The scientists have developed a drug that not only slows progression of the disease but also reverses damage to the organ.

Their discovery, published in PLoS Online on December 26, opens the door to treating and curing conditions that lead to excessive tissue scarring such as viral hepatitis, fatty liver disease, cirrhosis, pulmonary fibrosis, scleroderma and burns.

Researchers from University of California, San Diego, showed that by blocking a protein linked to overproduction of scar tissue, they can not only stop the progression of fibrosis in mice, but reverse some of the cell damage that already occurred.

In response to cirrhosis caused by alcohol - hepatic stellate cell (HSC) activated by oxidative stress - results in large amounts of collagen. Collagen is necessary to heal wounds, but excessive collagen causes scars in tissues.

Researchers showed that a protein called RSK results in HSC activation and is critical for the progression of liver fibrosis. They reasoned that if they could block the RSK signal they might be able to halt liver disease in its tracks.

To test the theory they took two groups of mice and treated both with a toxin that is known to cause liver damage.

"All control mice had severe liver fibrosis, while all mice that received the RSK-inhibitory peptide had minimal or no liver fibrosis," said Martina Buck, assistant professor of medicine at UCSD.

"The cells continue to do their normal, healing work but their excess proliferation is controlled. Remarkably, the death of HSC may also allow recovery from liver injury and reversal of liver fibrosis."

The researchers found a similar activation of RSK in activated HSC in humans with severe liver fibrosis. Liver biopsies from patients with liver fibrosis also showed activated RSK.

"Six years ago, we showed a way to prevent or stop the excessive scarring in animal models," said Buck. "Our latest finding proves that we can actually reverse the damage."

Trials on humans are expected to begin in the New Year.

Worldwide, almost 800,000 people die from liver cirrhosis each year, and there is currently no treatment for it. Excessive tissue repair in chronic liver disease induced by viral, toxic, immunologic and metabolic disorders all result in excessive scar tissue, and could benefit from therapy developed from the UCSD researchers' findings.

Professor Roger Williams, who used to treat alcoholic football legend George Best, warns it's not an excuse to keep on drinking. "That's going much too far, if people think it's a magical drug that will allow you to drink heavily, that's just science fiction."