Arthritis drug found effective in amoebic dysentery

Washington - Scientists have identified an arthritis drug that acts very effectively against a parasite causing amoebic dysentery and liver abscesses, which kill over 70,000 people worldwide annually.

Auranofin, a US Food and Drug Administration (FDA)-approved formulation for rheumatoid arthritis, was found to be very effective in targeting an enzyme that protects amoebae from oxygen attack (boosting sensitivity of the parasite to reactive oxygen-mediated killing).

Entamoeba histolytica, the parasite in question, is a protozoan intestinal parasite that causes amoebiasis, the world's fourth leading cause of death from protozoan parasites, the journal Nature Medicine reports.

"Because auranofin has already been approved by the FDA for human consumption, we can save years of expensive development," said Sharon L. Reed, professor of pathology and medicine at the University of California, San Francisco, US.

"In our studies in animal models, auranofin was 10 times more potent against this parasite than metronidazole," added Reed, who co-led the research with James McKerrow, her counterpart at the Sandler Center for Drug Discovery in California, US.

Current treatment against the parasite relies on metronidazole, which has adverse effects, and potential resistance to the drug is an increasing concern, according to a California statement.

The symptoms can be mild to severe depending on the location of infection. They include anaemia, indigestion, intermittent diarrhoea, dehydration, blood and mucus in the stool, abdominal bloating, cramps, fever and fatigue.

In a mouse model of amoebic colitis and a hamster model of amoebic liver abscess, the drug markedly decreased the number of parasites, damage from inflammation, and size of liver abscesses.

"This new use of an old drug represents a promising therapy for a major health threat, and highlights how research funded by the National Institutes of Health can benefit people around the world," Reed said.