Sodium-glucose cotransporter 1 (SGLT1) is a high affinity, low capacity transporter abundant in the small intestine, with some expression in the kidney as well. SGLT2 is a low affinity, high capacity transporter in the kidney that accounts for approximately 90% of glucose reabsorption into the blood stream. Selective inhibition of SGLT2 is a potential strategy for reducing plasma glucose levels as a treatment for diabetes. Phlorizin is a natural product, first isolated from the bark of apple trees, that reduces plasma glucose levels by blocking renal and intestinal glucose absorption through inhibition of SGLT1 and SGLT2. It competitively inhibits the initial rate of a-methyl-D-glucopyranoside (a-MDG) uptake in human COS-1 cells expressing hSGLT1 and hSGLT2 with IC50 values of 400 and 65 nM, respectively. In HEK293T cells expressing human SGLT1 and SGLT2, phlorizin exhibits Ki values of 140 and 11 nM, respectively, at 37°C.
