Figure 3.
SFE abrogates viral gene transcription, protein translation, and syncytial formation in HEp2 cells and reduces RSV–GFP replication in mice model. Hep2 cells (3 × 105 cell/well) were added to the six-well cell culture plate. After 12 h, a monolayer of HEp2 cells was infected with 0.1 MOI of RSV–GFP in 1% FBS containing media for 2 h. Next, cells were treated with 50 μg/mL of SFE. (A) RSV-G protein expression level was evaluated by immunoblot analysis assay with the cell lysates collected at indicated time points. RSV-G protein intensity was determined compared to β-actin. (B) Transcription levels of RSV-G protein at indicated time points were evaluated by qRT-PCR analysis. GAPDH was used for the normalization. (C) Cell and GFP images were taken at 48 hpi to see the syncytial formation inhibition by SFE (400× magnification), white arrow: cell to cell fusion and syncytial formation in HEp2 cells. (D) The syncytial number was counted using image software. (E) Five-weeks-old BALB/c mice (RSV–GFP, n = 6, RSV–GFP/SFE, n = 6, Control, n = 2,) were intranasally infected with RSV–GFP (1 × 106 PFU/mice) in a total volume of 28 μL. SFE were orally administrated with the dose of 200 μL/mice (0.5 mg/mL) at 6, 12, 18, and 24 hpi. The transcription level of RSV-G protein mRNA in the lung tissues of the mice at 5 dpi was determined by qRT-PCR. White arrow: RSV-syncytial formation. Scale bar-200 Μm. Western blot band intensity, mRNA transcription, syncytial number was expressed as the mean ± SD of three independent experiments. In vivo experiments were conducted twice. (* p < 0.05, ** p < 0.01, *** p < 0.001 regarded as significant difference).