Apoptotic and antiproliferative activity of olive oil hydroxytyrosol on breast cancer cells

Breast cancer is a major worldwide public health concern for women. It still remains the second most prevalent form of cancer which is terminal despite the advances made in the therapeutic approach. Polyphenols in olive oil and leaves have been known for their medicinal properties. The objective of the present study was to investigate the anti-cancer effect of hydroxytyrosol and to determine the mechanisms underlying its effects. The cytotoxic and antiproliferative effects of hydroxytyrosol were determined in SK-BR-3 and T-47D breast cancer cell lines using the WST-1 assay. Apoptosis was analysed using Annexin V, and cell cycle was investigated by flow cytometry. The key findings of the present study showed that hydroxytyrosol, a pharmacologically safe natural product of olive oil, has potent anti-breast cancer properties. Indeed, it exhibits specific cytotoxicity against SK-BR-3 and T-47D breast cancer cells. Furthermore, hydroxytyrosol triggered apoptosis that showed a dose-dependent increase in both cell lines. Moreover, hydroxytyrosol inhibited cell proliferation by delaying the cell cycle at G2/M phase. Therefore, hydroxytyrosol warrants further investigations to prove its utility in preventing/treating breast cancer.   Key words: Breast cancer, hydroxytyrosol, apoptosis, cytotoxicity, cell proliferation.