SR9079 - Evaluation of the Biological Activity of Selected Canola Fractions

Researcher:

Dr. Elzbieta M. Kurowska, KGK Synergize

Objectives:

1. To develop technology for recovery of biologically active canola fractions in quantities required for efficacy studies.

2. To evaluate biological activities of the above preparations in cell culture and animal models of cancer and hypercholesterolemia.

Expected Benefits:

1. A specialized oil seed processing industry could benefit from the commercial application of any extraction and purification technology developed.
   

2. The biomedical research community in Ontario will benefit and be strengthened by clinical trials and approval for human use. Development of nutraceutical or functional food based preventative therapies that have a positive impact on disease progression and mortality from these causes will have a tremendous benefit on the quality of life and the cost of the health care system.
   

Summary of Research Results:

Several free phenolic acid-enriched fractions have been isolated from canola meal. All fractions were evaluated for anti-cancer potential in human skin cancer cell line SK-MEL-5 and the most active preparation has been isolated in quantities sufficient for animal study. The selected preparation (containing more than 50% of free sinapic acid) has been fed to mice with chemically- induced skin cancer at the 0.06% and 0.2% level in the diet for a period of 23 weeks and tumor development was monitored twice per week. The results demonstrated that at both levels of supplementation, canola phenolic acids delayed development of skin tumors, reduced tumor incidence and also reduced total number of tumors and tumor size. These beneficial effects were not associated with toxicity, as confirmed by the normal growth and food consumption observed in animals fed canola phenolic acid diets. Our data suggest therefore that canola phenolic acid extract might become a novel dietary supplement useful for prevention of skin cancer in humans.

The total phenolics-enriched fraction from canola meal was also isolated in quantities sufficient for the cholesterol study in animals. The above fraction (containing 7.2% of principal canola phenolic compound, sinapine) was evaluated for the ability to lower blood cholesterol in hamsters with hypercholestrolemia induced by feeding casein-based diet. In the study, hamsters were fed the experimental diet with or without 1% supplement of canola phenolics and after five weeks of treatment, blood and liver samples were analyzed for lipid responses. The results showed that the canola phenolics extract had a tendency to produce beneficial, cholesterol-lowering responses in blood, however, this was associated with significant increases in liver cholesterol. The observed liver cholesterol accumulation might not be clinically relevant since previous studies suggested that in humans, liver metabolism of plant phenolics is different than in rodents.