Curcumin conjugates induce apoptosis via a mitochondrion dependent pathway in MCF-7 and MDA-MB-231 cell lines

Asian Pac J Cancer Prev. 2013;14(10):5797-804. doi: 10.7314/apjcp.2013.14.10.5797.

Abstract

In order to enhance the bioavailability of curcumin its conjugates with piperic acid and glycine were synthesized by esterifying the 4 and 4' phenolic hydroxyls, the sites of metabolic conjugation. Antiproliferative and apoptotic efficacy of synthesized conjugates was investigated in MCF-7 and MDA-MB-231 cell lines. IC50 values of di-O-glycinoyl (CDG) and di-O-piperoyl (CDP) esters of curcumin were found to be comparable with that of curcumin. Both conjugates induced chromatin condensation fragmentation and apoptotic body formation. CDP exposure to MCF-7 cells induced apoptosis initiating loss of mitochondrial membrane potential (Δψm) followed by inhibition of translocation of transcription factor NF-kB and release of Cytochrome-C. Reactive oxygen species (ROS) production was evaluated by fluorescent activated cell sorter. Change in ratio of Bcl2/ Bclxl was observed, suggesting permeablization of mitochondrial membrane leading to the release of AIF, Smac and other apoptogenic molecules. DNA fragmentation as a hallmark for apoptosis was monitored by TUNEL as well as agrose gel electrophoresis. Thus, it was proven that conjugation does not affect the therapeutic potential of parent molecule in vitro, while these could work in vivo as prodrugs with enhanced pharmacokinetic profile. Pharmacokinetics of these molecules under in vivo conditions is a further scope of this study.

MeSH terms

  • Apoptosis / drug effects*
  • Cell Line, Tumor
  • Curcumin / pharmacology*
  • Cytochromes c / metabolism
  • DNA Fragmentation / drug effects
  • Humans
  • MCF-7 Cells
  • Membrane Potential, Mitochondrial / drug effects
  • Mitochondria / drug effects*
  • Mitochondria / metabolism
  • NF-kappa B / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Reactive Oxygen Species / metabolism

Substances

  • NF-kappa B
  • Proto-Oncogene Proteins c-bcl-2
  • Reactive Oxygen Species
  • Cytochromes c
  • Curcumin