Extract from Aloysia polystachya Induces the Cell Death of Colorectal Cancer Stem Cells

Cancer stem cells (CSCs) are an important player in the resistance of cancers to therapy. In this work, we determined the flavonoids composition and biological action of Aloysia polystachya (AP) extracts in colorectal cancer. The chemical characterization of extracts was performed by HPLC. Assays of cytotoxicity, apoptosis, migration and invasion, metalloproteases activity, clonogenic growth, tumorspheres formation, Hoechts efflux, pluripotency marker expression and sensitization to chemotherapeutic drugs were performed in vitro in human HCT116 and murine CT26 colorectal cancer cells. The AP toxicity and effect in tumor growth administered alone or in combination with 5- Fluorouracile was analyzed in vivo, including histopathological studies. We found that AP extracts induced in vitro the apoptosis of colorectal cancer cell lines decreasing the CSC proportion. Moreover, they were capable to kill 5-Fluorouracile resistant side population cells. At not toxic doses in vivo, AP extracts inhibited tumor growth. Regarding the ability to reduce the CSC population, AP extracts deserves to be investigated as a useful therapy for colorectal cancer treatment.