Molecule In Oranges May Help Reduce Obesity: Study

A molecule found in sweet oranges and tangerines, called nobiletin, may reduce obesity and reverse its negative effects, according to a study in mice which may lead to new interventions against the condition. The study, published in the Journal of Lipid Research, said that mice fed a high-fat, high-cholesterol diet that were also given nobiletin were noticeably leaner compared to those that were fed a high-fat, high-cholesterol diet alone.

It also noted that the mice fed the high-fat diet had reduced levels of blood fats and insulin resistance -- a condition in which the body fails to use the hormone insulin to process glucose from the blood for energy. "We've shown that in mice that already have all the negative symptoms of obesity, we can use nobelitin to reverse those symptoms, and even start to regress plaque build-up in the arteries, known as atherosclerosis," said Murray Huff, study co-author from the University of Western Ontario in Canada.

The researchers initially suspected that the molecule could be acting on the pathway that regulates how fat is handled in the body. Called AMP Kinase, they said, this regulator turns on the machinery in the body that burns fats to create energy, and may also block the manufacture of fats.

However, when the researchers studied nobiletin's effects on mice that had been genetically modified to remove AMP Kinase, they reported the same effects. "This result told us that nobiletin is not acting on AMP Kinase, and is bypassing this major regulator of how fat is used in the body. What it still leaves us with is the question -- how is nobiletin doing this?" Huff said.

While this mystery remains, the researchers said the findings show that nobiletin may not interfere with other drugs that act on the AMP Kinase system. Huff said that current therapeutics for diabetes like metformin work through this pathway.