A combination of two drugs could hugely benefit people with diabetes by enhancing the production of cells essential to the production of insulin – the hormone that balances blood sugar levels.

Insulin is produced by special cells in the pancreas called beta cells. The new drug cocktail can make these cells proliferate at the highest rate ever observed in humans – a rate of 5 to 8 percent per day. The findings are published in the journal Cell Metabolism.

"Beta cell regeneration is a 'holy grail' for the treatment of diabetes," said Dr Peng Wang, associate professor of Medicine at Mount Sinai and first author on the study, in a statement. "We are excited to finally have drugs that can induce beta cell proliferation at rates that are likely to be effective in people with type 1 and type 2 diabetes."

Type 1 diabetes is an autoimmune condition where the body’s immune system turns on the beta cells and destroys them. This means that sufferers can’t produce their own insulin and have to inject insulin into their bodies. In the US, 1.25 million people have this condition, so finding alternatives to daily injections would be life-changing to these patients.

Meanwhile, type 2 diabetes occurs when the beta cells in the pancreas stop working so well, so not enough insulin is produced. This tends to occur later in life due to a combination of genetics and lifestyle factors such as obesity. Diabetes can lead to a number of health complications, including blindness and strokes, so finding a better treatment is key.

One of the drugs in the cocktail inhibits an enzyme known as dual specificity tyrosine-regulated kinase 1A (DYRK1A) and the other inhibits transforming growth factor beta superfamily members (TGFβSF). Together, these two drugs caused the beta cells to proliferate at a surprisingly fast rate.

"We are very excited about this new observation because for the first time, we are able to see rates of human cell beta cell replication that are sufficient to replenish beta cell mass in human beings," said Dr Andrew Stewart, director of the Mount Sinai Diabetes, Obesity, and Metabolism Institute. "We have discovered a drug combination that makes beta cells regenerate at rates that are suitable for treatment." 

While promising, the new research still has some way to go before the drugs can be used clinically in human patients. "The next big hurdle is figuring out how to deliver them directly to the pancreas," said Dr Stewart. 

“There are still challenges ahead, but this work brings us a little closer to therapies that can restore insulin production in people with the disease, and ultimately produce a cure," added study author Dr Francis J. Martin.