Objective: To investigate the effects of Qihong capsule (QH) on HeLa cells infected by coxsackievirus B3 (CVB3) in vitro and its potential antiviral mechanism.
Methods: HeLa cells were infected by CVB3 in vitro. XTT assay and plaque inhibition assay were performed to determine the 50 % effective dose, (ED50), 50 % inhibitory concentration (IC50), and 50% cytotoxicity concentration (CC50) of QH and the control drug, ribavirin. The total therapeutic index (TI) was calculated. Anti-viral time-course experiments were performed to compare the anti-viral effects at different time points. The inhibitory effects of QH on the attachment and penetration of CVB3 were also observed.
Results: XTT assay and plaque inhibition assay showed that the ED50 and IC50 were (7.16+/-0.80) mg/L and (2.63+/-0.50) mg/L in QH group and (4.35+/-0.40) mg/L and (1.92+/-0.30) mg/L in ribavirin group, respectively. CC50 was 16-fold higher in QH group than in ribavirin group QH: (1 648+/-219) mg/L vs. Ribavirin: (103+/-14) mg/L. Time-course studies demonstrated that antiviral effect of QH was mainly found 0-4 hours after infection. QH effectively blocked the attachment and penetration of CVB3 into cells.
Conclusion: By inhibiting the attachment and penetration of CVB3, QH can effectively inhibit the invasion of virus in vitro with low toxicity.