Carboxyfullerenes protect human keratinocytes from ultraviolet-B-induced apoptosis

J Invest Dermatol. 2000 Nov;115(5):835-41. doi: 10.1046/j.1523-1747.2000.00140.x.


Carboxyfullerene, a water-soluble carboxylic acid derivative of a fullerene, which acts as a free-radical scavenger, was investigated as a protective agent against ultraviolet-light-induced damage in human keratinocytes. First, we demonstrate that carboxyfullerene is not cytotoxic for these cells. In addition, this compound significantly reduces the ultraviolet-B-induced inhibition of keratinocyte proliferation and protects keratinocytes from apoptosis caused by ultraviolet B irradiation in a time- and dose-dependent fashion. Furthermore, the percentage of cells with depolarized mitochondria is significantly lower in ultraviolet-B-irradiated keratinocytes pretreated with carboxyfullerene than in cells provided with diluent alone. Carboxyfullerene also protects human keratinocytes from apoptosis induced by exposure to deoxy-D-ribose, a sugar that causes cell death through a pathway involving oxidative stress. On the other hand, ultraviolet B downregulates bcl-2 levels in human keratinocytes, and carboxyfullerene fails to prevent this effect. These results suggest that carboxy- fullerene protects human keratinocytes from ultraviolet B damage possibly via a mechanism interfering with the generation of reactive oxygen species from depolarized mitochondria without the involvement of bcl-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects
  • Apoptosis / radiation effects
  • Carbon / pharmacology*
  • Carboxylic Acids / pharmacology*
  • Deoxyribose / pharmacology
  • Flow Cytometry
  • Fullerenes*
  • Humans
  • Intracellular Membranes / physiology
  • Keratinocytes / cytology*
  • Membrane Potentials
  • Mitochondria
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Radiation-Protective Agents / pharmacology*
  • Ultraviolet Rays*


  • Carboxylic Acids
  • Fullerenes
  • Proto-Oncogene Proteins c-bcl-2
  • Radiation-Protective Agents
  • Deoxyribose
  • Carbon
  • fullerene C60