The discovery of herbal drugs and natural compounds as inhibitors of SARS-CoV-2 infection in vitro

Abstract

The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in 2019 has led to a global health crisis. Mutations of the SARS-CoV-2 genome have impeded the development of effective therapeutics and vaccines against SARS-CoV-2. Natural products are important for discovering therapeutics to treat the 2019 coronavirus disease (COVID-19). In the present study, we investigated the antiviral activity of herbal drug extracts from Polygala Root, Areca, and Quercus Bark and natural compounds derived from herbal drug such as baicalin and glabridin, with IC 50 values of 9.5 µg/ml, 1.2 µg/ml, 5.4 µg/ml, 8.8 µM, and 2.5 µM, respectively, against SARS CoV-2 infection in vitro. Certain herbal drug extracts and natural compounds were found to inhibit viral RNA levels and infectious titers of SARS-CoV-2 in a dose-dependent manner. Furthermore, viral protein analyses showed that herbal drug extracts and natural compounds effectively inhibited SARS-CoV-2 in the various entry treatments. Our study revealed that three herbal drugs are good candidates for further in vivo and clinical studies. Supplementary Information The online version contains supplementary material available at 10.1007/s11418-021-01596-w.

Computational exploration of the dual role of the phytochemical fortunellin: Antiviral activities against SARS-CoV-2 and immunomodulatory abilities against the host

“…Computational strategies are being extensively used to accelerate the discovery of low-cost and effective anti-SARS-CoV-2 potentials of phytocompounds against SARS-CoV-2 [ [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] ]. Several traditional herbal medicines have been reported as having inhibitory effects on SARS-CoV-2 infection in vitro and in vivo [ 20 , [22] , [23] , [24] ].…”

“…Computational strategies are being extensively used to accelerate the discovery of low-cost and effective anti-SARS-CoV-2 potentials of phytocompounds against SARS-CoV-2 [ [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] ]. Several traditional herbal medicines have been reported as having inhibitory effects on SARS-CoV-2 infection in vitro and in vivo [ 20 , [22] , [23] , [24] ]. Many herbs have been shown to contain active antiviral natural components that effectively diminish COVID-19 virus transmission and disease progression [ 19 , 20 , 22 ], and some have been reported to work by targeting both (dual role) host and viral proteins [ 13 , 25 ].…”

“…Several traditional herbal medicines have been reported as having inhibitory effects on SARS-CoV-2 infection in vitro and in vivo [ 20 , [22] , [23] , [24] ]. Many herbs have been shown to contain active antiviral natural components that effectively diminish COVID-19 virus transmission and disease progression [ 19 , 20 , 22 ], and some have been reported to work by targeting both (dual role) host and viral proteins [ 13 , 25 ]. However, understanding the mechanisms of action of antiviral compounds in herbal treatments could lead to more effective COVID-19 prevention and therapy.…”

5-Aminolevulinic acid antiviral efficacy against SARS-CoV-2 omicron variant in vitro

“…Vero E6 cells were treated with remdesivir or 5-ALA with or without SFC for 72 h (h) and then infected with SARS-CoV-2 Omicron variant (TY38-873, BA.1, provided by the Japan National Institute of Infectious Diseases) at a multiplicity of infection of 0.02. After 48 h post infection, the infected cell supernatants were harvested for viral RNA extraction [ 12 , 13 ]. The SARS-CoV-2 antiviral assay is based on previously established specific quantitative real time PCR (qRT-PCR) [ 12 ] using cell supernatant RNA.…”

“…1 B, C, Table 1 ). A cell viability assay was conducted in parallel with the antiviral assay [ 12 , 13 ] and no cytotoxic effects were observed with CC 50 (cell survival by 50%) of 5-ALA > 2000 µM and of SFC > 500 µM in Vero E6 cells (Table 1 ). The Omicron variant which has notable mutations in the receptor binding domain of spike glycoprotein appears to be highly transmissible and less responsive to several of the currently used drugs [ 14 ].…”