Antitumor effects of aloysia polystachya extract in colorectal cancer

MILENI SOARES MACHADO; LAURA C. PANELO; MARÍA C. LIRA; FRANCISCO D. ROSA; ALEJANDRA G. PALMA; GABRIELA MARINO; MARÍA F. RUBIO; ALEJANDRO J. URTREGER; MÓNICA A. COSTAS

Mar del Plata

Congreso; LXIII Reunión Científica de la Sociedad Argentina de Investigación Clínica (SAIC); 2018

Sociedad Argentina de Investigación Clínica (SAIC)

Aloysia Polystachya (AP) is an aromatic native plant of Verbenaceae family which is widely distributed in subtropical regions of South America and the North of Argentine. Uses in medicine of Aloysia species include diuretic, sedative, antispasmodic activities. We have previously demonstrated that AP extracts exert cytotoxic effects in several human tumor cell lines, including apoptosis. The aim of this work was to investigate if cytotoxic effects of AP extract could be extensive to cancer stem cells (CSC), and also, the possible sensitization or potentiation of chemotherapeutic drugs, using colorectal cancer model. Therefore, the colorectal cancer cell lines CT26 (mouse) and HCT116 (human), were stimulated with AP extract or vehicle, with or without 5-fluorouracyle (5-FURA) and then, the surviving and CSC properties were determined. The surviving was measured after crystal violet staining at 570nm and CSC phenotype was determined by measuring the CSC marker CD133 (PCR), colony formation (clonogenic assay) and the HOESCHT efflux capacity (chemotherapeutic drugs efflux via ABCG2 transporters). We found that AP extract (0,0004625 mg/ml of flavonoids) decreased the CD133 expression (98%), the colony formation and the efflux capacity of chemotherapeutic drugs respect to control cells. In addition, AP (0,0004625 mg/ml flavonoids) increased the cell death induced by 5-FURA (3,5 uM) treatment (20%) respect to cells stimulated with 5-FURA alone. Our results demonstrate that AP increases the 5-FURA effect and CSC population may be a target for AP-induced cell death. Being CSC the most resistant to chemotherapeutic drugs, responsible of cancer progression and perpetuation, the autochthonous plant derivatives could be attractive tools to be investigated as future oncologic therapeutics.