Cytotoxic effect of Zuccagnia punctata ethanolic extract and their flavonoids

Abstract

Zuccagnia punctata is a shrub from Fabaceae family which commonly grows distributed in arid and semiarid areas in western Argentina. This plant is used in ethnomedicine as antimicrobial and anti-inflammatory drug. Some biological properties were reported for Z. punctata extracts (antioxidant, anti-inflamatory, antigenotoxic, antimicrobial). The aim of the present study was to determine the in vitro cytotoxic effects of an ethanolic extract from Z. punctata aerial part and four of their flavonoids: 7-hydroxyflavanone (HF), 3,7-dihydroxyflavone (DHF), 2?,4?-dihydroxy-3?-methoxychalcone (DHMC) and 2?,4?-dihydroxychalcone (DHC) using mammalian cell cultures. The cytotoxicity of the natural products was tested using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) viability assay on MCF-7 human breast adenocarcinoma and CT26 mouse colon adenocarcinoma cells. The assays were performed at 24, 48 and 72 h. The results demonstrated that the Z. punctata ethanolic extract and their flavonoids induced cytotoxic effects on the two cell lines evaluated. The activity on cell lines after 72 h of exposing was in the following order: DHC >DHCM>DHF>Zp with IC50 values between 3.125 - 50 µg/ml and HF at the highest concentration (50 µg/ml) evaluated affected only 20 % the cell viability in all cases. The active samples reduced CT26 cell viability in a concentration-dependent manner and the effect increased with the incubation time. However, the activity of the active flavonoids was stronger on MCF7 and started from 72 h of treatment. These results suggest that the studied natural product could be applied as natural anticancer drug.