Korean Red Ginseng Relieves Inflammation and Modulates Immune Response Induced by Pseudo-Type SARS-CoV-2.

Few studies have reported the therapeutic effects of Korean red ginseng (KRG) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the positive effects of KRG on other viruses have been reported and the effects of KRG on pulmonary inflammatory diseases have also been studied. Therefore, this study investigated the therapeutic effects of KRG-water extract (KRG-WE) in a pseudo-type SARS-CoV-2 (PSV)-induced lung injury model. Constructing the pseudovirus, human angiotensin-converting enzyme 2 (hACE2) transgenic mice were infected via intranasal injection that had been orally administered with KRG-WE for six weeks. After 7-days post infection (dpi), the antiviral effects of KRG-WE were confirmed, followed by real-time polymerase chain reaction (PCR), western blot analysis, flow cytometric analysis, and an enzyme-linked immunoassay (ELISA). KRG-WE significantly inhibited an increase in immunoglobulin caused by PSV. Furthermore, KRG-WE effectively suppressed alveolar macrophages (AMs) inside the lungs and helped normalize the population of other immune cells. In addition, virus-induced gene expression and inflammatory signals such as nuclear factor-kappa B and other upstream molecules were downregulated. Moreover, KRG-WE also normalized gene expression and protein activity in the spleen. In conclusion, KRG-WE reduced AMs, normalized the immune response, and decreased the expression of inflammatory genes and activation of signaling pathway phosphorylation, thereby exhibiting anti-inflammatory effects and attenuating lung damage.