Investigation of the antiviral effects of Saussurea lappa root extract against SARS-CoV-2 virus.

SCOPE: The purpose of this study was to look into the antiviral activity of a plant extract derived from the roots of the Saussurea lappa as a food supplement against SARS-CoV-2 infection.

METHODS AND RESULTS: Vero E6 cells were used to test the neutralizing effect of Saussurea lappa extract against the SARS-CoV-2 virus. In our work, we used a real-time cell analyzer that's much more sensitive than the standard endpoint tests for anti-viral effectiveness determination, and a methodology with a very high rate of repetitive results that enables us to see the whole process. This technique allows the accurate monitoring of cell movement and changes in its ability to attach to the surface. The RTCA system is not only a well-known modern technique, but also a unique, noninvasive, and effective instrument for recording the dynamic biological condition of cells. A challenge experiment in mice was planned as a result of the in vitro analysis. A challenge test against SARS-CoV-2 was performed with 10 adult female K18-hACE2 transgenic mice in each group for this purpose. The challenge experiment on mice was based on how the Saussurea lappa extract was used in humans. The mice in Group 1 were gavaged two days before the virus was administered intranasally (in). The control group received PBS instead of the extract (Group 2). 105 TCID50 SARS-CoV-2 virus (Wuhan) was administered intranasally under anesthesia for the first three days of the experiment in the BSL-3 laboratory, and S. lappa extract was administered by gavage in the afternoon. Mice given the S. lappa extract and SARS-CoV-2 virus together survived the study on the 10th day, whereas mice in the control group given the virus and PBS became ill and/or died. In this study, the extract protected the mice against the SARS-CoV-2 virus in 90% of the cases.

CONCLUSIONS: Previous research has shown that the Saussurea plant has anti-inflammatory, antimicrobial, and analgesic properties (22, 33, 44). This study demonstrated its antiviral effect against SARS-CoV-2 in vitro and in vivo models. This article is protected by copyright. All rights reserved.