Untold numbers of laboratory rodents have been dispatched so that humans could know with certainty that all manner of substances are carcinogenic or otherwise deadly. But in a welcome turnabout, scientists from Sapporo Medical University in Japan reported recently in the journal Nature Biotechnology that they have used synthetic molecules to cure rats of cirrhosis.

Cirrhosis is the scarring of the liver that results from damage caused by alcohol abuse, hepatitis, or malnutrition, and until now, the only treatment has been a liver transplant. In developing the new therapy, the researchers took advantage of two characteristics of the stellate cells that create the scar tissue: their absorption of vitamin A and their production of collagen, the fibrous substance that hardens the liver. The scientists designed RNA molecules that would inhibit the production of collagen and then "disguised" them with a layer of vitamin A so the stellate cells would absorb the molecules.

The success of the experiment, wrote the researchers, "suggests its therapeutic potential for reversing human liver cirrhosis" - good news indeed. We just hope the discovery of this potential new treatment won't lead lab rats to hit the sauce with abandon.