CHICAGO: A once-a-day pill helped completely rebuild bone in rodents with severe osteoporosis. The finding could lead to a new class of drugs to treat the brittle-bone disease in humans, US researchers said.

The team tested a compound that blocks the production of serotonin produced in the gut of mice and rats with a severe form of the disease and found they completely recovered their bone density.

"If you break the bone, it looks like a normal bone," said Dr. Gerard Karsenty of Columbia University Medical Center in New York, whose study appears in the journal Nature Medicine.