CHICAGO, Oct. 11 (Xinhua) -- A common, safe and inexpensive drug for type 2 diabetes, metformin, decreases the risk of heart attacks and strokes caused by air pollution by reducing inflammation in the lungs that triggers clotting, according to a new Northwestern Medicine study.

In the study published Thursday in Cell Press, a pediatric formulation of metformin was given to mice in their drinking water for three days. It was an equivalent concentration to the dose people take for diabetes. Mice were exposed to air pollution in a specially designed chamber that concentrates the particles.

When mice were exposed to air pollution in the laboratory, their macrophages released an inflammatory molecule called IL-6, which has been linked to heart attacks and strokes. Metformin prevented the release of IL-6 and reduced the speed at which clots formed after an injury. The same findings were seen in lung macrophages from humans.

Three years ago, Northwestern University (NU) professor of Medicine and Cell Biology and his colleagues found that metformin inhibits cancer progression. They also discovered that metformin slows mitochondrial metabolism to prevent the growth of cancer.

To prove that targeting the mitochondria in macrophages could prevent inflammation in response to pollution, NU professor of Airway Diseases Scott Budinger and Chandel created mice where lung macrophages lacked key mitochondrial proteins. Like the mice treated with metformin, these mice were protected against pollution-induced inflammation.

These results suggest that "metformin is a pharmacological way of doing the same thing," Chandel explained. "We know it's an anti-diabetic drug, it can be an anti-cancer drug, and now our study suggests it's a reasonable anti-inflammatory drug."

"These findings suggest metformin as a potential therapy to prevent some of the premature deaths attributable to air pollution exposure worldwide," said Budinger.

Currently Chandel and Budinger are determining whether metformin can target mitochondrial metabolism to prevent or slow aging and age-related diseases including diabetes, inflammation, cancer and neurodegeneration.

More than 100 million people take metformin worldwide.