A chemical naturally occurring in the body, already proven to produce a feeling of being full when administered, has found an effective new route via a spray on the tongue, say health researchers from the University of Florida.
The chemical, called peptide YY, is a gut hormone released after eating that the researchers have been trying to exploit for the reproduction of feeling full after food, and so aiding weight loss.
Several years of work by the researchers have included some success in inducing this effect by injecting the hormone - but this route of administration straight to the bloodstream resulted in unacceptable side effects.
The clinical trials were stopped because of vomiting, the researchers say. Given in this way, peptide YY's effect went too far, telling the brain that the stomach was overfull, in turn resulting in the "visceral sickness."
Safer mode of delivery
Now, however, the study with mice - using a simple mouth spray containing the hormone - suggests that taking it via this route half an hour before food could prove a safer way to help with weight loss, the lead researcher says.
Sergei Zolotukhin, PhD, an associate professor of cellular and molecular therapy at the University of Florida's College of Medicine, says:
"When mice were treated with a solution of this peptide using a simple spray, with one puff they will consume less food and they will start losing weight."
Dr. Zolotukhin adds:"The implications are very simple: if you put peptide YY in a spray or gum and you take it half an hour before dinner, you will feel full faster and consume less food.
"It could be just a 5 or 10% difference, but it is enough to stimulate weight loss."
Hope for scientific sense in the oral spray market
The researchers note that other oral weight-loss sprays are already on the market, but they say that these are not "backed by medical science."
A search engine enquiry will turn up numerous herbal and homeopathic sprays from the diet system industry, and some preparations are available without prescription from pharmacies.
While many show no evidence of harm, nor do many show evidence of benefit, and some are unsafe and illegal.
One example, the "homeopathic" human chorionic gonadotropin (HCG) weight-loss products, have been the subject of action by the US Food and Drug Administration (FDA) and the Federal Trade Commission (FTC).
On an alert page for consumers last updated on September 20th, the FDA says these products are "potentially dangerous," adding:
"The FDA and the FTC have issued seven letters to companies warning them that they are selling illegal homeopathic HCG weight-loss drugs that have not been approved by FDA, and that make unsupported claims."
Effects on nerve pathways
The study from Dr. Zolotukhin and his colleagues is published in the The Journal of Neuroscience.
As well as trying injection, the team also explored delivery via gene therapy in previous work. It was during this process, the researchers say, that they became the first to discover that the YY peptide can be found in saliva.
Initial tests of the oral spray of the substance finally proved successful, however the researchers "needed to be sure that the spray would not stimulate the same sickness as injection." But the latest study showed that the salivary type of the peptide had different effects on nerve pathways than the body-systemic version that had proven too potent.
Dr. Zolotukhin says:
"Comparing systemic peptide YY versus salivary PYY, what we have found is that although salivary PYY induces similar neuronal pathways to induce fullness, at the same time, it does not induce the neuronal pathways that cause visceral sickness."
The potential treatment against obesity needs further research before human trials can begin, and the researchers are hoping to find a commercial partner to license the technology.
In other obesity research presented today, a new study suggests that African-American women need to consume fewer calories or do more activity to achieve the same weight-loss rates as Caucasian women who start the process at a similar size.
The team of metabolism experts from the University of Pittsburgh, PA, cite a lower metabolic rate to explain the greater difficulty for African-Americans in reducing obesity.