Molecular mechanisms of apoptosis induced by ajoene in 3T3-L1 adipocytes

Obesity (Silver Spring). 2006 Mar;14(3):388-97. doi: 10.1038/oby.2006.52.


Objective: Determine the biochemical pathways involved in induction of apoptosis by ajoene, an organosulfur compound from garlic.

Research methods and procedures: Mature 3T3-L1 adipocytes were incubated with ajoene at concentrations up to 200 microM. Viability and apoptosis were quantified using an MTS-based cell viability assay and an enzyme-linked immunosorbent assay for single-stranded DNA (ssDNA), respectively. Intracellular reactive oxygen species (ROS) production was measured based on production of the fluorescent dye, dichlorofluorescein. Activation of the mitogen-activated protein kinases extracellular signal-regulating kinase 1/2 (ERK) and c-Jun-N-terminal kinase (JNK) was shown by Western blot. Western blot was also used to show activation of caspase-3, translocation of apoptosis-inducing factor (AIF) from mitochondria to nucleus, and cleavage of 116-kDa poly(ADP-ribose) polymerase (PARP)-1.

Results: Ajoene induced apoptosis of 3T3-L1 adipocytes in a dose- and time-dependent manner. Ajoene treatment resulted in activation of JNK and ERK, translocation of AIF from mitochondria to nucleus, and cleavage of 116-kDa PARP-1 in a caspase-independent manner. Ajoene treatment also induced an increase in intracellular ROS level. Furthermore, the antioxidant N-acetyl-L-cysteine effectively blocked ajoene-mediated ROS generation, activation of JNK and ERK, translocation of AIF, and degradation of PARP-1.

Discussion: These results indicate that ajoene-induced apoptosis in 3T3-L1 adipocytes is initiated by the generation of hydrogen peroxide, which leads to activation of mitogen-activated protein kinases, degradation of PARP-1, translocation of AIF, and fragmentation of DNA. Ajoene can, thus, influence the regulation of fat cell number through the induction of apoptosis and may be a new therapeutic agent for the treatment of obesity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / drug effects*
  • Adipocytes / metabolism
  • Animals
  • Apoptosis / drug effects*
  • Apoptosis / physiology
  • Apoptosis Inducing Factor / metabolism
  • Caspases / metabolism
  • Cell Survival / drug effects
  • Cell Survival / physiology
  • Cells, Cultured
  • Disulfides / pharmacology*
  • Dose-Response Relationship, Drug
  • Enzyme Inhibitors / pharmacology*
  • Mice
  • Mitogen-Activated Protein Kinase Kinases / metabolism
  • Oxidative Stress / drug effects
  • Oxidative Stress / physiology
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases / metabolism
  • Reactive Oxygen Species / metabolism
  • Sulfoxides


  • Apoptosis Inducing Factor
  • Disulfides
  • Enzyme Inhibitors
  • Reactive Oxygen Species
  • Sulfoxides
  • ajoene
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases
  • Mitogen-Activated Protein Kinase Kinases
  • Caspases