Photodynamic efficiency of a chlorophyll-a derivative in vitro and in vivo

Biomed Pharmacother. 2016 Jul:81:265-272. doi: 10.1016/j.biopha.2016.04.007. Epub 2016 Apr 22.

Abstract

This paper reports the antitumor activity of a chlorophyll-a derivative, 2-[1-hydroxyethyl]-2-devinylpyropheophorbide-a (HEPa). Photophysical characteristics of HEPa were measured. And its cytotoxicity, intracellular localization, biodistribution, efficiency of photodynamic therapy (PDT), histological analysis were investigated using human bile duct carcinoma cells (QBC-939) and QBC-939 tumor bearing BABL/c nude mice as animal model. The results showed that HEPa was localized mainly within the cytoplasmic region and partially in lysosome. Biodistribution of HEPa in QBC-939 tumor bearing BABL/c nude mice showed its fast rate of clearance and high tumor selectivity. In vitro, HEPa had low dark toxicity and high photoxicity against QBC-939 cells. The inhibition rate of QBC-939 tumor could increase up to 92.3%, and H&E staining confirmed that HEPa could cause serious damage to the tumor with light dose of 100J/cm(2), implying that HEPa has potential to be a new antitumor candidate for photodynamic therapy (PDT).

Keywords: Chlorophyll-a; HEPa; Photodynamic therapy; Photosensitizer; Tumor.

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Chlorophyll / chemical synthesis
  • Chlorophyll / chemistry
  • Chlorophyll / therapeutic use*
  • Chlorophyll / toxicity
  • Chlorophyll A
  • Darkness
  • Humans
  • Intracellular Space / metabolism
  • Male
  • Mice, Inbred BALB C
  • Mice, Nude
  • Photochemotherapy*
  • Singlet Oxygen / analysis
  • Spectrophotometry, Ultraviolet
  • Tissue Distribution / drug effects

Substances

  • Chlorophyll
  • Singlet Oxygen
  • Chlorophyll A