Selective induction of apoptosis through activation of caspase-8 in human leukemia cells (Jurkat) by dandelion root extract

J Ethnopharmacol. 2011 Jan 7;133(1):86-91. doi: 10.1016/j.jep.2010.09.005. Epub 2010 Sep 16.


Aim of study: Dandelion extracts have been used in traditional Native American Medicine and Traditional Chinese Medicine (TCM) for treatment of leukemia and breast cancer; however, the mechanism of action remains unknown. Today, DRE is mainly marketed for management of gastrointestinal and liver disorders. The current study aims to determine the anti-cancer activity of dandelion root extract (DRE) against human leukemia, and to evaluate the specificity and mechanism of DRE-induced apoptosis.

Materials and methods: The effect of DRE on cell viability was evaluated using the colorimetric-based WST-1 assay. Apoptotic cell death was monitored by nuclear condensation and confirmed by exposure of phosphatidylserine to outer leaflet of plasma membrane. Activation of caspases was detected using a fluorogenic substrate specific to either caspase-8 or -3. Loss of mitochondrial membrane potential was observed by microscopy using JC-1 dye. The apoptotic effect of DRE was also evaluated on a dominant-negative FADD (Fas-associated death domain) cell line and non-cancerous peripheral blood mononuclear cells (PBMCs).

Results: Aqueous DRE effectively induces apoptosis in human leukemia cell lines in a dose and time dependent manner. Very early activation of caspase-8 and the subsequent activation of caspase-3 indicate that DRE may be inducing extrinsic or receptor-mediated apoptosis. Caspase inhibition rendered this extract ineffective, thus DRE-induced apoptosis is caspase-dependent. Moreover, the dominant-negative FADD cells that are unable to form a complete DISC (death-inducing signaling complex) were resistant to DRE treatment, which further confirms our hypothesis that DRE induces receptor-mediated apoptosis. Interestingly, non-cancerous peripheral blood mononuclear cells (PBMCs) exposed to aqueous DRE under the same treatment conditions as leukemia cells were not significantly affected.

Conclusion: Our results suggest that aqueous DRE contains components that act to induce apoptosis selectively in cultured leukemia cells, emphasizing the importance of this traditional medicine and thus presents a potential novel non-toxic alternative to conventional leukemia therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Antineoplastic Agents, Phytogenic / therapeutic use
  • Apoptosis*
  • Caspase 3 / metabolism
  • Caspase 8 / metabolism*
  • Cell Survival / drug effects
  • Enzyme Activation
  • Humans
  • Jurkat Cells
  • Leukemia / drug therapy*
  • Leukemia / enzymology
  • Leukemia / pathology*
  • Membrane Potential, Mitochondrial / drug effects
  • Phytotherapy
  • Plant Extracts / pharmacology*
  • Plant Extracts / therapeutic use
  • Plant Roots
  • Taraxacum*


  • Antineoplastic Agents, Phytogenic
  • Plant Extracts
  • Caspase 3
  • Caspase 8