Nov. 21, 2014

By Medical Discovery News

Your tongue isn’t the only part your body that can taste sweetness. Three years ago, scientists discovered that our intestines and pancreas have receptors that can sense the sugars glucose and fructose. This could revolutionize treatment for diabetics, who must closely monitor their blood sugar levels. A drug called New-Met, made by Eleclyx Therapeutics in San Diego, that is now in phase II clinical trials is attempting to do just that by targeting those sugar receptors in the digestive system.

It appears these taste receptors are basically sensors for specific chemicals that can serve functions other than taste in other parts of the body, although we don’t know what all those functions are yet. We do know the function of the T1R2/T1R3 taste receptor found on some cells in the intestine. When they detect sugar molecules, these cells secrete hormones called incretins, which in turn stimulate insulin production in the pancreas.

This neatly explains a phenomenon that had mystified scientists for over 50 years: eating glucose triggers significantly more insulin than injecting it directly into the bloodstream. When intestinal cells with sweet receptors detect sugar, they trigger neighboring cells to make a glucose transporter that allows the sugar to be absorbed by the body. The faster sugar is absorbed, the more signals are sent to the pancreas, and the more insulin it releases. Signals are also sent to the brain to tell us we are satiated. Artificial sweeteners can trigger the same effect. Understanding these signals is critically important in the control of blood sugar levels.

Metformin is a drug commonly prescribed to those with type 2 diabetes. It regulates blood sugar levels by decreasing the amount of glucose produced by the liver. Metformin may also modulate multiple components of the incretin signaling system. In combination with insulin, it increases the use of glucose in peripheral tissues like muscles and the liver, especially after meals, reducing blood sugar levels even further. Metformin is usually taken orally, so that it dissolves in the stomach and travels through the bloodstream to the liver.

New-Met is a novel formulation of metformin that dissolves when exposed to the pH in the intestine rather than the stomach. There, it binds to those sweet receptors and activates the release of incretins that stimulate the release of insulin, thereby regulating blood sugar levels. This mimics the natural signaling process triggered by sugars and is fast and direct. This reduces the amount of drug required to be effective by 70 percent. Patients on New-Met had fewer gastrointestinal side effects than those taking the standard metformin, which is the primary reason diabetics choose not to take it.

The number of people with diabetes will soon climb to 592 million, so the demand for better medications to treat them will continue to climb as well.

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