4种茶叶水提物对猪繁殖与呼吸综合征病毒的作用

采用小鼠体内试验和体外试验,利用Marc–145细胞体外培养系统,通过观察细胞病变来评价茶叶水提物对猪繁殖与呼吸综合征病毒(PRRSV)繁殖的抑制作用。改变加入茶叶水提取物的方式(茶叶水提物先与病毒感作后接种细胞、茶叶水提物与已感染病毒的细胞作用2种方式),初步探讨茶叶水提物对PRRSV的抑制与杀灭作用。体内试验是采用小鼠尾静脉注射的方法,将茶叶水提物注射到小鼠体内,测定小鼠血清对PRRSV的作用。结果表明,茶叶水提物对PRRSV具有杀灭与抑制作用,碧螺春茶(不发酵)、生普洱茶(不发酵)、铁观音茶(半发酵)、熟普洱茶(后发酵)的水提物对PRRSV的最小抑制质量浓度分别为31.3、31.3、31.3、125μg/mL,最小杀灭质量浓度分别为7.8、7.8、15.6、125μg/mL。不发酵型茶叶水提物比发酵型茶叶水提物对PRRSV的杀灭与抑制作用明显,小鼠尾静脉注射茶叶水提物后能正常生长,注射1 h内小鼠血清对PRRSV具有一定的杀灭作用。

Antiviral effect of aqueous extracts of four kinds of tea on porcine reproductive and respiratory syndrome virus

Based on both the in vivo and in vitro way and the Marc 145 cell culture system,the effects of aqueous extracts from teas on porcine reproductive and respiratory syndrome(PRRS) was assessed regarding the cytopathic effect(CPE).First,the antiviral effect of the aqueous extracts was investigated by infecting the cell after the virus reacted with the aqueous extracts and by simultaneously adding the virus and the aqueous extracts to the cells.Then,the in vivo experiment was conducted by measuring the anti-PRRSV effect of sera collected from the mice which were previously administered with the aqueous extracts through intravenous(IV) tail vein injection.The results showed that the aqueous extracts of teas had the killing and inhibiting effect on PRRSV.The minimum inhibitory concentration of Biluochun tea(non-fermented),Pu’er raw tea(non-fermented),Tieguanyin tea(half-fermented) and Pu’er ripe tea(post-fermented) were 31.3,31.3,31.3,125 μg/mL,respectively;and the corresponding minimum killing concentrations were 7.8,7.8,15.6,125 μg/mL.The aqueous extracts of non-fermented tea had more obvious killing and inhibition effect on PRRSV compared to the aqueous extracts of fermented tea.Tail vein injection of tea aqueous extract does not affect the normal growth of mice,and in a short period of time,the sera from the mice injected with tea aqueous extract showed killing effect on PRRS.