Buformin hydrochloride (NSC-528218) is a potent AMPK activator,an oral antidiabetic drug of the biguanide class. Buformin delays the absorption of glucose from the gastrointestinal tract increases insulin sensitivity and glucose uptake into cells and inhibits synthesis of glucose by the liver. Biguanides may antagonize the action of glucagon, thus reducing fasting glucose levels.

Buformin hydrochloride (0-10 mM; 5 days) inhibits SKBR3 and BT474 cells growth as a concentration-dependent manner, exhibits IC50 values of 246.7 μM and ?98.6 μM for erbB-2-overexpressing SKBR3 and BT474 cells, respectively[1].
Buformin hydrochloride (0-3 mM; 48 hours) increases the percentage of cells in G0/G1 phase and reduced the percentage of cells in S phase, especially in the SKBR3 cells[1].
Buformin hydrochloride (0-3 mM; 24 hours) suppresses RTK activation, including erbB-2 and IGF1R signaling downstream, and Akt activation/phosphorylation is inhibited in both SKBR3 and BT474 cells[1].

Buformin hydrochloride (oral administation; 7.6?mmol/kg of chow; 7 days) exhibits significantly reduced tumor volumes and weights, and?hinders mammary morphogenesis and proliferation in MMTV-erbB-2 transgenic mice[1].