Apoptotic and antiproliferative activity of olive oil hydroxytyrosol on breast cancer cells Maha H. Elamin1*, Zeinab K. Hassan1, Sawsan A. Omer1, Maha H. Daghestani1, Ebtesam M. Al-Olayan1, Promy Virk1, Mai A Elobeid1 and Osama B. Mohammed2
1Department of Zoology, College of Science, King Saud University, University Centre for Women Students, P. O. Box 22452, Riyadh 11495, Saudi Arabia. 2KSU Mammals Research Chair, Department of Zoology, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia.
Abstract 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.
Olive oil intake is inversely related to cancer prevalence: a systematic review and a metaanalysis of 13800 patients and 23340 controls in19 observational studies Theodora Psaltopoulou1*, Rena I Kosti1, Dimitrios Haidopoulos2, Meletios Dimopoulos3 and Demosthenes B Panagiotakos4
Abstract .Dietary fat, both in terms of quantity and quality, has been implicated to cancer development, either positively or negatively. The aim of this work was to evaluate whether olive oil or monounsaturated fat intake was associated with the development of cancer. A systematic search of relevant studies, published in English, between 1990 and March 1, 2011, was performed through a computer-assisted literature tool (i.e., Pubmed). In total 38 studies were initially allocated; of them 19 case-control studies were finally studied (13800 cancer patients and 23340 controls were included). Random effects meta-analysis was applied in order to evaluate the research hypothesis. It was found that compared with the lowest, the highest category of olive oil consumption was associated with lower odds of having any type of cancer (log odds ratio = -0.41, 95%CI -0.53, -0.29, Cohran’s Q = 47.52, p = 0.0002, I-sq = 62%); the latter was irrespective of the country of origin (Mediterranean or non-Mediterranean). Moreover, olive oil consumption was associated with lower odds of developing breast cancer (logOR = -0,45 95%CI -0.78 to -0.12), and a cancer of the digestive system (logOR = -0,36 95%CI -0.50 to -0.21), compared with the lowest intake. The strength and consistency of the findings states a hypothesis about the protective role of olive oil intake on cancer risk. However, it is still unclear whether olive oil’s monounsaturated fatty acid content or its antioxidant components are responsible for its beneficial effects.
Conclusion Nutritional factors play a major role in cancer initiation and development . The present systematic review and meta-analysis of observational studies revealed that, overall, olive oil consumption was associated with lower odds of cancer development. Most prominent results were observed for breast cancer and cancers of thedigestive system, while the aforementioned relationship was similar to studies performed in Mediterranean as well as non-Mediterranean countries. Meta-analyses have several weaknesses, due to inherent biases and differences in study designs (different control for residual confounding, different socio-demographic and other lifestyle characteristics that may alter food habits), publication bias, etc ....
The aim of the present study was to evaluate the possible protective role of olive oil on mammary carcinogenesis. Experimental studies can support epidemiologic data on the influence of some nutrients that can affect risk and prognosis of neoplastic lesions. In the present study, seventy two Sprague-dawley female rats 42 days old were equally divided in tree groups, being group C supplemented with olive oil (5%) and submitted to chemical carcinogenesis induction with 20 mg kg-1 of 7, 12-dimethylbenzanthracene (group B and C). At 150 days, all the animals were sacrificed and necropsy process was conducted. Animals from group A did not developed neoplastic lesions and group C showed significant differences on the number and volume of the neoplastic lesions when compared to animals from the group that was not supplemented with olive oil, it was also verified the absence of metastases in this group. The present data suggests a possible protective role of olive oil, due to its content of oleic acid and phenolic compounds, on growth and differentiation of mammary neoplastic lesions that should be confirmed on further investigation projects.