Inhibition of genotype I GCRV by EGCG derivatives and compound potassium peroxymonosulfate powder in vitro

Abstract:

[Objective] To evaluate the inhibitory and killing effects of two epigallocatechin gallate (EGCG) derivatives and compound potassium peroxymonosulfate powder (KMPS) on grass carp reovirus genotype I (GCRV) by in vitro cell experiments. [Methods] The safe concentrations of epigallocatechin gallate palmitate (EGCG-P), peracetylated epigallocatechin gallate (AcEGCG), and KMPS were assessed by MUSE and CCK-8 assays. Different concentrations of EGCG-P, AcEGCG, and KMPS were used to treat the cells infected with GCRV-JX01, and the inhibitory and killing effects of the three substances on the virus were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Furthermore, qRT-PCR was employed to determine the expression levels of the genes involved in host immune responses in the cells treated with the three substances and then infected with the virus. [Results] EGCG-P and AcEGCG suppressed the viral proliferation in a concentration- dependent manner, and EGCG-P outperformed AcEGCG. The EGCG-P of 10 μg/mL and 40 μg/mL decreased the titer of GCRV-JX01 by 10² copies/μL and 10³ copies/μL, respectively, compared with the control group, while AcEGCG achieved the same inhibitory effect at the concentrations of 60 μg/mL and 120 μg/mL, respectively. EGCG-P, AcEGCG, and KMPS all had killing effect on GCRV-JX01, and the lowest dose for effective killing followed the trend of KMPS (5 μg/mL)<EGCG-P (120 μg/mL)<AcEGCG (180 μg/mL). Moreover, EGCG-P, AcEGCG, and KMPS up-regulated the expression of interleukin-1β (IL-1β), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and myeloid differentiation factor (MyD88) compared with the control group. In particular, the up-regulation was more significant after the treatment with EGCG-P (50 μg/mL) for 8 h and AcEGCG (10 μg/mL) for 24 h. [Conclusion] EGCG-P, AcEGCG, and KMPS have good inhibitory and killing effects on GCRV-I. EGCG-P and KMPS at a concentration of 40 μg/mL can significantly inhibit GCRV replication without evoking an inflammatory response in 24 h. This study provides a reference for the development of environmentally friendly disinfection products for GCRV.