Diabetics have trouble regulating their blood sugar levels either because their bodies don't make enough insulin (a hormone that enables cells to take up glucose) or because they don't utilize insulin as well as they should. Moreover, in many diabetics the liver churns out excess glucose, which compounds the problem. Joseph Grimsby of pharmaceutical company Hoffmann-La Roche and his colleagues discovered a compound that binds to the enzyme glucokinase, a "glucose sensor" of sorts. Dubbed RO-28-1675, the drug boosts glucokinase activity in rat pancreas cells, causing them to secrete insulin. RO-28-1675 also lowers the ability of rat liver cells to release glucose. "By turning on glucokinase, this novel compound improves insulin secretion by the pancreas and stimulates glucose usage by the liver, both of which are abnormal in diabetes," study co-author Mark A. Magnuson explains.
The team next tested the drug on diabetic mice and rats and found that the animals' glucose levels dropped dramatically after the first dose. A benefit of RO-28-1675 is that it can be taken orally, meaning that diabetics could one day replace painful insulin injections with a pill. It will be years before that can happen, however, as clinical trials for humans are only in the planning stages. But Magnuson is hopeful: "[ RO-28-1675] has dramatic effects in animals, suggesting it has the potential to be a very powerful new drug."