Exercise pill one step closer?

In what may be a breakthrough that nearly everyone can appreciate, researchers from the US have identified a molecule in the blood, produced during exercise, that can effectively reduce food intake and tackle obesity in mice.

Researchers from Baylor College and Stanford School of Medicine found that in mice fed a high-fat diet, a large dose of the modified amino acid, Lac-Phe, halved the amount they ate over a 12-hour period without affecting their level of movement or energy expenditure.

When administered to the mice for 10 days, Lac-Phe demonstrably reduced cumulative food intake, lowered body weight and body fat, and improved glucose tolerance.

Dr. Yong Xu, author and professor of paediatrics, nutrition, and molecular and cellular biology at Baylor, said that their findings, published June 15th in Nature, improved scientists’ understanding of the physiological processes that underlie the interplay between exercise and hunger.

“Regular exercise has been proven to help weight loss, regulate appetite and improve the metabolic profile, especially for people who are overweight and obese,” Dr Xu said.

“If we can understand the mechanism by which exercise triggers these benefits, then we are closer to helping many people improve their health.

“For example, older or frail people who cannot exercise enough, may one day benefit from taking a medication that can help slow down osteoporosis, heart disease or other conditions.”

And whilst a George Jetson-like exercise pill may still be some way off, the team has already confirmed robust elevations in plasma Lac-Phe levels following physical activity in both racehorses and humans.

Xu’s colleague and co-author, Dr Jonathan Long, an assistant professor of pathology at Stanford Medicine and institute scholar at Stanford ChEM-H, explained that data from a human exercise cohort showed that sprint exercise induced the most dramatic increase in plasma Lac-Phe, followed by resistance, and then endurance training.

“This suggests that Lac-Phe is an ancient and conserved system that regulates feeding and is associated with physical activity in many animal species,” Dr Long said.

Lac-Phe is a modified amino acid synthesized from lactate (a by-product of strenuous exercise that is responsible for the burning sensation in muscles) and phenylalanine (an amino acid that is one of the building blocks of proteins).

The researchers also identified an enzyme called CNDP2 that is involved in the production of Lac-Phe and showed that mice lacking this enzyme did not lose as much weight on an exercise regime as a control group on the same exercise plan.

“Our next steps include finding more details about how Lac-Phe mediates its effects in the body, including the brain,” Xu said.

“Our goal is to learn to modulate this exercise pathway for therapeutic interventions.”