Figure 2.

Inhibition of Ery-Est against flavivirus infection with a broad spectrum and its cytotoxicity. BHK21 cells (2 × 10⁶) were infected by ZIKV strains (A) FLR, (B) MR766, (C) DENV II, and (D) YFV 17D with the treatment of serial concentrations of Ery-Est and Ery, and then covered with Dulbecco’s modified Eagle’s medium (DMEM) containing 2% FBS and 1% LMP agarose. After incubation for about 5 days, infected cells were stained with 1% crystal violet for plaque visualization and the inhibitions of infection were calculated. Huh7 cells (2 × 10⁴) were infected by (E) pseudotyped MERS-CoV and (F) VSV with the treatment of Ery-Est and Ery, the inhibitory activity was measured by the luciferase assay systems after incubation for 3 days. (G) BHK21 and (H) Vero cells (2 × 10⁴) were treated with Ery-Est and Ery for 72 h, and the cell counting kit-8 (CCK8) was used to detect cell viability. The experiments were tested in triplicate and data are represented as means ± SD. Each experiment was repeated at least twice and similar results were obtained. Statistical analysis: Two-way ANOVA with Sidak’s multiple comparisons for (A–F). * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001.