Flaxseed oil induces apoptosis in the aggressive murine melanoma cell line B16-BL6

Abstract

Flaxseed is classified as a functional food and is renowned for its exceptional nutrional value. These foods have the ability to either promote overall well-being and/or reduce the risk of certain diseases. Flaxseed, in the form of seed-derived oil,is the highest plant source of the omega-3 fatty acid, alpha linolenic acid. This nutraceutical has been credited with providing protective benefits against breast, colon and prostate cancers. Humans are unable to synthesize omega-3 fatty acids within the body and therefore must obtain sufficient amounts of this antioxidant through diet alone. Currently, the Western diet is grossly deficient in omega-3 fatty acids and this is in part due to the overwhelming presence of omega-6 fatty acids used in food processing and manufacturing techniques. As one of the highest sources of omega-3 fatty acids, flaxseed is often taken as a supplement to help balance the ratio of omega-3 to omega-6 fatty acids in Western cultures. Although flaxseed has been beneficial in alleviating certain symptoms in patients suffering from cardiovascular disease, diabetes, and cancer, the underlying mechanisms remain unclear. Previous animal studies have shown that a diet supplemented with 10% flaxseed, significantly decreased tumour growth in rodent cancer models. Our studies include the treatment of malignant cells with flaxseed oil in an in vitro model. We have shown that flaxseed oil has the ability to reduce cell growth in B16-BL6 cells, an aggressive murine melanoma. Furthermore, a total of seven different oils containing high concentrations of omega fatty acids, including flaxseed oil, olive, sunflower, canola, sesame, peanut and grapeseed, were characterized by HPLC and GC/MS analysis for fatty acid profiles, and these oils were also used to treat B16-BL6 cells. Although all seven oils contain various amounts of omega-3, -6 or -9 fatty acids, only treatment with flaxseed oil decreased the growth of the aggressive murine melanoma cell line B16-BL6. DNA laddering, acridine-orange staining, TUNEL staining, and FACS analysis using Annexin V and propidium iodide, showed that the flaxseed-treated cells were undergoing apoptosis, a type of cell suicide. Therefore, due to its ability to selectively inhibit malignant cell proliferation, flaxseed oil has significant potential as an anti-cancer therapeutic.