Red Light Combined with Blue Light Irradiation Regulates Proliferation and Apoptosis in Skin Keratinocytes in Combination with Low Concentrations of Curcumin

PLoS One. 2015 Sep 18;10(9):e0138754. doi: 10.1371/journal.pone.0138754. eCollection 2015.

Abstract

Curcumin is a widely known natural phytochemical from plant Curcuma longa. In recent years, curcumin has received increasing attention because of its capability to induce apoptosis and inhibit cell proliferation as well as its anti-inflammatory properties in different cancer cells. However, the therapeutic benefits of curcumin are severely hampered due to its particularly low absorption via trans-dermal or oral bioavailability. Phototherapy with visible light is gaining more and more support in dermatological therapy. Red light is part of the visible light spectrum, which is able to deeply penetrate the skin to about 6 mm, and directly affect the fibroblast of the skin dermis. Blue light is UV-free irradiation which is fit for treating chronic inflammation diseases. In this study, we show that curcumin at low concentrations (1.25-3.12 μM) has a strong anti-proliferative effect on TNF-α-induced psoriasis-like inflammation when applied in combination with light-emitting-diode devices. The treatment was especially effective when LED blue light at 405 nm was combined with red light at 630 or 660 nm, which markedly amplified the anti-proliferative and apoptosis-inducing effects of curcumin. The experimental results demonstrated that this treatment reduced the viability of human skin keratinocytes, decreased cell proliferation, induced apoptosis, inhibited NF-κB activity and activated caspase-8 and caspase-9 while preserving the cell membrane integrity. Moreover, the combined treatment also down-regulated the phosphorylation level of Akt and ERK. Taken together, our results indicated that the combination of curcumin with LED blue light united red light irradiation can attain a higher efficiency of regulating proliferation and apoptosis in skin keratinocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects
  • Apoptosis / radiation effects*
  • Caspase 9 / metabolism
  • Cell Line
  • Cell Proliferation / drug effects
  • Cell Proliferation / radiation effects*
  • Curcumin / pharmacology*
  • Humans
  • Keratinocytes / cytology
  • Keratinocytes / drug effects
  • Keratinocytes / metabolism
  • Keratinocytes / radiation effects*
  • Light*
  • NF-kappa B / metabolism
  • Phosphorylation
  • Signal Transduction / drug effects
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • NF-kappa B
  • Tumor Necrosis Factor-alpha
  • Caspase 9
  • Curcumin

Grants and funding

This work was supported by the National Science Foundation of China from Tianhui Niu, No. 31300638——in the study of data collection and analysis, decision to publish; the National Science Foundation of China from Yan Tian, No. 81101177——in the research desigh; the Foundation of The General Hospital of the Air Force from Tianhui Niu, No. kz2013041——in the study of preparation of the manuscript.