Aurintricarboxylic Acid Is a Potent Inhibitor of Influenza A and B Virus Neuraminidases

Hashem, Anwar M.; Flaman, Anathea S.; Farnsworth, Aaron; Brown, Earl G.; Van Domselaar, Gary; He, Runtao; Li, Xuguang

To examine whether the protective effect of ATA is due to inhibition of viral replication, the level of influenza nucleoprotein RNA isolated from PR8-infected MDCK cells was determined by reverse-transcription PCR. Cells infected with PR8 had low levels of b -actin RNA (Fig. 3 ), most likely due to cell death. However, the level of b-actin RNA remained relatively constant upon exposure to increasing ATA concentrations. Treatment with ATA To determine if ATA treatment also reduces the level of influenza viruses released into the medium, supernatants from ATA-treated infected cell cultures were subjected to the analyses of viral proteins by ELISA. As shown in Fig. 4 , treatment of cells with ATA dramatically reduced virus yield (p,0.0001). Doses of 50 mg/ml and 100 mg/ml of ATA reduced the abundance of PR8 by 93% and 95%, NC by 86% and 94%, and NY by only 72% and 81%, respectively. There is no statistically significant difference between the two H1N1 viruses (PR8 and NC), yet the H3N2 virus was slightly more resistant to the ATA treatment (see below for additional discussion).