cultured keratinocytes and melanocytes conducted by Yu and colleagues showed that helium-neon laser could stimulate proliferation and migration of melanocytes. Their study on the efficacy of this kind of laser on patients with segmental vitiligo revealed positive responses (> 50% repigmentation in 60% of patients with segmental vitiligo) (Yu et al, 2003).…”