Differential Effects of Punicic Acid on Cytotoxicity and Peroxiredoxin Expression in MCF-7 Breast Cancer and MCF-10A Normal Cells.

Background/aim: The pomegranate fruit has been associated with a variety of human health benefits based on its antioxidant and anti-inflammatory properties. Punicic acid (PA) is an omega-5 long chain polyunsaturated fatty acid that constitutes approximately 65-80% of the oil from pomegranate seeds and has been found to possesses anti-cancer activity in various cancer types. To better understand its cell specificity, we investigated the effects of punicic acid on both the MCF-7 human breast cancer cell line as well as the non-cancerous MCF-10A breast epithelial line.

Materials and methods: We treated both cell types with different concentrations of punicic acid and measured viable cell density, cytotoxicity and apoptosis, as well as peroxiredoxin (Prdx) antioxidant expression.

Results: We found that punicic acid was cytotoxic to both lines, but MCF-10A cells demonstrated higher levels of cytotoxicity and sensitivity to lower concentrations. We further demonstrated that cytotoxicity was associated with apoptosis in both lines. Using real time PCR, we demonstrated induction of all six Prdx mRNAs in MCF-7 cells, ranging from a 1.4-fold increase with 2 μg/ml, to over a 5-fold increase with 10 μg/ml. In stark contrast, MCF-10A cells exhibited considerably higher induction of all six Prdx mRNAs at 10μg/ml, exceeding a 30-fold induction of Prdx1, Prdx2 and Prdx5.

Conclusion: Our data are the first to demonstrate differential cytotoxicity and Prdx regulation by punicic acid in these two cell lines. These results may provide important insight into cell-specific mechanisms of punicic acid in breast cancer.