Jan 7 2009
When an obesity drug called Leptin was first discovered by scientists 13 years ago, experts hoped the appetite-suppressing hormone would be a possible cure for obesity.
Leptin failed to realise those expectations and it was discovered that overweight people became unresponsive to Leptin very quickly due to the development of resistance in the brain but scientists at Harvard University have now found a way to stop the brain blocking its influence.
They have discovered that the substances Buphenyl (4-PBA) and Tauroursodeoxycholic acid (TUDCA) stop the brain from ignoring Leptin and the drug is once again being considered as a way to deal with the escalating levels of obesity.
Dr. Umut Ozcan, who led the study, says most humans who are obese have Leptin resistance and researchers have been searching for years for a drug to make peoples' brains sensitive to Leptin again.
Leptin works by diminishing the amount of pleasure received from food and after treatment overweight patients find their hunger reduced, they became more particular about food and they lose weight. However, the brain quickly gets used to the hormone, builds up a resistance and Leptin loses its affect.
Both 4-PBA and TUDCA are available over the counter as treatments for cystic fibrosis and liver disease and are available in pill form and in experiments with mice Dr. Ozcan found that pre-treating them with 4-PBA or TUDCA, Leptin sensitivity was boosted and the mice had significant weight loss even when fed a high-fat diet.
Dr. Ozcan says the study provides evidence that chemical chaperones, particularly the PBA and TUDCA, can be used as leptin-sensitizing agents and as all have a high safety record, they could together present a new treatment option for obesity.
The study is published in the current issue of Cell Metabolism.