E-Newsletter No. 74

     Together with dieting and hitting the gym, obesity treatment may one day involve a needle. By targeting a hormone that helps thwart the body’s ability to maintain weight loss, researchers led by Marianna P. Monteiro, M.D., Ph.D., at the University of Porto, in Portugal, designed a vaccine against ghrelin. Paradoxically, levels of the appetite stimulating hormone are low in obese subjects, but after diet-induced weight loss, its production rises and thereby contributes to weight regain. Recent research has shown that the long-term success of bariatric surgeries may lie in their ability to suppress this gut hormone. In creating their vaccine, the researchers fused noninfectious, virus-like particles with ghrelin to provoke the immune system to produce antibodies against the hormone. 

     They vaccinated mice of either normal weight or diet-induced obesity three times; controls received only saline injections. A poster at ENDO 2011* presented the results. All the vaccinated mice showed increased amounts of anti-ghrelin antibodies, significant decreases in food intake and white adipose tissue, and a surge in calorie burning.

     Within 24 hours of the first vaccination, treated mice ate only 82% of the amount the control mice ate. This effect persisted until the final injection, by which time treated mice ate 50% of the volume eaten by controls. Vaccinated obese mice also expressed less neuropeptide Y, another appetitestimulating hormone, demonstrating that the vaccine packs a double punch in curbing feeding signals. The effects of each vaccination lasted for 2 months, which for a normal 18-month mouse lifespan corresponds to 4 human years, Dr. Monteiro told Endocrine News.

* Andrade S, Carreira M, Ribeiro A, et al. Development of an anti-ghrelin vaccine for obesity treatment.
ENDO 2011,
Abstract #P2-305.