Objective: To screen the safe and effective anti-enterovirus drugs for clinical application.
Methods: The cytotoxicity of Ribavirin, Shuanghuanglian and Garlic were evaluated through MTT colorimetry and cell morphology. The antiviral activity of Ribavirin, Shuanghuanglian and Garlic were studied in HEL and Vero cells infected with CBV3 and ECHO11 by observing cytopathic effect (CPE), MTT colorimetry and plaque-reduction assay. The antiviral activity of these three drugs were compared and that of Shuanghuanglian and Garlic were also compared before and after ECHO11 absorbing by plaque-reduction assay.
Results: (1) The cytotoxicity of these three drugs were expressed as TC50(50% toxic concentration). TC50 of Ribavirin was 2 mg/ml, of Shuanghuanglian 5 mg/ml, of Garlic 12.5 micrograms/ml. (2) Ribavirin could inhibit CBV3 and ECHO11 at the concentration ranged from 1 mg/ml to 1.5 mg/ml. Shuanghuanglian could inhibit CBV3 and ECHO11 at the concentration of 0.5 mg/ml and the viral inhibiting effect was concentration-dependent. Garlic could inhibit CBV3 and ECHO11 at the concentration ranged from 2.5 micrograms/ml to 7.5 micrograms/ml and 5 micrograms/ml was the most effective. (3) Plaque-reduction assay was used to test the anti-virus (CBV3 and ECHO11) activity of these three drugs: plaque reduction rate of 1.5 mg/ml Ribavirin was 43.2% and 37.2%, of 2.5 mg/ml Shuanghuanglian was 81.1% and 88.4% and of 5 micrograms/ml Garlic was 66.2% and 77.4% respectively. The plaque reduction rate of Ribavirin was lower than the other two drugs (P < 0.05), between these two showed no significant difference (P > 0.05). The anti-ECHO11 activity of Shanghuanglian before ECHO11 adsorbing was higher than after ECHO11 adsorbing (P < 0.05). There was no significant difference between the plaque reduction rates of Garlic before and after ECHO11 adsorbin.
Conclusion: All of the three drugs have anti-virus activity in vitro while Shuanghuanglian and Garlic are more effective. Among these three drugs, the cytotoxicity of Shuanghuanglian is the most weak and the anti-virus activity is the strongest. The antiviral activity of Shuanghuanglian adding before virus adsorbing was higher, so it seems that Shuanghuanglian can prevent EV infection.