Oral consumption of pomegranate fruit extract inhibits growth and progression of primary lung tumors in mice

Academic Article

Abstract

  • To develop novel mechanism-based preventive approaches for lung cancer, we examined the effect of oral consumption of a human achievable dose of pomegranate fruit extract (PFE) on growth, progression, angiogenesis, and signaling pathways in two mouse lung tumor protocols. Benzo(a)pyrene [B(a)P] and N-nitroso-tris-chloroethylurea (NTCU) were used to induce lung tumors, and PFE was given in drinking water to A/J mice. Lung tumor yield was examined on the 84th day and 140 days after B(a)P dosing and 240 days after NTCU treatment. Mice treated with PFE and exposed to B(a)P and NTCU had statistically significant lower lung tumor multiplicities than mice treated with carcinogens only. Tumor reduction was 53.9% and 61.6% in the B(a)P + PFE group at 84 and 140 days, respectively, compared with the B(a)P group. The NTCU + PFE group had 65.9% tumor reduction compared with the NTCU group at 240 days. Immunoblot analysis and immunohistochemistry were used to determine effect on cell survival pathways and markers of cellular proliferation and angiogenesis. PFE treatment caused inhibition of (a) activation of nuclear factor-κB and IκBα kinase, (b) degradation and phosphorylation of IκBα, (c) phosphorylation of mitogen-activated protein kinases (extracellular signal-regulated kinase 1/2, c-Jun NH2-terminal kinase 1/2, and p38), (d) phosphatidylinositol 3-kinase (p85 and p11O), (e) phosphorylation of Akt at Thr308, (f) activation of mammalian target of rapamycin signaling, (g) phosphorylation of c-met, and (h) markers of cell proliferation (Ki-67 and proliferating cell nuclear antigen) and angiogenesis (inducible nitric oxide synthase, CD31, and vascular endothelial growth factor) in lungs of B(a)P- and NTCU-treated mice. Thus, our data show that PFE significantly inhibits lung tumorigenesis in A/J mice and merits investigation as a chemopreventive agent for human lung cancer. ©2007 American Association for Cancer Research.
  • Published In

  • Cancer Research  Journal
  • Digital Object Identifier (doi)

    Author List

  • Khan N; Afaq F; Kweon MH; Kim KM; Mukhtar H
  • Start Page

  • 3475
  • End Page

  • 3482
  • Volume

  • 67
  • Issue

  • 7