Virostatic Agents against Bluetongue Virus Figure 5. Both C003 and C052 protects BSR cells from BTV induced CPE/apoptosis. In mock infected BSR cells (A), cells formed a monolayer with no cells detached from the plates. At 72 h.p.i., BTV infected cells showed CPE/apoptosis and were detached from the plate (B). When C003 at 10 mM was added to the BSR cells without BTV infection, there were no obvious changes in term of cell morphology (C). There were also no morphology changes when cells were treated with C003 and with BTV infection (D). Similarly, when C052 at 2.5 mM was added to the BSR cells without BTV infection, there were no cytotoxicity (E), and C052 could also block BTV-induced CPE/apoptosis (F). doi:10.1371/journal.pone.0043341.g005 C003 at 1.8 mM and 10 mM, there were 2.1- and 3.3-fold reductions of caspase-3/7 activity at 48 h.p.i, respectively, comparing with the caspase-3/7 activity in cells infected with BTV but without C003 treatment (Fig. 6A and B). When cells were treated with C052 at 0.27 mM and 2.5 mM, the inhibitions of caspase-3/7 activity were similar to the inhibition of C003 at PLOS ONE | www.plosone.org 4 August 2012 | Volume 7 | Issue 8 | e43341