Fig. 2

Green tea beverage (GTB) inhibits SARS-CoV-2 pseudovirus and variants infection. a GTB was prepared by soaking 1.8 g of green tea bag in 150 mL water at 90–95 °C for 30 s. After centrifugation at 4000 rpm for 10 min, supernatant was collected and filtrated through 0.22 μm filter, which was defined as 100% GTB. A two-fold serial dilution of GTB was prepared as indicated. b The VSVΔG-based pseudovirus bearing SARS-CoV-2 S (SARS-CoV-2-WT, D614G) was pre-incubated with diluted GTB for 30 min prior to infection of HEK293T-hACE2 or A549-hACE2 cells. At 48 h post-infection, cells were lysed and luciferase activity was measured to assess the viral infectivity expressed as a percentage relative to that of the control (untreated). c The VSVΔG-based pseudovirus bearing full-set mutant SARS-CoV-2 S (UK-B.1.1.7, SA-B.1.351, and CA-B.1.429) was pre-incubated with diluted GTB for 30 min prior to infection of HEK293T-hACE2 cells. At 48 h post-infection, cells were lysed and luciferase activity was measured to assess the viral infectivity expressed as a percentage relative to that of the control (untreated). d HCoV OC43 was pre-incubated with diluted GTB for 30 min prior to infection of HCT-8 cells. Intracellular HCoV OC43 RNA were determined at day 4 post-infection by RT-qPCR. e Live SARS-CoV-2 was pre-incubated with 20-fold diluted GTB for 30 min, and then infected Calu-3 cells for 1 h, cells were washed with pre-warmed medium to remove free virus, and then maintained in complete medium containing EGCG for 36 h. Supernatant was collected and added to Hela-ACE2 cells for plaque assay. Data are shown as mean ± SD, representative of at least two independent experiments with 3 replicates. ***P < 0.001