Characterization of Anti-Poliovirus Compounds Isolated from Edible Plants

Figures

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  Figure 1. Summary of the screening of anti-PV compound from edible plant extract library.

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  Figure 2. Identification and purification of an anti-PV compound from R. rhaponticum extract. (A) Procedure of purification of anti-PV compound from R. rhaponticum extract. Boxes highlight the fraction containing chrysophanol. Arrow indicates the band of chrysophanol. (B) Antiviral effect of chrysophanol on PV infection. (Left) Structure, cytotoxicity, and antiviral effect of chrysophanol. Viral infection and viability of RD cells in the presence of chrysophanol are shown. RD cells were infected with PV1pv, then luciferase activity was measured at 7 h p.i. Marked precipitation of chrysophanol was observed above 98 μM. Viral infection or the cell viability in the absence of chrysophanol were taken as 100%. (Right) Inhibitory effect of chrysophanol on the infection of a panel of drug-resistant PV1pv mutants. PV1pv infection at 7 h p.i. in RD(WT) cells in the presence or absence of chrysophanol (790 μM) is shown. PV1pv infection in the absence of chrysophanol is taken as 100%. n.s., not significant. ***, p < 0.001.

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  Figure 3. Identification and purification of an anti-PV compound from F. sachalinensis extract. (A) Procedure of purification of anti-PV compound from F. sachalinensis root extract. Boxes highlight the fraction containing vanicoside B. (B) Antiviral effect of VCB on PV infection. (Left) Structure of VCB, cytotoxicity, and antiviral activity of VCB. Viral infection and viability of RD cells in the presence of VCB are shown. RD cells were infected with PV1pv or SeV-luc, then luciferase activity was measured at 7 h p.i. (for PV1pv) or 24 h p.i. (for SeV-luc). Viral infection or the cell viability in the absence of VCB were taken as 100%. (Right) Antiviral effect of VCB on EV infection. RD cells on 96-well plates were infected with EV at an MOI of 0.005 (for PV), 0.05 (for EV-A71) or 0.5 (for EV-D68) in the absence (mock-treated) or the presence (VCB treated) of VCB at the indicated final concentration. The cells were fixed and stained at 2 days p.i. (for PV) or 4 days p.i. (for EV-A71 and EV-D68). The data are representative of two independent experiments with two to three biological replicates.

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  Figure 4. VCB is a novel PI4KB inhibitor. (A) Inhibitory effect of VCB on the infection of a panel of drug-resistant PV1pv mutants. PV1pv infection at 7 h p.i. in RD(WT) cells in the presence or absence of VCB is shown, except for the infection of the ΔPI4KB-resistant [−2C] mutant, which was analyzed at 17 h p.i. in RD(ΔPI4KB) cells. PV1pv infection in the absence of VCB is taken as 100%. (B) OSBP-EGFP-expressing HEK293 cells were incubated at 37 °C for 30 min in the presence of the compounds (10 μM T-00127-HEV2, 20 or 40 μM VCB, respectively). Localization of OSBP-EGFP in the cells is shown. (C) (Left) Inhibitory effect of VCB on in vitro PI4KB activity. (Right) Trans-rescue of PV infection in RD(ΔPI4KB) cells by indicated PI4KB variants in the presence of the compounds (20 μM T-00127-HEV1, 40 μM MDL-860, or 20 μM VCB, respectively). PV1pv infection in RD(ΔPI4KB) cells transfected with pTK-N-FLAG-PI4KB(WT, C646S, or D653A variants) in the absence of the compound is taken as 100%. The data are representative of two independent experiments with three biological replicates.