O3 An in vitro study on the anti-cancer properties of rapeseed pomace extracts

Abstract

Natural products have recently been exploited as alternative sources of cancer chemo-preventative agents. Induction of cell cycle arrest and apoptosis, and prevention of carcinogenesis and cancer progression are some of the mechanisms studied in cell systems and animal models. By-products from rapeseed oil extraction processes, however, have not been studied before: this study aims to assess the potential anti-cancer properties of extracts from rapeseed pomace (RSP), the by-product of cold pressed rapeseed oil production. RSP was extracted using accelerated solvent extraction (ASE) with different ethanol (EtOH) to water (dH 2 O) ratios: 50:50 EtOH:dH 2 O RSP extract showed significantly higher concentrations in Gallic Acid Equivalent (Folin Ciocalteu assay) compared to controls, and a significant increase in free radical scavenging properties (DPPH assay) was observed for 50:50 and 20:80 EtOH:dH 2 O RSP extracts. Moreover, extracts’ anticancer properties were assessed in a breast cancer cell line, MDA-MB-231. The three RSP extracts did not show cell cytotoxicity at concentrations ⩽1 mg/ml; however, at 2.5 mg/ml, 50:50 EtOH:dH 2 O RSP extract significantly decreased cell viability by 72% and, at 5 mg/ml, all extracts were cytotoxic. Cell treatment with 50:50 EtOH:dH 2 O RSP extract did not induce further DNA strand breaks (COMET assay) compared to untreated controls; however, an increase was measured with both 80:20 and 20:80 EtOH:dH 2 O RSP extracts. The anti-cancer properties of RSP extracts demonstrated in this study warrant further investigation and, potentially, open new avenues for the identification of chemo-preventative agents and reutilisation/revalorisation of rapeseed pomace.