Dandelion root extract affects colorectal cancer proliferation and survival through the activation of multiple death signaling pathways

November 2016
Pamela Ovadje, Saleem Ammar, Jose-Antonio Guerrero, John Thor Arnason, and Siyaram Pandey

Abstract

Dandelion extracts have been studied extensively in recent years for its anti-depressant and anti-inflammatory activity. Recent work from our lab, with in-vitro systems, shows the anti-cancer potential of an aqueous dandelion root extract (DRE) in several cancer cell models, with no toxicity to non-cancer cells. In this study, we examined the cancer cell-killing effectiveness of an aqueous DRE in colon cancer cell models.

Aqueous DRE induced programmed cell death (PCD) selectively in > 95% of colon cancer cells, irrespective of their p53 status, by 48 hours of treatment. The anti-cancer efficacy of this extract was confirmed in in-vivo studies, as the oral administration of DRE retarded the growth of human colon xenograft models by more than 90%. We found the activation of multiple death pathways in cancer cells by DRE treatment, as revealed by gene expression analyses showing the expression of genes implicated in programmed cell death.

Phytochemical analyses of the extract showed complex multi-component composition of the DRE, including some known bioactive phytochemicals such as α-amyrin, β-amyrin, lupeol and taraxasterol. This suggested that this natural extract could engage and effectively target multiple vulnerabilities of cancer cells. Therefore, DRE could be a non-toxic and effective anti-cancer alternative, instrumental for reducing the occurrence of cancer cells drug-resistance.

Conclusions

Our results showed that aqueous dandelion root extract (DRE) efficiently and selectively triggers programmed cell death pathways in in-vitro and in-vivo colorectal cancer models. The results confirmed our hypothesis that the molecular complexity of the DRE extract is responsible for its anti-cancer activity, as it allows the engaging of multiple signaling pathways in cancer cells, including the mitochondria. Therefore, we can conclude that DRE, as a complex mixture might provide a complementary alternative to currently available chemotherapies.

With these results, DRE is approved by Health Canada for Phase I clinical trials in hematological cancers. Their use might prove not only efficacious, but also associated with fewer and less severe side-effects and, thus, improve the quality of life and possibly increase the lifespan of cancer patients.