In a study published online June 8, 2021 in the journal Immunity, a multi-institution team led by researchers at University of California San Diego School of Medicine identified a molecular mechanism for the anti-inflammatory activity of metformin, an anti-diabetes drug used by millions. In mouse studies, was found that metformin prevents pulmonary or lung inflammation in animals infected with SARS-CoV-2, the virus that causes COVID-19. Other drugs used to control blood sugar levels do not appear to produce a similar effect. These clinical studies suggested metformin could be responsible for reduced COVID-19 severity and mortality. Metformin also produced a marked reduction in mortality in endotoxin-challenged mice and inhibited production and inflammasome assembly within alveolar macrophages, immune cells found in the lungs. Cell culture studies using macrophages revealed the underlying mechanism by which metformin exerts its anti-inflammatory activity: reduced production of ATP by mitochondria. However, there was some skepticism in their findings,” said corresponding study author Michael Karin, PhD, Distinguished Professor of Pharmacology and Pathology and Ben and Wanda Hildyard Chair for Mitochondrial and Metabolic Diseases at UC San Diego School of Medicine.
More studies are needed but the authors said the findings suggest metformin may have therapeutic potential for treating a variety of neurodegenerative and cardiovascular diseases in which NLRP3 inflammasome activation is a factor. “Inhibition of inflammasome activation may also account for the poorly explained anti-aging effect of metformin.”