Scientists at the Cleveland Clinic's Lerner Research Institute have found that levels of certain lung enzymes decrease during allergen-provoked asthma, creating the potential for novel drugs to fight the disease.
The results of the researchers, Dr. Serpil Erzurum, and Suzy Comhair Ph.D., are published in the Feb. 19 issue of The Lancet medical journal.
The researchers documented declines in the concentrations of the antioxidants superoxide dismutase and reduced glutathione in lung fluids from asthmatics 10 minutes after exposure to grass or ragweed allergens.
Nonasthmatic control volunteers, on the other hand, did not experience declines in lung antioxidant levels.
"Antioxidants play a key role in preserving healthy lungs in humans," said Erzurum, a staff physician in the Department of Pulmonary and Critical Care Medicine at the Cleveland Clinic.
"The lungs are frequently exposed to toxic oxidants from cigarette smoke, air pollutants, or from reactive oxidants released by inflammatory cells during inflammation," said Erzurum. Fortunately, the lung has an integrated defense system that uses antioxidants such as glutathione and superoxide dismutase to protect lung cells and tissue."
However, Erzurum added, acute asthmatic attacks impair that antioxidant defense system.
"When oxidants overwhelm antioxidants, tissue injury and disease results," said Erzurum. "Our studies show that chronic asthma features decreased levels of antioxidants in the lungs, and the decrease is worse during acute asthmatic attacks."
Therefore, Erzurum said the findings highlight the importance of testing new therapies for boosting antioxidant levels in the lungs of asthmatics.
As many as 150 million people worldwide suffer from asthma, and the number is rising, according to the World Health Organization.
In the United States, the number of asthmatics has risen 60 percent since the early 1980s.
There are approximately 5,000 asthma-related deaths each year in the United States, and 180,000 per year worldwide.