Anti Tumoral Properties of Punica Granatum (Pomegranate) Peel Extract on Different Human Cancer Cells

Background: Medicinal plants, especially examples rich in polyphenolic compounds, have been suggested tobe chemopreventive on account of antioxidative properties. Punica granatum (PG) (pomegranate) is a well knownfruit in this context, but its cytotoxicity in cancer cells has not been extensively studied. Here, we investigatedthe antiproliferative properties of a peel extract of PG from Iran in different human cancer cells. Materialsand
Methods: A methanolic extract of pomegranate peel (PPE) was prepared. Total phenolic content(TPC) andtotal flavonoid conetnt (TFC) were determined by colorimetric assays. Antioxidant activity was determined byDPPH radical scavenging activity. The cytotoxicity of different doses of PPE (0, 5, 20, 100, 250, 500, 1000 μg/ml)was evaluated by MTT assays with A549 (lung non small cell cancer), MCF-7 (breast adenocarcinoma), SKOV3(ovarian cancer), and PC-3 (prostate adenocarcinoma) cells.
Results: Significant (P<0.01) or very significant(P<0.0001) differences were observed in comparison with negative controls at all tested doses (5-1000 μg/ml). Inall studied cancer cells, PPE reduced the cell viability to values below 40%, even at the lowest doses. In all cases,IC50 was determined at doses below 5μg/ml. In this regard, MCF-7 breast adenocarcinoma cells were the mostresponsive cells to antiprolifreative effects of PPE with a maximum mean growth inhibition of 81.0% vs. 69.4%,79.3% and 77.5% in SKOV3, PC-3 and A549 cells, respectively.
Conclusions: Low doses of PPE exert potentanti-proliferative effects in different human cancer cells and it seems that MCF-7 breast adenocarcinoma cellsare the most cells and SKOV3 ovarian cancer cells the least responsive in this regard. However, the mechanismsof action need to be addressed.