In the 21st century, plant-derived metal nanoparticles (PDMNPs) have gained considerable interest because of their tremendous and remarkable potential as therapeutic agents as well as development of less expensive, safer, and easier biomedical equipment. PDMNPs are synthesized from metal salts or oxides by using plant extracts because plants have diversified bioactive compounds that can act as reducing and stabilizing agents at the time of nanoparticle synthesis. Besides, PDMNPs take advantages over the nanoparticles synthesized by other methods because of their low cost, environmental friendliness, and sustainability. The present review explains the synthesis of PDMNPs, their characterization techniques, and oxidative stress-mediated pharmacological effects. The mode of actions for antioxidant, antimicrobial, and anticancer properties has also been critically explored. Due to the plethora of data on plant-derived nanoparticles and their pharmacological properties, we have highlighted PDMNPs’ shape, size, metals of use, and experimental findings regarding their antioxidant, anti-microbial, and anticancer properties in a tabulated form for studies conducted in the last five years, from 2018 to 2022. Because of our review study, we, herein, contemplate that the scientific community as a whole will get a greater comprehension of PDMNPs and their numerous therapeutic applications in a single window.

The present study explores the efficacy of plant-derived natural products (PDNPs) against spike glycoproteins (S-glycoprotein) of SARS-CoV-2 variants using molecular docking, ADMET, molecular dynamics (MD) simulation and density-functional theory (DFT) analysis. In all, 100 PDNPs were screened against spike glycoprotein of SARS-CoV-2 variants, namely alpha (B.1.1.17), beta (B.1.351), delta (B.1.617), gamma (P.1) and omicron (B.1.1.529). Results showed that rutin, EGCG, hesperidin, withanolide G, rosmarinic acid, diosmetin, myricetin, epicatechin and quercetin were the top hit compounds against each of the SARS-CoV-2 variants. The most active compounds, rutin, hesperidin, EGCG and rosmarinic acid gave binding scores of −10.2, −8.1, −8.9, −8.3 and −9.2 kcal/mol, against omicron, delta, alpha, beta and gamma variants, respectively. Further, the stability of docked complexes was confirmed by the analysis of molecular descriptors (RMSD, RMSF, SASA, Rg and H-bonds) in molecular dynamic simulation analysis. Moreover, the physiochemical properties and drug-likeness of the tested compounds showed that they have no toxicity or carcinogenicity and may be used as druggable targets. In addition, the DFT study revealed the higher activity of the tested compounds against the target proteins. This led us to conclude that rutin, hesperidin, EGCG and rosmarinic acid are good candidates to target the S-glycoproteins of SARS-CoV-2 variants. Further, in vivo and clinical studies needed to develop them as drug leads against existing or new SARS-CoV-2 variants are currently underway in our laboratory.