Anti-viral Effects Of 4(3H) Quinazolinone From Folium Isatidis Against Influenza Virus A And PRRS Virus In Vitro

4(3H)quinazolinone is one of effective anti-viral components in Folium Isatidis, the pharmacological experiments showed that it has the effects of anti-viral, anti-tumor,anti-hyperlipidemia and anti- inflammation. The studies on anti-viral effects of 4(3H) quinazolinone against influenza virus A and PRRS Virus in Vitro were carried out respectively in this paper.The anti-viral effects against influenza virus A in vitro were studied by using MDCK cell infected by influenza virus A, to explore its possible mechanism, mainly to establish virus infected model in vitro. The experiments measured the protection function of 4(3H)quinazolinone diluted into five different concentrations(320, 160, 80, 40, 20μg/mL)to MDCK cell infected by influenza virus A, and through the experiments of influence of 4(3H)quinazolinone against influenza virus A's proliferation on cell and time-effect relationship of 4(3H)quinazolinone against influenza virus A in vitro,to evaluate its anti-viral function, adopted cell pathological changes observation method and MTT method, through three different drug-added ways. The experiment results indicated that the TCID50 of influenza virus A was 10-4.90/0.1 mL; the biggest non poisonous concentration of 4(3H)quinazolinone to MDCK cell in vitro was 320μg/mL; Within the scope of biggest non poisonous concentration,the effect of deactivating influenza virus A of 4(3H)quinazolinone is not obvious, compared with DAFEI, the difference of statistics was significant(P<0.05); but the effects of blocking target cell adsorbted by influenza virus A and inhibiting its hyperplasia were obvious, compared with DAFEI, the difference of statistics was all not significant(P>0.05), and the anti-viral effect depends on a measure relationship with drug concentrations (From20μg/mL to 320μg/); all different concentrations of 4(3H)quinazolinone can reduce the TCID50 of influenza virus A, they can reduce the TCID50 from 4.9 to 2.95(Drop nearly 2 orders of magnitude); the anti-viral effect of different 4(3H)quinazolinone shows a different time-effect relationship under different times, but the most obvious effect is in hour 72.Moreover,in order to explicit whether 4(3H)quinazolinone inhibit PRRS virus or not in Vitro, the activities of 4(3H)quinazolinone to inhibit PRRS virus were researched, to provide theoretical basis for the development of new antiviral drugs. We test the protect function of 4(3H)quinazolinone to Marc-145 cell infected by PRRS virus, adopt the above grouping methods,giving drug methods and testing methods. The results show that the TCID50 of PRRS virus is 10-5.63/0.1 mL; the biggest non poisonous concentration of 4(3H)quinazolinone to Marc-145 cell in vitro is 80μg/mL; Within the scope of biggest non poisonous concentration,the effect of deactivating PRRS virus and the effects of blocking and inhibiting PRRS virus of 4(3H)quinazolinone are all not obvious, compared with LAMIVUDING, the difference of statistics is all significant(P<0.05).The above results indicated that 4(3H)quinazolinone has obvious effects of blocking target cell adsorbted by influenza virus A and inhibiting its hyperplasia within 72 hours, but the effect against PRRS virus is not obvious. Therefore,the experiments provided experiment basis for developing drug to clinically treat influenza virus and PRRS virus, and also has the certain meaning to find efficacy of medicine material foundation of Folium Isatidis and to realize the valid evaluation of medicine material and product.