Multiple antiviral approaches of (–)-epigallocatechin-3-gallate (EGCG) against porcine reproductive and respiratory syndrome virus infection in vitro

• Published in: Antiviral research 2018-10, Vol.158, p.52-62
• Main Authors: Ge, Mengyun, Xiao, Yan, Chen, Hongjun, Luo, Fatao, Du, Guangshi, Zeng, Fanya
• Format: Article
• Language: English
• Subjects: (–)-Epigallocatechin-3-gallate; Antiviral; Porcine reproductive and respiratory syndrome virus; Pro-inflammatory cytokines; Virus binding
• ISSN: 0166-3542; 1872-9096
• DOI: 10.1016/j.antiviral.2018.07.012

Porcine reproductive and respiratory syndrome virus (PRRSV) remains an economically important pathogen in the global pig industry, effective measures to control the virus are still lacking. (–)-Epigallocatechin-3-gallate (EGCG), the most abundant and bioactive catechin in green tea, has been reported to have antiviral effect against the diverse groups of viruses. In this study, the comprehensive anti-PRRSV activity of EGCG was investigated using various in vitro assays. EGCG effectively inhibited PRRSV infection and replication in porcine alveolar macrophages (PAMs), regardless of whether it was administrated pre- or post-infection, and the cytotoxicity to PAMs was low. Next, anti-PRRSV approaches of EGCG were characterized in MARC-145 cells. EGCG was demonstrated to be able to significantly prevent PRRSV from infecting MARC-145 cells either through blocking of EGCG-treated viruses docking to susceptible cells involving a direct virus-EGCG interaction or by blocking of the infective virus binding to EGCG pre-treated cells via triggering down-regulation of viral receptors and/or related proteins required for infection. In addition, PRRSV replication was suppressed in MARC-145 cells treated with EGCG post-infection, likely because of down-regulation of pro-inflammatory cytokines, such as TNF-α, IL-6 and IL-8. Taken together, these data showed that treatment of primary PAMs with EGCG can inhibit PRRSV infection and revealed that multiple antiviral approaches of EGCG operate in PRRSV-susceptible MARC-145 cells. •EGCG effectively inhibited PRRSV infection and replication in PAMs and the cytotoxicity was low.•Multiple approaches of EGCG inhibition of PRRSV infection were identified in MARC-145 cells.•Blockade of EGCG-treated virions binding to susceptible cells may involve direct virus-EGCG interaction.•EGCG blocked virion binding to pre-treated MARC-145 cells by down-regulation of viral receptors and/or related proteins.•PRRSV replication was suppressed in post-infection treated MARC-145 cells by down-regulating pro-inflammatory cytokines.