Flaxseed lignan increased red blood cell glucose uptake

Abstract

The effect of flaxseed lignan, secoisolariciresinol diglycoside (SDG), on red blood cell (RBC) glucose uptake was investigated. Twelve-hour fasting blood samples were collected three times from a healthy donor. RBCs were separated and incubated with 0, 10, 50, or 100 μM SDG for 1 hr at 37 °C. Upon completion of the incubation with SDG, RBCs were incubated with 0 or 100 μU insulin/ml for 30 min at 37 °C. After the pretreatment with insulin, RBC glucose uptake was initiated by adding 3H-labeled 3-O-Methyl-D-glucopyranose solution and then stopped by adding stop solution at 30 sec, 1 min, and 25 min. Upon completion of glucose uptake, RBCs were washed, digested, and counted in a scintillation counter. There was no time effect on glucose uptake of RBCs. However, the pretreatment of RBCs with 50 or 100 μM SDG significantly increased glucose uptake compared to RBCs without SDG or with addition of 10 μM SDG (p<0.0001). RBCs incubated with insulin significantly increased glucose uptake compared to RBCs without insulin (p<0.0001). No interactions among time, SDG, and insulin were observed. The results indicate that flaxseed supplementation may improve glycemic control via increased RBC glucose uptake. Funding support: NDSU HDE College, Swenson Endowment, and ND EPSCoR; equipment support: USDA NRI CSREES #2005-35200-15258.