Viagra could be used to treat Crohn's disease, researchers say

The anti-impotence drug Viagra could potentially help treat Crohn's disease, British researchers propose.

Crohn's disease causes abdominal pain, bleeding ulcers and diarrhea. It can also affect the skin and eyes.

The anti-impotence drug Viagra increases blood flow.

Anthony Segal of University College London and his team believe the bowel disorder may be triggered by a weak immune system and Viagra may work to correct the resulting low blood flow in patients.

The origins of Crohn's disease remain a mystery, but there are two main schools of thought: bacterial infection or an overactive immune response that causes the body to attack its own tissues.

In Saturday's issue of the journal The Lancet, Segal's team propose an opposite hypothesis for the inflammation in Crohn's: too weak an immune response.

To investigate, they took intestinal and skin samples from a group of healthy people and those with Crohn's disease.

Researchers say the Crohn's patients did not generate enough white blood cells needed to fight problematic bacteria that may enter the intestines and can remain there, prompting the immune system to respond with inflammation.

And treating the inflammation may actually worsen the underlying immune deficiency, the researchers suggest.

To test the inflammatory response to bacteria, Segal's team injected a harmless form of E. coli under the skin and measured blood flow, a sign of immune response.

It's possible the abnormally low blood flow in the Crohn's group could be corrected by prescribing Viagra, best known for increasing blood flow for erectile dysfunction, the researchers said.