Extraction, purification and animal model testing of an anti-atherosclerotic lignan secoisolarichiresinol diglucoside from flaxseed (Linum usitatissimum)

A commercially practical process was developed for the extraction and purification of the lignan secoisolariciresinol diglucoside (SDG) from flaxseed meal (Linum usitatissimum). A simple reversed phase HPLC method was developed for the analysis of SDG in flaxseed extracts. Extraction of commercial flax meal with aqueous alcohol, hydrolysis of the extract, and subsequent purification of the extract using Solid Phase Extraction acid prep RP-HPLC, consistently yielded between 10 and 15 gm of 99% pure SDG for every Kg of meal extracted, depending upon the source of meal. The 99% pure SDG was fed (15 mg/kg body weight) to rabbits on a high cholesterol (1%) diet for a period of 8 weeks. Blood lipid profiles were obtained at 0, 4 and 8 weeks. At 8 weeks the rabbits were sacrificed and the degree of cholesterol deposition in the aortae was determined. Addition of SDG at 15 mg/kg resulted in a 33% reduction in serum total cholesterol and a 73% reduction in atherosclerotic plaques in rabbits on a high cholesterol diet compared to control rabbits on the high cholesterol diet alone.