| By the cell culture experiment in vitro, the cytotoxic influence and the antivirus mechanism of action of the five Chinese herbal medicines which were Isatis root, Isatis leaf, Houttuynia, Patrinia and Forsythia fruit, and their complex prescriptions on TGEV of swine, were systematically studied in three ways which were adding medicine before adding virus, adding after medicine and virus acted for a while, and adding virus before adding medicine.The three ways were respectively absorption activity against virus, direct destruction of virus and restrain of virus propagation.The best complex prescription in the three ways were screened out.So new method for selecting of effective antivirus Chinese herbal medicines could be provided.The results of cell culture experiment in vitro indicated that in the five single medicines, the cytotoxicity of Isatis root and Isatis leaf was lowest; the toxicity of Houttuynia and Patrinia was higher; the toxicity of Forsythia fruit was highest. To absorption activity against TGEV, the other four medicines except Forsythia fruit were effective. The treatment index of Isatis root, Isatis leaf, Houttuynia and Patrinia was 4, 1, 4 and 4 respectively.Those indicated the action of anti-TGEV absorption of Isatis root, Houttuynia and Patrinia was same, but Isatis leaf was hardly effective.To direct destruction of TGEV, the other four medicines except Isatis leaf were effective. The treatment index of Isatis root, Houttuynia, Patrinia and Forsythia fruit was 8, 8, 4 and 8. Those indicated the action of direct destruction of TGEV of Isatis root and Houttuynia was higher, but that of Patrinia and Forsythia fruit was lower.To restrain of TGEV propagation, all five medicines were effective. The treatment index of Isatis root, Isatis leaf, Houttuynia, Patrinia and Forsythia fruit was 8, 4, 8 and 4. Those indicated the action of direct destruction of TGEV of Isatis root and Patrinia was higher,but that of Isatis leaf, Houttuynia and Forsythia fruit was lower.In all three ways, it indicated the anti-TGEV effect of Isatis root, Houttuynia and Patrinia was higher but Isatis leaf and Forsythia fruit was lower.In complex composit, the cytotoxicity of complex prescription composed of Isatis root and Houttuynia was higher, the cytotoxicity of complex prescription composed of Isatis root and Patrinia, that composed of Houttuynia and Patrini, that composed of Isatis root , Houttuynia and Patrinia was lower.The results indicated cytotoxicity of complex medicines were obviously lower than that of single medicine. To absorption activity against TGEV, the treatment index of complex prescription composed of Isatis root and Houttuynia, that composed of Isatis root and Patrinia, that composed of Houttuynia and Patrinia, that composed of Isatis root, Houttuynia and Patrinia was 2, 8, 8 and 4. To direct destruction of TGEV, their treatment indexes were 8, 32, 128 and 8.To restrain of TGEV propagation, their treatment indexes were 4,128,128 and 8.Those indicated the effect of the complex prescriptioncomposed by Isatis root , Houttuynia and Patrinia was higher than each single medicine , which meaned there were a co-effection in this three medicine and the anti-TGEV effect of complex prescription composed of Houttuynia and Patrinia was the best in all three ways. This complex prescription was the best one of those which were screened out.In this study, for the first time the anti-TGEV effective complex prescriptions of Chinese herbal medicines by cell culture experiment in vitro were screened out and proved, as well as the influence of the medicines on the process of virus reproduction was studied.It provided theoretic basis for animal experiment to future study antivirus action , toxicity and pharmacokinetics.And also provided theoretic base for developing and researching effective anti-TGEV medicines and for determination of antivirus effective composition. |
