Puerarin for COVID-19

Abstract Aims The aim of the present review was to highlight natural product investigations in silico and in vitro to find plants and chemicals that inhibit or stimulate angiotensin-converting enzyme 2 (ACE-2). Background The global reduction of incidents and fatalities attributable to infections with SARS-CoV-2 is one of the most public health problems. In the absence of specific therapy for coronavirus disease 2019 (COVID-19), phytocompounds generated from plant extracts may be a promising strategy worth further investigation, motivating researchers to evaluate the safety and anti-SARS-CoV-2 effectiveness of these ingredients. Objective To review phytochemicals in silico for anti-SARS-CoV-2 activity and to assess their safety and effectiveness in vitro and in vivo. Methods The present review was conducted using various scientific databases and studies on anti-SARS-CoV-2 phytochemicals were analyzed and summarized. The results obtained from the in silico screening were subjected to extraction, isolation, and purification. The in vitro studies on anti-SarcoV-2 were also included in this review. In addition, the results of this research were interpreted, analyzed, and documented on the basis of the bibliographic information obtained. Results This review discusses recent research on using natural remedies to cure or prevent COVID-19 infection. The literature analysis shows that the various herbal preparations (extracts) and purified compounds can block the replication or entrance of the virus directly to carry out their anti-SARS-CoV-2 effects. It is interesting to note that certain items can prevent SARS-CoV-2 from infecting human cells by blocking the ACE-2 receptor or the serine protease TMPRRS2. Moreover, natural substances have been demonstrated to block proteins involved in the SARS-CoV-2 life cycle, such as papain- or chymotrypsin-like proteases. Conclusion The natural products may have the potential for use singly or in combination as alternative drugs to treat/prevent COVID-19 infection, including blocking or stimulating ACE-2. In addition, their structures may provide indications for the development of anti-SARS-CoV-2 drugs.

Neuropilin-1 (NRP-1) functions as an essential co-receptor for SARS-CoV-2, facilitating viral entry by binding the spike protein’s C-end rule (CendR) motif in its b1 domain, yet it has received less attention than ACE2 in therapeutic development. This in silico study evaluates plant-derived polyphenols as potential selective inhibitors of the NRP-1 CendR pocket to disrupt SARS-CoV-2 engagement, addressing limitations of synthetic inhibitors like EG01377, which exhibit modest affinity (−5.83 kcal/mol) and potential off-target risks. High-throughput molecular docking of 10,000 phytochemicals using AutoDock Vina identified 10 polyphenols with binding affinities ranging from −9.87 to −6.63 kcal/mol, led by 6“-O-acetyldaidzin (-9.87 kcal/mol) and phloretin (-8.64 kcal/mol), forming stable hydrogen bonds and π-cation interactions with critical residues (e.g., THR-401, GLU-367 for 6”-O-acetyldaidzin; PRO-311, ILE-400 for phloretin), as visualized in Discovery Studio. Notably, four of the top inhibitors are isoflavonoid derivatives, highlighting a chemical class enrichment. Molecular dynamics simulations over 100 ns using Desmond indicated moderate complex stability (RMSD: 0.6–3.8 Å; RMSF <0.5 Å at binding site ). ADMET-Tox profiling via SwissADME and ProTox-II revealed drug-like properties, including high gastrointestinal absorption (>70% for leads) and low toxicity (classes 4–5), though 6”-O-acetyldaidzin shows limited bioavailability due to its high H-bond acceptor count (10) and large size, suggesting need for formulation optimization. The NRP-1 b1 homology model, built with SWISS-MODEL, exhibited high fidelity (GMQE: 0.79; Ramachandran favored regions: 90.3% ). This focused computational screening of polyphenols against NRP-1 complements prior studies and identifies candidates for experimental validation as potential SARS-CoV-2 inhibitors. Limitations include the in silico nature, and lack of membrane/sialic acid models, necessitating in vitro and in vivo testing against SARS-CoV-2 variants.