Sodium Tanshinone ⅡA Sulfonate Affects Marek’s Disease Virus Replication In Chick Embryo Fibroblasts

Objectives: In this study, we evaluate the the inhibitory effect of Sodium Tanshinone IIA Sulfonate (STS),a derivative of Tanshinone IIA constituting a major active constituent from the root of Salvia miltiorrhiza Bunge, on regulation of UL27 (gB) gene and Meq gene of Marek’s disease virus (MDV).The present study examing the antiviral activity of STS, which provides information of antivirus mechanism of traditional Chianese medicine.Methods:The effects of STS on MDV gene UL27 (gB) and Meq, and gB protein were examined by real-time PCR and Western blot assay. Analysis Expression of gene UL27 (gB) and Meq on both DNA and mRNA were measured. In addition, acyclovir (ACV) was used as a positive control for a better evaluation of antivirus activity between STS and ACV.Results:1. Use of the real-time polymerase chain reaction (PCR) to amplify DNA products and cDNA products reverse transcribed from RNA is on the way to becoming a routine tool in molecular biology to study low abundance gene expression. Analysis above revealed the level of UL27 (gB) genome load at time point of 24 h,48 h,72 h and 96 h. In the level of DNA, addtion of STS in MDV infected cells resulted in a decrease in UL27 (gB) genome load compared with MDV cells at time point of 24 h,48 h,72 h and 96 h, and there was significant difference at 72 h and 96 h (P<0.05). In the level of mRNA, STS showed little effect on UL27 (gB) gene expression at 24 h, and STS decreased UL27 (gB) gene expression compared with MDV group from 48 h to 96 h, and also there was significant difference at 72 h and 96 h (P<0.05).2. Western blot detection was performed to analyse the MDV gB protein. We found that STS has an inhibitory effect on gB protein. At time point of 24 h,48 h,72 h and 96 h, STS showed an inhibitory effect on gB expression. And also, addition of STS showed better inhibitory effects than ACV at time point of 24h.3. Real-time PCR was conducted to analyse Meq genome load at different time points. In the level of DNA, at time point of 24 h,48 h, STS had no inhibitory function on Meq gene expression, while at 72h and 96 h. Meq genome load in STS group decreased significantly (P<0.05). In the level of mRNA, STS showed little effect on Meq gene expression at 24 h and 48 h. And compared with MDV cells, test for investigated Meq transcripts added with STS was decreased at 72 h and 96 h (P<0.05).Conclusion:Our study demonstrates that STS could effectively inhibit the MDV virus via multiple pathways. For one thing, treatment with STS can reduce the replication and proliferation by mediating the genome expresson of MDV UL27 gene and Meq gene. For the other, STS can also decrease the expression of gB protein.