According to researchers in the U.S., a drug which is currently prescribed to arthritis sufferers may also be an effective weapon against amoebic dysentery.
Amoebic dysentery — Amoebiasis — is an infection of the intestine which is caused by an amoeba called Entamoeba histolytica. It is known to cause severe diarrhoea with blood loss, cramps, fatigue and abdominal pain. If it is left untreated, it may lead to exhaustion, dehydration and death.
There are several different species of amoebae, but the most dangerous, including Entamoeba histolytica, live mainly in damp, humid tropical areas — which has resulted in what is believed to be thousands of deaths every year in developing countries. The current estimate is 70,000 fatalities per year.
Amoebae are parasites that are found in contaminated food or drink, and enter the body orally. Often, the cysts responsible for amoebic dysentery are found in polluted water. Once they have entered the body, they settle in the gut.
Drugs that are currently used to combat the condition include metronidazole. However, the researchers, based at UC San Diego School of Medicine, UC San Francisco and Wake Forest School of Medicine were searching for a cost-effective and more successful way to treat the condition that kills thousands worldwide.
Recently published in the journal Nature Medicine, the scientists used a high-throughput screen for drugs and tested amoebae infections to see whether any other drugs had higher rates of eradicating the parasites. They found that auranofin — a drug approved by the FDA (U.S. Food and Drug Administration) 25 years ago to treat arthritis is ten times more effective than metronidazole.
The drug works by honing in on an enzyme that defends the amoeba from oxygen-based attack — therefore rendering them more vulnerable to eradication.
Prof James McKerrow, from the Sandler Center for Drug Discovery at the University of California said:
“When we’re looking for new treatments for the developing world, we start with drugs that have already been approved.
“If we can find an approved drug that happens to kill these organisms, we’ve leapfrogged the development process that goes into assessing whether they are safe, which also makes them affordable throughout the world.”
The scientists tested a total of 910 drugs in the laboratory before making the transition to animal testing. Further studies with human subjects will be necessary to ascertain the drugs’ effectiveness when bonded to human physiology.
Image credit: Luz Adriana Villa A.