Pomegranate (Punica granatum L.) Seeds Ethanolic Extract: Chemical Characterization and Cytotoxic Activity against Human Tumor Cell Lines.

Pomegranate (Punica granatum L.) seeds are considered a waste of pomegranate juice production; however, they have attracted considerable interest because they are rich of bioactive compounds with antioxidant and anti-inflammatory activity. Most studies reported the beneficial effects of pomegranate seed oil extracted using non polar solvents, whereas little is known about the effects of an extract obtained using polar solvents. The ethanolic seed extract (ESE) was chemically characterized and its cytotoxic effects were evaluated on cultured human tumor cells by SRB assay. The test is based on the indirect estimation of the cell number by providing a sensitive index of total cellular protein content which is linear to cell density. Pomegranate extract was characterized by a conjugated linolenic acid, punicic acid (C18:3 ctcas the main component followed by -linoleic acid in the neutral lipids. The polar lipid fraction contained -linoleic and palmitic as the main fatty acids. The main glycolipid molecular species contained oleic acid and a C18:3 acid; all the main phospholipid classes were formed by the C18:2/C18:2 combination (by HPLC-ESI-MS/MS). The polyphenolic fraction was tentatively characterized by HPLC-ESI-MS/MS. Pomegranate seeds extract exhibited a strong cytotoxic activity against prostate cancer cell (LNCaP) and breast cancer cell (MCF-7) with IC50 values of 8.6 and 9.6 μg/mL, respectively. Our results are in agreement with previous study about citotoxicity of pomegranate extract against prostate cancer cells (PC3, D145 etc). An interesting activity was observed, also, against amelanotic melanoma (C32 cells) with IC50 value of 15.3 μg/mL