Reactive Study On Anti-Virus Of Several Chinese Herbal Medicinal Ingredients In Vitro

Infectious diseases of livestock and birds are the chief problem to harm the development of livestock farming especially, especially viral diseases. The natural medicines display definite advantage. Many researches have showed that many Chinese herbal medicinal ingredients have antiviral activity. In this study, extracts of 14 Chinese herbal medicines and 4 polysaccharides were selected as object, and their antiviral and immune-enhancing action and mechanism were investigated through a series of experiments in vitro. The purpose is to offer the theory basis for developing herbs as anti-virus praeparatum.Extracts of forteen Chinese herbal medicines,such as Flos lonicerae,Radix astragali, Radix isatidis and so on ,four Chinese herbal polysaccharides, astragalus polysaccharide (APS), isatis root polysaccharide (IRPS), Chinese yam polysaccharide (CYPS) and achyranthes root polysaccharide (ARPS), were selected as object and extracted by water-decoction and water-decoction and ethanol-precipitation method respectively. The contents of four polysaccharides were measured by Vitriol-anthracene ketone. The total contents (%) of APS, IRPS, CYPS and ARPS were 65.8, 56.7, 73.5 and 54.9 respectively. The total extractive rates (g/Kg) of them were 37.4, 59.1, 53.6 and 48.9 respectively. The four polysaccharides were prepared for the whole study.Extracts of forteen Chinese herbal medicines within safety concentration added into PK-15 and Marc-145 monolayer before, after and simultaneous with PRV and PRRSV respectively. CPE and neutral red colorant absorption method are employed to illustrate anti-virus effect. The cells OD values were determined in order to evaluate the effects of herbs on the virus infecting the cell. The results showed that Herba andrographitis,Folium isatidis,Herba euphorbiae humifusae,Radix isatidis,Radix et rhizome rhei and Herba epimedii six herbs inhibit infectivity of the PRV to PK-15 cell significantly; Forsythia suspensa,Radix isatidis,Folium isatidis,Radix pulsatilla,Radix et rhizome rhei,Flos chrysanthemi indici,Herba epimedii and Flos lonicerae eight herbs inhibit infectivity of the PRRSV to Marc-145 cell significantly, depengding on their concentrations.Four polysaccharides within safety concentration added into PK-15 and Marc-145 monolayer before, after and simultaneous with PRV and PRRSV respectively. CPE and neutral red colorant absorption method are employed to illustrate anti-virus effect. The results showed that APS, IRPS inhibit infectivity of the PRV and PRRSV to cell significantly, they could decrease CPE lesions and inhibit virus to infect the cell in dosages dependent, they behaved in inhibiting virus directly or promoting cell antivirus or both. It suggested that earlier administration should have better efficacy as clinical application.