Fighting Flu With Fish Oil

Influenza disables and kills people, and current drugs don’t work well in late-stage and severe cases. In a new study, a team of researchers from Japan have discovered a lipid derivative that could inspire a new way to stop the virus, possibly even in late-stage and critical cases. Such a drug is still far from reality, but the findings point to a day when flu might be fought more effectively. Antiviral drugs such as oseltamivir (Tamiflu) are approved for flu treatment but have only mild benefits and work best when administered to non-critically ill patients at an early stage of infection. For late-stage patients or those with serious complications, “there is lots of room for improvement,” says University of Manitoba pandemic flu expert Anand Kumar. Polyunsaturated fatty acids found in fish oils are the core structures of lipid cell-signalling compounds such as protectins, which exert powerful anti-inflammatory effects in response to tissue injury. But scientists did not know what role protectins play in flu. Now, biological informatics and experimental therapeutics professor Yumiko Imai of Akita University, in Japan, and coworkers report that that the protectin D1 isomer 10S,17S-dihydroxydocosahexaenoic acid blocks replication of the flu virus by inhibiting export of viral genomic material from host-cell nuclei (Cell, DOI: 10.1016/j.cell.2013.02.027). They found the compound by screening a lipid library. They learned that levels of protectin D1 isomer in the lungs are low during severe flu infection and climb as flu severity decreases. When the team administered additional protectin and an antiviral drug to mice with flu, symptoms and survival improved. They conclude that the protectin D1 isomer could thus “serve as a novel antiviral drug as well as a biomarker for severe and lethal influenza virus infections.” Kumar says the work “is a novel observation on influenza pathogenesis,” but he is less sanguine about drug possibilities. “It is very remote from clinical application. There are many observations of this sort with various diseases, and very few ever pan out as real therapies.”

Chemical & Engineering News, 11 march 2013 ; ;