Abstract 2943: Protective Effects of QiHong Capsule on Viral Myocarditis Infected by Coxsackievirus B3

Background : Viral myocarditis is an important human disease that affects about 5% to 20% of the population. Coxsackieviruses B 3 (CVB 3 ) is dominant causative agent for viral myocarditis. So far, not many effective treatments are available for the disease. The main components of QiHong capsule (QH) have been traditionally used to control common cold and other virus-induced disorders in China. Thus, the aim of this study was to investigate the antiviral effects of QH on CVB 3 in vivo and in vitro . Methods and Results: The effect of QH in vitro was evaluated in HeLa cells or cultured rat neonatal cardiac myocytes infected by CVB 3 , Ribavirin was chosen as positive control. Our results showed that QH possesses potent antiviral effects on CVB 3 in vitro by XTT and plaque forming assay (IC 50 was 7.16 ± 0.8 and 2.63 ± 0.5 μg/ml, respectively). CC 50 was 16-fold higher in QH treated cells than in Ribavirin treated cells (QH: 1648 ± 219 μg/ml vs. Ribavirin: 103 ± 14 μg/ml). Time course studies demonstrated that antiviral effect of QH was mainly found during 0 – 4 h of the infection. We further explored the mechanism of QH in CVB 3 and found that QH effectively blocked the attachment and penetration of CVB 3 into cells. To confirm the antiviral effect of QH in vivo , 4- week- old male Balb/C mice (n = 125) were used and inoculated intraperitoneally with 0.1 ml of CVB 3 suspension (10 PFU) or saline as control (n = 25). At 48h postinoculation, the infected mice were administered intragastrically with QH either 200 mg·kg −1 ·d −1 , 600 mg·kg −1 ·d −1 or 1800 mg·kg −1 ·d −1 , with Ribavirin (90 mg·kg −1 ·d −1 , PO) as positive control and saline as sham treatment group (n = 25 in each above group). After 28 days, QH treatment increased the survival rate from 16% (vehicle) to 64% (QH: 1800 mg·kg −1 ·d −1 ) by the Kaplan-Meier method. In addition, QH protected the cardiac pathological changes induced by CVB 3 , and decreased myocardial virus titer significantly (vehicle: 3.6 ± 1.7 vs. QH: 1.9 ± 0.9, p 0.05). Conclusions: The results showed that QH is a very promising potent antiviral agent with a highly significant effect on survival and pathological changes in CVB 3 -induced myocarditis.