Figure 2.

Kinetics of intracellular uptake (a) and effect of different concentrations and durations of enisamium treatment on dNHBE cells prior to influenza A/Brisbane/59/2007 (H1N1) virus inoculation (b). (a) Enisamium (2000 µM) was added to the basal compartment of uninfected dNHBE cells. The cell lysates were collected at 0.25, 0.5, 1, 2, 4, 8, and 24 h after exposure for determination of intracellular drug concentrations. (b) dNHBE cells were pretreated with enisamium (100, 500, or 1000 µM) 24 h prior to inoculation with influenza A/Brisbane/59/2007 (H1N1) virus (MOI of 0.001 PFU/cell). Enisamium was maintained in the basal compartment throughout the experiment. Oseltamivir carboxylate (final concentration, 1 µM) was added to the basal compartment 1 h before virus inoculation and remained for 24 or 48 h. The time of viral inoculation is indicated as 0 h. Supernatants were collected 24 (black bars) and 48 (gray bars) hpi, and virus titers were determined in MDCK cells by the TCID₅₀ assay at 37°C and expressed as log₁₀TCID₅₀/ml. Statistical significance was tested by comparing to virus-inoculated untreated NHBE cells by unpaired Student's t-test (*denotes P≤0.05 and **P ≤ 0.01 (as determined by unpaired t-test). TCID₅₀: 50% tissue culture infectious dose.