Silver nanoparticles were green synthesized with the aqueous leaf extract of the widely consumed green leafy vegetable, Rumex acetosa (sorrel) and the obtained silver nanoparticles (Ag NPs) were tested for their in vitro antioxidant potential, cytotoxicity against human osteosarcoma (HOS) cell lines and antibacterial effects against sixteen human pathogenic clinical isolates. Different analytical techniques viz. UV-vis, FTIR, XRD, SEM-EDX and TEM were employed to characterize the synthesized Ag NPs. Surface Plasmon spectra for the Ag NPs with brownish black color were centered approximately at 448 nm. FTIR analysis revealed the presence of reactive N-H and O-H groups that are effective in reducing Ag(I) ions to Ag(0) which then reacted with the contents of the extract to AgCl/Ag₂C₂O₄. From SEM and TEM analyses, the particles were found to be predominantly spherical in shape and ranged in size from 5 nm to 80 nm, but were largely in the range of 15 nm to 20 nm. Ag NPs showed considerable antioxidant activity, and all the sixteen clinical isolates of human pathogens tested were significantly inhibited. Also, HOS cell lines were significantly (p < 0.05) inhibited at 25% concentration of the Ag NPs extract, while showing a marginal revival at 50% and 100% concentrations.

Highly pathogenic influenza A virus (HPAIV) continues to pose a pandemic threat globally. From 2003 to 2017, H5N1 HPAIV caused 453 human deaths, giving it a high mortality rate (52.74%). This work shows that miR-324-5p suppresses H5N1 HPAIV replication by directly targeting the viral genome (thereby inhibiting viral gene expression) and cellular CUEDC2 gene, the negative regulator of the interferon pathway (thereby enhancing antiviral genes). Our study enhances the knowledge of the role of microRNAs in the cellular response to viral infection. Also, the study provides help in understanding how the host cells utilize small RNAs in controlling the viral burden.