An international group of scientists has discovered a new class of molecular compounds capable of killing the influenza virus.
You learned this from your parents; too much even of a good thing can be a killer and that same idea has led to manipulating an enzyme that is key to how influenza replicates and spreads. The newly discovered compounds interrupt the enzyme neuraminidase's facilitation of influenza's spread.
Tamiflu and another anti-influenza drug, Relenza, focus on interrupting neuraminidase's ability to help influenza detach from an infected cell's surface by digesting sialic acid, a sugar on the surface of the cell. The flu virus uses the same sugar to stick to the cell while invading it. Once attached, influenza can invade the cell and replicate. The newly discovered compounds clog up neuraminidase, stopping the enzyme from dissolving the sialic acid, which prevents the virus from escaping the infected cell and spreading.
The new compounds are also more effective because they're water-soluble. "They reach the patient's throat where the flu virus is replicating after being taken orally," says study co-author Masahiro Niikura, virologist at Simon Fraser University."Influenza develops resistance to Replenza less frequently, but it's not the drug of choice like Tamiflu because it's not water-soluble and has to be taken as a nasal spray. "Our new compounds are structurally more similar to sialic acid than Tamiflu. We expect this closer match will make it much more difficult for influenza to adapt to new drugs."
Ultimately, the new compounds will buy scientists more time to develop new vaccines for emerging strains of influenza that are resistant to existing vaccines.
Citation: Jin-Hyo Kim, Ricardo Resende, Tom Wennekes, Hong-Ming Chen, Nicole Bance, Sabrina Buchini, Andrew G. Watts, Pat Pilling, Victor A. Streltsov, Martin Petric, Richard Liggins, Susan Barrett, Jennifer L. McKimm-Breschkin, Masahiro Niikura, and Stephen G. Withers, 'Mechanism-Based Covalent Neuraminidase Inhibitors with Broad Spectrum Influenza Antiviral Activity', Science 1232552Published online 21 February 2013 DOI:10.1126/science.1232552