Protective effects of Chlorella-derived peptide against UVC-induced cytotoxicity through inhibition of caspase-3 activity and reduction of the expression of phosphorylated FADD and cleaved PARP-1 in skin fibroblasts

Molecules. 2012 Aug 2;17(8):9116-28. doi: 10.3390/molecules17089116.


UVC irradiation induces oxidative stress and leads to cell death through an apoptotic pathway. This apoptosis is caused by activation of caspase-3 and formation of poly(ADP-ribose) polymerase-1 (PARP-1). In this study, the underlying mechanisms of Chlorella derived peptide (CDP) activity against UVC-induced cytotoxicity were investigated. Human skin fibroblasts were treated with CDP, vitamin C, or vitamin E after UVC irradiation for a total energy of 15 J/cm². After the UVC exposure, cell proliferation and caspase-3 activity were measured at 12, 24, 48, and 72 h later. Expression of phosphorylated FADD and cleaved PARP-1 were measured 16 h later. DNA damage (expressed as pyrimidine (6-4) pyrimidone photoproducts DNA concentration) and fragmentation assay were performed 24 h after the UVC exposure. Results showed that UVC irradiation induced cytotoxicity in all groups except those treated with CDP. The caspase-3 activity in CDP-treated cells was inhibited from 12 h onward. Expression of phosphorylated FADD and cleaved PARP-1 were also reduced in CDP-treated cells. Moreover, UVC-induced DNA damage and fragmentation were also prevented by the CDP treatment. This study shows that treatment of CDP provides protective effects against UVC-induced cytotoxicity through the inhibition of caspase-3 activity and the reduction of phosphorylated FADD and cleaved PARP-1 expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects
  • Apoptosis / radiation effects
  • Caspase 3 / metabolism
  • Caspase Inhibitors / isolation & purification
  • Caspase Inhibitors / pharmacology*
  • Cell Survival / drug effects
  • Cell Survival / radiation effects
  • Cells, Cultured
  • Chlorella / chemistry*
  • DNA Fragmentation
  • Fas-Associated Death Domain Protein / metabolism*
  • Fibroblasts / drug effects*
  • Fibroblasts / metabolism
  • Fibroblasts / radiation effects
  • Humans
  • Peptides / isolation & purification
  • Peptides / pharmacology*
  • Phosphoproteins / metabolism
  • Plant Extracts / isolation & purification
  • Plant Extracts / pharmacology*
  • Plant Proteins / isolation & purification
  • Plant Proteins / pharmacology*
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases / metabolism*
  • Radiation-Protective Agents / isolation & purification
  • Radiation-Protective Agents / pharmacology*
  • Skin / cytology
  • Ultraviolet Rays


  • Caspase Inhibitors
  • FADD protein, human
  • Fas-Associated Death Domain Protein
  • Peptides
  • Phosphoproteins
  • Plant Extracts
  • Plant Proteins
  • Radiation-Protective Agents
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases
  • CASP3 protein, human
  • Caspase 3