Secoisolariciresinol diglucoside

Secoisolariciresinol diglucoside (SDG) is an antioxidant phytoestrogen present in flax, sunflower, sesame, and pumpkin seeds. In food, it can be found in commercial breads containing flaxseed. It is a precursor of mammal lignans which are produced in the colon from chemicals in foods.

Extraction

Secoisolariciresinol diglucoside can be isolated from de-fatted (hexane extraction) flaxseed by extraction of the lignan polymer precursor with a water/acetone mixture, followed by acetone removal and alkaline hydrolysis.

Studies on biological effects

Secoisolariciresinol diglucoside slows the growth of human breast cancer in mice.

Secoisolariciresinol diglucoside may be manipulated by different CYP enzymes in Eukaryotes. Due to its inherent size of 687Da, it will not pass the Blood–Brain Barrier (which is somewhat limited to molecules smaller than 500Da). For example, in one Histology group of adult patients with malignant glioma (Grade IV), consuming Secoisolariciresinol, resulted in 'poorer' survival outcomes, while the Grade III patients resulted in more positive outcomes (SDG with vitamin E).

In rabbits, SDG reduced hypercholesterolemic atherosclerosis and this effect was associated with a decrease in serum cholesterol, LDL-C, and lipid peroxidation product and an increase in HDL-C and antioxidant reserve.

SDG has been shown to counter oxidative stress in human colonic epithelial tissue and protect against mtDNA damage in vitro, by H₂O₂ exposure, in a dose-dependent manner, and counters (in-vitro) oxidative stress on heart cells caused by Iron overload.