Brilliant Black BN (E 151) is an azo dye and a food colorant. It is a promising antiviral agent against EV71 infection via inhibiting the interaction between EV71 and its cellular uncoating factor cyclophilin A.

EV71 (various strains):2.39 µM- 28.12 µM (IC50)

Brilliant black BN inhibited the infection EV71 -GFP at a concentration of 300 μM. Brilliant black BN exhibits the inhibition of EV71 -GFP as a dose-dependent manner in infected RD cells (IC50: 10.1 μM). Brilliant black BN is able to inhibit all tested 28 EV71, CVA16, and CVA6 strains. In rhabdomyosarcoma cells, 50% inhibitory concentration 29 of the dye E151 for various strains of EV71 ranged from 2.39 μM to 28.12 μM, whereas its 50% cytotoxic concentration is 1870 μM [2].

Brilliant black BN (i.p.; 200 mg/kg; 14 days)exhibits mild illness with clinical scores less than 3 and subsequently recovered when compared with PBS-group. All E151 270 treated mice are completely protected throughout the experiment [2].

Resting cell dye decolorization experiment
1. Deep-sea isolates were transferred to fresh 250 mL-GYE broth, centrifuged and added to 20 mM Tris-HCl (pH 7.6) for resting cell assays.
2. Cells were grown in 10 mL tubes (final cell dry weight up to 5.20–5.38 g/L), then Brilliant Black BN was added to a final concentration of 100 mg/L, the tubes were gently inverted several times, and incubated at 30°C, taking care not to shake;
3. Samples (200 μL) were collected regularly from 0 to 3 hours, immediately boiled in a dry heat bath for 5 minutes, and then centrifuged (13,000 g, 10 minutes);
4. The residual dye concentration of the supernatant was measured.