The natural tannins oligomeric proanthocyanidins and punicalagin are potent inhibitors of infection by SARS-CoV-2
- Graduate Institute of Biomedical Sciences, China Medical University, Taiwan
- Research Center for Cancer Biology, China Medical University, Taiwan
- Department of Biological Science and Technology, College of Life Sciences, China Medical University, Taiwan
- Center for Molecular Medicine, China Medical University Hospital, China Medical University, Taiwan
- Departments of Laboratory Medicine and Internal Medicine, China Medical University Hospital, School of Medicine, China Medical University, Taiwan
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taiwan
- Neuroscience and Brain Disease Center, China Medical University, Taiwan
- Institute of New Drug Development, China Medical University, Taiwan
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taiwan
- Department of Biotechnology, Asia University, Taiwan
- Institute of Biochemistry and Molecular Biology, China Medical University, Taiwan
Figures
Figure 1
Punicalagin efficiently blocked ACE2–Spike protein interaction and repress the main protease activity, while tannic acid and oligomeric proanthocyanidins (OPC) had higher inhibition activity against TMPRSS2.
(A) The percentage of Spike–ACE2 interaction from ELISA-based assay is shown with the indicated concentration of tannic acid, OPCs, or punicalagin. All data are shown as mean ± SD (n = 3). The …
-
Figure 1—source data 1
The table displays the inhibitory concentrations (IC50) of tannic acid, OPCs, and punicalagin for TMPRSS2 activity.
- https://cdn.elifesciences.org/articles/84899/elife-84899-fig1-data1-v1.xlsx
Figure 2
Three tannins could inhibit cell entry of Spike-viral pseudo-particles (Vpps) with low cytotoxicity in two cell lines.
(A–F) Orange line: 293T-ACE2 and NCI-H460 cells were pretreated with varying concentrations (2, 10, and 50 μg/ml) of tannic acid, oligomeric proanthocyanidins (OPCs), or punicalagin for 1 hr and …
-
Figure 2—source data 1
The table dispays the 50% cytotoxic concentration (CC50), 50% effective concentration (EC50), and selectivity index (SI) from the experiments in Figure 2A-F.
- https://cdn.elifesciences.org/articles/84899/elife-84899-fig2-data1-v1.xlsx
Figure 3
Tannic acid and oligomeric proanthocyanidins (OPC), but not punicalagin, had higher potency against viral pseudo-particles (Vpps) infection in the TMPRSS2-expressing cells.
(A) VeroE6 cells were treated with indicated concentrations (2, 10, 50, and 250 μg/ml) of tannic acid, OPCs, or punicalagin, and cell viability was detected with MTT assay. (B–D) VeroE6 cells with …
-
Figure 3—source data 1
The table dispays the 50% cytotoxic concentration (CC50), 50% effective concentration (EC50), and selectivity index (SI) from the experiments in Figure 3B-D.
- https://cdn.elifesciences.org/articles/84899/elife-84899-fig3-data1-v1.xlsx
Figure 4
Tannic acid and oligomeric proanthocyanidins (OPCs), but not punicalagin, could maintain their inhibitory activity against different variants of viral pseudo-particles (Vpps) infection.
(A–F) 293T-ACE2 and NCI-H460 cells were pretreated with 10 mg/ml tannic acid, OPCs, or punicalagin for 1 hr and infected with SARS-CoV-2 spike Vpps of different variants. After 24 hr of infection, …
Figure 5
Oligomeric proanthocyanidins (OPC) and punicalagin could inhibit more effectively the infection of omicron virus compared to tannic acid.
(A) The schematic illustrates tannic acid, OPCs, or punicalagin treatment of VeroE6 cells infected with the SARS-CoV-2 omicron virus. First, viruses were premixed with tannic acid, OPCs, or …
Figure 6
Grape seed extractant had the highest concentration of oligomeric proanthocyanidins (OPCs) and could inhibit the entry of wild-type and different variant Vpps.
(A) Mass ion chromatograms of (a) OPCs (10 μg/ml), (b) grape seed extractant, (c) grape peel extractant, and (d) grape flesh extractant. Peaks 1 and 3: dimer of catechins; peaks 2 and 4: catechins; …
-
Figure 6—source data 1
The table displays the OPC and Ttannic acid concentrations (mg/g) of different parts of grape water extractant or grape juice converted from the concentrations of the standard chemicals based on the mass ion chromatogram results.
- https://cdn.elifesciences.org/articles/84899/elife-84899-fig6-data1-v1.xlsx
Figure 7
Serum from the human subjects who intake grape seed extractants had better potency to block the entry of wild-type and different variant Vpps.
(A). The schematic illustrates the timeline of blood collection. First, the baseline blood sample was collected before taking control or grape seed extract (GSE) capsules. After baseline blood …
