Animal testing for human pharmaceutical products often centers on animal livers, but scientists have invented a fake liver that appears to be just as effective for drug testing purposes and requires no killing of critters.
The liver "stand in," announced today at the 247th National Meeting & Exposition of the American Chemical Society, could dramatically alter how drugs are made and tested.
"Researchers in drug discovery make small quantities of new potential drug compounds and then test them in animals," Mukund Chorghade, who worked on the project, said in a press release. "It is a very painstaking, laborious and costly process."
"Frequently, scientists have to sacrifice many animals, and even after all that, the results are not optimal," added Chorghade, who is chief scientific officer of Empiriko Corporation and president of THINQ Pharma.
The traditional drug testing process usually involves what's known as metabolic profiling. Researchers administer a test drug to an animal, see if it works, and then monitor how the liver breaks down the drug. They watch for molecular byproducts, or metabolites, which are often responsible for causing nasty side effects.
Most drugs come with a laundry list of side effects, but the good of the drug should obviously outweigh the bad. The tests for metabolites are therefore very important.
Instead of using real livers for such tests, Chorghade and his colleagues have developed "chemosynthetic livers," which seem to work just as well. The faux livers are really a mix of chemicals that function like compounds in actual livers. Researchers add them to a test tube, along with the drug being tested, and look for the resulting metabolites, per usual.
"These chemosynthetic livers not only produce the same metabolites as live animals in a fraction of the time," Chorghade said, "but they also provide a more comprehensive metabolic profile, in far larger quantities for further testing and analysis."
The chemosynthetic livers have not yet been approved to take the place of animal tests. Chorghade's team has tested more than 50 drugs so far to show that the liver stand-in accurately mimics how the human body processes these drugs. The U.S. Food and Drug Administration requires testing of at least 100 drugs, however, for regulatory approval.
Approval should be worth the wait, though, as the new "livers" could also be used to detoxify blood for liver transplant patients, according to the researchers. They say their new tests could also help in predicting side effects when multiple drugs are taken together.
(Image: a sheep liver with parts numbered; Credit: Wikimedia Commons)