Anti-inflammatory drug mefenamic acid completely reversed memory loss and brain inflammation in mice genetically engineered to develop symptoms of Alzheimer’s disease and amyloid beta-induced memory loss, a team led by David Brough, PhD, from the University of Manchester has discovered.

The non-steroidal anti-inflammatory drug (NSAID) drug targets an important inflammatory pathway called the NLRP3 inflammasome, which damages brain cells, according to Brough. This is the first time a drug has been shown to target this inflammatory pathway, highlighting its importance in the disease model, Brough said.

“Because this drug is already available and the toxicity and pharmacokinetics of the drug is known, the time for it to reach patients should, in theory, be shorter than if we were developing completely new drugs. We are now preparing applications to perform early phase II trials to determine a proof-of-concept that the molecules have an effect on neuroinflammation in humans.”

“There is experimental evidence now to strongly suggest that inflammation in the brain makes Alzheimer’s disease worse. Until now, no drug has been available to target this pathway, so we are very excited by this result.”

The research, funded by the Medical Research Council and the Alzheimer’s Society, paves the way for human trials that the team hopes to conduct in the future, but Brough cautions that more research is needed to identify its impact on humans and the long-term implications of its use.

The findings were published Thursday Aug. 11 in an open-access paper authored by Brough and colleagues in the journal Nature Communications.

Abstract of Fenamate NSAIDs inhibit the NLRP3 inflammasome and protect against Alzheimer’s disease in rodent models

Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase-1 (COX-1) and COX-2 enzymes. The NLRP3 inflammasome is a multi-protein complex responsible for the processing of the proinflammatory cytokine interleukin-1β and is implicated in many inflammatory diseases. Here we show that several clinically approved and widely used NSAIDs of the fenamate class are effective and selective inhibitors of the NLRP3 inflammasome via inhibition of the volume-regulated anion channel in macrophages, independently of COX enzymes. Flufenamic acid and mefenamic acid are efficacious in NLRP3-dependent rodent models of inflammation in air pouch and peritoneum. We also show therapeutic effects of fenamates using a model of amyloid beta induced memory loss and a transgenic mouse model of Alzheimer’s disease. These data suggest that fenamate NSAIDs could be repurposed as NLRP3 inflammasome inhibitors and Alzheimer’s disease therapeutics.