RESUMO
Avian influenza (AI) has become a disease of great importance for human and animal health. Beside adverse side effects, there is resistance mutation for about all the conventional drugs that target viral proteins. This study aimed to evaluate antiviral activity of silver nanoparticles combined with epigallocatechingallate (EGCG-AgNPs) and co-administered with zinc sulphate (Zn+2) as alternative treatment strategy to control AI H9N2. EGCG conjugated silver nanoparticles (EGCG-AgNPs) were synthesized. Virus propagation was performed using embryonated Specific-Pathogen-Free (SPF) hen's eggs. Viral EID50 titers were determined before and after treatments. The antiviral activity was determined as Log virucidal reduction. A commercial tetrazolium MTS assay kit was used to determine cytotoxicity. Results showed that 50 µM EGCG was the most significant concentration reduced the logEID50/mL of AI H9N2. Co-treatment with zinc sulphate (1.3 mg/mL) increased the EGCG antiviral effect. The most effective antiviral activity was obtained when combined EGCG-AgNPs with zinc sulphate with the greatest virucidal log reduction. No cytotoxic effect in Vero cells was observed among all of these forms at concentrations of interest used in this study. In conclusion, the topical application of EGCG-AgNPs/ZnSO4 demands additional antiviral strategies against H9N2 AI. This combination may prevent virus transmission, inhibit virus replication within neighboring cells and inhibit microbial resistance by making microbial adaptability very difficult.