title: Boldo prevents UV light and nitric oxide-mediated plasmid DNA damage and reduces the expression of Hsp70 protein in melanoma cancer cells.
abstract: OBJECTIVE
  This study was designed to investigate the potential protective effect of a methanolic extract of Peumus boldus leaves on UV light and nitric oxide (NO)-mediated DNA damage. In addition, we investigated the growth inhibitory activity of this natural product against human melanoma cells (M14).
  
  
  METHODS
  Boldine, catechin, quercetin and rutin were identified using a HPLC method. The extract was incubated with plasmid DNA and, before irradiating the samples with UV-R, H(2) O(2) was added. For analysis of DNA single-strand breaks induced by NO, the experiments were performed by incubating the extract with Angeli's salt. In the study on M14 cell line, cell viability was measured using MTT assay. Release of lactate dehydrogenase, a marker of membrane breakdown, was also measured. For the detection of apoptosis, the evaluation of DNA fragmentation (COMET assay) and caspase-3 activity assay were employed. The expression of heat shock protein 70 (Hsp70) was detected by Western blot analysis. Generation of reactive oxygen species was measured by using a fluorescent probe.
  
  
  RESULTS
  The extract (demonstrating the synergistic effect of the constituents boldine and flavonoids), showed a protective effect on plasmid DNA and selectively inhibited the growth of melanoma cells. But a novel finding was that apoptosis evoked by this natural product in M14 cells, appears to be mediated, at least in part, via the inhibition of Hsp70 expression, which may be correlated with a modulation of redox-sensitive mechanisms.
  
  
  CONCLUSIONS
  These results confirm the promising biological properties of Peumus boldus and encourage in-vivo investigations into its potential anti-cancer activity.
authors.affiliation: Department of Biological Chemistry, Medical Chemistry and Molecular Biology, University of Catania, Catania, Italy. alrusso@unict.it
authors.forename: Alessandra
authors.initials: A
authors.lastname: Russo
authors.forename: Venera
authors.initials: V
authors.lastname: Cardile
authors.forename: Silvia
authors.initials: S
authors.lastname: Caggia
authors.forename: Germán
authors.initials: G
authors.lastname: Gunther
authors.forename: Nicolas
authors.initials: N
authors.lastname: Troncoso
authors.forename: Juan
authors.initials: J
authors.lastname: Garbarino
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects*; D018840:HSP70 Heat-Shock Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D008545:Melanoma / Q000378:metabolism / Q000517:prevention & control*; D009569:Nitric Oxide / Q000009:adverse effects; D010084:Oxidation-Reduction; D031611:Peumus / Q000737:chemistry*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D018515:Plant Leaves; D010957:Plasmids / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D018840:HSP70 Heat-Shock Proteins; D010936:Plant Extracts; D009569:Nitric Oxide