P-326 - Eucalyptus globulus Labill. decoction extract inhibits the growth of human tumor cell lines

Abstract

Eucalyptus globulus Labill. is a widespread evergreen plant with a plethora of medicinal properties, most notably antitumoral activity. The aims of this work were to: (i) test the cell growth inhibitory effect of the E. globulus, prepared by decoction and infusion, in three human tumor cell lines models: lung (NCI-H460), colorectal (HCT-15) and pancreatic (PANC-1) cancer; (ii) study the mechanism of action of the most potent extract in the most sensitive cell line. Both extracts inhibited the growth of all cell lines and revealed gallotannins as the main compounds. The decoction extract was the most potent in inhibiting the NCI-H460 cell growth. Thus, we further investigated the effect of the decoction extract on the NCI-H460 cell viability (Trypan blue exclusion assay), cell cycle profile, apoptosis (Flow cytometry) and protein expression (Western blot). Interestingly, the E. globulus decoction extract caused a dose-dependent decrease in cell number, which was correlated with a cell cycle arrest in the G1 phase and an increase in p53 and p21 proteins expression. However, no differences were found in the levels of programmed cell death. The relevance of identifying novel bioactive compounds with antitumoral activity in Eucalyptus globulus L. is thus highlighted in this work.