A team of French scientists has used advanced 3D modeling and computer screening of molecules to show Naproxen, commonly sold as Aleve, is effective at blocking flu virus replication in cells and showed its success in mice infected with the flu. Naproxen is currently approved throughout the world and for pain relief and inhibits a pain pathway called COX-2.

Researchers first solved the three dimensional structure of a key protein, called a nucleoprotein, used by flu viruses to replicate in 2006 with more research on the structure performed recently. The importance in understanding the structure of the protein is to figure out if a small molecule, or pharmaceutical drug, can block its function easily. The nucleoprotein is highly conserved across flu viruses and is therefore a valuable drug target for researchers.

The team from the Institut National de la Recherche Agronomique, Jouy en Josas, France led by Anny Slama-Schwok performed a virtual screening of compounds from Sigma-Aldrich's online catalog of biochemicals. They found that the over the counter chemical Naproxen, or sold commonly as Aleve, interacted with the nucleoprotein to block its function.

The researchers then took the testing out of the virtual world and began testing the compound in the lab. They found that it blocks a grove in the protein that is important for RNA binding and necessary for flu virus replication. When they infected cells with an H1N1 influenza virus or a H3N2 flu virus they found that treatment with the pain killer reduced the viral load in cells. Moving on to mice, they found that the infection was lessened and the 'therapeutic index' of the treatment was far superior to any other anti-inflammatory drug used.

The team wrote that the drug could be used as a springboard for developing other novel anti-flu medications and tweaking its structure could lead to more effective treatments that could shorten flu infections in people.

The research published in the journal Antimicrobial Agents and Chemotherapy can be found here.