Anti Tumoral Properties of Punica granatum (Pomegranate) Seed Extract in Different Human Cancer Cells

Background: Punica granatum (PG) has been demonstrated to possess antitumor effects on various types of cancer cells. In this study, we determined antiproliferative properties of a seed extract of PG (PSE) from Iran in different human cancer cells. Materials and Methods: A methanolic extract of pomegranate seeds was prepared. Total phenolic content (TPC) and total flavonoid content (TFC) were assessed by colorimetric assays. Antioxidant activity was determined with reference to DPPH radical scavenging activity. The cytotoxicity of different doses of PSE (0, 5, 20, 100, 250, 500, 1000 g/ml) was evaluated by MTT assays with A549 (lung non small cell carcinoma), MCF-7 (breast adenocarcinoma), SKOV3 (ovarian cancer cells), and PC-3 (prostate adenocarcinoma) cells. Results: Significant (P<0.01) or very significant (P<0.0001) differences were observed in comparison to negative controls at all tested doses (5-1000 g/ml). In all studied cancer cells, PSE reduced the cell viability to values below 23%, even at the lowest doses. In all cases, IC50 was determined at doses below 5 g/ml. In this regard, SKOV3 ovarian cancer cells were the most responsive to antiproliferative effects of PSE with a maximum mean growth inhibition of 86.8% vs. 82.8%, 81.4% and 80.0% in MCF-7, PC-3 and A549 cells, respectively. Conclusions: Low doses of PSE exert potent antiproliferative effects on different human cancer cells SKOV3 ovarian cancer cells as most and A549 cells ar least responsive regarding cytotoxic effects. However, the mechanisms of action need to be addressed.