Abstract

FRACTIONS FROM EUPHORBIA UMBELLATA (PAX) BRUYNS SAP ARE CYTOTOXIC TO BREAST AND COLORECTAL CELLS

Luiza Stolz Cruz*, Carla Cristine Kanunfre, Shabana Khan, Ikhlas Khan and Flávio Luís Beltrame

ABSTRACT

It has previously been shown that extracts (fractions and subfractions) from Euphorbia umbellata sap possess cytotoxic and anticancer effects against different cell lineages. However, there are few studies regarding the effects of such sap extracts upon breast and colorectal cell lineages. Therefore, the aims of this study were as follows: to evaluate the cytotoxic potential and selectivity against of extracts against five different cell lineages (human colorectal cancer cells: HT-29 and HCT 116; human breast cancer: MCF-7 and MDA-MB 231; and human renal embryonic: HEK-293); and to try to assess the mechanism of action of these extracts and also a major compound obtained from E. umbellata sap (euphol). The cytotoxicity was determined by MTT reduction assay, and the IC50 values were used to calculate the selectivity indices; caspase-3 and caspase-7 activation was assessed for the most sensitive cells. The results showed that only the methanol fraction was unable to reduce cell viability at the tested concentrations. MDA-MB 231 presented the lowest IC50 value and the highest selectivity index when treated with the ethyl acetate fraction (IC50: 7.77±3.11 μg/mL, SI: 9.85). Euphol was cytotoxic to all the tested cells and selective for MDA-MB 231 and HT-29. The ethyl acetate fraction, dichloromethane subfraction, and euphol all induced caspase-3 and caspase-7 activity. These extracts, and the main compound obtained from E. umbellata sap (euphol) are cytotoxic to breast and colorectal cells, and their activity may be associated with apoptosis.

Keywords: Euphol, Triterpenes, MTT assay, Caspase.