It takes guts to build bones

Osteoporosis Supplement: Researchers have found a potential new treatment for osteoporosis

Using an investigational drug that inhibits serotonin synthesis in the gut cured osteoporosis in post-menopausal rodents, according to an international team led by researchers from Columbia University Medical Center in the United States. The findings appear in Nature Medicine (1).
The research involved the experimental drug LP533401 that inhibits serotonin production in the gut, an area that regulates bone formation.
The drug was given in small doses orally for six weeks in a population of rodents with postmenopausal osteoporosis. Results showed that the experimental compound prevented osteoporosis from developing in some rats, while curing osteoporosis in others who already had the bone disease.
Serotonin levels in the brain were unaffected, thereby avoiding many potential side effects.
“New therapies that inhibit the production of serotonin in the gut have the potential to become a novel class of drugs to be added to the therapeutic arsenal against osteoporosis,” Dr Gerard Karsenty, the lead author of the study and chair of the Department of Genetics and Development at Columbia University College, stated in a press release.
Serotonin
Serotonin assists the transmission of messages between nerve cells and has a big impact on mood. But 95 per cent of the body’s serotonin is found in the gut, where its major function is to inhibit bone formation, said the researchers.
By shutting off intestinal serotonin production, the scientists prevented osteoporosis in post-menopausal female mice. In humans, the menopause is known to increase the risk of the disease dramatically.
It is hoped that the findings may lead to the development of an alternative to current treatments for osteoporosis. However, clinical trials will be needed to confirm positive results in humans, as serotonin has many other effects outside of bone.
Bone formation
Karsenty and his colleagues had previously discovered that serotonin released in the gut inhibits bone formation, and that regulating serotonin synthesis in the gut affects the formation of bone. These findings led them to postulate that an inhibitor of serotonin synthesis should be an effective treatment for osteoporosis.
Soon after, they learned of LP533401, which inhibits serotonin synthesis in the gut.
“We thought that it was important to test it as proof of principle that there could be novel ways to treat osteoporosis with therapies that can be taken orally and regulate the formation of serotonin,” Karsenty stated.
Most current osteoporosis drugs can only prevent the breakdown of old bone. According to the release, there is one drug on the market can generate new bone.
However, it must be taken by injection once a day, and it is restricted for short-term use in women with severe osteoporosis because it has been shown to increase the risk of cancer in rats.
References:
(1) Yadav VK, Balaji S, Suresh PS, et al. Pharmacological inhibition of gut-derived serotonin synthesis is a potential bone anabolic treatment for osteoporosis. Nat Med. 2010 Feb 7.