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 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.

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