Dec. 22 (Bloomberg) -- Mice that inhaled cigarette smoke five hours daily avoided lung damage in a study by eating a chemical compound.

The mice were exposed to smoke in a laboratory to study emphysema, a progressive lung disease that causes shortness of breath and often is fatal. The compound, CDDO-imidazole, boosted the animals’ production of antioxidants that keep lung cells from dying and decrease inflammation, according to a report today in the Proceedings of the National Academy of Sciences.

Cigarette smoke is the most common cause of emphysema. The research, from the Bloomberg School of Public Health at Johns Hopkins University in Baltimore, may show drugmakers where to focus efforts to treat the malady, said James Kiley, the director of the division of lung diseases at the National Heart, Lung, and Blood Institute.

“Is it going to bring a new therapy tomorrow?” said Kiley, who wasn’t involved in the study. “Absolutely not. We don’t have any therapies that will cure the disease or halt the progression once it’s started, so it’s a step toward that.”

The study, funded by the institute, was led by Shyam Biswal, an associate professor of environmental health at Johns Hopkins. Biswal’s team will evaluate whether CDDO-Im can reverse the damage from emphysema.

Smoking Discouraged

The study results shouldn’t be seen as encouragement to smoke, Biswal said in an e-mailed statement.

“It would be most beneficial to patients who have mild or moderate disease,” he said, and may help prevent the illness from worsening.

Previous research showed that if mice have a gene called NRF2 that is blocked from functioning, they have earlier-onset and more-severe emphysema when exposed to smoke. Studies also found that CDDO-Im activates the gene.

In the new study, mice that were fed the drug had less damage from smoke exposure than the other animals regardless of whether the eaters of the compound carried the NRF2 gene. This suggests the drug has a protective effect, Kiley said.

The NRF2 gene is important for preventing inflammation, said Steven Shapiro, chairman of the medicine department at the University of Pittsburgh School of Medicine. This study helps to establish how smoking damages lungs by causing inflammation that leads to tissue destruction, and to pinpoint drug targets, he said.

Drug Studied for Cancer

A compound similar to CDDO-Im has been evaluated by the National Cancer Institute in early testing in people with lymphoma that has spread in the body, the Johns Hopkins researchers wrote.

Michael Bloomberg, New York’s mayor and the founder and majority owner of Bloomberg LP, the parent of Bloomberg News, is an alumnus and benefactor of Johns Hopkins University. Bloomberg School of Public Health is named in his honor.

To contact the reporter on this story: Elizabeth Lopatto in New York at elopatto@bloomberg.net.

Last Updated: December 22, 2008 17:00 EST