Scopoletin for COVID-19

Scopoletin has been reported as potentially beneficial for COVID-19 in the following studies.
COVID-19 involves the interplay of 400+ viral and host proteins and factors providing many therapeutic targets. Scientists have proposed 10,000+ potential treatments. c19early.org analyzes 210+ treatments. We have not reviewed scopoletin in detail.
Shaer et al., Potential of Artemisia annua Bioactives as Antiviral Agents Against SARS-CoV-2 and Other Health Complications, Pharmaceuticals, doi:10.3390/ph18121904
This review highlights Artemisia annua, a medicinal plant which grows in the Kingdom of Saudi Arabia, known for its abundant therapeutic properties. A. annua serves as a rich source of various bioactive compounds, including sesquiterpenoid lactones, flavonoids, phenolic acids, and coumarins. Among these, artemisinin and its derivatives are most extensively studied due to their potent antimalarial properties. Extracts and isolates of A. annua have demonstrated a range of therapeutic effects, such as antioxidant, anticancer, anti-inflammatory, antimicrobial, antimalarial, and antiviral properties. Given its significant antiviral activity, A. annua could be investigated for the development of new nutraceutical bioactive compounds to combat SARS-CoV-2. Artificial Intelligence (AI) can assist in drug discovery by optimizing the selection of more effective and safer natural bioactives, including artemisinin. It can also predict potential clinical outcomes through in silico modeling of protein–ligand interactions. In silico studies have reported that artemisinin and its derivatives possess a strong ability to bind with the Lys353 and Lys31 hotspots of the SARS-CoV-2 spike protein, demonstrating their effective antiviral effects against COVID-19. This integrated approach may accelerate the identification of effective and safer natural antiviral agents against COVID-19.
Bano et al., Biochemical Screening of Phytochemicals and Identification of Scopoletin as a Potential Inhibitor of SARS-CoV-2 Mpro, Revealing Its Biophysical Impact on Structural Stability, Viruses, doi:10.3390/v17030402
The main protease (Mpro or 3CLpro or nsp5) of SARS-CoV-2 is crucial to the life cycle and pathogenesis of SARS-CoV-2, making it an attractive drug target to develop antivirals. This study employed the virtual screening of a few phytochemicals, and the resultant best compound, Scopoletin, was further investigated by a FRET-based enzymatic assay, revealing an experimental IC50 of 15.75 µM. The impact of Scopoletin on Mpro was further investigated by biophysical and MD simulation studies. Fluorescence spectroscopy identified a strong binding constant of 3.17 × 104 M⁻1 for Scopoletin binding to Mpro, as demonstrated by its effective fluorescence quenching of Mpro. Additionally, CD spectroscopy showed a significant reduction in the helical content of Mpro upon interaction with Scopoletin. The findings of thermodynamic measurements using isothermal titration calorimetry (ITC) supported the spectroscopic data, indicating a tight binding of Scopoletin to Mpro with a KA of 2.36 × 103 M−1. Similarly, interaction studies have also revealed that Scopoletin forms hydrogen bonds with the amino acids nearest to the active site, and this has been further supported by molecular dynamics simulation studies. These findings indicate that Scopoletin may be developed as a potential antiviral treatment for SARS-CoV-2 by targeting Mpro.