New York, July 31 (IANS): Scientists have found a way to produce large amounts of functional liver cells from human embryonic and genetic engineered stem cells.

As toxicity of new drug has to be tested in human liver cells, which are in short supply, the new research could lead to faster drug discovery.

"This is quite a revolution for pharmaceutical drug discovery," said the study's senior author Yaakov Nahmias, professor at Hebrew University of Jerusalem in Israel.

As the gatekeeper of the digestive track, the liver is responsible for drug breakdown and is therefore the first to be injured due to overdose or misuse.

Evaluating this drug-induced liver injury is a critical part of pharmaceutical drug discovery and must be carried out on human liver cells.

Regretfully, human liver cells, called hepatocytes, are in scarce supply as they can only be isolated from donated organs.

"While other groups have been able to produce liver cells before us, their cells showed little functional activity, and could not be reliably used for drug discovery,” Nahmias noted.

"In fact, up until now stem cell-derived hepatocytes showed little ability to predict clinical outcome," Nahmias said.

The researchers demonstrated that liver cells produced from either embryonic stem cells or genetically engineered skin cells, can detect the toxic effect of over a dozen drugs with greater than 97 percent accuracy.

The limited availability of functional hepatocytes for drug testing is a major bottleneck bringing pharmaceutical companies to spend $1 billion/year on liver cells alone, the study said.

"Our ability to produce an unlimited supply of functional liver cells from human pluripotent stem cells can change all that," Nahmias noted.

The findings appeared in the journal Hepatology.