Use of lactate dehydrogenase to evaluate the anti-viral activity against influenza A virus

The detection of lactate dehydrogenase (LDH) can be used to evaluate efficiently anti-influenza A virus agents. LDH levels in the virus-infected Madin-Darby canine kidney cell cultures were significantly higher than in controls, were in proportion to the degree of virus infection, and corresponded to a decrease in mitochondrial dehydrogenase activity as assayed using a tetrazolium colorimetric assay (MTT method). The EC50 value and cytotoxicity of ribavirin, 3-deazaguanine, pyrazofurin, and carbodine against influenza A virus as measured by the LDH detection method was equivalent to that derived by the MTT method.