Fig. 4.

The inhibitory effect of TOF against viral infection at early stages. (A, B) TOF at concentrations of 50, 100, and 200 μg/ml or medium were mixed with H1N1 IAV at 4 °C for 1 h to treat RAW 264.7 cells. The detailed methods for evaluating to effect on attachment, entry, and virucidal stages were shown in the materials and methods. (A) The brightfield and fluorescent images were captured under fluorescence microscopy at a magnification of 200x. (B) The cells were fixed and analyzed by FACS. (C) TOF at 10, 50 μg/ml, or medium were mixed with H1N1 IAV at 4 °C for 1 h to treat RAW 264.7 cells for 2 h at 37 °C. The cells were washed with PBS and subjected to RNA isolation. The relative level of three regions of viral RNA (segment 5, NP, and M2) entered in RAW 264.7 cells. Data are expressed as the mean ± SD (n = 3). ^⁎⁎⁎p< 0.001 compared with the virus-only group. M; Mock group, V; Virus-only group, and TOF; 50, 100, and 200 μg/ml group.