title: Inhibitory effects of (-)-epigallocatechin-3-gallate and pterostilbene on pancreatic cancer growth in vitro.
abstract: BACKGROUND
  It has been previously shown that the naturally occurring antioxidant (-)-epigallocatechin-3-gallate (EGCG), found in green tea, and pterostilbene, a stilbenoid derived from blueberries, inhibit pancreatic cancer in vitro when used individually. We hypothesized that the combination of EGCG and pterostilbene would reveal additive effects in vitro.
  
  
  METHODS
  Using the pancreatic cancer cell lines MIA PaCa-2 and PANC-1, efficacy and synergism were evaluated for cell proliferation and viability (3-(4,5-dimethyltiazol-2-y1)-2,5-diphenltetrazolium bromide assays, cell cycle analysis) and mitochondrial apoptosis (mitochondrial depolarization, cytochrome C release, caspase-3/7 activity, cell death detection using enzyme-linked immunosorbent assay).
  
  
  RESULTS
  Cell proliferation assays revealed significant additive antiproliferative effects with pterostilbene and EGCG in both cell lines at the later, 72-h, point (P < 0.05). MIA underwent S-phase arrest with the combination (10-12% increase); however, cell cycle arrest was not observed in PANC. The combination induced mitochondrial depolarization and upregulated cytochrome C (P < 0.05) in MIA, but these effects were not observed in PANC. EGCG increased caspase-3/7 in MIA; however, the combination did not significantly increase the activity in either cell line (P < 0.05). Apoptosis was only observed in PANC (P < 0.05). The reduction in proliferation in MIA in the 3-(4,5-dimethyltiazol-2-y1)-2,5-diphenltetrazolium bromide assays with the combination indicated that cell death occurs, possibly through another mechanism.
  
  
  CONCLUSIONS
  Our results are encouraging regarding the future use of EGCG and pterostilbene to improve traditional pancreatic cancer therapies. In conclusion, EGCG and pterostilbene have additive, antiproliferative effects in vitro and alter the apoptotic mechanisms in both cell lines by modulation at different points in the mechanism.
authors.affiliation: University of Vermont College of Medicine, Burlington, VT, USA.
authors.forename: Shannon F
authors.initials: SF
authors.lastname: Kostin
authors.forename: Debbie E
authors.initials: DE
authors.lastname: McDonald
authors.forename: David W
authors.initials: DW
authors.lastname: McFadden
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002277:Carcinoma / Q000188:drug therapy*; D020169:Caspases / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation; D004353:Drug Evaluation, Preclinical; D006801:Humans; D010190:Pancreatic Neoplasms / Q000188:drug therapy*; D013267:Stilbenes / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D016588:Anticarcinogenic Agents; D013267:Stilbenes; C107773:pterostilbene; D002392:Catechin; D045304:Cytochromes c; C045651:epigallocatechin gallate; D020169:Caspases