Molecule found in oranges may reduce obesity

A molecule found sweet oranges and tangerines called nobiletin could drastically reduce obesity and reverse its negative side-effects, according new research published in the Journal of Lipid Research.

For the study, led by researchers from the University of Western Ontario, mice fed a high-fat, high-cholesterol diet with nobiletin were noticeably leaner and had reduced levels of insulin resistance and blood fats compared to mice that were fed a high-fat, high-cholesterol diet alone.

"We've shown that in mice that already have all the negative symptoms of obesity, we can use nobiletin to reverse those symptoms, and even start to regress plaque build-up in the arteries, known as atherosclerosis,” said Murray Huff, PhD, lead author of the study.

Huff said the research team has not been able to pinpoint exactly how nobiletin works. The researchers hypothesized that the molecule was likely acting on the pathway that regulates how fat is handled in the body. This regulator, adenosine monophosphate (AMP)-activated protein kinase, turns on the machinery in the body that burns fats to create energy, and it blocks the manufacture of fats.

When the researchers studied nobiletin's effects on mice that had been genetically modified to remove AMP-kinase, the effects were the same, Huff said. He said while the mystery remains, this result is still clinically important because it shows that nobiletin won't interfere with other drugs that act on the AMP-kinase system. He says current therapeutics for diabetes, like metformin, work through this pathway.

The next step is to move these studies into humans to determine if nobiletin has the same positive metabolic effects in human trials.

"Obesity and its resulting metabolic syndromes are a huge burden to our health care system, and we have very few interventions that have been shown to work effectively," said Huff in a statement. "We need to continue this emphasis on the discovery of new therapeutics."